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Sample records for para-aortic nodal dissection

  1. Assessing the risk of pelvic and para-aortic nodal involvement in apparent early-stage ovarian cancer: A predictors- and nomogram-based analyses.

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    Bogani, Giorgio; Tagliabue, Elena; Ditto, Antonino; Signorelli, Mauro; Martinelli, Fabio; Casarin, Jvan; Chiappa, Valentina; Dondi, Giulia; Leone Roberti Maggiore, Umberto; Scaffa, Cono; Borghi, Chiara; Montanelli, Luca; Lorusso, Domenica; Raspagliesi, Francesco

    2017-10-01

    To estimate the prevalence of lymph node involvement in early-stage epithelial ovarian cancer in order to assess the prognostic value of lymph node dissection. Data of consecutive patients undergoing staging for early-stage epithelial ovarian cancer were retrospectively evaluated. Logistic regression and a nomogram-based analysis were used to assess the risk of lymph node involvement. Overall, 290 patients were included. All patients had lymph node dissection including pelvic and para-aortic lymphadenectomy. Forty-two (14.5%) patients were upstaged due to lymph node metastatic disease. Pelvic and para-aortic nodal metastases were observed in 22 (7.6%) and 42 (14.5%) patients. Lymph node involvement was observed in 18/95 (18.9%), 1/37 (2.7%), 4/29 (13.8%), 11/63 (17.4%), 3/41 (7.3%) and 5/24 (20.8%) patients with high-grade serous, low-grade-serous, endometrioid G1, endometrioid G2&3, clear cell and undifferentiated, histology, respectively (p=0.12, Chi-square test). We observed that high-grade serous histology was associated with an increased risk of pelvic node involvement; while, histology rather than low-grade serous and bilateral tumors were independently associated with para-aortic lymph node involvement (p<0.05). Nomograms displaying the risk of nodal involvement in the pelvic and para-aortic areas were built. High-grade serous histology and bilateral tumors are the main characteristics suggesting lymph node positivity. Our data suggested that high-grade serous and bilateral early-stage epithelial ovarian cancer are at high risk of having disease harboring in the lymphatic tissues of both pelvic and para-aortic area. After receiving external validation, our data will help to identify patients deserving comprehensive retroperitoneal staging. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Techniques and usefulness of para-aortic nodal irradiation in carcinoma of the cervix

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    Nori, D.

    1987-01-01

    In this chapter the authors evaluate irradiation of para-aortic node metastasis in carcinoma of the cervix and the outcome of patients who have undergone such treatment. They also present an approach designed to minimize complications of investigation and treatment. The technical details of surgical procedure and preliminary analysis of these data have been published earlier

  3. A Web-based nomogram predicting para-aortic nodal metastasis in incompletely staged patients with endometrial cancer: a Korean Multicenter Study.

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    Kang, Sokbom; Lee, Jong-Min; Lee, Jae-Kwan; Kim, Jae-Weon; Cho, Chi-Heum; Kim, Seok-Mo; Park, Sang-Yoon; Park, Chan-Yong; Kim, Ki-Tae

    2014-03-01

    The purpose of this study is to develop a Web-based nomogram for predicting the individualized risk of para-aortic nodal metastasis in incompletely staged patients with endometrial cancer. From 8 institutions, the medical records of 397 patients who underwent pelvic and para-aortic lymphadenectomy as a surgical staging procedure were retrospectively reviewed. A multivariate logistic regression model was created and internally validated by rigorous bootstrap resampling methods. Finally, the model was transformed into a user-friendly Web-based nomogram (http://http://www.kgog.org/nomogram/empa001.html). The rate of para-aortic nodal metastasis was 14.4% (57/397 patients). Using a stepwise variable selection, 4 variables including deep myometrial invasion, non-endometrioid subtype, lymphovascular space invasion, and log-transformed CA-125 levels were finally adopted. After 1000 repetitions of bootstrapping, all of these 4 variables retained a significant association with para-aortic nodal metastasis in the multivariate analysis-deep myometrial invasion (P = 0.001), non-endometrioid histologic subtype (P = 0.034), lymphovascular space invasion (P = 0.003), and log-transformed serum CA-125 levels (P = 0.004). The model showed good discrimination (C statistics = 0.87; 95% confidence interval, 0.82-0.92) and accurate calibration (Hosmer-Lemeshow P = 0.74). This nomogram showed good performance in predicting para-aortic metastasis in patients with endometrial cancer. The tool may be useful in determining the extent of lymphadenectomy after incomplete surgery.

  4. Are Radiation Therapy Oncology Group Para-aortic Contouring Guidelines for Pancreatic Neoplasm Applicable to Other Malignancies—Assessment of Nodal Distribution in Gynecological Malignancies

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    Kabolizadeh, Peyman; Fulay, Suyash; Beriwal, Sushil, E-mail: beriwals@upmc.edu

    2013-09-01

    Purpose: Intensity modulated radiation therapy is used to reduce dose to adjacent critical structures while maintaining adequate target coverage, but it requires precise target localization. We report the 3-dimensional distribution of para-aortic (PA) lymph nodes (LN) in pelvic malignancies. We propose a guideline to accurately define the PA LN by anatomic landmarks and compare our data with published guidelines for pancreatic cancer. Methods and Materials: A retrospective analysis was performed on 46 patients with pelvic malignancies and positive PA LNs. Positive LNs were defined based on size and morphology or fluorodeoxyglucose avidity. All PA LNs were characterized into 3 groups based on location: left PA (between aorta and left psoas muscle), aortocaval (between aorta and inferior vena cava), and right paracaval (between inferior vena cava and right psoas muscle). Patients with retrocrural LNs were also analyzed. Results: One hundred thirty-three positive PA LNs were evaluated. The majority of the PA LNs were in the left PA (59%) and aortocaval (35) regions, and only 8% were in the right paracaval region. All patients with positive right paracaval LNs also had involved left PA LNs, with only 1 exception. The highest PA LN involvement was at the level of the renal vessels and was seen in 28% of patients. Of these patients with disease extending to renal vessels, 38% had retrocrural LN involvement. Conclusions: The nodal contouring for the PA region should not be defined by a fixed circumferential margin around the vessels. The left PA and aortocaval spaces should be covered adequately because these are common locations of PA LNs. For microscopic disease superiorly, contouring should extend up to renal vessels rather than a fixed bony landmark. For patients who have nodal involvement at renal vessels, one can consider including retrocrural LNs. Radiation Therapy Oncology Group Para-aortic Contouring Guidelines for Pancreatic Neoplasm are not applicable to

  5. Are Radiation Therapy Oncology Group Para-aortic Contouring Guidelines for Pancreatic Neoplasm Applicable to Other Malignancies—Assessment of Nodal Distribution in Gynecological Malignancies

    International Nuclear Information System (INIS)

    Kabolizadeh, Peyman; Fulay, Suyash; Beriwal, Sushil

    2013-01-01

    Purpose: Intensity modulated radiation therapy is used to reduce dose to adjacent critical structures while maintaining adequate target coverage, but it requires precise target localization. We report the 3-dimensional distribution of para-aortic (PA) lymph nodes (LN) in pelvic malignancies. We propose a guideline to accurately define the PA LN by anatomic landmarks and compare our data with published guidelines for pancreatic cancer. Methods and Materials: A retrospective analysis was performed on 46 patients with pelvic malignancies and positive PA LNs. Positive LNs were defined based on size and morphology or fluorodeoxyglucose avidity. All PA LNs were characterized into 3 groups based on location: left PA (between aorta and left psoas muscle), aortocaval (between aorta and inferior vena cava), and right paracaval (between inferior vena cava and right psoas muscle). Patients with retrocrural LNs were also analyzed. Results: One hundred thirty-three positive PA LNs were evaluated. The majority of the PA LNs were in the left PA (59%) and aortocaval (35) regions, and only 8% were in the right paracaval region. All patients with positive right paracaval LNs also had involved left PA LNs, with only 1 exception. The highest PA LN involvement was at the level of the renal vessels and was seen in 28% of patients. Of these patients with disease extending to renal vessels, 38% had retrocrural LN involvement. Conclusions: The nodal contouring for the PA region should not be defined by a fixed circumferential margin around the vessels. The left PA and aortocaval spaces should be covered adequately because these are common locations of PA LNs. For microscopic disease superiorly, contouring should extend up to renal vessels rather than a fixed bony landmark. For patients who have nodal involvement at renal vessels, one can consider including retrocrural LNs. Radiation Therapy Oncology Group Para-aortic Contouring Guidelines for Pancreatic Neoplasm are not applicable to

  6. Fluorodeoxyglucose positron emission tomography?computed tomography in evaluation of pelvic and para-aortic nodal involvement in early stage and operable cervical cancer: Comparison with surgicopathological findings

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    Bansal, Vandana; Damania, Kaizad; Sharma, Anshu Rajnish

    2011-01-01

    Introduction: Nodal metastases in cervical cancer have prognostic implications. Imaging is used as an adjunct to clinical staging for evaluation of nodal metastases. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has an advantage of superior resolution of its CT component and detecting nodal disease based on increased glycolytic activity rather than node size. But there are limited studies describing its limitations in early stage cervical cancers. Objectiv...

  7. Fluorodeoxyglucose positron emission tomography-computed tomography in evaluation of pelvic and para-aortic nodal involvement in early stage and operable cervical cancer: comparison with surgicopathological findings

    International Nuclear Information System (INIS)

    Bansal, Vandana; Damania, Kaizad; Sharma, Anshu Rajnish

    2011-01-01

    Nodal metastases in cervical cancer have prognostic implications. Imaging is used as an adjunct to clinical staging for evaluation of nodal metastases. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has an advantage of superior resolution of its CT component and detecting nodal disease based on increased glycolytic activity rather than node size. But there are limited studies describing its limitations in early stage cervical cancers. We have done meta-analysis with an objective to evaluate the efficacy of FDG PET/CT and its current clinical role in early stage and operable cervical cancer. Studies in which FDG PET/CT was performed before surgery in patients with early stage cervical cancers were included for analysis. PET findings were confirmed with histopathological diagnosis rather than clinical follow-up. The current data suggest that FDG PET/CT is suboptimal in nodal staging in early stage cervical cancer

  8. Fluorodeoxyglucose positron emission tomography–computed tomography in evaluation of pelvic and para-aortic nodal involvement in early stage and operable cervical cancer: Comparison with surgicopathological findings

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    Bansal, Vandana; Damania, Kaizad; Sharma, Anshu Rajnish

    2011-01-01

    Introduction: Nodal metastases in cervical cancer have prognostic implications. Imaging is used as an adjunct to clinical staging for evaluation of nodal metastases. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has an advantage of superior resolution of its CT component and detecting nodal disease based on increased glycolytic activity rather than node size. But there are limited studies describing its limitations in early stage cervical cancers. Objective: We have done meta-analysis with an objective to evaluate the efficacy of FDG PET/CT and its current clinical role in early stage and operable cervical cancer. Materials and Methods: Studies in which FDG PET/CT was performed before surgery in patients with early stage cervical cancers were included for analysis. PET findings were confirmed with histopathological diagnosis rather than clinical follow-up. FDG PET/CT showed lower sensitivity and clinically unacceptable negative predictive value in detecting nodal metastases in early stage cervical cancer and therefore, can not replace surgicopathological staging. False negative results in presence of microscopic disease and sub-centimeter diseased nodes are still the area of concern for metabolic imaging. However, these studies are single institutional and performed in a small group of patients. There is enough available evidence of clinical utility of FDG PET/CT in locally advanced cervical cancer. But these results can not be extrapolated for early stage disease. Conclusion: The current data suggest that FDG PET/CT is suboptimal in nodal staging in early stage cervical cancer. PMID:23559711

  9. Adjuvant radiotherapy after salvage lymph node dissection because of nodal relapse of prostate cancer versus salvage lymph node dissection only

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    Rischke, Hans Christian; Schultze-Seemann, Wolfgang; Kroenig, Malte; Schlager, Daniel; Jilg, Cordula Annette; Wieser, Gesche; Drendel, Vanessa; Stegmaier, Petra; Henne, Karl; Volegova-Neher, Natalia; Grosu, Anca-Ligia; Krauss, Tobias; Kirste, Simon

    2015-01-01

    Nodal pelvic/retroperitoneal recurrent prostate cancer (PCa) after primary therapy can be treated with salvage lymph node dissection (salvage-LND) in order to delay disease progression and offer cure for a subset of patients. Whether adjuvant radiotherapy (ART) in affected regions improves the outcome by elimination of residual tumour burden remains unclear. A total of 93 patients with exclusively nodal PCa relapse underwent choline-positron-emission tomography-computed-tomography-directed pelvic/retroperitoneal salvage-LND; 46 patients had surgery only and 47 patients received ART in regions with proven lymph node metastases. In case of subsequent prostate specific antigen (PSA) progression, different imaging modalities were performed to confirm next relapse within or outside the treated region (TR). Mean follow-up was 3.2 years. Lymphatic tumour burden was balanced between the two groups. Additional ART resulted in delayed relapse within TR (5-year relapse-free rate 70.7 %) versus surgery only (5-year relapse-free rate 26.3 %, p < 0.0001). In both treatment arms, time to next relapse outside the TR was almost equal (median 27 months versus 29.6 months, p = 0.359). With respect to the detection of the first new lesion, regardless if present within or outside the TR, 5 years after the treatment 34.3 % of patients in the group with additional ART were free of relapse, versus 15.4 % in the surgery only group (p = 0.0122). ART had no influence on the extent of PSA reduction at latest follow-up compared to treatment with surgery only. ART after salvage-LND provides stable local control in TR and results in overall significant improved next-relapse-free survival, compared to patients who received surgery only in case of nodal PCa-relapse. (orig.) [de

  10. Prophylactic Level VII Nodal Dissection as a Prognostic Factor in Papillary Thyroid Carcinoma: a Pilot Study of 27 Patients.

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    Fayek, Ihab Samy

    2015-01-01

    Prognostic value of prophylactic level VII nodal dissection in papillary thyroid carcinoma has been highlighted. A total of 27 patients with papillary thyroid carcinoma with N0 neck underwent total thyroidectomy with level VI and VII nodal dissection through same collar neck incision. Multicentricity, bilaterality, extrathyroidal extension, level VI and VII lymph nodes were studied as separate and independent prognostic factors for DFS at 24 months. 21 females and 6 males with a mean age of 34.6 years old, tumor size was 5-24 mm. (mean 12.4 mm.), multicentricity in 11 patients 2-4 foci (mean 2.7), bilaterality in 8 patients and extrathyroidal extension in 8 patients. Dissected level VI LNs 2-8 (mean 5 LNs) and level VII LNs 1-4 (mean 1.9). Metastatic level VI LNs 0-3 (mean 1) and level VII LNs 0-2 (mean 0.5). Follow-up from 6-51 months (mean 25.6) with 7 patients showed recurrence (3 local and 4 distant). Cumulative DFS at 24 months was 87.8% and was significantly affected in relation to bilaterality (p-valueVII positive ((p-valueVII nodal involvement. Level VII prophylactic nodal dissection is an important and integral prognostic factor in papillary thyroid carcinoma. A larger multicenter study is crucial to reach a satisfactory conclusion about the necessity and safety of this approach.

  11. Can pelvic node dissection at radical prostatectomy influence the nodal recurrence at salvage lymphadenectomy for prostate cancer?

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    Arjun Sivaraman

    2018-03-01

    Full Text Available Purpose: To verify the quality of pelvic lymph node dissection (PLND performed at radical prostatectomy (RP and its impact on nodal recurrence in patients undergoing salvage lymph node dissection (sLND. Materials and Methods: Retrospective review of 48 patients who underwent sLND for presumed nodal recurrence, to describe the PLND characteristics at RP and correlate the anatomical sites and number of suspicious nodes reported in radiological imaging and final pathology of sLND. Results: Overall, at RP, 8 (16.7% did not undergo PLND, 32 (66.7% and 8 (16.7% received a “limited” (between external iliac vein and obturator nerve and an “extended” (external iliac, hypogastric, and obturator dissection, respectively. Median nodes removed during limited and extended dissection were 2 and 24, respectively. At sLND, the mean age was 61.3 years and median prostate specific antigen (PSA was 1.07 ng/mL. Median nodes removed at sLND were 17 with a median of 2 positive nodes. Recurrent nodes were identified within the template of an extended PLND in 62.5%, 50.0% and 12.5% patients, respectively, following prior no, limited and extended dissection at RP. Recurrence outside the expected lymphatic drainage pathway was noted in 37.5% patients with prior extended dissection at RP. There was a correlation between imaging and pathology specimen in 83% for node location and 58.3% for number of anatomical sites involved. Conclusions: In prostate cancer patients undergoing sLND, most had inadequate PLND at the original RP. Pattern of nodal recurrence may be influenced by the prior dissection and pre sLND imaging appears to underestimate the nodal recurrence.

  12. Can pelvic node dissection at radical prostatectomy influence the nodal recurrence at salvage lymphadenectomy for prostate cancer?

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    Sivaraman, Arjun; Benfante, Nicole; Touijer, Karim; Coleman, Jonathan; Scardino, Peter; Laudone, Vincent; Eastham, James

    2018-03-01

    To verify the quality of pelvic lymph node dissection (PLND) performed at radical prostatectomy (RP) and its impact on nodal recurrence in patients undergoing salvage lymph node dissection (sLND). Retrospective review of 48 patients who underwent sLND for presumed nodal recurrence, to describe the PLND characteristics at RP and correlate the anatomical sites and number of suspicious nodes reported in radiological imaging and final pathology of sLND. Overall, at RP, 8 (16.7%) did not undergo PLND, 32 (66.7%) and 8 (16.7%) received a "limited" (between external iliac vein and obturator nerve) and an "extended" (external iliac, hypogastric, and obturator) dissection, respectively. Median nodes removed during limited and extended dissection were 2 and 24, respectively. At sLND, the mean age was 61.3 years and median prostate specific antigen (PSA) was 1.07 ng/mL. Median nodes removed at sLND were 17 with a median of 2 positive nodes. Recurrent nodes were identified within the template of an extended PLND in 62.5%, 50.0% and 12.5% patients, respectively, following prior no, limited and extended dissection at RP. Recurrence outside the expected lymphatic drainage pathway was noted in 37.5% patients with prior extended dissection at RP. There was a correlation between imaging and pathology specimen in 83% for node location and 58.3% for number of anatomical sites involved. In prostate cancer patients undergoing sLND, most had inadequate PLND at the original RP. Pattern of nodal recurrence may be influenced by the prior dissection and pre sLND imaging appears to underestimate the nodal recurrence.

  13. Long-term results of para-aortic irradiation for patients with stage I seminoma of the testis

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    Niazi, Tamim M.; Souhami, Luis; Sultanem, Khalil; Duclos, Marie; Shenouda, George; Freeman, Carolyn

    2005-01-01

    Purpose: Adjuvant postoperative para-aortic lymph nodal irradiation is an acceptable alternative to para-aortic and ipsilateral pelvic irradiation postorchiectomy for patients with Stage I seminoma of the testis. In this article, we report the long-term results of our prospective evaluation of para-aortic irradiation only for such patients. Methods and materials: Between March 1991 and September 2000, 71 patients with Stage I seminoma were treated with adjuvant irradiation to the para-aortic region only after radical inguinal orchiectomy. Radiotherapy was delivered using parallel-opposed fields extending from T11 to L5. A total dose of 25 Gy in 15 fractions was prescribed to midpoint. Follow-up was performed every 3 months for the first year, every 4 months for the second and third years, every 6 months for the fourth and fifth years, and annually thereafter. Chest X-ray, tumor markers, and computed tomography scan of the pelvis were performed routinely as part of the follow-up investigation. Results: At a median follow-up of 75 months, 68 of 71 patients are alive and free of relapse. Only 1 patient (1.4%) experienced failure in the ipsilateral inguinal nodal region. Two patients (2.8%) died of unrelated causes. The actuarial 10-year relapse free survival is 98.5% and the actuarial 10-year overall survival is 92%. No late toxicity has been encountered. Conclusion: Patients with Stage I seminoma of the testis may be safely treated with para-aortic radiotherapy only. Risk of pelvic failure is very low and treatment toxicity minimal

  14. Role of pelvic and para-aortic lymphadenectomy in abandoned radical hysterectomy in cervical cancer.

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    Barquet-Muñoz, Salim Abraham; Rendón-Pereira, Gabriel Jaime; Acuña-González, Denise; Peñate, Monica Vanessa Heymann; Herrera-Montalvo, Luis Alonso; Gallardo-Alvarado, Lenny Nadia; Cantú-de León, David Francisco; Pareja, René

    2017-01-14

    Cervical cancer (CC) occupies fourth place in cancer incidence and mortality worldwide in women, with 560,505 new cases and 284,923 deaths per year. Approximately, nine of every ten (87%) take place in developing countries. When a macroscopic nodal involvement is discovered during a radical hysterectomy (RH), there is controversy in the literature between resect macroscopic lymph node compromise or abandonment of the surgery and sending the patient for standard chemo-radiotherapy treatment. The objective of this study is to compare the prognosis of patients with CC whom RH was abandoned and bilateral pelvic lymphadenectomy and para-aortic lymphadenectomy was performed with that of patients who were only biopsied or with removal of a suspicious lymph node, treated with concomitant radiotherapy/chemotherapy in the standard manner. A descriptive and retrospective study was conducted in two institutions from Mexico and Colombia. Clinical records of patients with early-stage CC programmed for RH with an intraoperative finding of pelvic lymph, para-aortic nodes, or any extracervical involvement that contraindicates the continuation of surgery were obtained. Between January 2007 and December 2012, 42 clinical patients complied with study inclusion criteria and were selected for analysis. In patients with CC whom RH was abandoned due to lymph node affectation, there is no difference in overall survival or in disease-free period between systematic lymphadenectomy and tumor removal or lymph node biopsy, in pelvic lymph nodes as well as in para-aortic lymph nodes, when these patients receive adjuvant treatment with concomitant radiotherapy/chemotherapy. This is a hypothesis-generator study; thus, the recommendation is made to conduct randomized prospective studies to procure better knowledge on the impact of bilateral pelvic and para-aortic lymphadenectomy on this group of patients.

  15. Para-aortic lymph node radiation in advanced cervical cancer

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    Emami, B.; Watring, W.G.; Tak, W.; Anderson, B.; Piro, A.J.

    1980-01-01

    Thirty-six patients with advanced carcinoma of the uterine cervix and with iliac or para-aortic nodes interpreted as un-equivocally positive on lymphangiography have received radiation therapy to the para-aortic area at the Department of Therapeutic Radiology at Tufts-New England Medical Center Hospital. Of 29 patients who received para-aortic area irradiation as part of their initial treatment, local control was achieved in 18 patients (62%). Overall, four patients developed major complications requiring surgical intervention. Detailed results and our current pre-treatment evaluation policy including lymphangiography, percutaneous needle biopsy and selective extra-peritoneal lymph node biopsy will be discussed

  16. Impact of primary para-aortic lymphadenectomy on distant failure in locally advanced cervical cancer patients treated in the era of image-guided adaptive brachytherapy.

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    Chargari, Cyrus; Mazeron, Renaud; Dunant, Ariane; Gouy, Sébastien; Petit, Claire; Maroun, Pierre; Uzan, Catherine; Annede, Pierre; Bentivegna, Enrica; Balleyguier, Corinne; Genestie, Catherine; Pautier, Patricia; Leary, Alexandra; Lhomme, Catherine; Deutsch, Eric; Morice, Philippe; Haie-Meder, Christine

    2016-12-01

    To investigate the impact of a primary para-aortic lymphadenectomy (PAL) in locally advanced cervical cancer patients receiving definitive chemoradiation, we reviewed the clinical records of consecutive patients treated in our Institution and receiving an external beam irradiation followed with an image-guided adaptive brachytherapy for a locally advanced cervical cancer. We examined the impact of performing a primary PAL as part of primary staging for guiding irradiation fields in patients without extra-pelvic PET uptake. The outcome of patients presenting para-aortic lymph node uptake (PALNU) was also examined. 186 patients were identified. Median follow-up was 44.4 months. Patients receiving a primary PAL (PAL group) and those who received upfront pelvic chemoradiation (no-PAL group) did not significantly differ for loco-regional failures. Survival without distant failure (DFFS), including para-aortic relapses, was at 3 years 87 % (95 % CI 84-90 %) in PAL group, 67 % (95 % CI 59-85 %) in the no-PAL group and 44 % (95 % CI 32-66 %) in the PALNU group (p = 0.04 for comparison between PAL and no-PAL groups). In a multivariate model including para-aortic lymphadenectomy, pelvic nodal uptake and high-risk clinical target volume as adjustment variables, a para-aortic lymphadenectomy was significant for DFS (HR = 0.47, 95 % CI 0.26-0.84, p = 0.01). Although confounding factors could account for these retrospective results, a primary PAL with tailored irradiation fields based on para-aortic histological findings seems to be associated with a better control for distant metastases. A randomized trial is testing the benefit of this strategy.

  17. Successful resection of metachronous para-aortic, Virchow lymph node and liver metastatic recurrence of rectal cancer.

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    Takeshita, Nobuyoshi; Fukunaga, Toru; Kimura, Masayuki; Sugamoto, Yuji; Tasaki, Kentaro; Hoshino, Isamu; Ota, Takumi; Maruyama, Tetsuro; Tamachi, Tomohide; Hosokawa, Takashi; Asai, Yo; Matsubara, Hisahiro

    2015-11-28

    A 66-year-old female presented with the main complaint of defecation trouble and abdominal distention. With diagnosis of rectal cancer, cSS, cN0, cH0, cP0, cM0 cStage II, Hartmann's operation with D3 lymph node dissection was performed and a para-aortic lymph node and a disseminated node near the primary tumor were resected. Histological examination showed moderately differentiated adenocarcinoma, pSS, pN3, pH0, pP1, pM1 (para-aortic lymph node, dissemination) fStage IV. After the operation, the patient received chemotherapy with FOLFIRI regimen. After 12 cycles of FOLFIRI regimen, computed tomography (CT) detected an 11 mm of liver metastasis in the postero-inferior segment of right hepatic lobe. With diagnosis of liver metastatic recurrence, we performed partial hepatectomy. Histological examination revealed moderately differentiated adenocarcinoma as a metastatic rectal cancer with cut end microscopically positive. After the second operation, the patient received chemotherapy with TS1 alone for 2 years. Ten months after the break, CT detected a 20 mm of para-aortic lymph node metastasis and a 10 mm of lymph node metastasis at the hepato-duodenal ligament. With diagnosis of lymph node metastatic recurrences, we performed lymph node dissection. Histological examination revealed moderately differentiated adenocarcinoma as metastatic rectal cancer in para-aortic and hepato-duodenal ligament areas. After the third operation, we started chemotherapy with modified FOLFOX6 regimen. After 2 cycles of modified FOLFOX6 regimen, due to the onset of neutropenia and liver dysfunction, we switched to capecitabine alone and continued it for 6 mo and then stopped. Eleven months after the break, CT detected two swelling 12 mm of lymph nodes at the left supraclavicular region. With diagnosis of Virchow lymph node metastatic recurrence, we started chemotherapy with capecitabine plus bevacizumab regimen. Due to the onset of neutropenia and hand foot syndrome (Grade 3), we managed to

  18. Role of pelvic and para-aortic lymphadenectomy in endometrial cancer: Current evidence

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    Bogani, Giorgio; Dowdy, Sean C.; Cliby, William A.; Ghezzi, Fabio; Rossetti, Diego; Mariani, Andrea

    2015-01-01

    The aim of the present review is to summarize the current evidence on the role of pelvic and para-aortic lymphadenectomy in endometrial cancer. In 1988, the International Federation of Obstetrics and Gynecology recommended surgical staging for endometrial cancer patients. However, 25 years later, the role of lymph node dissection remains controversial. Although the findings of two large independent randomized trials suggested that pelvic lymphadenectomy provides only adjunctive morbidity with no clear influence on survival outcomes, the studies have many pitfalls that limit interpretation of the results. Theoretically, lymphadenectomy may help identify patients with metastatic dissemination, who may benefit from adjuvant therapy, thus reducing radiation-related morbidity. Also, lymphadenectomy may eradicate metastatic disease. Because lymphatic spread is relatively uncommon, our main effort should be directed at identifying patients who may potentially benefit from lymph node dissection, thus reducing the rate of unnecessary treatment and associated morbidity. This review will discuss the role of lymphadenectomy in endometrial cancer, focusing on patient selection, extension of the surgical procedure, postoperative outcomes, quality of life and costs. The need for new surgical studies and efficacious systemic drugs is recommended. PMID:24472047

  19. Toxicity and quality of life after choline-PET/CT directed salvage lymph node dissection and adjuvant radiotherapy in nodal recurrent prostate cancer

    International Nuclear Information System (INIS)

    Jilg, Cordula A; Leifert, Anja; Schnell, Daniel; Kirste, Simon; Volegova-Neher, Natalia; Schlager, Daniel; Wieser, Gesche; Henne, Karl; Schultze-Seemann, Wolfgang; Grosu, Anca-L; Rischke, Hans Christian

    2014-01-01

    In a previous study we demonstrated that, based on 11 C/ 18 F-choline positron emission tomography-computerized-tomography as a diagnostic tool, salvage lymph node dissection (LND) plus adjuvant radiotherapy (ART) is feasible for treatment of pelvic/retroperitoneal nodal recurrence of prostate cancer (PCa). However, the toxicity of this combined treatment strategy has not been systematically investigated before. The aim of the current study was to evaluate the acute and late toxicity and quality of life of ART after LND in pelvic/retroperitoneal nodal recurrent PCa. 43 patients with nodal recurrent PCa were treated with 46 LND followed by ART (mean 49.6 Gy total dose) at the sites of nodal recurrence. Toxicity of ART was analysed by physically examination (31/43, 72.1%), by requesting 15 frequent items of adverse events from the Common-Terminology-Criteria for Adverse Events Version 4.0-catalogue and by review of medical records. QLQ-C30 (EORTC quality of life assessment) and PR25 (prostate cancer module) questionnaires were used to investigate quality of life. Toxicity was evaluated before starting of ART, during ART (acute toxicity), after ART (mean 2.3 months) and at end of follow up (mean 3.2 years after end of ART) reflecting late toxicity. 71.7% (33/46) of 46 ART were treatment of pelvic, 10.9% (5/46) of retroperitoneal only and 28.3% (13/46) of pelvic and retroperitoneal regions. Overall 52 symptoms representing toxicities were observed before ART, 107 during ART, 88 after end of ART and 52 at latest follow up. Leading toxicities during ART were diarrhoea (19%, 20/107), urinary incontinence (16%, 17/107) and fatigue (16%, 17/107). The spectrum of late toxicities was almost equal to those before beginning of ART. No grade 3 adverse events or chronic lymphedema at extremities were observed. We observed no clear correlation between localisation of treated regions, technique of ART and frequency or severity of toxicities. Mean quality of life at final evaluation

  20. Prophylactic irradiation of para-aortic lymph nodes in carcinoma of the uterine cervix

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    Chatani, M.; Matayoshi, Y.; Masaki, N.; Narumi, Y.; Teshima, T.; Inoue, T.

    1995-01-01

    For assessment of the advantages and side effects of para-aortic lymph nodes irradiation under the evaluation by computer tomography, a prospective randomized study was started in 1986. The results for survival, local control and late complications are presented in the following. From November 1986 to October 1990, 93 patients with cervical carcinoma were randomly allocated for treatment with either pelvic irradiation (pelvic group) or pelvic plus para-aortic lymph nodes irradiation (para-aortic group). Thirty-six patients underwent external irradiation and intracavitary therapy (RT arm) and 57 patients, extended radical hysterectomy and external irradiation (OP-RT arm). Para-aortic lymph nodes irradiation delivered 45 Gy in 1.8 Gy per day for 5 days per week through anterior-posterior fields. The 3-year cause specific survival rates were para-aortic group: 57% and pelvic group: 89% in RT arm group, and para-aortic group: 70% and pelvic group: 86% in OP-RT arm group. Differences for the 2 groups in each treatment arm were not significant. In pelvic failure, para-aortic lymph nodes metastases and distant metastases showed no statistically significant differences for the 2 groups in each treatment arm. In the para-aortic group, complications were more frequent than in the pelvic group (13/45 vs. 2/48, p [de

  1. Intraoperative radiation in the canine para-aortic abdomen

    International Nuclear Information System (INIS)

    Hoopes, P.J.; Gillette, E.L.

    1984-01-01

    Twenty adult beagle dogs received intraoperatively delivered 6 MeV electrons to the para-aortic abdomen and bladder. The dogs were equally divided into 4 dose groups receiving 22 Gy, 30 Gy, 38.5 Gy and 47 Gy. The 5 cm x 8 cm radiation field included a variable portion of the left kidney, the left ureter, the abdominal aorta and vena cava, the base of the bladder and the left sciatic and femoral nerves. The lesions observed were fibroelastic proliferation of the aortic intima, severe renal atrophy and fibrosis, ureteral stenosis, bladder fibrosis and demyelinating peripheral neuropathies. Histologic, morphometric and dose response analyses are compared with responses of dogs receiving more conventional fractionated doses to a total of 60 Gy, 70 Gy or 80 Gy x-ray in 6 weeks

  2. Technique to match mantle and para-aortic fields

    International Nuclear Information System (INIS)

    Lutz, W.R.; Larsen, R.D.

    1983-01-01

    A technique is described to match the mantle and para-aortic fields used in treatment of Hodgkin's disease, when the patient is treated alternately in supine and prone position. The approach is based on referencing the field edges to a point close to the vertebral column, where uncontrolled motion is minimal and where accurate matching is particularly important. Fiducial surface points are established in the simulation process to accomplish the objective. Dose distributions have been measured to study the combined effect of divergence differences, changes in body angulation and setup errors. Even with the most careful technique, the use of small cord blocks of 50% transmission is an advisable precaution for the posterior fields

  3. Dissecting Dissection.

    Science.gov (United States)

    AV Magazine, 1996

    1996-01-01

    This journal features articles covering various aspects of dissection. "Biology--The Study of Life" (George Russell) offers students experiments that do not require using invasive procedures. "Animal Cruelty--Behind the Scenes" (Zoe Weil) describes sources of laboratory animals. "Doing without Dissection" (Juliana…

  4. Para-aortic lymphadenectomy in advanced stage cervical cancer, a protocol for comparing safety, feasibility and diagnostic accuracy of surgical staging versus PET-CT; PALDISC trial.

    Science.gov (United States)

    Tax, Casper; Abbink, Karin; Rovers, Maroeska M; Bekkers, Ruud L M; Zusterzeel, Petra L M

    2018-01-01

    Currently, a PET-CT is used to assess the need for extended field radiotherapy of para-aortic lymph nodes (PALN) in International Federation of Gynaecology and Obstetrics (FIGO) stage IB2, IIA2-IVA (locally advanced stage) cervical cancer. A small study established a sensitivity and specificity estimate for PALN metastases of 50% (95% CI; 7-93%) and 83% (95% CI; 52-98%), respectively. Surgical staging of PALN may lead to a higher diagnostic accuracy. However, surgical staging of para-aortic lymph nodes in locally advanced stage cervical cancer is not common practice. Therefore, a phase 2 randomised controlled trial is needed to assess its safety and feasibility. In addition to standard imaging (MRI or CT scan) with PET-CT, 30 adult women with FIGO stage IB2, IIA2-IVA cervical cancer will be randomised to receive either surgical staging or usual PET-CT staging. Administering extended field radiotherapy will be based on lymphadenectomy results for the intervention group and on the PET-CT results for the control group. Follow-up visits at 0, 3, 6, 9 and 12 months will assess health-related quality of life and progression-free survival.Primary safety and feasibility outcomes of surgical staging will be assessed by calculating means with 95% confidence intervals for duration of surgery, number of complications, blood loss, nodal yield after para-aortic lymphadenectomy and treatment delay due to surgical staging. Secondary patient-centred outcomes on quality of life and first year survival will be documented and compared between the two groups. Estimates of sensitivity, specificity and negative and positive predictive values of MRI, PET-CT and surgical staging will be presented with 95% CI.. All analysis will be performed according to the intention to treat principle. This study will assess safety and feasibility, expressed as the number and severity of complications, effect on quality of life and the treatment delay due to surgically staging para-aortic lymph nodes in

  5. Complications from high-dose para-aortic and pelvic irradiation for malignant genitourinary tumors

    International Nuclear Information System (INIS)

    Komaki, R.; Barber-Derus, S.; Glisch, C.; Lawton, C.A.; Cox, J.D.; Wilson, J.F.

    1986-01-01

    Between 1967 and 1982, 59 patients (33 with gynecologic malignancies and 26 with malignant tumors of the genitourinary system) received irradiation of 40 Gy or more for metastases to the para-aortic lymph nodes, in addition to pelvic irradiation. Disease in the para-aortic lymph nodes was controlled in 50 patients; the treatment failed in nine. Moderately acute side effects were seen in 25 patients, but none was severe. Late effects of irradiation were moderate in five patients and severe in three. Thirty patients are alive at 5 years. The benefits of local control and prolonged disease-free survival appear to outweigh considerably the risk of late effects from pelvic and para-aortic irradiation for advanced malignant tumors of the genitourinary system

  6. Dosimetric Predictors of Duodenal Toxicity After Intensity Modulated Radiation Therapy for Treatment of the Para-aortic Nodes in Gynecologic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Jonathan [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Sulman, Erik P.; Jhingran, Anuja [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Tucker, Susan L. [Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rauch, Gaiane M. [Department of Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Eifel, Patricia J. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Klopp, Ann H., E-mail: aklopp@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-02-01

    Purpose: To determine the incidence of duodenal toxicity in patients receiving intensity modulated radiation therapy (IMRT) for treatment of para-aortic nodes and to identify dosimetric parameters predictive of late duodenal toxicity. Methods and Materials: We identified 105 eligible patients with gynecologic malignancies who were treated with IMRT for gross metastatic disease in the para-aortic nodes from January 1, 2005, through December 31, 2009. Patients were treated to a nodal clinical target volume to 45 to 50.4 Gy with a boost to 60 to 66 Gy. The duodenum was contoured, and dosimetric data were exported for analysis. Duodenal toxicity was scored according to Radiation Therapy Oncology Group criteria. Univariate Cox proportional hazards analysis and recursive partitioning analysis were used to determine associations between dosimetric variables and time to toxicity and to identify the optimal threshold that separated patients according to risk of toxicity. Results: Nine of the 105 patients experienced grade 2 to grade 5 duodenal toxicity, confirmed by endoscopy in all cases. The 3-year actuarial rate of any duodenal toxicity was 11.7%. A larger volume of the duodenum receiving 55 Gy (V55) was associated with higher rates of duodenal toxicity. The 3-year actuarial rates of duodenal toxicity with V55 above and below 15 cm{sup 3} were 48.6% and 7.4%, respectively (P<.01). In Cox univariate analysis of dosimetric variables, V55 was associated with duodenal toxicity (P=.029). In recursive partitioning analysis, V55 less than 13.94% segregated all patients with duodenal toxicity. Conclusions: Dose-escalated IMRT can safely and effectively treat para-aortic nodal disease in gynecologic malignancies, provided that care is taken to limit the dose to the duodenum to reduce the risk of late duodenal toxicity. Limiting V55 to below 15 cm{sup 3} may reduce the risk of duodenal complications. In cases where the treatment cannot be delivered within these constraints

  7. Three-dimensional computer-assisted dissection of pancreatic lymphatic anatomy on human fetuses: a step toward automatic image alignment.

    Science.gov (United States)

    Bardol, T; Subsol, G; Perez, M-J; Genevieve, D; Lamouroux, A; Antoine, B; Captier, G; Prudhomme, M; Bertrand, M M

    2018-05-01

    Pancreatic cancer is the fourth cause of death by cancer worldwide. Lymph node (LN) involvement is known to be the main prognostic factor. However, lymphatic anatomy is complex and only partially characterized. The aim of the study was to study the pancreatic lymphatic system using computer-assisted anatomic dissection (CAAD) technique and also to update CAAD technique by automatizing slice alignment. We dissected three human fetuses aged from 18 to 34 WA. 5-µm serial sections of duodeno-pancreas and spleen blocks were stained (hematoxylin-eosin, hematoxylin of Mayer and Masson trichrome), scanned, aligned and modeled in three dimensions. We observed a rich, diffuse but not systematized lymphatic network in the peri-pancreatic region. There was an equal distribution of LNs between the cephalic and body-tail portions. The lymphatic vascularization appeared in continuity from the celiac trunk to the distal ends of its hepatic and splenic arterial branches parallel to the nerve ramifications of the celiac plexus. We also observed a continuity between the drainage of the pancreatic head and the para-aortic region posteriorly. In view of the wealth of peri-pancreatic LNs, the number of LNs to harvest could be increased to improve nodal staging and prognostic evaluation. Pancreatic anatomy as described does not seem to be compatible with the sentinel LN procedure in pancreatic surgery. Finally, we are now able to offer an alternative to manual alignment with a semi-automated alignment.

  8. Prostate cancer nodal oligometastasis accurately assessed using prostate-specific membrane antigen positron emission tomography-computed tomography and confirmed histologically following robotic-assisted lymph node dissection.

    Science.gov (United States)

    O'Kane, Dermot B; Lawrentschuk, Nathan; Bolton, Damien M

    2016-01-01

    We herein present a case of a 76-year-old gentleman, where prostate-specific membrane antigen positron emission tomography-computed tomography (PSMA PET-CT) was used to accurately detect prostate cancer (PCa), pelvic lymph node (LN) metastasis in the setting of biochemical recurrence following definitive treatment for PCa. The positive PSMA PET-CT result was confirmed with histological examination of the involved pelvic LNs following pelvic LN dissection.

  9. Prostate cancer nodal oligometastasis accurately assessed using prostate-specific membrane antigen positron emission tomography-computed tomography and confirmed histologically following robotic-assisted lymph node dissection

    Directory of Open Access Journals (Sweden)

    Dermot B O′Kane

    2016-01-01

    Full Text Available We herein present a case of a 76-year-old gentleman, where prostate-specific membrane antigen positron emission tomography-computed tomography (PSMA PET-CT was used to accurately detect prostate cancer (PCa, pelvic lymph node (LN metastasis in the setting of biochemical recurrence following definitive treatment for PCa. The positive PSMA PET-CT result was confirmed with histological examination of the involved pelvic LNs following pelvic LN dissection.

  10. Testicular shield for para-aortic radiotherapy and estimation of gonad doses

    OpenAIRE

    Ravichandran, R.; Binukumar, J. P.; Kannadhasan, S.; Shariff, M. H.; Ghamrawy, Kamal El

    2008-01-01

    For radiotherapy of para-aortic and abdominal regions in male patients, gonads are to be protected to receive less than 2% of the prescribed dose. A testicular shield was fabricated for abdominal radiotherapy with 15 MV X-rays ((Clinac 2300 CD, Varian AG) with low melting point alloy (Cerroband). The dimensions of the testicular shield were 6.5 cm diameter and 3.5 cm depth with 1.5 cm wall thickness. During treatment, this shield was held in position by a rectangular sponge and Styrofo...

  11. Scattered radiation to gonads: Role of testicular shielding for para-aortic and homolateral illiac nodal radiotherapy

    International Nuclear Information System (INIS)

    Singhal, M.K.; Kapoor, A.; Singh, D.; Bagri, P.K.; Narayan, S.; Nirban, R.K.; Kumar, H.S.

    2014-01-01

    Background: Scattered radiation to organs at risk deserves great attention during radiotherapy especially when the concern is about fertility. Minimizing the delivery of scattered radiation to the gonads while treating abdominal nodes or pelvic fields in male patients requires adequate shielding of the testes to preserve testicular functions. We constructed a testicular shield with cerrobend for the purpose of treatment of seminoma of testis stage I and IIA disease. Materials and methods: An outer shell of coconut of required dimensions was taken as a base over which cerrobend was poured to obtain two semi-spherical half testicular shields. Five patients of seminoma early stage (stage I and IIA) were treated with this testicular shield. Results: The estimated total dose received by the testis by scatter radiation after completion of the treatment was 0.115 Gy (0.28%) of total mid-plane dose of 40 Gy delivered by inverted Y field. At a distance of 8 cm from the inferior field border the 2 cm thick cerrobend testicular shield provided a shielding factor of 3.2/0.3 =10.33. Conclusions: With proper testicular shielding, doses as low as 0.28% of the prescribed dose can be achieved. This low dose is believed to maintain the fertility of the patient.

  12. Scattered radiation to gonads: role of testicular shielding for para-aortic and homolateral illiac nodal radiotherapy.

    Science.gov (United States)

    Singhal, Mukesh Kumar; Kapoor, Akhil; Singh, Daleep; Bagri, Puneet Kumar; Narayan, Satya; Nirban, Raj Kumar; Kumar, Harvindra Singh

    2014-06-01

    Scattered radiation to organs at risk deserves great attention during radiotherapy especially when the concern is about fertility. Minimizing the delivery of scattered radiation to the gonads while treating abdominal nodes or pelvic fields in male patients requires adequate shielding of the testes to preserve testicular functions. We constructed a testicular shield with cerrobend for the purpose of treatment of seminoma of testis stage I and IIA disease. An outer shell of coconut of required dimensions was taken as a base over which cerrobend was poured to obtain two semi-spherical half testicular shields. Five patients of seminoma early stage (stage I and IIA) were treated with this testicular shield. The estimated total dose received by the testis by scatter radiation after completion of the treatment was 0.115Gy (0.28%) of total mid-plane dose of 40Gy delivered by inverted Y field. At a distance of 8cm from the inferior field border the 2cm thick cerrobend testicular shield provided a shielding factor of 3.2/0.3=10.33. With proper testicular shielding, doses as low as 0.28% of the prescribed dose can be achieved. This low dose is believed to maintain the fertility of the patient. Copyright © 2014. Production and hosting by Elsevier B.V.

  13. Encountering the Accessory Polar Renal Artery during Laparoscopic Para-Aortic Lymphadenectomy.

    Science.gov (United States)

    Lee, Won Moo; Choi, Joong Sub; Bae, Jaeman; Jung, Un Suk; Eom, Jeong Min

    2018-01-01

    A 60-year-old Korean woman underwent laparoscopic bilateral salpingo-oophorectomy and was confirmed to have high-grade serous carcinoma of both ovaries with a huge omental cake, extensive agglutinated intra-abdominal metastatic masses, extensive serosa invasion of the intestines, and mesenterial deposits. She underwent 3 cycles of neoadjuvant chemotherapy followed by laparoscopic interval debulking surgery, including hysterectomy, pelvic and para-aortic lymphadenectomy, appendectomy, partial peritonectomy, and omentectomy. We encountered the right accessory polar renal artery (APRA) during the surgery and carefully preserved the right APRA from the abdominal aorta to the right kidney (Fig. 1). Postoperative computed tomography angiography showed an intact right APRA and normal-appearing kidney (Fig. 2). The patient had adjuvant chemotherapy and is alive without disease recurrence. Because APRA is a functional end artery, it is important to preserve it during surgery to prevent ischemic damage and renal failure [1]. It is very important for the gynecologic-oncologist to have knowledge of the retroperitoneal vascular anatomy, experience in laparoscopic surgery, and an accurate surgical technique to avoid vascular injury during laparoscopic para-aortic lymphadenectomy. Copyright © 2017 AAGL. Published by Elsevier Inc. All rights reserved.

  14. Extraperitoneal Robotic-Assisted Para-Aortic Lymphadenectomy in Gynecologic Cancer Staging: Current Evidence.

    Science.gov (United States)

    Bogani, Giorgio; Ditto, Antonino; Martinelli, Fabio; Signorelli, Mauro; Chiappa, Valentina; Sabatucci, Ilaria; Scaffa, Cono; Lorusso, Domenica; Raspagliesi, Francesco

    2016-01-01

    We reviewed the current evidence on the safety, effectiveness, and applicability of extraperitoneal robotic-assisted para-aortic lymphadenectomy (ExtRA-PAL) as the staging procedure of gynecologic malignancies. PubMed (MEDLINE), Scopus, Web of Science databases, and ClinicalTrials.gov were searched for original studies reporting outcomes of ExtRA-PAL. Quality of the included studies and their level of recommendation were assessed using the Grading of Recommendations, Assessment, Development, and Evaluation and the American College of Obstetricians and Gynecologists guidelines, respectively. Overall, 62 studies were identified; after a process of evidence acquisition 5 original investigations were available for this review that included 98 patients undergoing ExtRA-PAL. The main surgical indication was staging for cervical cancer (n = 71, 72%). The mean (SD) number of para-aortic node yielded was 15.4 (±4.7) nodes. Blood transfusion and intraoperative complication rates were 2% and 6%, respectively. ExtRA-PAL was completed in 88 patients (90%). Six (6%) and 4 (4%) patients had conversion to other minimally invasive procedures and open surgery, respectively. Success rate was 99% among patients undergoing ExtRA-PAL without concomitant procedures. Overall, mean (SD) length of hospital stay was 2.8 (±0.5) days. Twenty-four patients (24%) developed postoperative events. According to the Clavien-Dindo grading system, grades IIIa and IIIb morbidity rates were 12% and 2%, respectively. No grades IV and V morbidity occurred. ExtRA-PAL is associated with a high success rate and a relative low morbidity rate. However, because of the limited data on this issue, further studies are warranted to assess the long-term effectiveness of this procedure. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

  15. FIGO IVB (Para-aortic lymph adenopathy) squamous cell carcinoma of uterine cervix associated with a left pelvic kidney: a therapeutic challenge

    International Nuclear Information System (INIS)

    Ali, N.; Karsan, F.; Abbasi, A.N.; Khan, Z.R.

    2012-01-01

    The standard of care for locally advanced carcinoma of uterine cervix is concurrent chemoradiation therapy followed by intracavitary brachytherapy, when there is para-aortic lymphadenopathy, radiation field needs to be extended to para-aortic region. In the latter case dose limiting organs are spinal cord, kidneys and small intestine. We present a challenging case of FIGO IVB squamous cell carcinoma of cervix and a pelvic kidney. This patient received chemoradiation to pelvis and para-aortic field, brachytherapy was not performed as patient already had undergone attempted hysterectomy. Treatment, outcome and challenges encountered in this case are presented and literature is reviewed. (author)

  16. Extended field chemoradiation for cervical cancer patients with histologically proven para-aortic lymph node metastases after laparoscopic lymphadenectomy

    Energy Technology Data Exchange (ETDEWEB)

    Marnitz, Simone; Schram, Johanna; Budach, Volker [Charite University Medicine, Department of Radiation Oncology, Berlin (Germany); Sackerer, Irina [Technische Universitaet Muenchen, Department of Radiation Oncology, Muenchen (Germany); Vercellino, Giuseppe Filiberto [University Medicine Berlin, Department of Gynecology, Campus Benjamin Franklin, Berlin (Germany); Sehouli, Jalid [University Medicine Berlin, Department of Gynecology, Campus Benjamin Franklin and Virchow, Berlin (Germany); Koehler, Christhardt [ASKLEPIOS Clinic Hamburg-Harburg, Department of Specialized Surgical and Oncologic Gynecology, Hamburg (Germany)

    2015-05-01

    The purpose of this work was to evaluate the use of extended-field chemoradiation (EFRT) with concomitant chemotherapy in patients with histologically confirmed para-aortic metastases after laparoscopic para-aortic and pelvic lymphadenectomy (LAE) with regard to oncologic results and treatment-related toxicity. A total of 44 women with squamous cell carcinoma (82 %) and adenocarcinoma (18 %) of the cervix in FIGO stages IIA (n = 3), IIB (n = 29); IIIB (n = 9), and IVA (n = 3) and histologically proven para-aortic metastases underwent EFRT and chemotherapy. Laparoscopic LAE was performed in 40 patients. Patients underwent chemoradiation with conventional fractionation of 1.8-50.4 Gy to the para-aortic and pelvic region. In addition, MRI-guided brachytherapy was performed to the cervix with 5-6 single doses of 5 Gy for a total dose of 25-30 Gy. The mean number of harvested lymph nodes was 17 in the pelvic as well as para-aortic regions, respectively. Laparoscopic intervention did not delay chemoradiation. Follow-up was 6-76 months (mean 25.1 months). There was no grade 4 or 5 acute radiation toxicity. In all, 8, 4, and 11 % grade 1, 2, and 3 gastrointestinal late toxicities and 7, 11, and 19 % grade 1, 2 and 3 genitourinary late toxicities were recorded. Despite the excellent locoregional (pelvic) control rates of 89.1 and 82.8 % after 2 and 5 years, respectively, the overall survival rates were 68.4 and 54.1 % after 2 and 5 years, respectively. Of the 44 patients, 43 remained tumor free in the para-aortic region. In patients with proven para-aortic disease, excellent pelvic and para-aortic control could be achieved by laparoscopic LAE followed by EFRT. More than half of the patients were long-term survivors. The high risk of distant metastases should be addressed by further improving systemic treatment. (orig.) [German] Ziel dieser Arbeit war es,die onkologischen Ergebnisse und die Toxizitaet der ''Extended-field''-Radiochemotherapie (EFRT) im

  17. Seminoma of the testis: is scrotal shielding necessary when radiotherapy is limited to the para-aortic nodes?

    Science.gov (United States)

    Bieri, S; Rouzaud, M; Miralbell, R

    1999-03-01

    To evaluate the influence of different shielding conditions and field geometry on the scatter dose to the remaining testicle during postoperative radiotherapy (RT) in seminoma. Testicular dose measurements were made with LiF thermoluminescent dosimeters (TLD) in 29 patients with stage I and IIA seminoma. The target volume consisted of para-aortic (PA) and para-aortic and homolateral iliac (PAI) lymph nodes in 14 and 15 patients, respectively. All patients had a scrotal shield as well as an additional block extending 7 cm inferiorly from the caudal field edge to shield the testicle from external scatter and collimator leakage. Doses with and without testicular blocks were measured for all patients. In seven patients treated exclusively to the PA region the gonadal dose was assessed according to four different shielding conditions: without any protection, with a gonadal shield alone, with the addition of an inferior field border block to the gonadal shield, and with the field border block alone. For patients treated with PAI fields the mean testicular doses per fraction were 3.89 cGy (S.D. +/- 1.44) and 1.48 cGy (S.D. +/- 0.51) without and with gonadal shielding, respectively (P-value shielding conditions, the additional external block to the testicular shield did not reduce significantly the measured dose on the testis. These results suggest a benefit of gonadal shielding even in seminoma patients undergoing radiotherapy limited to the para-aortic region.

  18. Dosimetric comparison of intensity modulated radiation, Proton beam therapy and proton arc therapy for para-aortic lymph node tumor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hoon [Dept. of Radiation Oncology, Konyang University Hospital. Daejeon (Korea, Republic of)

    2014-12-15

    To test feasibility of proton arc therapy (PAT) in the treatment of para-aortic lymph node tumor and compare its dosimetric properties with advanced radiotherapy techniques such as intensity modulated radiation therapy (IMRT) and conventional 3D conformal proton beam therapy (PBT). The treatment plans for para-aortic lymph node tumor were planned for 9 patients treated at our institution using IMRT, PBT, and PAT. Feasibility test and dosimetric evaluation were based on comparisons of dose volume histograms (DVHs) which reveal mean dose, D{sub 30%}, D{sub 60%}, D{sub 90%}, V{sub 30%}, V{sub 60%}, V{sub 90}%, organ equivalent doses (OEDs), normal tissue complication probability (NTCP), homogeneity index (HI) and conformity index (CI). The average doses delivered by PAT to the liver, kidney, small bowel, duodenum, stomach were 7.6%, 3%, 17.3%, 26.7%, and 14.4%, of the prescription dose (PD), respectively, which is higher than the doses delivered by IMRT (0.4%, 7.2%, 14.2%, 15.9%, and 12.8%, respectively) and PBT (4.9%, 0.5%, 14.12%, 16.1% 9.9%, respectively). The average homogeneity index and conformity index of tumor using PAT were 12.1 and 1.21, respectively which were much better than IMRT (21.5 and 1.47, respectively) and comparable to PBT (13.1 and 1.23, respectively). The result shows that both NTCP and OED of PAT are generally lower than IMRT and PBT. This study demonstrates that PAT is better in target conformity and homogeneity than IMRT and PBT but worse than IMRT and PBT for most of dosimetric factor which indicate that PAT is not recommended for the treatment of para-aortic lymph node tumor.

  19. Seminoma of the testis: is scrotal shielding necessary when radiotherapy is limited to the para-aortic nodes?

    International Nuclear Information System (INIS)

    Bieri, S.; Rouzaud, M.; Miralbell, R.

    1999-01-01

    Purpose: To evaluate the influence of different shielding conditions and field geometry on the scatter dose to the remaining testicle during postoperative radiotherapy (RT) in seminoma.Materials and methods: Testicular dose measurements were made with LiF thermoluminescent dosimeters (TLD) in 29 patients with stage I and IIA seminoma. The target volume consisted of para-aortic (PA) and para-aortic and homolateral iliac (PAI) lymph nodes in 14 and 15 patients, respectively. All patients had a scrotal shield as well as an additional block extending 7 cm inferiorly from the caudal field edge to shield the testicle from external scatter and collimator leakage. Doses with and without testicular blocks were measured for all patients. In seven patients treated exclusively to the PA region the gonadal dose was assessed according to four different shielding conditions: without any protection, with a gonadal shield alone, with the addition of an inferior field border block to the gonadal shield, and with the field border block alone.Results: For patients treated with PAI fields the mean testicular doses per fraction were 3.89 cGy (S.D.±1.44) and 1.48 cGy (S.D.±0.51) without and with gonadal shielding, respectively (P-value <0.001); the corresponding values for PA fields were 1.86 cGy (S.D.±0.86) and 0.65 cGy (S.D.±0.35). For the patients treated to the PA region and assessed according to the four different shielding conditions, the additional external block to the testicular shield did not reduce significantly the measured dose on the testis.Conclusions: These results suggest a benefit of gonadal shielding even in seminoma patients undergoing radiotherapy limited to the para-aortic region. (Copyright (c) Elsevier Science B.V., Amsterdam. All rights reserved.)

  20. Functional and morphological alterations of the stomach in case of irradiation of the para-aortic area

    Energy Technology Data Exchange (ETDEWEB)

    Beyer-Enke, S.A.; Gladisch, R.; Heine, M.; Georgi, M.

    1987-12-01

    Six assays were conducted in order to determine some functional and morphological parameters of the gastric mucosa in patients who underwent Co/sup 60/ irradiations of the para-aortic area. Slight as well as marked morphological alterations were observed whereas the functional alterations were found to be marked in all cases. Basal gastric secretion and serum gastrin level showed a continous reduction, however, in case of severe gastritis the stimulated secretion was increased. A possible correlation with increased tissue histamine levels is discussed.

  1. KEK NODAL user's guide

    International Nuclear Information System (INIS)

    Akiyama, Atsuyoshi; Katoh, Tadahiko; Kikutani, Eiji; Koiso, Haruyo; Kurokawa, Shin-ichi; Oide, Katsunobu.

    1984-06-01

    NODAL is an interpreter language for accelerator control developed at CERN SPS and has been used successfully since 1974. At present NODAL or NODAL-like languages are used at DESY PETRA and CERN CPS. At KEK, we have also adopted NODAL for the control of TRISTAN, a 30 GeV x 30 GeV electron-positron colliding beam facility. The KEK version of NODAL has the following improvements on the SPS NODAL: (1) the fast execution speed due to the compiler-interpreter scheme, and (2) the full-screen editing facility. This manual explains how to use the KEK NODAL. It is based on the manual of the SPS NODAL, THE NODAL SYSTEM FOR THE SPS, by M.C. Crowley-Milling and G.C. Shering, CERN 78-07. We have made some additions and modifications to make the manual more appropriate for the KEK NODAL system, paying attention to retaining the good features of the original SPS NODAL manual. We acknowledge Professor M.C. Crowley-Milling, Dr G.C. Shering and CERN for their kind permission for this modification. (author)

  2. Testicular shield for para-aortic radiotherapy and estimation of gonad doses.

    Science.gov (United States)

    Ravichandran, R; Binukumar, J P; Kannadhasan, S; Shariff, M H; Ghamrawy, Kamal El

    2008-10-01

    For radiotherapy of para-aortic and abdominal regions in male patients, gonads are to be protected to receive less than 2% of the prescribed dose. A testicular shield was fabricated for abdominal radiotherapy with 15 MV X-rays ((Clinac 2300 CD, Varian AG) with low melting point alloy (Cerroband). The dimensions of the testicular shield were 6.5 cm diameter and 3.5 cm depth with 1.5 cm wall thickness. During treatment, this shield was held in position by a rectangular sponge and Styrofoam support. Phantom measurement was carried out with a humanoid phantom and a 0.6 cc ion chamber. The mean energy of the scattered photon was calculated for single scattering at selected distances from the beam edge and with different field dimensions. One patient received radiotherapy with an inverted Y field and gonad doses were estimated using calibrated thermo-luminescent detector (TLD) chips. Measured doses with the ion chamber were 7.1 and 3.5% of the mid-plane doses without a shield at 3 and 7.5 cm off-field respectively. These values decreased to 4.6 and 1.7% with the bottom shield alone, and to 1.7 and 0.8% with both bottom and top shields covering the ion chamber. The measured doses at the gonads during the patient's treatment were 0.5-0.92% for the AP field (0.74 +/- 0.17%, n = 5) and 0.5-1.2% for the PA field (0.88 +/- 0.24%, n = 5). The dose received by the testis for the full course of treatment was 32 cGy (0.8%) for a total mid-plane dose of 40 Gy. The first-scatter energy estimated at the gonads is around 1.14 MeV for a primary beam of 15 MV for a long axis dimension of 37 cm of primary field. During the patient's treatment, the estimated absorbed doses at the gonads were comparable with reported values in similar treatments. The testicular shield reported in this study is of light weight and could be used conveniently in treatments of abdominal fields.

  3. Testicular shield for para-aortic radiotherapy and estimation of gonad doses

    Directory of Open Access Journals (Sweden)

    Ravichandran R

    2008-01-01

    Full Text Available For radiotherapy of para-aortic and abdominal regions in male patients, gonads are to be protected to receive less than 2% of the prescribed dose. A testicular shield was fabricated for abdominal radiotherapy with 15 MV X-rays ((Clinac 2300 CD, Varian AG with low melting point alloy (Cerroband. The dimensions of the testicular shield were 6.5 cm diameter and 3.5 cm depth with 1.5 cm wall thickness. During treatment, this shield was held in position by a rectangular sponge and Styrofoam support. Phantom measurement was carried out with a humanoid phantom and a 0.6 cc ion chamber. The mean energy of the scattered photon was calculated for single scattering at selected distances from the beam edge and with different field dimensions. One patient received radiotherapy with an inverted Y field and gonad doses were estimated using calibrated thermo-luminescent detector (TLD chips. Measured doses with the ion chamber were 7.1 and 3.5% of the mid-plane doses without a shield at 3 and 7.5 cm off-field respectively. These values decreased to 4.6 and 1.7% with the bottom shield alone, and to 1.7 and 0.8% with both bottom and top shields covering the ion chamber. The measured doses at the gonads during the patient′s treatment were 0.5-0.92% for the AP field (0.74 ± 0.17%, n = 5 and 0.5-1.2% for the PA field (0.88 ± 0.24%, n = 5. The dose received by the testis for the full course of treatment was 32 cGy (0.8% for a total mid-plane dose of 40 Gy. The first-scatter energy estimated at the gonads is around 1.14 MeV for a primary beam of 15 MV for a long axis dimension of 37 cm of primary field. During the patient′s treatment, the estimated absorbed doses at the gonads were comparable with reported values in similar treatments. The testicular shield reported in this study is of light weight and could be used conveniently in treatments of abdominal fields.

  4. KEK NODAL system

    International Nuclear Information System (INIS)

    Kurokawa, S.; Abe, K.; Akiyama, A.; Katoh, T.; Kikutani, E.; Koiso, H.; Kurihara, N.; Oide, K.; Shinomoto, M.

    1985-01-01

    The KEK NODAL system, which is based on the NODAL devised at the CERN SPS, works on an optical-fiber token ring network of twenty-four minicomputers (Hitachi HIDIC 80's) to control the TRISTAN accelerator complex, now being constructed at KEK. KEK NODAL retains main features of the original NODAL: the interpreting scheme, the multi-computer programming facility, and the data-module concept. In addition, it has the following characteristics: fast execution due to the compiler-interpreter method, a multicomputer file system, a full-screen editing facility, and a dynamic linkage scheme of data modules and NODAL functions. The structure of the KEK NODAL system under PMS, a real-time multitasking operating system of HIDIC 80, is described; the NODAL file system is also explained

  5. Mapping of nodal disease in locally advanced prostate cancer: Rethinking the clinical target volume for pelvic nodal irradiation based on vascular rather than bony anatomy

    International Nuclear Information System (INIS)

    Shih, Helen A.; Harisinghani, Mukesh; Zietman, Anthony L.; Wolfgang, John A.; Saksena, Mansi; Weissleder, Ralph

    2005-01-01

    Purpose: Toxicity from pelvic irradiation could be reduced if fields were limited to likely areas of nodal involvement rather than using the standard 'four-field box.' We employed a novel magnetic resonance lymphangiographic technique to highlight the likely sites of occult nodal metastasis from prostate cancer. Methods and Materials: Eighteen prostate cancer patients with pathologically confirmed node-positive disease had a total of 69 pathologic nodes identifiable by lymphotropic nanoparticle-enhanced MRI and semiquantitative nodal analysis. Fourteen of these nodes were in the para-aortic region, and 55 were in the pelvis. The position of each of these malignant nodes was mapped to a common template based on its relation to skeletal or vascular anatomy. Results: Relative to skeletal anatomy, nodes covered a diffuse volume from the mid lumbar spine to the superior pubic ramus and along the sacrum and pelvic side walls. In contrast, the nodal metastases mapped much more tightly relative to the large pelvic vessels. A proposed pelvic clinical target volume to encompass the region at greatest risk of containing occult nodal metastases would include a 2.0-cm radial expansion volume around the distal common iliac and proximal external and internal iliac vessels that would encompass 94.5% of the pelvic nodes at risk as defined by our node-positive prostate cancer patient cohort. Conclusions: Nodal metastases from prostate cancer are largely localized along the major pelvic vasculature. Defining nodal radiation treatment portals based on vascular rather than bony anatomy may allow for a significant decrease in normal pelvic tissue irradiation and its associated toxicities

  6. Patterns of practice of regional nodal irradiation in breast cancer: results of the European Organization for Research and Treatment of Cancer (EORTC) NOdal Radiotherapy (NORA) survey

    NARCIS (Netherlands)

    Belkacemi, Y.; Kaidar-Person, O.; Poortmans, P.; Ozsahin, M.; Valli, M.-C.; Russell, N.; Kunkler, I.; Hermans, J.; Kuten, A.; van Tienhoven, G.; Westenberg, H.

    2015-01-01

    Predicting outcome of breast cancer (BC) patients based on sentinel lymph node (SLN) status without axillary lymph node dissection (ALND) is an area of uncertainty. It influences the decision-making for regional nodal irradiation (RNI). The aim of the NORA (NOdal RAdiotherapy) survey was to examine

  7. Out-of-field organ doses and associated radiogenic risks from para-aortic radiotherapy for testicular seminoma

    Energy Technology Data Exchange (ETDEWEB)

    Mazonakis, Michalis, E-mail: mazonak@med.uoc.gr; Berris, Theocharis; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P. O. Box 2208, 71003 Iraklion, Crete (Greece); Varveris, Charalambos; Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)

    2014-05-15

    Purpose: The aims of this study were to (a) calculate the radiation dose to out-of-field organs from radiotherapy for stage I testicular seminoma and (b) estimate the associated radiogenic risks. Methods: Monte Carlo methodology was employed to model radiation therapy with typical anteroposterior and posteroanterior para-aortic fields on an anthropomorphic phantom simulating an average adult. The radiation dose received by all main and remaining organs that defined by the ICRP publication 103 and excluded from the treatment volume was calculated. The effect of field dimensions on each organ dose was determined. Additional therapy simulations were generated by introducing shielding blocks to protect the kidneys from primary radiation. The gonadal dose was employed to assess the risk of heritable effects for irradiated male patients of reproductive potential. The lifetime attributable risks (LAR) of radiotherapy-induced cancer were estimated using gender- and organ-specific risk coefficients for patient ages of 20, 30, 40, and 50 years old. The risk values were compared with the respective nominal risks. Results: Para-aortic irradiation to 20 Gy resulted in out-of-field organ doses of 5.0–538.6 mGy. Blocked field treatment led to a dose change up to 28%. The mean organ dose variation by increasing or decreasing the applied field dimensions was 18.7% ± 3.9% and 20.8% ± 4.5%, respectively. The out-of-field photon doses increased the lifetime intrinsic risk of developing thyroid, lung, bladder, prostate, and esophageal cancer by (0.1–1.4)%, (0.4–1.1)%, (2.5–5.4)%, (0.2–0.4)%, and (6.4–9.2)%, respectively, depending upon the patient age at exposure and the field size employed. A low risk for heritable effects of less than 0.029% was found compared with the natural incidence of these defects. Conclusions: Testicular cancer survivors are subjected to an increased risk for the induction of bladder and esophageal cancer following para-aortic radiotherapy. The

  8. High-dose Extended-Field Irradiation and High-Dose-Rate Brachytherapy With Concurrent Chemotherapy for Cervical Cancer With Positive Para-Aortic Lymph Nodes

    International Nuclear Information System (INIS)

    Kim, Young Seok; Kim, Jong Hoon; Ahn, Seung Do; Lee, Sang-wook; Shin, Seong Soo; Nam, Joo-Hyun; Kim, Young-Tak; Kim, Yong-Man; Kim, Jong-Hyeok; Choi, Eun Kyung

    2009-01-01

    Purpose: To determine the efficacy and toxicity of extended-field radiotherapy (RT) with concurrent platinum-based chemotherapy in patients with uterine cervical carcinoma and positive para-aortic nodes. Methods and Materials: We retrospectively reviewed the results for 33 women with Stage IB-IVB cervical cancer. Each patient had received 59.4 Gy, including a three-dimensional conformal boost to the para-aortic lymph nodes and 41.4-50.4 Gy of external beam radiotherapy to the pelvis. Each patient also underwent six or seven applications of high-dose-rate brachytherapy (median, 5 Gy to point A at each session). Results: The median follow-up period of surviving patients was 39 months. The most common acute toxicity was hematologic, observed in 23 women. Severe acute and late gastrointestinal toxicity was observed in 3 and 4 patients, respectively. More than three-quarters of patients showed a complete response, encompassing the primary mass, metastatic pelvic, and para-aortic lymph nodes. Of the 33 women, 15 had no evidence of disease, 6 had persistent disease, 4 developed in-field failures, and 6 developed distant failures. The 5-year overall and disease-free survival rate was 47% and 42%, respectively. Conclusion: Concurrent chemoradiotherapy with extended-field radiotherapy is feasible in women with uterine cervical carcinoma and positive para-aortic lymph nodes, with acceptable late morbidity and a high survival rate, although it was accompanied by substantial acute toxicity.

  9. Significance of prophylactic para-aortic lymph node irradiation in the postoperatic treatment of the cervical cancer. Relationship between prognosis and lymph node metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Kumano, Machiko; Arita, Shigehiro; Ishida, Osamu; Murano, Yoshihiko; Sumita, Mitsugu; Okumura, Masahiko; Nanbu, Hidekazu [Kinki Univ., Osaka-Sayama, Osaka (Japan). School of Medicine

    1995-12-01

    Between 1976 and 1989, 163 patients were treated by postoperative radiotherapy for cervical cancer stage Ib and IIb. Before irradiation for the whole pelvis, a total dose of 50 Gy was given in 5 weeks. Cumulative 5-year survival rates according to the number of pelvic lymph node metastasis were 100% for Ib L{sub 1} (one node involvement) in 10 patients, 60% for Ib L{sub 2} {up_arrow} (two or more involved) in 10, 73% for IIb L{sub 1} in 23, 78% for IIb L{sub 2} in 9, 47% for IIb L{sub 3} {up_arrow} in 18. The first recurrent sites of stage Ib were distant organ via lymphatic routes in 3 patients and hematogenous routes in 2. IIb were via lymphatic routes in 10 patients, hematogenous routes in 10, and regional recurrence in 6. After introduced para-aortic node irradiation, the pelvic plus para-aortic irradiation delivered 45 Gy in 5 weeks for two or more lymph nodes involvement. The cumulative 5-year survival rates were 100% for Ib L{sub 1} in 10 patients, 100% for Ib L{sub 2} in 7, 65% for Ib L{sub 3} {up_arrow} in 9, 82% for IIb L{sub 1} in 17, 68% for IIb L{sub 2} in 27, and 48% for IIb L{sub 3} {up_arrow} in 23. The first recurrent sites for Ib with introduction of para-aortic node irradiation were distant organs via lymphatic routes in 1 patient and hematogenous routes in 2, and the sites for IIb were via lymphatic routes in 10, hematogenous 7, peritonitis carcinomatous 1, and in the pelvic field of 6. Late effects developed in 3 (19%) of Ib and 19 (29%) of IIb. Side effects increased with prophylactic para-aortic node irradiation. No significant difference was observed in survival rates between pelvic and pelvic plus para-aortic node irradiation group. (S.Y.).

  10. Prophylactic lower para-aortic irradiation using intensity-modulated radiotherapy mitigates the risk of para-aortic recurrence in locally advanced cervical cancer: A 10-year institutional experience.

    Science.gov (United States)

    Lee, Jie; Lin, Jhen-Bin; Chang, Chih-Long; Jan, Ya-Ting; Sun, Fang-Ju; Wu, Meng-Hao; Chen, Yu-Jen

    2017-07-01

    To evaluate the effects of prophylactic sub-renal vein radiotherapy (SRVRT) using intensity-modulated radiotherapy (IMRT) for cervical cancer. A total of 206 patients with FIGO stage IB2-IVA cervical cancer and negative para-aortic lymph nodes (PALNs) who underwent pelvic IMRT (PRT) or SRVRT between 2004 and 2013 at our institution were reviewed. SRVRT cranially extended the PRT field for PALNs up to the left renal vein level. The prescribed dose was consistent 50.4Gy in 28 fractions. Overall, 110 and 96 patients underwent PRT and SRVRT, respectively. The SRVRT group had more advanced disease based on FIGO stage and positive pelvic lymph nodes (PLNs). The median follow-up time was 60months (range, 7-143). For the total study population, the 5-year PALN recurrence-free survival (PARFS) and overall survival (OS) for PRT vs. SRVRT were 87.6% vs. 97.9% (p=0.03) and 74.5% vs. 87.8% (p=0.04), respectively. In patients with FIGO III-IVA or positive PLNs, the 5-year PARFS and OS for PRT vs. SRVRT were 80.1% vs. 96.4% (p=0.02) and 58.1% vs. 83.5% (p=0.012), respectively. However, there were no significant differences in these outcomes for patients with FIGO IB-IIB and negative PLNs. In a multivariate analysis, only SRVRT was associated with better PARFS (HR, 0.21; 95% CI, 0.06-0.78; p=0.02). The SRVRT did not significantly increase severe late toxicities. Prophylactic SRVRT using IMRT reduced PALN recurrence with tolerable toxicities, supporting the application of risk-based radiation fields for cervical cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Nodal-chain metals.

    Science.gov (United States)

    Bzdušek, Tomáš; Wu, QuanSheng; Rüegg, Andreas; Sigrist, Manfred; Soluyanov, Alexey A

    2016-10-06

    The band theory of solids is arguably the most successful theory of condensed-matter physics, providing a description of the electronic energy levels in various materials. Electronic wavefunctions obtained from the band theory enable a topological characterization of metals for which the electronic spectrum may host robust, topologically protected, fermionic quasiparticles. Many of these quasiparticles are analogues of the elementary particles of the Standard Model, but others do not have a counterpart in relativistic high-energy theories. A complete list of possible quasiparticles in solids is lacking, even in the non-interacting case. Here we describe the possible existence of a hitherto unrecognized type of fermionic excitation in metals. This excitation forms a nodal chain-a chain of connected loops in momentum space-along which conduction and valence bands touch. We prove that the nodal chain is topologically distinct from previously reported excitations. We discuss the symmetry requirements for the appearance of this excitation and predict that it is realized in an existing material, iridium tetrafluoride (IrF 4 ), as well as in other compounds of this class of materials. Using IrF 4 as an example, we provide a discussion of the topological surface states associated with the nodal chain. We argue that the presence of the nodal-chain fermions will result in anomalous magnetotransport properties, distinct from those of materials exhibiting previously known excitations.

  12. PET-NECK: a multicentre randomised Phase III non-inferiority trial comparing a positron emission tomography-computerised tomography-guided watch-and-wait policy with planned neck dissection in the management of locally advanced (N2/N3) nodal metastases in patients with squamous cell head and neck cancer.

    Science.gov (United States)

    Mehanna, Hisham; McConkey, Chris C; Rahman, Joy K; Wong, Wai-Lup; Smith, Alison F; Nutting, Chris; Hartley, Andrew Gj; Hall, Peter; Hulme, Claire; Patel, Dharmesh K; Zeidler, Sandra Ventorin von; Robinson, Max; Sanghera, Bal; Fresco, Lydia; Dunn, Janet A

    2017-04-01

    Planned neck dissection (ND) after radical chemoradiotherapy (CRT) for locally advanced nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) remains controversial. Thirty per cent of ND specimens show histological evidence of tumour. Consequently, a significant proportion of clinicians still practise planned ND. Fludeoxyglucose positron emission tomography (PET)-computerised tomography (CT) scanning demonstrated high negative predictive values for persistent nodal disease, providing a possible alternative paradigm to ND. Evidence is sparse and drawn mainly from retrospective single-institution studies, illustrating the need for a prospective randomised controlled trial. To determine the efficacy and cost-effectiveness of PET-CT-guided surveillance, compared with planned ND, in a multicentre, prospective, randomised setting. A pragmatic randomised non-inferiority trial comparing PET-CT-guided watch-and-wait policy with the current planned ND policy in HNSCC patients with locally advanced nodal metastases and treated with radical CRT. Patients were randomised in a 1 : 1 ratio. Primary outcomes were overall survival (OS) and cost-effectiveness [incremental cost per incremental quality-adjusted life-year (QALY)]. Cost-effectiveness was assessed over the trial period using individual patient data, and over a lifetime horizon using a decision-analytic model. Secondary outcomes were recurrence in the neck, complication rates and quality of life. The recruitment of 560 patients was planned to detect non-inferior OS in the intervention arm with a 90% power and a type I error of 5%, with non-inferiority defined as having a hazard ratio (HR) of no higher than 1.50. An intention-to-treat analysis was performed by Cox's proportional hazards model. Thirty-seven head and neck cancer-treating centres (43 NHS hospitals) throughout the UK. Patients with locally advanced nodal metastases of oropharynx, hypopharynx, larynx, oral or occult HNSCC receiving

  13. Experimental discovery of nodal chains

    Science.gov (United States)

    Yan, Qinghui; Liu, Rongjuan; Yan, Zhongbo; Liu, Boyuan; Chen, Hongsheng; Wang, Zhong; Lu, Ling

    2018-05-01

    Three-dimensional Weyl and Dirac nodal points1 have attracted widespread interest across multiple disciplines and in many platforms but allow for few structural variations. In contrast, nodal lines2-4 can have numerous topological configurations in momentum space, forming nodal rings5-9, nodal chains10-15, nodal links16-20 and nodal knots21,22. However, nodal lines are much less explored because of the lack of an ideal experimental realization23-25. For example, in condensed-matter systems, nodal lines are often fragile to spin-orbit coupling, located away from the Fermi level, coexist with energy-degenerate trivial bands or have a degeneracy line that disperses strongly in energy. Here, overcoming all these difficulties, we theoretically predict and experimentally observe nodal chains in a metallic-mesh photonic crystal having frequency-isolated linear band-touching rings chained across the entire Brillouin zone. These nodal chains are protected by mirror symmetry and have a frequency variation of less than 1%. We use angle-resolved transmission measurements to probe the projected bulk dispersion and perform Fourier-transformed field scans to map out the dispersion of the drumhead surface state. Our results establish an ideal nodal-line material for further study of topological line degeneracies with non-trivial connectivity and consequent wave dynamics that are richer than those in Weyl and Dirac materials.

  14. Clinical Response of Pelvic and Para-aortic Lymphadenopathy to a Radiation Boost in the Definitive Management of Locally Advanced Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rash, Dominique L. [Department of Radiation Oncology, University of California Davis Medical Center, Sacramento, California (United States); Lee, Yongsook C. [Department of Radiation Oncology, University of Kansas School of Medicine, Kansas City, Kansas (United States); Kashefi, Amir [Division of Nuclear Medicine, Department of Radiology, University of California Davis Medical Center, Sacramento, California (United States); Durbin-Johnson, Blythe [Division of Biostatistics, Department of Public Health Sciences, University of California Davis School of Medicine, Sacramento, California (United States); Mathai, Mathew; Valicenti, Richard [Department of Radiation Oncology, University of California Davis Medical Center, Sacramento, California (United States); Mayadev, Jyoti S., E-mail: jyoti.mayadev@ucdmc.ucdavis.edu [Department of Radiation Oncology, University of California Davis Medical Center, Sacramento, California (United States)

    2013-10-01

    Purpose: Optimal treatment with radiation for metastatic lymphadenopathy in locally advanced cervical cancer remains controversial. We investigated the clinical dose response threshold for pelvic and para-aortic lymph node boost using radiographic imaging and clinical outcomes. Methods and Materials: Between 2007 and 2011, 68 patients were treated for locally advanced cervical cancer; 40 patients had clinically involved pelvic and/or para-aortic lymph nodes. Computed tomography (CT) or 18F-labeled fluorodeoxyglucose-positron emission tomography scans obtained pre- and postchemoradiation for 18 patients were reviewed to assess therapeutic radiographic response of individual lymph nodes. External beam boost doses to involved nodes were compared to treatment response, assessed by change in size of lymph nodes by short axis and change in standard uptake value (SUV). Patterns of failure, time to recurrence, overall survival (OS), and disease-free survival (DFS) were determined. Results: Sixty-four lymph nodes suspicious for metastatic involvement were identified. Radiation boost doses ranged from 0 to 15 Gy, with a mean total dose of 52.3 Gy. Pelvic lymph nodes were treated with a slightly higher dose than para-aortic lymph nodes: mean 55.3 Gy versus 51.7 Gy, respectively. There was no correlation between dose delivered and change in size of lymph nodes along the short axis. All lymph nodes underwent a decrease in SUV with a complete resolution of abnormal uptake observed in 68%. Decrease in SUV was significantly greater for lymph nodes treated with ≥54 Gy compared to those treated with <54 Gy (P=.006). Median follow-up was 18.7 months. At 2 years, OS and DFS for the entire cohort were 78% and 50%, respectively. Locoregional control at 2 years was 84%. Conclusions: A biologic response, as measured by the change in SUV for metastatic lymph nodes, was observed at a dose threshold of 54 Gy. We recommend that involved lymph nodes be treated to this minimum dose.

  15. Avoided intersections of nodal lines

    International Nuclear Information System (INIS)

    Monastra, Alejandro G; Smilansky, Uzy; Gnutzmann, Sven

    2003-01-01

    We consider real eigenfunctions of the Schroedinger operator in 2D. The nodal lines of separable systems form a regular grid, and the number of nodal crossings equals the number of nodal domains. In contrast, for wavefunctions of non-integrable systems nodal intersections are rare, and for random waves, the expected number of intersections in any finite area vanishes. However, nodal lines display characteristic avoided crossings which we study in this work. We define a measure for the avoidance range and compute its distribution for the random wave ensemble. We show that the avoidance range distribution of wavefunctions of chaotic systems follows the expected random wave distributions, whereas for wavefunctions of classically integrable but quantum non-separable systems, the distribution is quite different. Thus, the study of the avoidance distribution provides more support to the conjecture that nodal structures of chaotic systems are reproduced by the predictions of the random wave ensemble

  16. The SINTRAN III NODAL system

    International Nuclear Information System (INIS)

    Skaali, T.B.

    1980-10-01

    NODAL is a high level programming language based on FOCAL and SNOBOL4, with some influence from BASIC. The language was developed to operate on the computer network controlling the SPS accelerator at CERN. NODAL is an interpretive language designed for interactive use. This is the most important aspect of the language, and is reflected in its structure. The interactive facilities make it possible to write, debug and modify programs much faster than with compiler based languages like FORTRAN and ALGOL. Apart from a few minor modifications, the basic part of the Oslo University NODAL system does not differ from the CERN version. However, the Oslo University implementation has been expanded with new functions which enable the user to execute many of the SINTRAN III monitor calls from the NODAL level. In particular the most important RT monitor calls have been implemented in this way, a property which renders possible the use of NODAL as a RT program administrator. (JIW)

  17. NODAL interpreter for CP/M

    International Nuclear Information System (INIS)

    Oide, Katsunobu.

    1982-11-01

    A NODAL interpreter which works under CP/M operating system is made for microcomputers. This interpreter language named NODAL-80 has a similar structure to the NODAL of SPS, but its commands, variables, and expressions are modified to increase the flexibility of programming. NODAL-80 also uses a simple intermediate code to make the execution speed fast without imposing any restriction on the dynamic feature of NODAL language. (author)

  18. Long-term results of high-dose conformal radiotherapy for patients with medically inoperable T1-3N0 non-small-cell lung cancer: Is low incidence of regional failure due to incidental nodal irradiation?

    International Nuclear Information System (INIS)

    Chen Ming; Hayman, James A.; Haken, Randall K. ten; Tatro, Daniel; Fernando, Shaneli; Kong, F.-M.

    2006-01-01

    Purpose: To report the results of high-dose conformal irradiation and examine incidental nodal irradiation and nodal failure in patients with inoperable early-stage non-small-cell lung cancer (NSCLC). Methods and Materials: This analysis included patients with inoperable CT-staged T1-3N0M0 NSCLC treated on our prospective dose-escalation trial. Patients were treated with radiation alone (total dose, 63-102.9 Gy in 2.1-Gy daily fractions) with a three-dimensional conformal technique without intentional nodal irradiation. Bilateral highest mediastinal and upper/lower paratracheal, prevascular and retrotracheal, sub- and para-aortic, subcarinal, paraesophageal, and ipsilateral hilar regions were delineated individually. Nodal failure and doses of incidental irradiation were studied. Results: The potential median follow-up was 104 months. For patients who completed protocol treatment, median survival was 31 months. The actuarial overall survival rate was 86%, 61%, 43%, and 21% and the cause-specific survival rate was 89%, 70%, 53%, and 35% at 1, 2, 3, and 5 years, respectively. Weight loss (p = 0.008) and radiation dose in Gy (p = 0.013) were significantly associated with overall survival. In only 22% and 13% of patients examined did ipsilateral hilar and paratracheal (and subaortic for left-sided tumor) nodal regions receive a dose of ≥40 Gy, respectively. Less than 10% of all other nodal regions received a dose of ≥40 Gy. No patients failed initially at nodal sites. Conclusions: Radiation dose is positively associated with overall survival in patients with medically inoperable T1-3N0 NSCLC, though long-term results remain poor. The nodal failure rate is low and does not seem to be due to high-dose incidental irradiation

  19. Nodal metastasis in thyroid cancer

    International Nuclear Information System (INIS)

    Samuel, A.M.

    1999-01-01

    The biological behavior and hence the prognosis of thyroid cancer (TC) depends among other factors on the extent of spread of the disease outside the thyroid bed. This effect is controversial, especially for nodal metastasis of well differentiated thyroid carcinoma (WDC). Nodal metastasis at the time of initial diagnosis behaves differently depending on the histology, age of the patient, presence of extrathyroidal extension, and the sex of the individual. The type of the surgery, administration of 131 I and thyroxin suppression also to some extent influence the rate of recurrence and mortality. Experience has shown that it is not as innocuous as a small intrathyroidal tumor without any invasion outside the thyroid bed and due consideration should be accorded to the management strategies for handling patients with nodal metastasis

  20. The adjoint variational nodal method

    International Nuclear Information System (INIS)

    Laurin-Kovitz, K.; Lewis, E.E.

    1993-01-01

    The widespread use of nodal methods for reactor core calculations in both diffusion and transport approximations has created a demand for the corresponding adjoint solutions as a prerequisite for performing perturbation calculations. With some computational methods, however, the solution of the adjoint problem presents a difficulty; the physical adjoint obtained by discretizing the adjoint equation is not the same as the mathematical adjoint obtained by taking the transpose of the coefficient matrix, which results from the discretization of the forward equation. This difficulty arises, in particular, when interface current nodal methods based on quasi-one-dimensional solution of the diffusion or transport equation are employed. The mathematical adjoint is needed to perform perturbation calculations. The utilization of existing nodal computational algorithms, however, requires the physical adjoint. As a result, similarity transforms or related techniques must be utilized to relate physical and mathematical adjoints. Thus far, such techniques have been developed only for diffusion theory

  1. Nodal in computerized control systems of accelerators

    International Nuclear Information System (INIS)

    Kagarmanov, A.A.; Koval'tsov, V.I.; Korobov, S.A.

    1994-01-01

    Brief description of the Nodal language programming structure is presented. Its possibilities as high-level programming language for accelerator control systems are considered. The status of the Nodal language in the HEPI is discussed. 3 refs

  2. A variational synthesis nodal discrete ordinates method

    International Nuclear Information System (INIS)

    Favorite, J.A.; Stacey, W.M.

    1999-01-01

    A self-consistent nodal approximation method for computing discrete ordinates neutron flux distributions has been developed from a variational functional for neutron transport theory. The advantage of the new nodal method formulation is that it is self-consistent in its definition of the homogenized nodal parameters, the construction of the global nodal equations, and the reconstruction of the detailed flux distribution. The efficacy of the method is demonstrated by two-dimensional test problems

  3. Tumour thickness as a predictor of nodal metastases in oral cancer: comparison between tongue and floor of mouth subsites.

    Science.gov (United States)

    Balasubramanian, Deepak; Ebrahimi, Ardalan; Gupta, Ruta; Gao, Kan; Elliott, Michael; Palme, Carsten E; Clark, Jonathan R

    2014-12-01

    To identify whether tumour thickness as a predictor of nodal metastases in oral squamous cell carcinoma differs between tongue and floor of mouth (FOM) subsites. Retrospective review of 343 patients treated between 1987 and 2012. The neck was considered positive in the presence of pathologically proven nodal metastases on neck dissection or during follow-up. There were 222 oral tongue and 121 FOM tumours. In patients with FOM tumours 2.1-4mm thick, the rate of nodal metastases was 41.7%. In contrast, for tongue cancers of a similar thickness the rate was only 11.2%. This increased to 38.5% in patients with tongue cancers that were 4.1-6mm thick. Comparing these two subsites, FOM cancers cross the critical 20% threshold of probability for nodal metastases between 1 and 2mm whereas tongue cancers cross the 20% threshold just under 4mm thickness. On logistic regression adjusting for relevant covariates, there was a significant difference in the propensity for nodal metastases based on tumour thickness according to subsite (p=0.028). Thin FOM tumours (2.1-4mm) have a high rate of nodal metastases. Elective neck dissection is appropriate in FOM tumours ⩾2mm thick and in tongue tumours ⩾4mm thick. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The Problems of Dissection.

    Science.gov (United States)

    Davis, Pat

    1997-01-01

    Describes some problems of classroom dissection including the cruelty that animals destined for the laboratory suffer. Discusses the multilevel approach that the National Anti-Vivisection Society (NAVS) has developed to address the problems of animal dissection such as offering a dissection hotline, exhibiting at science teacher conferences, and…

  5. NESTLE: A nodal kinetics code

    International Nuclear Information System (INIS)

    Al-Chalabi, R.M.; Turinsky, P.J.; Faure, F.-X.; Sarsour, H.N.; Engrand, P.R.

    1993-01-01

    The NESTLE nodal kinetics code has been developed for utilization as a stand-alone code for steady-state and transient reactor neutronic analysis and for incorporation into system transient codes, such as TRAC and RELAP. The latter is desirable to increase the simulation fidelity over that obtained from currently employed zero- and one-dimensional neutronic models and now feasible due to advances in computer performance and efficiency of nodal methods. As a stand-alone code, requirements are that it operate on a range of computing platforms from memory-limited personal computers (PCs) to supercomputers with vector processors. This paper summarizes the features of NESTLE that reflect the utilization and requirements just noted

  6. Nodal lymphomas of the abdomen

    International Nuclear Information System (INIS)

    Bruneton, J.N.; Caramella, E.; Manzino, J.J.

    1986-01-01

    Modern imaging modalities have greatly contributed to current knowledge about intra-abdominal nodal lymphomas. Since both intra and retroperitoneal node involvement can be demonstrated by computed tomography (CT) and ultrasonography, it seems legitimate to treat these two sites together in the same chapter, particularly since the older separation between intraperitoneal and retroperitoneal nodal disease was based to a large degree on the limitations of lymphography. Hodgkin's disease (HD) has benefited less from recent technological advances. The diversity in the incidence of nodal involvement between HD and NHL, the diagnostic capabilities of modern imaging techniques, and the histopathological features of lymphomatous non-Hodgkin and Hodgkin nodes, justify adoption of an investigatory approach which takes all of these factors into account. Details of this investigative strategy are discussed in this paper following a review of available imaging modalities. In current practice, the four main methods for the exploration of abdominal lymph nodes are lymphography, ultrasonography, CT, and radionuclide studies. The first three techniques are also utilized to guide biopsies for staging purposes and for the evaluation of response to treatment

  7. Long-term outcomes after resection of para-aortic lymph node metastasis from left-sided colon and rectal cancer.

    Science.gov (United States)

    Nakai, Nozomu; Yamaguchi, Tomohiro; Kinugasa, Yusuke; Shiomi, Akio; Kagawa, Hiroyasu; Yamakawa, Yushi; Numata, Masakatsu; Furutani, Akinobu

    2017-07-01

    Para-aortic lymph node (PALN) metastasis from colorectal cancer is rare and often not suitable for surgery. However, in selected patients, radical resection may bring about longer survival. The aim of this study was to evaluate long-term outcomes of resection of left-sided colon or rectal cancer with simultaneous PALN metastasis. The study included 2122 patients with left-sided colon or rectal cancer (30 patients with and 2092 patients without PALN metastasis) who underwent resection with curative intent between 2002 and 2013. Clinicopathological characteristics, long-term outcomes of resection, and factors related to poor postoperative survival in patients with PALN metastasis were investigated. Of a total of 2122 total patients, 16 of 50 patients (32.0%) with lymph node metastasis at the root of the inferior mesenteric artery had PALN metastasis. The 5-year overall survival rates for 18 patients who underwent R0 resection and 12 patients who did not were 29.1 and 10.4%, respectively (p = 0.017). Factors associated with poor postoperative survival among patients who underwent R0 resection were presence of conversion therapy, lack of adjuvant chemotherapy, carcinoembryonic antigen >20 ng/mL, and lateral lymph node metastasis in rectal cancer patients. The 5-year recurrence-free survival rate was 14.8%. Although recurrence was frequent, R0 resection for left-sided colon or rectal cancer with PALN metastasis was associated with longer survival than R1/R2 resection. Furthermore, the 5-year overall survival rate in the R0 group was relatively favorable for stage IV. Therefore, R0 resection may prolong survival compared with chemotherapy alone in selected patients.

  8. Validity and QOL of neck dissection preceding radiation therapy for hypopharyngeal cancer

    International Nuclear Information System (INIS)

    Uemura, Hirokazu; Yoshino, Kunitoshi; Fujii, Takashi; Suzuki, Motoyuki

    2009-01-01

    Thirty-one cases of hypopharyngeal cancer with neck dissection preceding radiation and 16 cases of hypopharyngeal cancer with neck dissection for locoregional recurrences after radiation were reviewed in order to make comparative evaluations of difficulty in surgical operation, postoperative complications, laryngeal preservation rate, and cause specific 5-year survival rate retrospectively. And quality of life (QOL) after neck dissection was additionally evaluated through the questionnaire. Since neck dissection preceding radiation for hypopharyngeal cancer may be superior to neck dissection for radiation failure, with easy surgical approach an non-lymphoid tissue preservation, that modality can be a reasonable choice of treatment for patients with nodal lesions, which are probably difficult to treat with radiation alone. Even though further investigation on QOL questionnaire is necessary, this modality can make a contribution to the neck and shoulder condition after neck dissection. (author)

  9. Development of nodal interface conditions for a PN approximation nodal model

    International Nuclear Information System (INIS)

    Feiz, M.

    1993-01-01

    A relation was developed for approximating higher order odd-moments from lower order odd-moments at the nodal interfaces of a Legendre polynomial nodal model. Two sample problems were tested using different order P N expansions in adjacent nodes. The developed relation proved to be adequate and matched the nodal interface flux accurately. The development allows the use of different order expansions in adjacent nodes, and will be used in a hybrid diffusion-transport nodal model. (author)

  10. Sampling versus systematic full lymphatic dissection in surgical treatment of non-small cell lung cancer.

    Science.gov (United States)

    Koulaxouzidis, Georgios; Karagkiouzis, Grigorios; Konstantinou, Marios; Gkiozos, Ioannis; Syrigos, Konstantinos

    2013-04-22

    The extent of mediastinal lymph node assessment during surgery for non-small cell cancer remains controversial. Different techniques are used, ranging from simple visual inspection of the unopened mediastinum to an extended bilateral lymph node dissection. Furthermore, different terms are used to define these techniques. Sampling is the removal of one or more lymph nodes under the guidance of pre-operative findings. Systematic (full) nodal dissection is the removal of all mediastinal tissue containing the lymph nodes systematically within anatomical landmarks. A Medline search was conducted to identify articles in the English language that addressed the role of mediastinal lymph node resection in the treatment of non-small cell lung cancer. Opinions as to the reasons for favoring full lymphatic dissection include complete resection, improved nodal staging and better local control due to resection of undetected micrometastasis. Arguments against routine full lymphatic dissection are increased morbidity, increase in operative time, and lack of evidence of improved survival. For complete resection of non-small cell lung cancer, many authors recommend a systematic nodal dissection as the standard approach during surgery, and suggest that this provides both adequate nodal staging and guarantees complete resection. Whether extending the lymph node dissection influences survival or recurrence rate is still not known. There are valid arguments in favor in terms not only of an improved local control but also of an improved long-term survival. However, the impact of lymph node dissection on long-term survival should be further assessed by large-scale multicenter randomized trials.

  11. The Nudo, Rollo, Melon codes and nodal correlations

    International Nuclear Information System (INIS)

    Perlado, J.M.; Aragones, J.M.; Minguez, E.; Pena, J.

    1975-01-01

    Analysis of nodal calculation and checking results by the reference reactor experimental data. Nudo code description, adapting experimental data to nodal calculations. Rollo, Melon codes as improvement in the cycle life calculations of albedos, mixing parameters and nodal correlations. (author)

  12. Impact of receptor phenotype on nodal burden in patients with breast cancer who have undergone neoadjuvant chemotherapy

    LENUS (Irish Health Repository)

    Boland, M. R.

    2017-07-31

    Optimal evaluation and management of the axilla following neoadjuvant chemotherapy(NAC) in patients with node-positive breast cancer remains controversial. The aim of this study wasto examine the impact of receptor phenotype in patients with nodal metastases who undergo NAC to seewhether this approach can identify those who may be suitable for conservative axillary management.Methods: Between 2009 and 2014, all patients with breast cancer and biopsy-proven nodal diseasewho received NAC were identied from prospectively developed databases. Details of patients who hadaxillary lymph node dissection (ALND) following NAC were recorded and rates of pathological completeresponse (pCR) were evaluated for receptor phenotype.

  13. Heterogeneous treatment in the variational nodal method

    International Nuclear Information System (INIS)

    Fanning, T.H.

    1995-01-01

    The variational nodal transport method is reduced to its diffusion form and generalized for the treatment of heterogeneous nodes while maintaining nodal balances. Adapting variational methods to heterogeneous nodes requires the ability to integrate over a node with discontinuous cross sections. In this work, integrals are evaluated using composite gaussian quadrature rules, which permit accurate integration while minimizing computing time. Allowing structure within a nodal solution scheme avoids some of the necessity of cross section homogenization, and more accurately defines the intra-nodal flux shape. Ideally, any desired heterogeneity can be constructed within the node; but in reality, the finite set of basis functions limits the practical resolution to which fine detail can be defined within the node. Preliminary comparison tests show that the heterogeneous variational nodal method provides satisfactory results even if some improvements are needed for very difficult, configurations

  14. Clinical analysis of neck dissection patients

    International Nuclear Information System (INIS)

    Sato, Katsuro; Takahashi, Sugata

    2008-01-01

    Neck dissection is a highly important surgical procedure in the treatment of squamous cell carcinoma (SCC) of the head and neck since the control of the nodal disease is highly important in these patients. In this paper, 131 patients (210 necks) treated in our department were analyzed. The most frequent primary lesion site was the oral cavity, followed by larynx, hypopharynx and mesopharynx, and treatment of metastatic nodes was considered important especially in patients with SCC in those regions. As the surgical procedure for neck dissection, (modified) radical neck dissection was chosen for higher N stage cases, although it was also applied to lower N stage cases. Postoperative irradiation was performed for 70% of the patients, and control of the neck was considered good as recurrent neck disease occurred in 8% of the patients, and only 20% of those died of recurrent neck disease. The most common primary site showing cervical recurrence was the oral cavity, and control of neck disease is considered important, especially in patients with SCC of the oral cavity. Patients with ≤number of pN 1 receiving postoperative irradiation, and patients with pN (-) and ≤number of pN 1 without postoperative irradiation showed significantly higher survival rates. Postoperative irradiation should be done for patients with ≥number of pN 2, and follow-up without postoperative treatment should be considered for the cases of ≤number of pN 1. Further consideration of patient selection with regard to the area of dissection and the indication for postoperative irradiation without decreasing the survival rate is needed to further improve the treatment of head and neck SCCs. (author)

  15. Clinical investigation: Regional nodal failure patterns in breast cancer patients treated with mastectomy without radiotherapy

    International Nuclear Information System (INIS)

    Strom, Eric A.; Woodward, Wendy A.; Katz, Angela; Buchholz, Thomas A.; Perkins, George H.; Jhingran, Anuja; Theriault, Richard; Singletary, Eva; Sahin, Aysegul; McNeese, Marsha D.

    2005-01-01

    Purpose: The purpose of this study was to describe regional nodal failure patterns in patients who had undergone mastectomy with axillary dissection to define subgroups of patients who might benefit from supplemental regional nodal radiation to the axilla or supraclavicular fossa/axillary apex. Methods and Materials: The cohort consisted of 1031 patients treated with mastectomy (including a level I-II axillary dissection) and doxorubicin-based systemic therapy without radiation on five clinical trials at M.D. Anderson Cancer Center. Patient records, including pathology reports, were retrospectively reviewed. All regional recurrences (with or without distant metastasis) were recorded. Median follow-up was 116 months (range, 6-262 months). Results: Twenty-one patients recurred within the low-mid axilla (10-year actuarial rate 3%). Of these, 16 were isolated regional failures (no chest wall failure). The risk of failure in the low-mid axilla was not significantly higher for patients with increasing numbers of involved nodes, increasing percentage of involved nodes, larger nodal size or gross extranodal extension. Only 3 of 100 patients with 20% involved axillary nodes, and the presence of gross extranodal extension (10-year actuarial rates 15%, 14%, and 19%, respectively, p 20% involved axillary nodes, or gross extranodal extension are at increased risk of failure in the supraclavicular fossa/axillary apex and should receive radiation to undissected regions in addition to the chest wall

  16. Robot-assisted Salvage Lymph Node Dissection for Clinically Recurrent Prostate Cancer.

    Science.gov (United States)

    Montorsi, Francesco; Gandaglia, Giorgio; Fossati, Nicola; Suardi, Nazareno; Pultrone, Cristian; De Groote, Ruben; Dovey, Zach; Umari, Paolo; Gallina, Andrea; Briganti, Alberto; Mottrie, Alexandre

    2017-09-01

    Salvage lymph node dissection has been described as a feasible treatment for the management of prostate cancer patients with nodal recurrence after primary treatment. To report perioperative, pathologic, and oncologic outcomes of robot-assisted salvage nodal dissection (RASND) in patients with nodal recurrence after radical prostatectomy (RP). We retrospectively evaluated 16 patients affected by nodal recurrence following RP documented by positive positron emission tomography/computed tomography scan. Surgery was performed using DaVinci Si and Xi systems. A pelvic nodal dissection that included lymphatic stations overlying the external, internal, and common iliac vessels, the obturator fossa, and the presacral nodes was performed. In 13 (81.3%) patients a retroperitoneal lymph node dissection that included all nodal tissue located between the aortic bifurcation and the renal vessels was performed. Perioperative outcomes consisted of operative time, blood loss, length of hospital stay, and complications occurred within 30 d after surgery. Biochemical response (BR) was defined as a prostate-specific antigen level <0.2 ng/ml at 40 d after RASND. Median operative time, blood loss, and length of hospital stay were 210min, 250ml, and 3.5 d. The median number of nodes removed was 16.5. Positive lymph nodes were detected in 11 (68.8%) patients. Overall, four (25.0%) and five (31.2%) patients experienced intraoperative and postoperative complications, respectively. Overall, one (6.3%) and four (25.0%) patients had Clavien I and II complications within 30 d after RASND, respectively. Overall, five (33.3%) patients experienced BR after surgery. Our study is limited by the small cohort of patients evaluated and by the follow-up duration. RASND represents a feasible procedure in patients with nodal recurrence after RP and provides acceptable short-term oncologic outcomes, where one out of three patients experience BR immediately after surgery. Long-term data are needed to

  17. Nodal pricing in a coupled electricity market

    OpenAIRE

    Bjørndal, Endre; Bjørndal, Mette; Cai, Hong

    2014-01-01

    This paper investigates a pricing model for an electricity market with a hybrid congestion management method, i.e. part of the system applies a nodal pricing scheme and the rest applies a zonal pricing scheme. The model clears the zonal and nodal pricing areas simultaneously. The nodal pricing area is affected by the changes in the zonal pricing area since it is directly connected to the zonal pricing area by commercial trading. The model is tested on a 13-node power system. Within the area t...

  18. A comparison of two nodal codes : Advanced nodal code (ANC) and analytic function expansion nodal (AFEN) code

    International Nuclear Information System (INIS)

    Chung, S.K.; Hah, C.J.; Lee, H.C.; Kim, Y.H.; Cho, N.Z.

    1996-01-01

    Modern nodal methods usually employs the transverse integration technique in order to reduce a multi-dimensional diffusion equation to one-dimensional diffusion equations. The use of the transverse integration technique requires two major approximations such as a transverse leakage approximation and a one-dimensional flux approximation. Both the transverse leakage and the one-dimensional flux are approximated by polynomials. ANC (Advanced Nodal Code) developed by Westinghouse employs a modern nodal expansion method for the flux calculation, the equivalence theory for the homogenization error reduction and a group theory for pin power recovery. Unlike the conventional modern nodal methods, AFEN (Analytic Function Expansion Nodal) method expands homogeneous flux distributions within a node into non-separable analytic basis functions, which eliminate two major approximations of the modern nodal methods. A comparison study of AFEN with ANC has been performed to see the applicability of AFEN to commercial PWR and different types of reactors such as MOX fueled reactor. The qualification comparison results demonstrate that AFEN methodology is accurate enough to apply for commercial PWR analysis. The results show that AFEN provides very accurate results (core multiplication factor and assembly power distribution) for cores that exhibit strong flux gradients as in a MOX loaded core. (author)

  19. Maternal Nodal inversely affects NODAL and STOX1 expression in the fetal placenta

    Directory of Open Access Journals (Sweden)

    Hari Krishna Thulluru

    2013-08-01

    Full Text Available Nodal, a secreted signaling protein from the TGFβ-super family plays a vital role during early embryonic development. Recently, it was found that maternal decidua-specific Nodal knockout mice show intrauterine growth restriction (IUGR and preterm birth. As the chromosomal location of NODAL is in the same linkage area as the susceptibility gene STOX1, associated with the familial form of early-onset, IUGR-complicated pre-eclampsia, their potential maternal-fetal interaction was investigated. Pre-eclamptic mothers with children who carried the STOX1 susceptibility allele themselves all carried the NODAL H165R SNP, which causes a 50% reduced activity. Surprisingly, in decidua Nodal knockout mice the fetal placenta showed up-regulation of STOX1 and NODAL expression. Conditioned media of human first trimester decidua and a human endometrial stromal cell line (T-HESC treated with siRNAs against NODAL or carrying the H165R SNP were also able to induce NODAL and STOX1 expression when added to SGHPL-5 first trimester extravillous trophoblast cells. Finally, a human TGFß-BMP-Signaling-Pathway PCR-Array on decidua and the T-HESC cell line with Nodal knockdown revealed upregulation of Activin-A, which was confirmed in conditioned media by ELISA. We show that maternal decidua Nodal knockdown gives upregulation of NODAL and STOX1 mRNA expression in fetal extravillous trophoblast cells, potentially via upregulation of Activin-A in the maternal decidua. As both Activin-A and Nodal have been implicated in pre-eclampsia, being increased in serum of pre-eclamptic women and upregulated in pre-eclamptic placentas respectively, this interaction at the maternal-fetal interface might play a substantial role in the development of pre-eclampsia.

  20. Quantum oscillations in nodal line systems

    Science.gov (United States)

    Yang, Hui; Moessner, Roderich; Lim, Lih-King

    2018-04-01

    We study signatures of magnetic quantum oscillations in three-dimensional nodal line semimetals at zero temperature. The extended nature of the degenerate bands can result in a Fermi surface geometry with topological genus one, as well as a Fermi surface of electron and hole pockets encapsulating the nodal line. Moreover, the underlying two-band model to describe a nodal line is not unique, in that there are two classes of Hamiltonian with distinct band topology giving rise to the same Fermi-surface geometry. After identifying the extremal cyclotron orbits in various magnetic field directions, we study their concomitant Landau levels and resulting quantum oscillation signatures. By Landau-fan-diagram analyses, we extract the nontrivial π Berry phase signature for extremal orbits linking the nodal line.

  1. Sensitivity of SBLOCA analysis to model nodalization

    International Nuclear Information System (INIS)

    Lee, C.; Ito, T.; Abramson, P.B.

    1983-01-01

    The recent Semiscale test S-UT-8 indicates the possibility for primary liquid to hang up in the steam generators during a SBLOCA, permitting core uncovery prior to loop-seal clearance. In analysis of Small Break Loss of Coolant Accidents with RELAP5, it is found that resultant transient behavior is quite sensitive to the selection of nodalization for the steam generators. Although global parameters such as integrated mass loss, primary inventory and primary pressure are relatively insensitive to the nodalization, it is found that the predicted distribution of inventory around the primary is significantly affected by nodalization. More detailed nodalization predicts that more of the inventory tends to remain in the steam generators, resulting in less inventory in the reactor vessel and therefore causing earlier and more severe core uncovery

  2. Twisted Vector Bundles on Pointed Nodal Curves

    Indian Academy of Sciences (India)

    Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.

  3. The NODAL system for the SPS

    International Nuclear Information System (INIS)

    Crowley-Milling, M.C.; Shering, G.C.

    1978-01-01

    A comprehensive description is given of the NODAL system used for computer control of the CERN Super-Proton Synchrotron. Details are given of NODAL, a high-level programming language based on FOCAL and SNOBOL4, designed for interactive use. It is shown how this interpretive language is used with a network of computers and how it can be extended by adding machine-code modules. The report updates and replaces an earlier one published in 1974. (Auth.)

  4. Nodal coupling by response matrix principles

    International Nuclear Information System (INIS)

    Ancona, A.; Becker, M.; Beg, M.D.; Harris, D.R.; Menezes, A.D.; VerPlanck, D.M.; Pilat, E.

    1977-01-01

    The response matrix approach has been used in viewing a reactor node in isolation and in characterizing the node by reflection and trans-emission factors. These are then used to generate invariant imbedding parameters, which in turn are used in a nodal reactor simulator code to compute core power distributions in two and three dimensions. Various nodal techniques are analyzed and converted into a single invariant imbedding formalism

  5. Magnonic triply-degenerate nodal points

    Science.gov (United States)

    Owerre, S. A.

    2017-12-01

    We generalize the concept of triply-degenerate nodal points to non-collinear antiferromagnets. Here, we introduce this concept to insulating quantum antiferromagnets on the decorated honeycomb lattice, with spin-1 bosonic quasiparticle excitations known as magnons. We demonstrate the existence of magnonic surface states with constant energy contours that form pairs of magnonic arcs connecting the surface projection of the magnonic triple nodal points. The quasiparticle excitations near the triple nodal points represent three-component bosons beyond that of magnonic Dirac, Weyl, and nodal-line cases. They can be regarded as a direct reflection of the intrinsic spin carried by magnons. Furthermore, we show that the magnonic triple nodal points can split into magnonic Weyl points, as the system transits from a non-collinear spin structure to a non-coplanar one with a non-zero scalar spin chirality. Our results not only apply to insulating antiferromagnets, but also provide a platform to seek for triple nodal points in metallic antiferromagnets.

  6. Neck control after definitive radiochemotherapy without planned neck dissection in node-positive head and neck cancers

    International Nuclear Information System (INIS)

    Jang, Na Young; Lee, Keun-Wook; Ahn, Soon-Hyun; Kim, Jae-Sung; Ah Kim, In

    2012-01-01

    The purpose of this study was to evaluate neck control outcomes after definitive radiochemotherapy without planned neck dissection in node-positive head and neck cancer. We retrospectively reviewed medical records of fifty patients with node-positive head and neck cancer who received definitive radiochemotherapy. Twelve patients subsequently underwent neck dissection for suspicious recurrent or persistent disease. A median dose of 70 Gy (range 60-70.6) was delivered to involved nodes. Response evaluation was performed at a median of 5 weeks after completion of radiotherapy. Neck failure was observed in 11 patients and the 3-year regional control (RC) rate was 77.1%. Neck dissection was performed in 10 of the 11 patients; seven of these cases were successfully salvaged, and the ultimate rate of neck control was 92%. The remaining two patients who received neck dissection had negative pathologic results. On univariate analysis, initial nodal size > 2 cm, a less-than-complete response at the primary site, post-radiotherapy nodal size > 1.5 cm, and post-radiotherapy nodal necrosis were associated with RC. On multivariate analysis, less-than-complete primary site response and post-radiotherapy nodal necrosis were identified as independent prognostic factors for RC. The neck failure rate after definitive radiochemotherapy without planned neck dissection was 22%. Two-thirds of these were successfully salvaged with neck dissection and the ultimate neck control rate was 92%. Our results suggest that planned neck dissection might not be necessary in patients with complete response of primary site, no evidence of residual lesion > 1.5 cm, or no necrotic lymph nodes at the 1-2 months follow-up evaluation after radiotherapy

  7. Radiotherapy for esthesioneuroblastoma: is elective nodal irradiation warranted in the multimodality treatment approach?

    Science.gov (United States)

    Noh, O Kyu; Lee, Sang-wook; Yoon, Sang Min; Kim, Sung Bae; Kim, Sang Yoon; Kim, Chang Jin; Jo, Kyung Ja; Choi, Eun Kyung; Song, Si Yeol; Kim, Jong Hoon; Ahn, Seung Do

    2011-02-01

    The role of elective nodal irradiation (ENI) in radiotherapy for esthesioneuroblastoma (ENB) has not been clearly defined. We analyzed treatment outcomes of patients with ENB and the frequency of cervical nodal failure in the absence of ENI. Between August 1996 and December 2007, we consulted with 19 patients with ENB regarding radiotherapy. Initial treatment consisted of surgery alone in 2 patients; surgery and postoperative radiotherapy in 4; surgery and adjuvant chemotherapy in 1; surgery, postoperative radiotherapy, and chemotherapy in 3; and chemotherapy followed by radiotherapy or concurrent chemoradiotherapy in 5. Five patients did not receive planned radiotherapy because of disease progression. Including 2 patients who received salvage radiotherapy, 14 patients were treated with radiotherapy. Elective nodal irradiation was performed in 4 patients with high-risk factors, including 3 with cervical lymph node metastasis at presentation. Fourteen patients were analyzable, with a median follow-up of 27 months (range, 7-64 months). The overall 3-year survival rate was 73.4%. Local failure occurred in 3 patients (21.4%), regional cervical failure in 3 (21.4%), and distant failure in 2 (14.3%). No cervical nodal failure occurred in patients treated with combined systemic chemotherapy regardless of ENI. Three cervical failures occurred in the 4 patients treated with ENI or neck dissection (75%), none of whom received systemic chemotherapy. ENI during radiotherapy for ENB seems to play a limited role in preventing cervical nodal failure. Omitting ENI may be an option if patients are treated with a combination of radiotherapy and chemotherapy. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Radiotherapy for Esthesioneuroblastoma: Is Elective Nodal Irradiation Warranted in the Multimodality Treatment Approach?

    International Nuclear Information System (INIS)

    Noh, O Kyu; Lee, Sang-wook; Yoon, Sang Min; Kim, Sung Bae; Kim, Sang Yoon; Kim, Chang Jin; Jo, Kyung Ja; Choi, Eun Kyung; Song, Si Yeol; Kim, Jong Hoon; Ahn, Seung Do

    2011-01-01

    Purpose: The role of elective nodal irradiation (ENI) in radiotherapy for esthesioneuroblastoma (ENB) has not been clearly defined. We analyzed treatment outcomes of patients with ENB and the frequency of cervical nodal failure in the absence of ENI. Methods and Materials: Between August 1996 and December 2007, we consulted with 19 patients with ENB regarding radiotherapy. Initial treatment consisted of surgery alone in 2 patients; surgery and postoperative radiotherapy in 4; surgery and adjuvant chemotherapy in 1; surgery, postoperative radiotherapy, and chemotherapy in 3; and chemotherapy followed by radiotherapy or concurrent chemoradiotherapy in 5. Five patients did not receive planned radiotherapy because of disease progression. Including 2 patients who received salvage radiotherapy, 14 patients were treated with radiotherapy. Elective nodal irradiation was performed in 4 patients with high-risk factors, including 3 with cervical lymph node metastasis at presentation. Results: Fourteen patients were analyzable, with a median follow-up of 27 months (range, 7-64 months). The overall 3-year survival rate was 73.4%. Local failure occurred in 3 patients (21.4%), regional cervical failure in 3 (21.4%), and distant failure in 2 (14.3%). No cervical nodal failure occurred in patients treated with combined systemic chemotherapy regardless of ENI. Three cervical failures occurred in the 4 patients treated with ENI or neck dissection (75%), none of whom received systemic chemotherapy. Conclusions: ENI during radiotherapy for ENB seems to play a limited role in preventing cervical nodal failure. Omitting ENI may be an option if patients are treated with a combination of radiotherapy and chemotherapy.

  9. Role of CT/PET in predicting nodal disease in head and neck cancers

    International Nuclear Information System (INIS)

    Singham, S.; Iyer, G.; Clark, J.

    2009-01-01

    Full text:Introduction: Pre-treatment evaluation of the presence of cervical nodal metastases is important in head and neck cancers and has major prognostic implications. In this study, we aim to determine the accuracy of CT/PET as a tool for identifying such metastases. Methods: All patients from Royal Prince Alfred and Liverpool Hospitals, who underwent CT/PET for any cancer arising from the head and neck, and who underwent subsequent surgery (which included a neck dissection) within 8 weeks of the CT/PET were included. Nodal staging was undertaken by utilising imaging-based nodal classification, and comparison with pathologic data from the surgical specimen was made. PET was considered positive if the SUV was greater than 2. Results: We identified 111 patients from the above criteria. 80 of such patients were treated for squamous cell carcinoma (SCC). CT/PET identified unsuspected metastatic disease in 6 patients. Correlation of CT/PET findings and the presence of disease at the primary site: sensitivity: 98%, specificity: 93%, positive predictive value (PPV): 98% and negative predictive value (NPV): 93%. Correlating CT/PET findings with the presence of nodal disease at any level: sensitivity: 95%, specificity: 88%, PPV: 95% and NPV: 88%. CT/PET was anatomically accurate in predicting the site of metastases in 62/74 (84%). Conclusion: PET is accurate in predicting both presence of nodal metastases and the level of involvement. CT/PET should be undertaken as a pre-operative tool to assist in planning the extent of surgery required in head and neck cancers.

  10. Virtual reality haptic dissection.

    Science.gov (United States)

    Erolin, Caroline; Wilkinson, Caroline; Soames, Roger

    2011-12-01

    This project aims to create a three-dimensional digital model of the human hand and wrist which can be virtually 'dissected' through a haptic interface. Tissue properties will be added to the various anatomical structures to replicate a realistic look and feel. The project will explore the role of the medical artist, and investigate cross-discipline collaborations in the field of virtual anatomy. The software will be used to train anatomy students in dissection skills, before experience on a real cadaver. The effectiveness of the software will be evaluated and assessed both quantitatively as well as qualitatively.

  11. The analytic nodal method in cylindrical geometry

    International Nuclear Information System (INIS)

    Prinsloo, Rian H.; Tomasevic, Djordje I.

    2008-01-01

    Nodal diffusion methods have been used extensively in nuclear reactor calculations, specifically for their performance advantage, but also for their superior accuracy. More specifically, the Analytic Nodal Method (ANM), utilising the transverse integration principle, has been applied to numerous reactor problems with much success. In this work, a nodal diffusion method is developed for cylindrical geometry. Application of this method to three-dimensional (3D) cylindrical geometry has never been satisfactorily addressed and we propose a solution which entails the use of conformal mapping. A set of 1D-equations with an adjusted, geometrically dependent, inhomogeneous source, is obtained. This work describes the development of the method and associated test code, as well as its application to realistic reactor problems. Numerical results are given for the PBMR-400 MW benchmark problem, as well as for a 'cylindrisized' version of the well-known 3D LWR IAEA benchmark. Results highlight the improved accuracy and performance over finite-difference core solutions and investigate the applicability of nodal methods to 3D PBMR type problems. Results indicate that cylindrical nodal methods definitely have a place within PBMR applications, yielding performance advantage factors of 10 and 20 for 2D and 3D calculations, respectively, and advantage factors of the order of 1000 in the case of the LWR problem

  12. Encapsulation of nodal segments of lobelia chinensis

    Directory of Open Access Journals (Sweden)

    Weng Hing Thong

    2015-04-01

    Full Text Available Lobelia chinensis served as an important herb in traditional chinese medicine. It is rare in the field and infected by some pathogens. Therefore, encapsulation of axillary buds has been developed for in vitro propagation of L. chinensis. Nodal explants of L. chinensis were used as inclusion materials for encapsulation. Various combinations of calcium chloride and sodium alginate were tested. Encapsulation beads produced by mixing 50 mM calcium chloride and 3.5% sodium alginate supported the optimal in vitro conversion potential. The number of multiple shoots formed by encapsulated nodal segments was not significantly different from the average of shoots produced by non-encapsulated nodal segments. The encapsulated nodal segments regenerated in vitro on different medium. The optimal germination and regeneration medium was Murashige-Skoog medium. Plantlets regenerated from the encapsulated nodal segments were hardened, acclimatized and established well in the field, showing similar morphology with parent plants. This encapsulation technology would serve as an alternative in vitro regeneration system for L. chinensis.

  13. Treatment results of neck dissection with the preservation of cervical nerves for hypopharyngeal cancer

    International Nuclear Information System (INIS)

    Hasegawa, Toshifumi; Iwae, Shigemichi; Tanaka, Hironori; Yonezawa, Kouichiro; Inoue, Kenzo

    2007-01-01

    Treatment results of neck dissection with the preservation of cervical nerves for hypopharyngeal cancer were analyzed retrospectively by comparing neck dissection with the preservation of cervical nerves and that with the resection of cervical nerves. Pharyngolaryngectomy or pharyngolaryngoesophagectomy with bilateral neck dissection was performed in 76 hypopharyngeal cancer cases between January 1992 and November 2001. Neck dissection with the resection of cervical nerves was performed on 42 sides of the neck in 21 cases (the cervical nerve-resected group). In 55 cases we attempted to employ neck dissection with the preservation of cervical nerves, but in 9 cases the cervical nerves were resected because of their nodal adhesion or involvement Neck dissection with the preservation of cervical nerves was performed on 92 sides of the neck in 46 cases (the cervical nerve-preserved group). There were significant differences between background factors of two groups about age, sex, induction chemotherapy, preservation of accessory nerve, and pN classification. The 5-year cumulative control rates of cervical lymph nodes were 81.3% for the cervical nerve-resected group and 79.7% for the cervical nerve-preserved group. There was no significant difference between the two groups. It was suggested that neck dissection with the preservation of cervical nerves for cases whose cervical nerves were able to be preserved from metastatic lymph nodes under induction chemotherapy and post-operative irradiation was as effective to control cervical lymph nodes as neck dissection with the resection of cervical nerves. (author)

  14. A Geometric Dissection Problem

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 7. A Geometric Dissection Problem. M N Deshpande. Think It Over Volume 7 Issue 7 July 2002 pp 91-91. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/007/07/0091-0091. Author Affiliations.

  15. Imaging in aortic dissection

    International Nuclear Information System (INIS)

    Yu-Qing Liu, M.D.

    1995-01-01

    Aortic dissection (AD) is a catastrophic aortic disease. Imaging techniques play an invaluable role in the diagnostic evaluation and management of patients with AD. Major signs of AD with different imaging modalities are described in this article with a pertinent discussion on guidelines for the optimized approach of imaging study (13 refs.)

  16. Imaging in aortic dissection

    Energy Technology Data Exchange (ETDEWEB)

    Yu-Qing Liu, M D [Chinese Academy of Medical Sciences, Beijing, BJ (China). Dept. of Radiology, Fu Wai Hospital and Cardiovascular Inst.

    1996-12-31

    Aortic dissection (AD) is a catastrophic aortic disease. Imaging techniques play an invaluable role in the diagnostic evaluation and management of patients with AD. Major signs of AD with different imaging modalities are described in this article with a pertinent discussion on guidelines for the optimized approach of imaging study (13 refs.).

  17. Mastectomy using ultrasonic dissection

    DEFF Research Database (Denmark)

    Galatius, Hanne; Okholm, Mette; Hoffmann, Jack

    2003-01-01

    on seroma formation and other complications: 59 patients with operable breast cancer underwent modified radical mastectomy, performed in 30 of them with an Ultracision Harmonic scalpel and in 29 with scissors and electrocautery. In all cases a standard level II axillary dissection was performed...

  18. Complex models of nodal nuclear data

    International Nuclear Information System (INIS)

    Dufek, Jan

    2011-01-01

    During the core simulations, nuclear data are required at various nodal thermal-hydraulic and fuel burnup conditions. The nodal data are also partially affected by thermal-hydraulic and fuel burnup conditions in surrounding nodes as these change the neutron energy spectrum in the node. Therefore, the nodal data are functions of many parameters (state variables), and the more state variables are considered by the nodal data models the more accurate and flexible the models get. The existing table and polynomial regression models, however, cannot reflect the data dependences on many state variables. As for the table models, the number of mesh points (and necessary lattice calculations) grows exponentially with the number of variables. As for the polynomial regression models, the number of possible multivariate polynomials exceeds the limits of existing selection algorithms that should identify a few dozens of the most important polynomials. Also, the standard scheme of lattice calculations is not convenient for modelling the data dependences on various burnup conditions since it performs only a single or few burnup calculations at fixed nominal conditions. We suggest a new efficient algorithm for selecting the most important multivariate polynomials for the polynomial regression models so that dependences on many state variables can be considered. We also present a new scheme for lattice calculations where a large number of burnup histories are accomplished at varied nodal conditions. The number of lattice calculations being performed and the number of polynomials being analysed are controlled and minimised while building the nodal data models of a required accuracy. (author)

  19. Prediction of Neck Dissection Requirement After Definitive Radiotherapy for Head-and-Neck Squamous Cell Carcinoma

    International Nuclear Information System (INIS)

    Thariat, Juliette; Ang, K. Kian; Allen, Pamela K.; Ahamad, Anesa; Williams, Michelle D.; Myers, Jeffrey N.; El-Naggar, Adel K.; Ginsberg, Lawrence E.; Rosenthal, David I.; Glisson, Bonnie S.; Morrison, William H.; Weber, Randal S.; Garden, Adam S.

    2012-01-01

    Background: This analysis was undertaken to assess the need for planned neck dissection in patients with a complete response (CR) of involved nodes after irradiation and to determine the benefit of a neck dissection in those with less than CR by tumor site. Methods: Our cohort included 880 patients with T1-4, N1-3M0 squamous cell carcinoma of the oropharynx, larynx, or hypopharynx who received treatment between 1994 and 2004. Survival curves were calculated by the Kaplan-Meier Method, comparisons of rates with the log–rank test and prognostic factors by Cox's proportional hazard model. Results: Nodal CR occurred in 377 (43%) patients, of whom 365 patients did not undergo nodal dissection. The 5-year actuarial regional control rate of patients with CR was 92%. Two hundred sixty-eight of the remaining patients (53%) underwent neck dissections. The 5-year actuarial regional control rate for patients without a CR was 84%. Those who had a neck dissection fared better with 5-year actuarial regional control rates of 90% and 76% for those operated and those not operated (p < 0.001). Variables associated with poorer regional control rates included higher T and N stage, non-oropharynx cancers, non-CR, both clinical and pathological. Conclusions: With 92% 5-year neck control rate without neck dissection after CR, there is little justification for systematic neck dissection. The addition of a neck dissection resulted in higher neck control after partial response though patients with viable tumor on pathology specimens had poorer outcomes. The identification of that subgroup that benefits from additional treatment remains a challenge.

  20. Nodal Structure of the Electronic Wigner Function

    DEFF Research Database (Denmark)

    Schmider, Hartmut; Dahl, Jens Peder

    1996-01-01

    On the example of several atomic and small molecular systems, the regular behavior of nodal patterns in the electronic one-particle reduced Wigner function is demonstrated. An expression found earlier relates the nodal pattern solely to the dot-product of the position and the momentum vector......, if both arguments are large. An argument analogous to the ``bond-oscillatory principle'' for momentum densities links the nuclear framework in a molecule to an additional oscillatory term in momenta parallel to bonds. It is shown that these are visible in the Wigner function in terms of characteristic...

  1. Can neck irradiation be an alternative to neck dissection in early stage carcinoma oral tongue operated for primary alone? Experience from a single institute

    Directory of Open Access Journals (Sweden)

    Sushmita Ghoshal

    2016-07-01

    Full Text Available Purpose: To study pattern of failure, locoregional control rates (LCR and disease free survival (DFS in post-operative patients of carcinoma oral tongue, and to study the impact of nodal dissection on DFS in stage I and II patients.Methods: 102 patients of carcinoma oral tongue treated between January 2009 and December 2013 were analyzed. All patients were operated for primary disease, but neck dissection was done in 78 (76.5% patients only. However, radiation to primary site along with neck region was received by all patients. Pattern of failure, LCR and DFS were estimated.Results: At median follow up of 12 months, 10.8% patients failed locally, 10.8% in nodal region, 2.9% both at local and nodal site, and 5.9% patients failed distally. 2 year LCR and DFS was 71.2%, 90.9%, 79.5%, 0% and 55.2%, 64.4%, 57.8%, 0% in stage I, II, III, IV respectively. 2 year DFS in stage I patients, who underwent nodal dissection and post-operative radiation (14 patients was 64.3% and in whom only neck irradiation was done (15 patients, it was 45.8%, however difference was not significant (p = 0.5. But in stage II patients, 33 patients who underwent nodal dissection and post-operative radiation, 2 year DFS was 85.4% and it was 21.4% in 7 patients who underwent neck radiation only, and difference showed trend towards significance (p = 0.05. 2 or more positive lymph nodes post dissection was the only poor prognostic factor that correlated with DFS (p = 0.02Conclusion: While in stage I, neck irradiation alone can be a possible alternative to neck dissection and post-operative radiation; for stage II, neck dissection is mandatory.

  2. Staging of women with breast cancer after introduction of sentinel node guided axillary dissection

    DEFF Research Database (Denmark)

    Tvedskov, Tove Filtenborg

    2012-01-01

    Today, sentinel lymph node dissection (SLND) has replaced axillary lymph node dissection (ALND) as standard procedure for staging of the axilla in the treatment of breast cancer. SLND can accurately stage the axilla by removing on average only two lymph nodes. Only in case of metastatic spread...... was not significantly different in the two periods, whereas the proportion of patients with micrometastases increased significantly from 5.1% to 9.0%. However, the proportion of patients offered adjuvant systemic treatment due to positive nodal status as the only high-risk criterion did only increase from 7.8% to 8...

  3. Elective nodal irradiation (ENI) in definitive chemoradiotherapy (CRT) for squamous cell carcinoma of the thoracic esophagus.

    Science.gov (United States)

    Onozawa, Masakatsu; Nihei, Keiji; Ishikura, Satoshi; Minashi, Keiko; Yano, Tomonori; Muto, Manabu; Ohtsu, Atsushi; Ogino, Takashi

    2009-08-01

    There are some reports indicating that prophylactic three-field lymph node dissection for esophageal cancer can lead to improved survival. But the benefit of ENI in CRT for thoracic esophageal cancer remains controversial. The purpose of the present study is to retrospectively evaluate the efficacy of elective nodal irradiation (ENI) in definitive chemoradiotherapy (CRT) for thoracic esophageal cancer. Patients with squamous cell carcinoma (SCC) of the thoracic esophagus newly diagnosed between February 1999 and April 2001 in our institution was recruited from our database. Definitive chemoradiotherapy consisted of two cycles of cisplatin/5FU repeated every 5 weeks, with concurrent radiation therapy of 60 Gy in 30 fractions. Up to 40 Gy radiation therapy was delivered to the cervical, periesophageal, mediastinal and perigastric lymph nodes as ENI. One hundred two patients were included in this analysis, and their characteristics were as follows: median age, 65 years; male/female, 85/17; T1/T2/T3/T4, 16/11/61/14; N0/N1, 48/54; M0/M1, 84/18. The median follow-up period for the surviving patients was 41 months. Sixty patients achieved complete response (CR). After achieving CR, only one (1.0%; 95% CI, 0-5.3%) patient experienced elective nodal failure without any other site of recurrence. In CRT for esophageal SCC, ENI is effective for preventing regional nodal failure. Further evaluation of whether ENI leads to an improved overall survival is needed.

  4. Isospectral graphs with identical nodal counts

    International Nuclear Information System (INIS)

    Oren, Idan; Band, Ram

    2012-01-01

    According to a recent conjecture, isospectral objects have different nodal count sequences (Gnutzmann et al 2005 J. Phys. A: Math. Gen. 38 8921–33). We study generalized Laplacians on discrete graphs, and use them to construct the first non-trivial counterexamples to this conjecture. In addition, these examples demonstrate a surprising connection between isospectral discrete and quantum graphs. (paper)

  5. Comparison of neutronic transport equation resolution nodal methods

    International Nuclear Information System (INIS)

    Zamonsky, O.M.; Gho, C.J.

    1990-01-01

    In this work, some transport equation resolution nodal methods are comparatively studied: the constant-constant (CC), linear-nodal (LN) and the constant-quadratic (CQ). A nodal scheme equivalent to finite differences has been used for its programming, permitting its inclusion in existing codes. Some bidimensional problems have been solved, showing that linear-nodal (LN) are, in general, obtained with accuracy in CPU shorter times. (Author) [es

  6. Vertebral basilar artery dissections

    International Nuclear Information System (INIS)

    Zimmerman, R.A.; Bilaniuk, L.T.; Hackney, D.B.; Grossman, R.I.; Goldberg, H.I.; Atlas, S.W.

    1988-01-01

    Eleven patients (ten male, one female; range, 2-56 years) presented with posterior circulation ischemic symptoms and were evaluated with computed tomography (CT) (eta=11), arteriography (eta=11), and magnetic resonance (MR) imaging (eta=6). Angiography showed dissection of a vertebral artery (eta=8), a basilar artery (eta=1), or a combination of both (eta=2). On CT and/or MR images, infarctions were demonstrated in ten of 11 cases. Most frequently involved were the thalmus (eta=7), cerebellum (eta=6), occipital lobes (eta=4), and pons (eta=3). The site of infarction did not correlate with the side or site of angiographic abnormality. In six cases evaluated by all modalities, MR imaging showed more extensive and widespread infarction than did CT and also showed whether or not the infarcts were hemorrhagic. MR imaging was able to demonstrate the presence of intramural dissecting hematoma prior to angiography and to indicate whether or not flow was reconstituted on follow-up examination

  7. Cervicocephalic arterial dissection

    International Nuclear Information System (INIS)

    Suyama, Kazuhiko; Hayashi, Kentaro; Nagata, Izumi

    2008-01-01

    The authors review the clinical and neuroradiological features of cervicocephalic arterial dissection, which is occasionally seen in young adults, with special reference to the differences in the region of occurrence of these lesions between patients in Western countries and Japan. In Western countries, the cervical internal carotid artery is the most common site of occurrence of these lesions; however, in Japan, these lesions have been frequently reported to occure in the intracranial vertebral artery. Most clinical manifestations of cervical arterial dissection are non-hemorrhagic events such as headaches associated with arterial dissection or cerebral ischemia caused by a distal embolism following thrombus formation in the cervical lesion. On the other hand, a subarachnoid hemorrhage and cerebral infarction are frequently observed in intracranial arterial dissections. Non-invasive procedures, including MR imaging, are useful for demonstrating characteristic features of this condition such as the presence of an intimal flap or a double lumen, and for monitoring the chronological changes in the lesions, which may regress spontaneously. Since the pathological mechanisms underlying the progression and/or the regression of this condition are still unknown, the clinical evidence indicating the optimal therapeutic strategies has not yet been reported. Nevertheless, conservative therapy, including antithrombotic treatment, is widely used for the treatment of non-hemorrhagic lesions, which generally results in good clinical outcomes. Further, surgical intervention is essential for the treatment of lesions with a subarachnoid hemorrhage to prevent fatal rebleeding, and it is also required for the treatment of certain non-hemorrhagic lesions. Recent advancements in surgical procedures, especially endovascular treatments, may therefore be helpful in the management of similar complicated vascular conditions. (author)

  8. Neck dissection following chemo radiation for node positive head and neck carcinomas

    International Nuclear Information System (INIS)

    Thariat, J.; Thariat, J.; Marcy, P.Y.; Bozec, A.; Peyrade, F.; Hofman, P.; Hamoir, M.; Janot, F.; De Mones, E.; Marcy, P.Y.; Carrier, P.; Bozec, I.; Guevara, J.; Santini, J.; Albert, S.; Vedrine, P.O.; Graff, P.; Peyrade, F.; Hofman, P.; Bourhis, J.; Lapeyre, M.

    2009-01-01

    The optimal timing and extent of neck dissection in the context of chemo radiation for head and neck cancer remains controversial. For some institutions, it is uncertain whether neck dissection should still be performed up front especially for cystic nodes. For others, neck dissection can be performed after chemo radiation and can be omitted for N1 disease as long as a complete response to chemo radiation is obtained. The question is debated for N2 and N3 disease even after a complete response as the correlation between radiological and clinical assessment and pathology may not be reliable. Response rates are greater than or equal to 60% and isolated neck failures are less than or equal to 10% with current chemo radiation protocols. Some therefore consider that systematic up front or planned neck dissection would lead to greater than or equal to 50% unnecessary neck dissections for N2-N3 disease. Positron-emission tomography (PET) scanning to assess treatment response and have shown a very high negative predictive value of greater than or equal to 95% when using a standard uptake value of 3 for patients with a negative PET at four months after the completion of therapy. These data may support the practice of observing PET-negative necks. More evidence-based data are awaited to assess the need for neck dissection on PET. Selective neck dissection based on radiological assessment and preoperative findings and not exclusively on initial nodal stage may help to limit morbidity and to improve the quality of life without increasing the risk of neck failure. Adjuvant regional radiation boosts might be discussed on an individual basis for aggressive residual nodal disease with extra-capsular spread and uncertain margins but evidence is missing. Medical treatments aiming at reducing the metastatic risk especially for N3 disease are to be evaluated

  9. The role of elective nodal irradiation for esthesioneuroblastoma patients with clinically negative neck.

    Science.gov (United States)

    Jiang, Wen; Mohamed, Abdallah S R; Fuller, Clifton David; Kim, Betty Y S; Tang, Chad; Gunn, G Brandon; Hanna, Ehab Y; Frank, Steven J; Su, Shirley Y; Diaz, Eduardo; Kupferman, Michael E; Beadle, Beth M; Morrison, William H; Skinner, Heath; Lai, Stephen Y; El-Naggar, Adel K; DeMonte, Franco; Rosenthal, David I; Garden, Adam S; Phan, Jack

    2016-01-01

    Although adjuvant radiation to the tumor bed has been reported to improve the clinic outcomes of esthesioneuroblastoma (ENB) patients, the role of elective neck irradiation (ENI) in clinically node-negative (N0) patients remains controversial. Here, we evaluated the effects of ENI on neck nodal relapse risk in ENB patients treated with radiation therapy as a component of multimodality treatment. Seventy-one N0 ENB patients irradiated at the University of Texas MD Anderson Cancer Center between 1970 and 2013 were identified. ENI was performed on 22 of these patients (31%). Survival analysis was performed with focus on comparative outcomes of those patients who did and did not receive ENI. The median follow-up time for our cohort is 80.8 months (range, 6-350 months). Among N0 patients, 13 (18.3%) developed neck nodal relapses, with a median time to progression of 62.5 months. None of these 13 patients received prophylactic neck irradiation. ENI was associated with significantly improved regional nodal control at 5 years (regional control rate of 100% for ENI vs 82%, P ENI developed isolated neck recurrences. All had further treatment for their neck disease, including neck dissection (n = 10), radiation (n = 10), or chemotherapy (n = 5). Six of these 11 patients (54.5%) demonstrated no evidence of further recurrence with a median follow-up of 55.5 months. ENI significantly reduces the risk of cervical nodal recurrence in ENB patients with clinically N0 neck, but this did not translate to a survival benefit. Multimodality treatment for isolated neck recurrence provides a reasonable salvage rate. The greatest benefit for ENI appeared to be among younger patients who presented with Kadish C disease. Further studies are needed to confirm these findings. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  10. The role of elective-nodal irradiation for esthesioneuroblastoma patients with clinically negative neck

    Science.gov (United States)

    Jiang, Wen; Mohamed, Abdallah Sherif; Fuller, Clifton David; Kim, Betty Y.S.; Tang, Chad; Gunn, G. Brandon; Hanna, Ehab Y.; Frank, Steven J.; Su, Shirley Y.; Diaz, Eduardo; Kupferman, Michael E.; Beadle, Beth M.; Morrison, William H.; Skinner, Heath; Lai, Stephen Y.; El-Naggar, Adel K.; DeMonte, Franco; Rosenthal, David I.; Garden, Adam S.; Phan, Jack

    2017-01-01

    Purpose Although adjuvant radiation to the tumor bed has been reported to improve the clinic outcomes of esthesioneuroblastoma (ENB) patients, the role of elective neck irradiation (ENI) in clinically node negative (N0) patients remains controversial. Here, we evaluated the effects of ENI on neck nodal relapse risk in ENB patients treated with radiotherapy as a component of multi-modality treatment. Methods and Materials Seventy-one N0 ENB patients irradiated at XXXXXXXXX between 1970 and 2013 were identified. ENI was performed on 22 of these patients (31%). Survival analysis was performed with focus on comparative outcomes of those patients who did and did not receive ENI. Results The median follow up time for our cohort is 80.8 months (range 6 – 350 month). Among N0 patients, 13 (18.3%) developed neck nodal relapses, with a median time to progression of 62.5 months. None of these 13 patients received prophylactic neck irradiation. ENI was associated with significantly improved regional nodal control at 5-year (regional control rate of 100% for ENI vs 82%, p ENI developed isolated neck recurrences. All had further treatment for their neck disease, including neck dissection (n=10), radiation (n=10), or chemotherapy (n=5). Six of these 11 patients (54.5%) demonstrated no evidence of further recurrence with a median follow up of 55.5 month. Conclusion ENI significantly reduces the risk of cervical nodal recurrence in ENB patients with clinically N0 neck but this did not translate to a survival benefit. Multimodality treatment for isolated neck recurrence provides a reasonable salvage rate. The greatest benefit for ENI appeared to be among younger patients who presented with Kadish C disease. Further studies are needed to confirm these findings. PMID:26979544

  11. Pathology of nodal marginal zone lymphomas.

    Science.gov (United States)

    Pileri, Stefano; Ponzoni, Maurilio

    Nodal marginal zone B cell lymphomas (NMZLs) are a rare group of lymphoid disorders part of the spectrum of marginal zone B-cell lymphomas, which encompass splenic marginal one B-cell lymphoma (SMZL) and extra nodal marginal zone of B-cell lymphoma (EMZL), often of MALT-type. Two clinicopathological forms of NMZL are recognized: adult-type and pediatric-type, respectively. NMZLs show overlapping features with other types of MZ, but distinctive features as well. In this review, we will focus on the salient distinguishing features of NMZL mostly under morphological/immunophenotypical/molecular perspectives in views of the recent acquisitions and forthcoming updated 2016 WHO classification of lymphoid malignancies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Quantum anomalies in nodal line semimetals

    Science.gov (United States)

    Burkov, A. A.

    2018-04-01

    Topological semimetals are a new class of condensed matter systems with nontrivial electronic structure topology. Their unusual observable properties may often be understood in terms of quantum anomalies. In particular, Weyl and Dirac semimetals, which have point band-touching nodes, are characterized by the chiral anomaly, which leads to the Fermi arc surface states, anomalous Hall effect, negative longitudinal magnetoresistance, and planar Hall effect. In this paper, we explore analogous phenomena in nodal line semimetals. We demonstrate that such semimetals realize a three-dimensional analog of the parity anomaly, which is a known property of two-dimensional Dirac semimetals arising, for example, on the surface of a three-dimensional topological insulator. We relate one of the characteristic properties of nodal line semimetals, namely, the drumhead surface states, to this anomaly, and derive the field theory, which encodes the corresponding anomalous response.

  13. Temporal quadratic expansion nodal Green's function method

    International Nuclear Information System (INIS)

    Liu Cong; Jing Xingqing; Xu Xiaolin

    2000-01-01

    A new approach is presented to efficiently solve the three-dimensional space-time reactor dynamics equation which overcomes the disadvantages of current methods. In the Temporal Quadratic Expansion Nodal Green's Function Method (TQE/NGFM), the Quadratic Expansion Method (QEM) is used for the temporal solution with the Nodal Green's Function Method (NGFM) employed for the spatial solution. Test calculational results using TQE/NGFM show that its time step size can be 5-20 times larger than that of the Fully Implicit Method (FIM) for similar precision. Additionally, the spatial mesh size with NGFM can be nearly 20 times larger than that using the finite difference method. So, TQE/NGFM is proved to be an efficient reactor dynamics analysis method

  14. Acceleration of the FERM nodal program

    International Nuclear Information System (INIS)

    Nakata, H.

    1985-01-01

    It was tested three acceleration methods trying to reduce the number of outer iterations in the FERM nodal program. The results obtained indicated that the Chebychev polynomial acceleration method with variable degree results in a economy of 50% in the computer time. Otherwise, the acceleration method by source asymptotic extrapolation or by zonal rebalance did not result in economy of the global computer time, however some acceleration had been verified in outer iterations. (M.C.K.) [pt

  15. Acceleration of the nodal program FERM

    International Nuclear Information System (INIS)

    Nakata, H.

    1985-01-01

    Acceleration of the nodal FERM was tried by three acceleration schemes. Results of the calculations showed the best acceleration with the Tchebyshev method where the savings in the computing time were of the order of 50%. Acceleration with the Assymptotic Source Extrapoltation Method and with the Coarse-Mesh Rebalancing Method did not result in any improvement on the global computational time, although a reduction in the number of outer iterations was observed. (Author) [pt

  16. Nodal method for fast reactor analysis

    International Nuclear Information System (INIS)

    Shober, R.A.

    1979-01-01

    In this paper, a nodal method applicable to fast reactor diffusion theory analysis has been developed. This method has been shown to be accurate and efficient in comparison to highly optimized finite difference techniques. The use of an analytic solution to the diffusion equation as a means of determining accurate coupling relationships between nodes has been shown to be highly accurate and efficient in specific two-group applications, as well as in the current multigroup method

  17. Imaging of thoracic aortic dissection

    International Nuclear Information System (INIS)

    Vu, F.H.; Young, N.; Soo, Y.S.

    1994-01-01

    Acute thoracic aortic dissection has a high mortality rate if untreated, so the diagnosis must be rapidly made. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause of death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 out of 12 patients studied and correctly classified the type in only five. Aortography was preformed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were preformed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention. 17 refs., 4 tabs., 4 figs

  18. Nodal methods in numerical reactor calculations

    International Nuclear Information System (INIS)

    Hennart, J.P.; Valle, E. del

    2004-01-01

    The present work describes the antecedents, developments and applications started in 1972 with Prof. Hennart who was invited to be part of the staff of the Nuclear Engineering Department at the School of Physics and Mathematics of the National Polytechnic Institute. Since that time and up to 1981, several master theses based on classical finite element methods were developed with applications in point kinetics and in the steady state as well as the time dependent multigroup diffusion equations. After this period the emphasis moved to nodal finite elements in 1, 2 and 3D cartesian geometries. All the thesis were devoted to the numerical solution of the neutron multigroup diffusion and transport equations, few of them including the time dependence, most of them related with steady state diffusion equations. The main contributions were as follows: high order nodal schemes for the primal and mixed forms of the diffusion equations, block-centered finite-differences methods, post-processing, composite nodal finite elements for hexagons, and weakly and strongly discontinuous schemes for the transport equation. Some of these are now being used by several researchers involved in nuclear fuel management. (Author)

  19. Nodal methods in numerical reactor calculations

    Energy Technology Data Exchange (ETDEWEB)

    Hennart, J P [UNAM, IIMAS, A.P. 20-726, 01000 Mexico D.F. (Mexico); Valle, E del [National Polytechnic Institute, School of Physics and Mathematics, Department of Nuclear Engineering, Mexico, D.F. (Mexico)

    2004-07-01

    The present work describes the antecedents, developments and applications started in 1972 with Prof. Hennart who was invited to be part of the staff of the Nuclear Engineering Department at the School of Physics and Mathematics of the National Polytechnic Institute. Since that time and up to 1981, several master theses based on classical finite element methods were developed with applications in point kinetics and in the steady state as well as the time dependent multigroup diffusion equations. After this period the emphasis moved to nodal finite elements in 1, 2 and 3D cartesian geometries. All the thesis were devoted to the numerical solution of the neutron multigroup diffusion and transport equations, few of them including the time dependence, most of them related with steady state diffusion equations. The main contributions were as follows: high order nodal schemes for the primal and mixed forms of the diffusion equations, block-centered finite-differences methods, post-processing, composite nodal finite elements for hexagons, and weakly and strongly discontinuous schemes for the transport equation. Some of these are now being used by several researchers involved in nuclear fuel management. (Author)

  20. Endoscopic Submucosal Dissection: Indications and Application in Western Endoscopy Practice.

    Science.gov (United States)

    Bourke, Michael J; Neuhaus, Horst; Bergman, Jacques J

    2018-05-01

    Endoscopic submucosal dissection was developed in Japan, early in this century, to provide a minimally invasive yet curative treatment for the large numbers of patients with early gastric cancer identified by the national screening program. Previously, the majority of these patients were treated surgically at substantial cost and with significant risk of short- and long-term morbidity. En-bloc excision of these early cancers, most with a limited risk of nodal metastasis, allowed complete staging of the tumor, stratification of the subsequent therapeutic approach, and potential cure. This transformative innovation changed the nature of endoscopic treatment for superficial mucosal neoplasia and, ultimately, for the first time allowed endoscopists to assert that the early cancer had been definitively cured. Subsequently, Western endoscopists have increasingly embraced the therapeutic possibilities offered by endoscopic submucosal dissection, but with some justifiable scientific caution. Here we provide an evidence-based critical appraisal of the role of endoscopic submucosal dissection in advanced endoscopic tissue resection. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

  1. On the non-uniqueness of the nodal mathematical adjoint

    International Nuclear Information System (INIS)

    Müller, Erwin

    2014-01-01

    Highlights: • We evaluate three CMFD schemes for computing the nodal mathematical adjoint. • The nodal mathematical adjoint is not unique and can be non-positive (nonphysical). • Adjoint and forward eigenmodes are compatible if produced by the same CMFD method. • In nodal applications the excited eigenmodes are purely mathematical entities. - Abstract: Computation of the neutron adjoint flux within the framework of modern nodal diffusion methods is often facilitated by reducing the nodal equation system for the forward flux into a simpler coarse-mesh finite-difference form and then transposing the resultant matrix equations. The solution to the transposed problem is known as the nodal mathematical adjoint. Since the coarse-mesh finite-difference reduction of a given nodal formulation can be obtained in a number of ways, different nodal mathematical adjoint solutions can be computed. This non-uniqueness of the nodal mathematical adjoint challenges the credibility of the reduction strategy and demands a verdict as to its suitability in practical applications. This is the matter under consideration in this paper. A selected number of coarse-mesh finite-difference reduction schemes are described and compared. Numerical calculations are utilised to illustrate the differences in the adjoint solutions as well as to appraise the impact on such common applications as the computation of core point kinetics parameters. Recommendations are made for the proper application of the coarse-mesh finite-difference reduction approach to the nodal mathematical adjoint problem

  2. Impacts of Contingency Reserve on Nodal Price and Nodal Reliability Risk in Deregulated Power Systems

    DEFF Research Database (Denmark)

    Zhao, Qian; Wang, Peng; Goel, Lalit

    2013-01-01

    The deregulation of power systems allows customers to participate in power market operation. In deregulated power systems, nodal price and nodal reliability are adopted to represent locational operation cost and reliability performance. Since contingency reserve (CR) plays an important role...... in reliable operation, the CR commitment should be considered in operational reliability analysis. In this paper, a CR model based on customer reliability requirements has been formulated and integrated into power market settlement. A two-step market clearing process has been proposed to determine generation...

  3. Automatic Dissection Of Plantlets

    Science.gov (United States)

    Batchelor, B. G.; Harris, I. P.; Marchant, J. A.; Tillett, R. D.

    1989-03-01

    Micropropagation is a technique used in horticulture for generating a monoclonal colony of plants. A tiny plantlet is cut into several parts, each of which is then replanted. At the moment, the cutting is performed manually. Automating this task would have significant economic benefits. A robot designed to dissect plants would need to be equipped with intelligent visual sensing. This article is concerned with the image acquisition and processing techniques which such a machine might use. A program, which can calculate where to cut a plant with an "open" structure, is presented. This is expressed in the ProVision language, which is described in another article presented at this conference. (Article 1002-65)

  4. Phase I clinical trial of parenteral hydroxyurea in combination with pelvic and para-aortic external radiation and brachytherapy for patients with advanced squamous cell cancer of the uterine cervix

    International Nuclear Information System (INIS)

    Beitler, Jonathan J.; Anderson, Patrick; Haynes, Hilda; Sood, Brij; Fields, Abbi; Goldberg, Gary; Vikram, Bhadrasain; Runowicz, Carolyn D.; Wadler, Scott

    2002-01-01

    Purpose: Oral hydroxyurea (HU) is a potent radiation sensitizer, but in vitro studies have suggested that prolonged exposure to HU by way of continuous parenteral infusion would enhance clinical efficacy. The objective of this study was to determine the maximal tolerated dose and identify the toxicities of continuous infusion HU in combination with pelvic and para-aortic external beam radiotherapy (RT) and intrauterine brachytherapy in patients with locally advanced carcinoma of the uterine cervix. Methods: This Phase I study of concomitant RT was designed with an escalating dose schedule of HU administered by continuous infusion. HU was administered parenterally as a continuous infusion, 5 d/wk, during the first 21 days of external radiation, during the final 5 days of external beam RT, followed by another 5-day infusion schedule bracketing the single fraction of brachytherapy. The maximal tolerated dose was defined as the highest dose level at which 3 of 3 or 5 of 6 patients could be treated without dose-limiting toxicity. Results: At dose level 1 (0.25 mg/m 2 /min), 0 of 4 patients experienced Grade 4 toxicities and 2 patients experienced Grade 3 hematologic toxicities that were not considered dose-limiting. One of the first 4 patients at level 2 (0.375 mg/m 2 /min) had Grade 3 diarrhea, but the 3 subsequent patients tolerated the dose. At level 3 (0.5 mg/m 2 /min), 4 of 5 patients failed to complete therapy without a >7-day interruption in HU. Conclusions: The maximal tolerated dose of parenteral HU was 0.375 mg/m 2 /min when administered with concomitant RT. The most common toxicities were hematologic. A new trial, incorporating concurrent cisplatin, HU, and RT is planned

  5. Patterns of practice of regional nodal irradiation in breast cancer: results of the European Organization for Research and Treatment of Cancer (EORTC) NOdal Radiotherapy (NORA) survey.

    Science.gov (United States)

    Belkacemi, Y; Kaidar-Person, O; Poortmans, P; Ozsahin, M; Valli, M-C; Russell, N; Kunkler, I; Hermans, J; Kuten, A; van Tienhoven, G; Westenberg, H

    2015-03-01

    Predicting outcome of breast cancer (BC) patients based on sentinel lymph node (SLN) status without axillary lymph node dissection (ALND) is an area of uncertainty. It influences the decision-making for regional nodal irradiation (RNI). The aim of the NORA (NOdal RAdiotherapy) survey was to examine the patterns of RNI. A web-questionnaire, including several clinical scenarios, was distributed to 88 EORTC-affiliated centers. Responses were received between July 2013 and January 2014. A total of 84 responses were analyzed. While three-dimensional (3D) radiotherapy (RT) planning is carried out in 81 (96%) centers, nodal areas are delineated in only 51 (61%) centers. Only 14 (17%) centers routinely link internal mammary chain (IMC) and supraclavicular node (SCN) RT indications. In patients undergoing total mastectomy (TM) with ALND, SCN-RT is recommend by 5 (6%), 53 (63%) and 51 (61%) centers for patients with pN0(i+), pN(mi) and pN1, respectively. Extra-capsular extension (ECE) is the main factor influencing decision-making RNI after breast conserving surgery (BCS) and TM. After primary systemic therapy (PST), 49 (58%) centers take into account nodal fibrotic changes in ypN0 patients for RNI indications. In ypN0 patients with inner/central tumors, 23 (27%) centers indicate SCN-RT and IMC-RT. In ypN1 patients, SCN-RT is delivered by less than half of the centers in patients with ypN(i+) and ypN(mi). Twenty-one (25%) of the centers recommend ALN-RT in patients with ypN(mi) or 1-2N+ after ALND. Seventy-five (90%) centers state that age is not considered a limiting factor for RNI. The NORA survey is unique in evaluating the impact of SLNB/ALND status on adjuvant RNI decision-making and volumes after BCS/TM with or without PST. ALN-RT is often indicated in pN1 patients, particularly in the case of ECE. Besides the ongoing NSABP-B51/RTOG and ALLIANCE trials, NORA could help to design future specific RNI trials in the SLNB era without ALND in patients receiving or not PST.

  6. Topological surface states in nodal superconductors.

    Science.gov (United States)

    Schnyder, Andreas P; Brydon, Philip M R

    2015-06-24

    Topological superconductors have become a subject of intense research due to their potential use for technical applications in device fabrication and quantum information. Besides fully gapped superconductors, unconventional superconductors with point or line nodes in their order parameter can also exhibit nontrivial topological characteristics. This article reviews recent progress in the theoretical understanding of nodal topological superconductors, with a focus on Weyl and noncentrosymmetric superconductors and their protected surface states. Using selected examples, we review the bulk topological properties of these systems, study different types of topological surface states, and examine their unusual properties. Furthermore, we survey some candidate materials for topological superconductivity and discuss different experimental signatures of topological surface states.

  7. Twisted vector bundles on pointed nodal curves

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    by identifying the points p1 and p2. If m ≥ 2, let R1,...,Rm−1 be m − 1 copies of the projective line P1 and let xi,yi be two distinct points in Ri. Let R be the nodal curve which arises from the union. R0 ⊔ R1 ⊔···⊔ Rm−1 ⊔ Rm by identifying p1 ∈ R0 and p2 ∈ Rm with x1 ∈ R1 and ym−1 ∈ Rm−1 respectively and by identifying ...

  8. Routine use of standard breast MRI compared to axillary ultrasound for differentiating between no, limited and advanced axillary nodal disease in newly diagnosed breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Nijnatten, T.J.A. van, E-mail: Thiemovn@gmail.com [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht (Netherlands); Ploumen, E.H. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); Schipper, RJ. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Catharina Hospital, Eindhoven (Netherlands); Goorts, B. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht (Netherlands); Andriessen, E.H. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); Vanwetswinkel, S.; Schavemaker, M. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Nelemans, P. [Department of Epidemiology, Maastricht University Medical Center+, Maastricht (Netherlands); Vries, B. de [Department of Pathology, Zuyderland Hospital, Heerlen (Netherlands); and others

    2016-12-15

    Objectives: To compare standard breast MRI to dedicated axillary ultrasound (with or without tissue sampling) for differentiating between no, limited and advanced axillary nodal disease in breast cancer patients. Methods: All patients who underwent breast MRI and dedicated axillary ultrasound between 2009 and 2014 were eligible. Exclusion criteria were recurrent disease, neoadjuvant systemic therapy and not receiving completion axillary lymph node dissection after positive sentinel lymph node biopsy (SLNB). Two radiologists independently reassessed all MRI exams. Axillary ultrasound findings were retrospectively collected. Probability of advanced axillary nodal disease (pN2-3) given clinically node negative (cN0) or limited (cN1) findings was calculated, with corresponding negative predictive value (NPV) to exclude pN2-3 and positive predictive value (PPV) to identify axillary nodal disease. Histopathology served as gold standard. Results: A total of 377 cases resulted in 81.4% no, 14.4% limited and 4.2% advanced axillary nodal disease at final histopathology. Probability of pN2-3 given cN0 for breast MRI and axillary ultrasound was 0.7–0.9% versus 1.5% and probability of pN2-3 given cN1 was 11.6–15.4% versus 29.0%. When cN1 on breast MRI was observed, PPV to identify positive axillary nodal disease was 50.7% and 59.0%. Conclusions: Evaluation of axillary nodal status on standard breast MRI is comparable to dedicated axillary ultrasound in breast cancer patients. In patients who underwent preoperative standard breast MRI, axillary ultrasound is only required in case of suspicious nodal findings on MRI.

  9. The Role of Central Neck Lymph Node Dissection in the Management of Papillary Thyroid Cancer.

    Science.gov (United States)

    Shirley, Lawrence A; Jones, Natalie B; Phay, John E

    2017-01-01

    Papillary thyroid cancer (PTC) is the most common thyroid malignancy, and cervical nodal metastases are frequent at presentation. The most common site for nodal metastases from PTC is the central compartment of the ipsilateral neck in the paratracheal and pretracheal regions. The decision to resect these lymph nodes at the time of thyroidectomy often depends on if nodes with suspected malignancy can be identified preoperatively. If nodal spread to the central neck nodes is known, then the consensus is to remove all nodes in this area. However, there remains significant controversy regarding the utility of removing central neck lymph nodes for prophylactic reasons. Herein, we review the potential utility of central neck lymph node dissection as well as the risks of performing this procedure. As well, we review the potential of molecular testing to stratify patients who would most benefit from this procedure. We advocate a selective approach in which patients undergo clinical neck examination coupled with ultrasound to detect any concerning lymph nodes that warrant additional evaluation with either fine needle aspiration or excisional biopsy in the operating room. In lieu of clinical lymphadenopathy, we suggest the use of patient and disease characteristics as identified by multiple groups, such as the American Thyroid Association and European Society of Endocrine Surgeons, which include extremes of ages, large primary tumor size, and male gender, when deciding to perform central neck lymph node dissection. Patients should be educated on the potential long-terms risks versus the lack of known long-term benefits.

  10. The Role of Central Neck Lymph Node Dissection in the Management of Papillary Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Lawrence A. Shirley

    2017-06-01

    Full Text Available Papillary thyroid cancer (PTC is the most common thyroid malignancy, and cervical nodal metastases are frequent at presentation. The most common site for nodal metastases from PTC is the central compartment of the ipsilateral neck in the paratracheal and pretracheal regions. The decision to resect these lymph nodes at the time of thyroidectomy often depends on if nodes with suspected malignancy can be identified preoperatively. If nodal spread to the central neck nodes is known, then the consensus is to remove all nodes in this area. However, there remains significant controversy regarding the utility of removing central neck lymph nodes for prophylactic reasons. Herein, we review the potential utility of central neck lymph node dissection as well as the risks of performing this procedure. As well, we review the potential of molecular testing to stratify patients who would most benefit from this procedure. We advocate a selective approach in which patients undergo clinical neck examination coupled with ultrasound to detect any concerning lymph nodes that warrant additional evaluation with either fine needle aspiration or excisional biopsy in the operating room. In lieu of clinical lymphadenopathy, we suggest the use of patient and disease characteristics as identified by multiple groups, such as the American Thyroid Association and European Society of Endocrine Surgeons, which include extremes of ages, large primary tumor size, and male gender, when deciding to perform central neck lymph node dissection. Patients should be educated on the potential long-terms risks versus the lack of known long-term benefits.

  11. Robust doubly charged nodal lines and nodal surfaces in centrosymmetric systems

    Science.gov (United States)

    Bzdušek, Tomáš; Sigrist, Manfred

    2017-10-01

    Weyl points in three spatial dimensions are characterized by a Z -valued charge—the Chern number—which makes them stable against a wide range of perturbations. A set of Weyl points can mutually annihilate only if their net charge vanishes, a property we refer to as robustness. While nodal loops are usually not robust in this sense, it has recently been shown using homotopy arguments that in the centrosymmetric extension of the AI symmetry class they nevertheless develop a Z2 charge analogous to the Chern number. Nodal loops carrying a nontrivial value of this Z2 charge are robust, i.e., they can be gapped out only by a pairwise annihilation and not on their own. As this is an additional charge independent of the Berry π -phase flowing along the band degeneracy, such nodal loops are, in fact, doubly charged. In this manuscript, we generalize the homotopy discussion to the centrosymmetric extensions of all Atland-Zirnbauer classes. We develop a tailored mathematical framework dubbed the AZ +I classification and show that in three spatial dimensions such robust and multiply charged nodes appear in four of such centrosymmetric extensions, namely, AZ +I classes CI and AI lead to doubly charged nodal lines, while D and BDI support doubly charged nodal surfaces. We remark that no further crystalline symmetries apart from the spatial inversion are necessary for their stability. We provide a description of the corresponding topological charges, and develop simple tight-binding models of various semimetallic and superconducting phases that exhibit these nodes. We also indicate how the concept of robust and multiply charged nodes generalizes to other spatial dimensions.

  12. Cine MRI of dissecting aneurysm

    International Nuclear Information System (INIS)

    Takaki, Hajime

    1991-01-01

    Cine MRI was performed in 25 cases of aortic dissection and comparative study among cine MRI, spin-echo static MRI, contrast-enhanced CT and intravenous digital subtraction angiography (IVDSA) was made. Cine MRI accurately detected aortic dissection. It was most accurate among various diagnostic methods in demonstration of entry site of dissection. Take-off of renal artery and its relation to true and false channels was also accurately demonstrated by cine MRI. The above results suggest that cine MRI can be an important diagnostic modality with almost equal diagnostic quality to those of conventional angiography. However, further technical improvement to shorten the imaging time seems necessary to replace angiography. (author)

  13. Radiotherapy of adult nodal non Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Gamen, G.; Thirion, P.

    1999-01-01

    The role of radiotherapy in the treatment of nodal non-Hodgkin's lymphoma has been modified by the introduction of efficient chemotherapy and the development of different pathological classifications. The recommended treatment of early-stage aggressive lymphomas is primarily a combination chemotherapy. The interest of adjuvant radiotherapy remains unclear and has to be established through large prospective trials. If radiation therapy has to be delivered, the historical results of exclusive radiation therapy showed that involved-fields and a dose of 35-40 Gy (daily fraction of 1.8 Gy, 5 days a week) are the optimal schedule. The interest of radiotherapy in the treatment of advanced-stage aggressive lymphoma is yet to be proven. Further studies had to stratify localized stages according to the factors of the International Prognostic Index. For easy-stage low-grade lymphoma, radiotherapy remains the standard treatment. However, the appropriate technique to use is controversial. Involved-field irradiation at a dose of 35 Gy seems to be the optimal schedule, providing a 10 year disease-free survival rate of 50 % and no major toxicity. There is no standard indication of radiotherapy in the treatment advanced-stage low-grade lymphoma. For 'new' nodal lymphoma's types, the indication of radiotherapy cannot be established (mantle-zone lymphoma, marginal zone B-cell lymphoma) or must take into account the natural history (Burkitt's lymphoma, peripheral T-cell lymphoma) and the sensibility to others therapeutic methods. (authors)

  14. Error estimation for variational nodal calculations

    International Nuclear Information System (INIS)

    Zhang, H.; Lewis, E.E.

    1998-01-01

    Adaptive grid methods are widely employed in finite element solutions to both solid and fluid mechanics problems. Either the size of the element is reduced (h refinement) or the order of the trial function is increased (p refinement) locally to improve the accuracy of the solution without a commensurate increase in computational effort. Success of these methods requires effective local error estimates to determine those parts of the problem domain where the solution should be refined. Adaptive methods have recently been applied to the spatial variables of the discrete ordinates equations. As a first step in the development of adaptive methods that are compatible with the variational nodal method, the authors examine error estimates for use in conjunction with spatial variables. The variational nodal method lends itself well to p refinement because the space-angle trial functions are hierarchical. Here they examine an error estimator for use with spatial p refinement for the diffusion approximation. Eventually, angular refinement will also be considered using spherical harmonics approximations

  15. Biomedicine: an ontological dissection.

    Science.gov (United States)

    Baronov, David

    2008-01-01

    Though ubiquitous across the medical social sciences literature, the term "biomedicine" as an analytical concept remains remarkably slippery. It is argued here that this imprecision is due in part to the fact that biomedicine is comprised of three interrelated ontological spheres, each of which frames biomedicine as a distinct subject of investigation. This suggests that, depending upon one's ontological commitment, the meaning of biomedicine will shift. From an empirical perspective, biomedicine takes on the appearance of a scientific enterprise and is defined as a derivative category of Western science more generally. From an interpretive perspective, biomedicine represents a symbolic-cultural expression whose adherence to the principles of scientific objectivity conceals an ideological agenda. From a conceptual perspective, biomedicine represents an expression of social power that reflects structures of power and privilege within capitalist society. No one perspective exists in isolation and so the image of biomedicine from any one presents an incomplete understanding. It is the mutually-conditioning interrelations between these ontological spheres that account for biomedicine's ongoing development. Thus, the ontological dissection of biomedicine that follows, with particular emphasis on the period of its formal crystallization in the latter nineteenth and early twentieth century, is intended to deepen our understanding of biomedicine as an analytical concept across the medical social sciences literature.

  16. Spontaneous Arterial Dissection.

    Science.gov (United States)

    Brandt, Tobias; Caplan, Louis

    2001-09-01

    There is no controlled study for the best treatment or management of cervico-cerebral artery dissection (CAD). Rationale initial empiric treatment in acute CAD to prevent secondary embolism is partial thromboplastin time (PTT)-guided anticoagulation by intravenous heparin followed by anticoagulation with warfarin. Carotid surgery for treatment of CAD is not recommended anymore with the possible exception of persisting severe stenosis of the proximal internal carotid artery (ICA). There could be use of carotid angioplasty by balloon dilatation and stenting in selected cases of severe cerebral hemodynamic impairment by bilateral CAD. Duration of secondary prophylaxis by anticoagulation is best guided by Doppler sonography follow-up, and should be continued until normalization of blood flow or until at least 1 year after the vessel is occluded. There is no evidence that pseudoaneurysms increase the risk for embolic complication, and there is no evidence for surgery or continuation of anticoagulation in patients with pseudoaneurysms. Caution should be recommended for exercises that involve excessive head movements (eg, bungee jumping, trampoline jumping, and chiropractic maneuvers). The patient should be informed that recurrent rate is low in nonfamilial cases. Doppler sonography is a low-cost and high-sensitivity method for patients at risk.

  17. Elective nodal irradiation (ENI) in definitive chemoradiotherapy (CRT) for squamous cell carcinoma of the thoracic esophagus

    International Nuclear Information System (INIS)

    Onozawa, Masakatsu; Nihei, Keiji; Ishikura, Satoshi; Minashi, Keiko; Yano, Tomonori; Muto, Manabu; Ohtsu, Atsushi; Ogino, Takashi

    2009-01-01

    Background and purpose: There are some reports indicating that prophylactic three-field lymph node dissection for esophageal cancer can lead to improved survival. But the benefit of ENI in CRT for thoracic esophageal cancer remains controversial. The purpose of the present study is to retrospectively evaluate the efficacy of elective nodal irradiation (ENI) in definitive chemoradiotherapy (CRT) for thoracic esophageal cancer. Materials and methods: Patients with squamous cell carcinoma (SCC) of the thoracic esophagus newly diagnosed between February 1999 and April 2001 in our institution was recruited from our database. Definitive chemoradiotherapy consisted of two cycles of cisplatin/5FU repeated every 5 weeks, with concurrent radiation therapy of 60 Gy in 30 fractions. Up to 40 Gy radiation therapy was delivered to the cervical, periesophageal, mediastinal and perigastric lymph nodes as ENI. Results: One hundred two patients were included in this analysis, and their characteristics were as follows: median age, 65 years; male/female, 85/17; T1/T2/T3/T4, 16/11/61/14; N0/N1, 48/54; M0/M1, 84/18. The median follow-up period for the surviving patients was 41 months. Sixty patients achieved complete response (CR). After achieving CR, only one (1.0%; 95% CI, 0-5.3%) patient experienced elective nodal failure without any other site of recurrence. Conclusion: In CRT for esophageal SCC, ENI is effective for preventing regional nodal failure. Further evaluation of whether ENI leads to an improved overall survival is needed.

  18. The role of postradiotherapy neck dissection in supraglottic carcinoma

    International Nuclear Information System (INIS)

    Chan, Annie W.; Ancukiewicz, Marek; Carballo, Natalia; Montgomery, William; Wang, C.C.

    2001-01-01

    Purpose: To evaluate our policy of performing neck dissection based on regional response after definitive radiotherapy in patients with supraglottic carcinoma and to identify the prognostic factors in this group of patients. Methods and Materials: Between 1970 and 1995, 121 patients with node-positive squamous cell carcinoma of the supraglottic larynx were treated with definitive radiotherapy. Sixty-nine percent of patients presented with 1997 AJCC Stage IV disease. The N-stage distribution was N1, 49; N2, 62; and N3, 10. The median size of the lymph nodes was 3 cm (range, 0.5-8 cm). Forty-five patients received once-a-day treatment with a median total dose of 65 Gy (range, 58.0-70.8 Gy) in 1.8-2.0 Gy per fraction over 48 days, and 76 patients received split-course accelerated hyperfractionation with a median total dose of 67.2 Gy (range, 63.2-73.6 Gy) in 1.6 Gy twice a day over 43 days. Patients whose lymph nodes were not clinically detectable at 4-6 weeks after the completion of radiotherapy (complete response) were followed without any neck dissection. Patients with persistent neck adenopathy (partial response) underwent neck dissection whenever possible. Mean follow-up of the living patients was 6.5 years. Results: Regional response was related to the size of lymph nodes at presentation. Eighty-seven percent of patients with nodal size of 3 cm or less had a complete response, whereas 43% of patients with nodal size greater than 3 cm had a partial response. The rate of regional control at 3 years for all patients in the study was 66%. The 3-year ultimate regional control rate after salvage neck dissection was 75%. A relapse in both the primary and regional sites was the most common pattern of relapse, accounting for 39% of all the failures. Local failure was associated with subsequent regional relapse with a relative risk of 4.3. For patients with completeresponse in whom postradiotherapy neck dissection was withheld, the regional control rates were 75% and 86

  19. Torsionfree Sheaves over a Nodal Curve of Arithmetic Genus One

    Indian Academy of Sciences (India)

    We classify all isomorphism classes of stable torsionfree sheaves on an irreducible nodal curve of arithmetic genus one defined over C C . Let be a nodal curve of arithmetic genus one defined over R R , with exactly one node, such that does not have any real points apart from the node. We classify all isomorphism ...

  20. A nodalization study of steam separator in real time simulation

    International Nuclear Information System (INIS)

    Horugshyang, Lein; Luh, R.T.J.; Zen-Yow, Wang

    1999-01-01

    The motive of this paper is to investigate the influence of steam separator nodalization on reactor thermohydraulics in terms of stability and level response. Three different nodalizations of steam separator are studied by using THEATRE and REMARK Code in a BWR simulator. The first nodalization is the traditional one with two nodes for steam separator. In this nodalization, the steam separation is modeled in the outer node, i.e., upper downcomer. Separated steam enters the Steen dome node and the liquid goes to the feedwater node. The second nodalization is similar to the first one with the steam separation modeled in the inner node. There is one additional junction connecting steam dome node and the inner node. The liquid fallback junction connects the inner node and feedwater node. The third nodalization is a combination of the former two with an integrated node for steam separator. Boundary conditions in this study are provided by a simplified feedwater and main steam driver. For comparison purpose, three tests including full power steady state initialisation, recirculation pumps runback and reactor scram are conducted. Major parameters such as reactor pressure, reactor level, void fractions, neutronic power and junction flows are recorded for analysis. Test results clearly show that the first nodalization is stable for steady state initialisation. However it has too responsive level performance in core flow reduction transients. The second nodalization is the closest representation of real plant structure, but not the performance. Test results show that an instability occurs in the separator region for both steady state initialisation and transients. This instability is caused by an unbalanced momentum in the dual loop configuration. The magnitude of the oscillation reduces as the power decreases. No superiority to the other nodalizations is shown in the test results. The third nodalization shows both stability and responsiveness in the tests. (author)

  1. Topological surface states in nodal superconductors

    International Nuclear Information System (INIS)

    Schnyder, Andreas P; Brydon, Philip M R

    2015-01-01

    Topological superconductors have become a subject of intense research due to their potential use for technical applications in device fabrication and quantum information. Besides fully gapped superconductors, unconventional superconductors with point or line nodes in their order parameter can also exhibit nontrivial topological characteristics. This article reviews recent progress in the theoretical understanding of nodal topological superconductors, with a focus on Weyl and noncentrosymmetric superconductors and their protected surface states. Using selected examples, we review the bulk topological properties of these systems, study different types of topological surface states, and examine their unusual properties. Furthermore, we survey some candidate materials for topological superconductivity and discuss different experimental signatures of topological surface states. (topical review)

  2. Nodal aberration theory applied to freeform surfaces

    Science.gov (United States)

    Fuerschbach, Kyle; Rolland, Jannick P.; Thompson, Kevin P.

    2014-12-01

    When new three-dimensional packages are developed for imaging optical systems, the rotational symmetry of the optical system is often broken, changing its imaging behavior and making the optical performance worse. A method to restore the performance is to use freeform optical surfaces that compensate directly the aberrations introduced from tilting and decentering the optical surfaces. In order to effectively optimize the shape of a freeform surface to restore optical functionality, it is helpful to understand the aberration effect the surface may induce. Using nodal aberration theory the aberration fields induced by a freeform surface in an optical system are explored. These theoretical predications are experimentally validated with the design and implementation of an aberration generating telescope.

  3. Histopathological Parameters predicting Occult Nodal Metastases in Tongue Carcinoma Cases: An Indian Perspective.

    Science.gov (United States)

    Jacob, Tina Elizabeth; Malathi, N; Rajan, Sharada T; Augustine, Dominic; Manish, N; Patil, Shankargouda

    2016-01-01

    It is a well-established fact that in squamous cell carcinoma cases, the presence of lymph node metastases decreased the 5-year survival rate by 50% and also caused the recurrence of the primary tumor with development of distant metastases. Till date, the predictive factors for occult cervical lymph nodes metastases in cases of tongue squamous cell carcinoma remain inconclusive. Therefore, it is imperative to identify patients who are at the greatest risk for occult cervical metastases. This study was thus performed with the aim to identify various histopathologic parameters of the primary tumor that predict occult nodal metastases. The clinicopathologic features of 56 cases of lateral tongue squamous cell carcinoma with cT1NoMo/cT2NoMo as the stage and without prior radiotherapy or chemotherapy were considered. The surgical excision of primary tumor was followed by elective neck dissection. The glossectomy specimen along with the neck nodes were fixed in formalin and 5 urn thick sections were obtained. The hematoxylin & eosin stained sections were then subjected to microscopic examination. The primary tumor characteristics that were analyzed include tumor grade, invading front, depth of tumor, lymphovascular invasion, perineural invasion and inflammatory response. The nodes were examined for possible metastases using hematoxylin & eosin followed by cytokeratin immunohistochemistry. A total of 12 cases were found with positive occult nodal metastases. On performing univariate analysis, the histopathologic parameters that were found to be statistically significant were lymphovascular invasion (p = 0.004) and perineural invasion (p = 0.003) along with a cut-off depth of infiltration more than 5 mm (p = 0.01). Histopathologic assessment of the primary tumor specimen therefore continues to provide information that is central to guide clinical management, particularly in cases of occult nodal metastases. Clinical significance The study highlights the importance of

  4. Brachial plexus endoscopic dissection and correlation with open dissection.

    Science.gov (United States)

    Lafosse, T; Masmejean, E; Bihel, T; Lafosse, L

    2015-12-01

    Shoulder endoscopy is evolving and becoming extra-articular. More and more procedures are taking place in the area of the brachial plexus (BP). We carried out an anatomical study to describe the endoscopic anatomy of the BP and the technique used to dissect and expose the BP endoscopically. Thirteen fresh cadavers were dissected. We first performed an endoscopic dissection of the BP, using classical extra-articular shoulder arthroscopy portals. Through each portal, we dissected as many structures as possible and identified them. We then did an open dissection to corroborate the endoscopic findings and to look for damage to the neighboring structures. In the supraclavicular area, we were able to expose the C5, C6 and C7 roots, and the superior and middle trunks in 11 of 13 specimens through two transtrapezial portals by following the suprascapular nerve. The entire infraclavicular portion of the BP (except the medial cord and its branches) was exposed in 11 of 13 specimens. The approach to the infraclavicular portion of the BP led directly to the lateral and posterior cords, but the axillary artery hid the medial cord. The musculocutaneous nerve was the first nerve encountered when dissecting medially from the anterior aspect of the coracoid process. The axillary nerve was the first nerve encountered when following the anterior border of the subscapularis medially from the posterior aspect of the coracoid process. Knowledge of the endoscopic anatomy of the BP is mandatory to expose and protect this structure while performing advanced arthroscopic shoulder procedures. Copyright © 2015 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  5. A nodal expansion method using conformal mapping for hexagonal geometry

    International Nuclear Information System (INIS)

    Chao, Y.A.; Shatilla, Y.A.

    1993-01-01

    Hexagonal nodal methods adopting the same transverse integration process used for square nodal methods face the subtle theoretical problem that this process leads to highly singular nonphysical terms in the diffusion equation. Lawrence, in developing the DIF3D-N code, tried to approximate the singular terms with relatively simple polynomials. In the HEX-NOD code, Wagner ignored the singularities to simplify the diffusion equation and introduced compensating terms in the nodal equations to restore the nodal balance relation. More recently developed hexagonal nodal codes, such as HEXPE-DITE and the hexagonal version of PANTHER, used methods similar to Wagner's. It will be shown that for light water reactor applications, these two different approximations significantly degraded the accuracy of the respective method as compared to the established square nodal methods. Alternatively, the method of conformal mapping was suggested to map a hexagon to a rectangle, with the unique feature of leaving the diffusion operator invariant, thereby fundamentally resolving the problems associated with transverse integration. This method is now implemented in the Westinghouse hexagonal nodal code ANC-H. In this paper we report on the results of comparing the three methods for a variety of problems via benchmarking against the fine-mesh finite difference code

  6. Benchmarking with high-order nodal diffusion methods

    International Nuclear Information System (INIS)

    Tomasevic, D.; Larsen, E.W.

    1993-01-01

    Significant progress in the solution of multidimensional neutron diffusion problems was made in the late 1970s with the introduction of nodal methods. Modern nodal reactor analysis codes provide significant improvements in both accuracy and computing speed over earlier codes based on fine-mesh finite difference methods. In the past, the performance of advanced nodal methods was determined by comparisons with fine-mesh finite difference codes. More recently, the excellent spatial convergence of nodal methods has permitted their use in establishing reference solutions for some important bench-mark problems. The recent development of the self-consistent high-order nodal diffusion method and its subsequent variational formulation has permitted the calculation of reference solutions with one node per assembly mesh size. In this paper, we compare results for four selected benchmark problems to those obtained by high-order response matrix methods and by two well-known state-of-the-art nodal methods (the open-quotes analyticalclose quotes and open-quotes nodal expansionclose quotes methods)

  7. Pathogenesis Concept Of Extracranial Dissections In Iran

    Directory of Open Access Journals (Sweden)

    Kavian Ghandehari

    2017-02-01

    Full Text Available Background: Dissection of Extracranial Internal Carotid Artery (EICA and Extracranial Vertebral Artery (EVA is an amportant cause of brain infarction with miscellaneous etiologies around the world. Methods: A prospective observational clinical study was conducted in Ghaem Hospital, Mashhad, Iran between 2008-2016. Diagnosis of brain infarction and TIA was made by stroke neurologist. Detection of EICA and EVA dissections were made by performing CT angiography  and MR angiography  or DSA in the suspected patients. Demographic features, clinical manifestations, territorial involvement, pathophysiology and pathogenesis of dissections were assessed in all of the patients. Pathogenesis of dissections was classified as Idiopathic, Trumatic, Postural and Genetic categories. Results: Twenty eight patients (21 males, 7 females were admitted with extracranial arterial dissection. Mean age of males and females with dissection was 39.81± 4.2 and 35.71±6.1 years respectively. Influence of gender on age of the patients was not significant, p>0.05. Among patients with extracranial dissection only 3.6% had atherosclerosis risk factors and 96.4% had no other cause for brain infarction. 100% of extracranial dissections in males occured in carotid territory, while 28.6% of females had dissection in the EVA. The influence of gender in territory of dissection was significant, p<0.05. Idiopathic dissections and genetic susceptibility was found in 10.7% and 3.6% of extracranial dissections respectively. 53.5% of the patienrs had trumatic pathogenesis for extracranial dissections and 32.1% developed dissection due to special neck  postures. Important details in pathophysiology and pathogenesis of extracranial dissections will be presented in the lecture. Conclusion: Stroke patients with extracranial dissections have characteristic demographic and  territorial involvement. Trumatic pathogenesis is the most frequent cause of dissection in Iran followed by neck

  8. A Hennart nodal method for the diffusion equation

    International Nuclear Information System (INIS)

    Lesaint, P.; Noceir, S.; Verwaerde, D.

    1995-01-01

    A modification of the Hennart nodal method for neutron diffusion problems is presented. The final system of equations obtained by this method is not positive definite. However, a flux elimination technique leads to a simple positive definite system, which can be solved by the traditional iterative methods. Calculations of a two-dimensional International Atomic Energy Agency benchmark problem are performed and compared with results of the original Hennart nodal method and some finite element methods. The high computational efficiency of this modified nodal method is clearly demonstrated

  9. Modifying nodal pricing method considering market participants optimality and reliability

    Directory of Open Access Journals (Sweden)

    A. R. Soofiabadi

    2015-06-01

    Full Text Available This paper develops a method for nodal pricing and market clearing mechanism considering reliability of the system. The effects of components reliability on electricity price, market participants’ profit and system social welfare is considered. This paper considers reliability both for evaluation of market participant’s optimality as well as for fair pricing and market clearing mechanism. To achieve fair pricing, nodal price has been obtained through a two stage optimization problem and to achieve fair market clearing mechanism, comprehensive criteria has been introduced for optimality evaluation of market participant. Social welfare of the system and system efficiency are increased under proposed modified nodal pricing method.

  10. Endoluminal treatment of aortic dissection

    Energy Technology Data Exchange (ETDEWEB)

    Chavan, Ajay; Lotz, Joachim; Galanski, Michael [Department of Diagnostic Radiology, Hannover Medical School, Carl Neuberg Strasse 1, 30625, Hannover (Germany); Oelert, Frank; Haverich, Axel; Karck, Matthias [Department of Thoracic and Cardiovascular Surgery, Hannover Medical School, Carl Neuberg Strasse 1, 30625, Hannover (Germany)

    2003-11-01

    Aortic dissection is most often a catastrophic medical emergency which, if untreated, can be potentially fatal. The intention of therapy in patients with aortic dissection is to prevent aortic rupture or aneurysm formation as well as to relieve branch vessel ischaemia. Patients with aortic dissection are often poor candidates for anaesthesia and surgery and the surgical procedure itself is challenging requiring thoracotomy, aortic cross clamping, blood transfusion as well as prolonged hospital stay in some cases. Operative mortality is especially high in patients with critical mesenteric or renal ischaemia. The past decade has experienced the emergence of a number of interventional radiological or minimally invasive techniques which have significantly improved the management of patients with aortic dissection. These include stent grafting for entry site closure to prevent aneurysmatic widening of the false lumen as well as percutaneous techniques such as balloon fenestration of the intimal flap and aortic true lumen stenting to alleviate branch vessel ischaemia. False lumen thrombosis following entry closure with stent grafts has been observed in 86-100% of patients, whereas percutaneous interventions are able to effectively relieve organ ischaemia in approximately 90% of the cases. In the years to come, it is to be expected that these endoluminal techniques will become the method of choice for treating most type-B dissections and will assist in significantly reducing the number of open surgical procedures required for type-A dissections. The intention of this article is to provide an overview of the current status of these endoluminal techniques based on our own experience as well as on a review of the relevant literature. (orig.)

  11. Endoluminal treatment of aortic dissection

    International Nuclear Information System (INIS)

    Chavan, Ajay; Lotz, Joachim; Galanski, Michael; Oelert, Frank; Haverich, Axel; Karck, Matthias

    2003-01-01

    Aortic dissection is most often a catastrophic medical emergency which, if untreated, can be potentially fatal. The intention of therapy in patients with aortic dissection is to prevent aortic rupture or aneurysm formation as well as to relieve branch vessel ischaemia. Patients with aortic dissection are often poor candidates for anaesthesia and surgery and the surgical procedure itself is challenging requiring thoracotomy, aortic cross clamping, blood transfusion as well as prolonged hospital stay in some cases. Operative mortality is especially high in patients with critical mesenteric or renal ischaemia. The past decade has experienced the emergence of a number of interventional radiological or minimally invasive techniques which have significantly improved the management of patients with aortic dissection. These include stent grafting for entry site closure to prevent aneurysmatic widening of the false lumen as well as percutaneous techniques such as balloon fenestration of the intimal flap and aortic true lumen stenting to alleviate branch vessel ischaemia. False lumen thrombosis following entry closure with stent grafts has been observed in 86-100% of patients, whereas percutaneous interventions are able to effectively relieve organ ischaemia in approximately 90% of the cases. In the years to come, it is to be expected that these endoluminal techniques will become the method of choice for treating most type-B dissections and will assist in significantly reducing the number of open surgical procedures required for type-A dissections. The intention of this article is to provide an overview of the current status of these endoluminal techniques based on our own experience as well as on a review of the relevant literature. (orig.)

  12. Virtual reality haptic human dissection.

    Science.gov (United States)

    Needham, Caroline; Wilkinson, Caroline; Soames, Roger

    2011-01-01

    This project aims to create a three-dimensional digital model of the human hand and wrist which can be virtually 'dissected' through a haptic interface. Tissue properties will be added to the various anatomical structures to replicate a realistic look and feel. The project will explore the role of the medical artist and investigate the cross-discipline collaborations required in the field of virtual anatomy. The software will be used to train anatomy students in dissection skills before experience on a real cadaver. The effectiveness of the software will be evaluated and assessed both quantitatively as well as qualitatively.

  13. CT simulation in nodal positive breast cancer

    International Nuclear Information System (INIS)

    Horst, E.; Schuck, A.; Moustakis, C.; Schaefer, U.; Micke, O.; Kronholz, H.L.; Willich, N.

    2001-01-01

    Background: A variety of solutions are used to match tangential fields and opposed lymph node fields in irradiation of nodal positive breast cancer. The choice is depending on the technical equipment which is available and the clinical situation. The CT simulation of a non-monoisocentric technique was evaluated in terms of accuracy and reproducibility. Patients, Material and Methods: The field match parameters were adjusted virtually at CT simulation and were compared with parameters derived mathematically. The coordinate transfer from the CT simulator to the conventional simulator was analyzed in 25 consecutive patients. Results: The angles adjusted virtually for a geometrically exact coplanar field match corresponded with the angles calculated for each set-up. The mean isocenter displacement was 5.7 mm and the total uncertainty of the coordinate transfer was 6.7 mm (1 SD). Limitations in the patient set-up became obvious because of the steep arm abduction necessary to fit the 70 cm CT gantry aperture. Required modifications of the arm position and coordinate transfer errors led to a significant shift of the marked matchline of >1.0 cm in eight of 25 patients (32%). Conclusion: The virtual CT simulation allows a precise and graphic definition of the field match parameters. However, modifications of the virtual set-up basically due to technical limitations were required in a total of 32% of cases, so that a hybrid technique was adapted at present that combines virtual adjustment of the ideal field alignment parameters with conventional simulation. (orig.) [de

  14. Present Status of GNF New Nodal Simulator

    International Nuclear Information System (INIS)

    Iwamoto, T.; Tamitani, M.; Moore, B.

    2001-01-01

    This paper presents core simulator consolidation work done at Global Nuclear Fuel (GNF). The unified simulator needs to supercede the capabilities of past simulator packages from the original GNF partners: GE, Hitachi, and Toshiba. At the same time, an effort is being made to produce a simulation package that will be a state-of-the-art analysis tool when released, in terms of the physics solution methodology and functionality. The core simulator will be capable and qualified for (a) high-energy cycles in the U.S. markets, (b) mixed-oxide (MOX) introduction in Japan, and (c) high-power density plants in Europe, etc. The unification of the lattice physics code is also in progress based on a transport model with collision probability methods. The AETNA core simulator is built upon the PANAC11 software base. The goal is to essentially replace the 1.5-energy-group model with a higher-order multigroup nonlinear nodal solution capable of the required modeling fidelity, while keeping highly automated library generation as well as functionality. All required interfaces to PANAC11 will be preserved, which minimizes the impact on users and process automation. Preliminary results show statistical accuracy improvement over the 1.5-group model

  15. BEACON: An application of nodal methods for operational support

    International Nuclear Information System (INIS)

    Boyd, W.A.; Nguyen, T.Q.

    1992-01-01

    A practical application of nodal methods is on-line plant operational support. However, to enable plant personnel to take full advantage of a nodal model to support plant operations, (a) a core nodal model must always be up to date with the current core history and conditions, (b) the nodal methods must be fast enough to allow numerous core calculations to be performed in minutes to support engineering decisions, and (c) the system must be easily accessible to engineering personnel at the reactor, their offices, or any other location considered appropriate. A core operational support package developed by Westinghouse called BEACON (best estimate analysis of core operations - nuclear) has been installed at several plants. Results from these plants and numerous in-core flux maps analyzed have demonstrated the accuracy of the model and the effectiveness of the methodology

  16. Aircraft Nodal Data Acquisition System (ANDAS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an Aircraft Nodal Data Acquisition System (ANDAS) based upon the short haul Zigbee networking standard is proposed. It employs a very thin (135 um)...

  17. Hybrid nodal loop metal: Unconventional magnetoresponse and material realization

    Science.gov (United States)

    Zhang, Xiaoming; Yu, Zhi-Ming; Lu, Yunhao; Sheng, Xian-Lei; Yang, Hui Ying; Yang, Shengyuan A.

    2018-03-01

    A nodal loop is formed by a band crossing along a one-dimensional closed manifold, with each point on the loop a linear nodal point in the transverse dimensions, and can be classified as type I or type II depending on the band dispersion. Here, we propose a class of nodal loops composed of both type-I and type-II points, which are hence termed as hybrid nodal loops. Based on first-principles calculations, we predict the realization of such loops in the existing electride material Ca2As . For a hybrid loop, the Fermi surface consists of coexisting electron and hole pockets that touch at isolated points for an extended range of Fermi energies, without the need for fine-tuning. This leads to unconventional magnetic responses, including the zero-field magnetic breakdown and the momentum-space Klein tunneling observable in the magnetic quantum oscillations, as well as the peculiar anisotropy in the cyclotron resonance.

  18. A nodal method based on matrix-response method

    International Nuclear Information System (INIS)

    Rocamora Junior, F.D.; Menezes, A.

    1982-01-01

    A nodal method based in the matrix-response method, is presented, and its application to spatial gradient problems, such as those that exist in fast reactors, near the core - blanket interface, is investigated. (E.G.) [pt

  19. Nodal prices determination with wind integration for radial ...

    African Journals Online (AJOL)

    With competitive electricity market operation, open access to the transmission and distribution network is essential ... The results have been obtained for IEEE 33 ...... The value of intermittent wind DG under nodal prices and amp – mile tariffs.

  20. Nodal aberration theory for wild-filed asymmetric optical systems

    Science.gov (United States)

    Chen, Yang; Cheng, Xuemin; Hao, Qun

    2016-10-01

    Nodal Aberration Theory (NAT) was used to calculate the zero field position in Full Field Display (FFD) for the given aberration term. Aiming at wide-filed non-rotational symmetric decentered optical systems, we have presented the nodal geography behavior of the family of third-order and fifth-order aberrations. Meanwhile, we have calculated the wavefront aberration expressions when one optical element in the system is tilted, which was not at the entrance pupil. By using a three-piece-cellphone lens example in optical design software CodeV, the nodal geography is testified under several situations; and the wavefront aberrations are calculated when the optical element is tilted. The properties of the nodal aberrations are analyzed by using Fringe Zernike coefficients, which are directly related with the wavefront aberration terms and usually obtained by real ray trace and wavefront surface fitting.

  1. Extension of the analytic nodal method to four energy groups

    International Nuclear Information System (INIS)

    Parsons, D.K.; Nigg, D.W.

    1985-01-01

    The Analytic Nodal Method is one of several recently-developed coarse mesh numerical methods for efficiently and accurately solving the multidimensional static and transient neutron diffusion equations. This summary describes a mathematically rigorous extension of the Analytic Nodal Method to the frequently more physically realistic four-group case. A few general theoretical considerations are discussed, followed by some calculated results for a typical steady-state two-dimensional PWR quarter core application. 8 refs

  2. Animal Rights Activism Threatens Dissection.

    Science.gov (United States)

    Holden, Constance

    1990-01-01

    Discussed is the movement against the use of dissections in science laboratories. Examples of protests across the United States are included. Compared is the plight of using animals in a biology classroom and the demise of the teaching of evolution in some areas. (KR)

  3. Dissecting spontaneous cerebrospinal fluid collection.

    Science.gov (United States)

    Champagne, Pierre-Olivier; Decarie, Jean-Claude; Crevier, Louis; Weil, Alexander G

    2018-04-01

    Hydrocephalus is a common condition in the pediatric population known to have many causes and presentation patterns. We report from the analysis of 2 cases the existence of a new complication of pediatric hydrocephalus. Naming this entity "dissecting intraparenchymal cerebrospinal fluid collection", we advance a hypothesis regarding its pathophysiology and discuss its clinical implications and management. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Bilinear nodal transport method in weighted diamond difference form

    International Nuclear Information System (INIS)

    Azmy, Y.Y.

    1987-01-01

    Nodal methods have been developed and implemented for the numerical solution of the discrete ordinates neutron transport equation. Numerical testing of these methods and comparison of their results to those obtained by conventional methods have established the high accuracy of nodal methods. Furthermore, it has been suggested that the linear-linear approximation is the most computationally efficient, practical nodal approximation. Indeed, this claim has been substantiated by comparing the accuracy in the solution, and the CPU time required to achieve convergence to that solution by several nodal approximations, as well as the diamond difference scheme. Two types of linear-linear nodal methods have been developed in the literature: analytic linear-linear (NLL) methods, in which the transverse-leakage terms are derived analytically, and approximate linear-linear (PLL) methods, in which these terms are approximated. In spite of their higher accuracy, NLL methods result in very complicated discrete-variable equations that exhibit a high degree of coupling, thus requiring special solution algorithms. On the other hand, the sacrificed accuracy in PLL methods is compensated for by the simple discrete-variable equations and diamond-difference-like solution algorithm. In this paper the authors outline the development of an NLL nodal method, the bilinear method, which can be written in a weighted diamond difference form with one spatial weight per dimension that is analytically derived rather than preassigned in an ad hoc fashion

  5. [Modern treatment of type B dissections

    DEFF Research Database (Denmark)

    Klitfod, L.; Baekgaard, N.; Just, S.

    2008-01-01

    Rapid classification is essential in the management of aortic dissections, as Type A dissections require surgery, while the optimal treatment of Type B dissections is controversial. Medical treatment with antihypertensive medication and analgesics has so far been the main treatment of uncomplicated...... Type B dissections, while surgery has been reserved for complications and persistent pain in spite of medical treatment. Endovascular techniques are less invasive than open repair and show promising early results Udgivelsesdato: 2008/9/8...

  6. Uniqueness Theorem for the Inverse Aftereffect Problem and Representation the Nodal Points Form

    Directory of Open Access Journals (Sweden)

    A. Neamaty

    2015-03-01

    Full Text Available In this paper, we consider a boundary value problem with aftereffect on a finite interval. Then, the asymptotic behavior of the solutions, eigenvalues, the nodal points and the associated nodal length are studied. We also calculate the numerical values of the nodal points and the nodal length. Finally, we prove the uniqueness theorem for the inverse aftereffect problem by applying any dense subset of the nodal points.

  7. Uniqueness Theorem for the Inverse Aftereffect Problem and Representation the Nodal Points Form

    OpenAIRE

    A. Neamaty; Sh. Akbarpoor; A. Dabbaghian

    2015-01-01

    In this paper, we consider a boundary value problem with aftereffect on a finite interval. Then, the asymptotic behavior of the solutions, eigenvalues, the nodal points and the associated nodal length are studied. We also calculate the numerical values of the nodal points and the nodal length. Finally, we prove the uniqueness theorem for the inverse aftereffect problem by applying any dense subset of the nodal points.

  8. Type A dissection following endovascular repair of type B dissection

    International Nuclear Information System (INIS)

    Juszkat, R.; Zabicki, M.; Jemielity, M.; Buczkowski, P.; Urbanowicz, T.

    2009-01-01

    Background: We present a patient, who was treated with thoracic stentgraft implantation, because of acute type B aortic dissection (according to Stanford classification). The endovascular procedure was performed without any complications. Case Report: The patient was discharged in the 3 rd postprocedural day and was transferred to another hospital for further recovery. Nine days after the procedure, the patient was readmitted in cardiogenic shock to the Cardiac Surgery Department. The patient was immediately operated on, after dissection of the ascending aorta and pericardial tamponade had been diagnosed in transthoracic echocardiography. Conclusions: Total replacement of the aortic arch and its ascending part was performed successfully. The surgery was carried out in deep hypothermia with temporary circulatory arrest. The patient was discharged from the Cardiac Surgery Unit 15 days after the surgery, and transferred to another unit for further recovery. (authors)

  9. Dynamic CT in dissecting aortic aneurysm

    International Nuclear Information System (INIS)

    Fujita, Nobuyuki; Matsuoka, Yosuke; Mizuo, Hideyo; Shirato, Hiroki; Irie, Goro

    1985-01-01

    especially about the branching of major vessels Eight cases of aortic dissection were analysed to evaluate detectability of the branching of major vessels from a ture or false lumen, by dynamic CT. Although recognition of the branching is easy when the direct continuity to a dissected lumen is demonstrated, but without visualization of direct continuity or with no information about dissected lumens, it is sometimes difficult or leads us to misdiagnosis. The diagnostic accuracy is 100% when direct continuity to a dissected lumen is demonstrated, or dynamic CT revealed branching pattern distinctly. Dynamic CT is useful for a diagnosis of dissecting aneurysm and branching pattern of major vessels. (author)

  10. Spontaneous Dissection of the Superior Mesenteric Artery

    International Nuclear Information System (INIS)

    Sheldon, Patrick J.; Esther, James B.; Sheldon, Elana L.; Sparks, Steven R.; Brophy, David P.; Oglevie, Steven B.

    2001-01-01

    Spontaneous dissection of the superior mesenteric artery (SMA) is a rare occurrence, especially when not associated with aortic dissection. Currently, only 28 cases appear to have been reported. Due to the scarcity of cases in the literature, the natural history of isolated, spontaneous SMA dissection is unclear. CT has been reported to be useful for the initial diagnosis of SMA dissection [2-5]. We present two recent cases of spontaneous SMA dissection in which enhanced spiral CT was instrumental in following the disease process and guiding clinical decision making

  11. [Pregnancy and coronary artery dissection].

    Science.gov (United States)

    Martínez-Quintana, Efrén; Rodríguez-González, Fayna

    2015-01-01

    Acute myocardial infarction during pregnancy is associated with high maternal and fetal mortality. Coronary atherosclerosis is the most common cause due to an increase in the age of the patients and the association with cardiovascular risk factors such as smoking, hypertension, diabetes mellitus, preeclampsia, and the existence of family history of coronary disease. However, thrombosis, coronary dissection or coronary vasospasms are other causes that may justify it. We report the case of a 33 weeks pregnant first-time mother, without cardiovascular risk factors, who presented an acute coronary event in the context of atherosclerotic disease and coronary dissection after percutaneous coronary intervention. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  12. Conservative neck dissection in oral cancer patients: A 5 years retrospective study

    Directory of Open Access Journals (Sweden)

    Wan Mahadzir Wan Mustafa

    2016-06-01

    Full Text Available The impact of ablative oral cancer surgery was studied, with reference to recurrence and nodal metastasis,  survival probability and prognostic indicators and to determine if ethnicity influences the survival of patients. Patients who underwent major ablative surgery of the head and neck region with neck dissection were identified and assessed. Those with stage I-IV oral and oropharyngeal malignancies necessitating resection with or without radiotherapy from 2004 to 2009 were included in this study. All individuals had a pre-operative assessment and post operative assessment. Survival distributions were analyzed using Kaplan-Meier curves. Eighty seven patients (males: 38%; females: 62% were included in this study, with an age range of 21-85 years. Some 78% underwent neck dissections while 63% had surgery and radiotherapy. Nodal and primary site recurrence was 5.7% and 20.5%. The median survival time was 57 months. One year Overall Survival (OS rate was 72.7% and three year overall survival rate 61.5%. The log-rank test showed a significant difference of survival between Malay and Chinese patients (Bonferroni correction p=0.033. Recurrence-Free Survival (RFS analysis revealed that 25% of the patients have reached the event of recurrence at 46 months. The three year survival rate was 76.1%. In the RFS analysis, the log-rank test showed a significant difference in the event of recurrence and nodal metastasis (p<0.001. Conservative neck effectively controls neck metastases. Ethnicity influence  survival.

  13. Investigation on generalized Variational Nodal Methods for heterogeneous nodes

    International Nuclear Information System (INIS)

    Wang, Yongping; Wu, Hongchun; Li, Yunzhao; Cao, Liangzhi; Shen, Wei

    2017-01-01

    Highlights: • We developed two heterogeneous nodal methods based on the Variational Nodal Method. • Four problems were solved to evaluate the two heterogeneous nodal methods. • The function expansion method is good at treating continuous-changing heterogeneity. • The finite sub-element method is good at treating discontinuous-changing heterogeneity. - Abstract: The Variational Nodal Method (VNM) is generalized for heterogeneous nodes and applied to four kinds of problems including Molten Salt Reactor (MSR) core problem with continuous cross section profile, Pressurized Water Reactor (PWR) control rod cusping effect problem, PWR whole-core pin-by-pin problem, and heterogeneous PWR core problem without fuel-coolant homogenization in each pin cell. Two approaches have been investigated for the treatment of the nodal heterogeneity in this paper. To concentrate on spatial heterogeneity, diffusion approximation was adopted for the angular variable in neutron transport equation. To provide demonstrative numerical results, the codes in this paper were developed in slab geometry. The first method, named as function expansion (FE) method, expands nodal flux by orthogonal polynomials and the nodal cross sections are also expressed as spatial depended functions. The second path, named as finite sub-element (FS) method, takes advantage of the finite-element method by dividing each node into numbers of homogeneous sub-elements and expanding nodal flux into the combination of linear sub-element trial functions. Numerical tests have been carried out to evaluate the ability of the two nodal (coarse-mesh) heterogeneous VNMs by comparing with the fine-mesh homogeneous VNM. It has been demonstrated that both heterogeneous approaches can handle heterogeneous nodes. The FE method is good at continuous-changing heterogeneity as in the MSR core problem, while the FS method is good at discontinuous-changing heterogeneity such as the PWR pin-by-pin problem and heterogeneous PWR core

  14. Implications of inaccurate clinical nodal staging in pancreatic adenocarcinoma.

    Science.gov (United States)

    Swords, Douglas S; Firpo, Matthew A; Johnson, Kirsten M; Boucher, Kenneth M; Scaife, Courtney L; Mulvihill, Sean J

    2017-07-01

    Many patients with stage I-II pancreatic adenocarcinoma do not undergo resection. We hypothesized that (1) clinical staging underestimates nodal involvement, causing stage IIB to have a greater percent of resected patients and (2) this stage-shift causes discrepancies in observed survival. The Surveillance, Epidemiology, and End Results (SEER) research database was used to evaluate cause-specific survival in patients with pancreatic adenocarcinoma from 2004-2012. Survival was compared using the log-rank test. Single-center data on 105 patients who underwent resection of pancreatic adenocarcinoma without neoadjuvant treatment were used to compare clinical and pathologic nodal staging. In SEER data, medium-term survival in stage IIB was superior to IB and IIA, with median cause-specific survival of 14, 9, and 11 months, respectively (P < .001). Seventy-two percent of stage IIB patients underwent resection vs 28% in IB and 36% in IIA (P < .001). In our institutional data, 12.4% of patients had clinical evidence of nodal involvement vs 69.5% by pathologic staging (P < .001). Among clinical stage IA-IIA patients, 71.6% had nodal involvement by pathologic staging. Both SEER and institutional data support substantial underestimation of nodal involvement by clinical staging. This finding has implications in decisions regarding neoadjuvant therapy and analysis of outcomes in the absence of pathologic staging. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Nodal methods for problems in fluid mechanics and neutron transport

    International Nuclear Information System (INIS)

    Azmy, Y.Y.

    1985-01-01

    A new high-accuracy, coarse-mesh, nodal integral approach is developed for the efficient numerical solution of linear partial differential equations. It is shown that various special cases of this general nodal integral approach correspond to several high efficiency nodal methods developed recently for the numerical solution of neutron diffusion and neutron transport problems. The new approach is extended to the nonlinear Navier-Stokes equations of fluid mechanics; its extension to these equations leads to a new computational method, the nodal integral method which is implemented for the numerical solution of these equations. Application to several test problems demonstrates the superior computational efficiency of this new method over previously developed methods. The solutions obtained for several driven cavity problems are compared with the available experimental data and are shown to be in very good agreement with experiment. Additional comparisons also show that the coarse-mesh, nodal integral method results agree very well with the results of definitive ultra-fine-mesh, finite-difference calculations for the driven cavity problem up to fairly high Reynolds numbers

  16. Predictive factors for perioperative blood transfusion in neck dissection.

    Science.gov (United States)

    Abu-Ghanem, Sara; Warshavsky, Anton; Carmel, Narin-Nard; Abu-Ghanem, Yasmin; Abergel, Avraham; Fliss, Dan M; Yehuda, Moshe

    2016-04-01

    There is growing interest in reducing the exposure of patients to allogeneic blood transfusions by lowering preoperative cross-matched blood ordering and adopting alternative practices, such as autologous blood donations. Our aim was to investigate the predictors for perioperative blood transfusion (PBT) in head and neck cancer patients undergoing neck dissection (ND). Retrospective cohort study. Retrospective observational study. All patients who underwent ND between January 2011 and August 2014. The primary outcome measure was PBT. Predictors tested included: gender, age, American Society of Anesthesiologists comorbidity score, Charlson comorbidity index, preoperative hemoglobin level, head and neck primary tumor location, tumor and nodal staging, side and laterality of ND, central versus lateral ND, elective ND, preoperative chemotherapy/radiotherapy/I(131) therapy, history of previous ND, other surgical procedures in addition to the ND, bone resection, use and type of reconstruction, and the use of bony free flap reconstruction. Twenty-one preoperative and operative variables were tested for an association with PBT using univariate and multivariate analyses. Multivariate analysis found only the following three predictors to be significantly associated with PBT in patients undergoing ND: low preoperative hemoglobin level, advanced N stage, and concurrent reconstructive surgery. Evaluation of specific risk factors for predicting the need for PBT prior to neck dissection may be helpful in identifying the head and neck cancer patients in whom preoperative ordering of cross-matched blood is required or who could benefit from alternative means, such as preoperative autologous blood donation. 4. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  17. Analytic function expansion nodal method for nuclear reactor core design

    International Nuclear Information System (INIS)

    Noh, Hae Man

    1995-02-01

    In most advanced nodal methods the transverse integration is commonly used to reduce the multi-dimensional diffusion equation into equivalent one- dimensional diffusion equations when derving the nodal coupling equations. But the use of the transverse integration results in some limitations. The first limitation is that the transverse leakage term which appears in the transverse integration procedure must be appropriately approximated. The second limitation is that the one-dimensional flux shapes in each spatial direction resulted from the nodal calculation are not accurate enough to be directly used in reconstructing the pinwise flux distributions. Finally the transverse leakage defined for a non-rectangular node such as a hexagonal node or a triangular node is too complicated to be easily handled and may contain non-physical singular terms of step-function and delta-function types. In this thesis, the Analytic Function Expansion Nodal (AFEN) method and its two variations : the Polynomial Expansion Nodal (PEN) method and the hybrid of the AFEN and PEN methods, have been developed to overcome the limitations of the transverse integration procedure. All of the methods solve the multidimensional diffusion equation without the transverse integration. The AFEN method which we believe is the major contribution of this study to the reactor core analysis expands the homogeneous flux distributions within a node in non-separable analytic basis functions satisfying the neutron diffusion equations at any point of the node and expresses the coefficients of the flux expansion in terms of the nodal unknowns which comprise a node-average flux, node-interface fluxes, and corner-point fluxes. Then, the nodal coupling equations composed of the neutron balance equations, the interface current continuity equations, and the corner-point leakage balance equations are solved iteratively to determine all the nodal unknowns. Since the AFEN method does not use the transverse integration in

  18. On the Nodal Lines of Eisenstein Series on Schottky Surfaces

    Science.gov (United States)

    Jakobson, Dmitry; Naud, Frédéric

    2017-04-01

    On convex co-compact hyperbolic surfaces {X=Γ backslash H2}, we investigate the behavior of nodal curves of real valued Eisenstein series {F_λ(z,ξ)}, where {λ} is the spectral parameter, {ξ} the direction at infinity. Eisenstein series are (non-{L^2}) eigenfunctions of the Laplacian {Δ_X} satisfying {Δ_X F_λ=(1/4+λ^2)F_λ}. As {λ} goes to infinity (the high energy limit), we show that, for generic {ξ}, the number of intersections of nodal lines with any compact segment of geodesic grows like {λ}, up to multiplicative constants. Applications to the number of nodal domains inside the convex core of the surface are then derived.

  19. A computational study of nodal-based tetrahedral element behavior.

    Energy Technology Data Exchange (ETDEWEB)

    Gullerud, Arne S.

    2010-09-01

    This report explores the behavior of nodal-based tetrahedral elements on six sample problems, and compares their solution to that of a corresponding hexahedral mesh. The problems demonstrate that while certain aspects of the solution field for the nodal-based tetrahedrons provide good quality results, the pressure field tends to be of poor quality. Results appear to be strongly affected by the connectivity of the tetrahedral elements. Simulations that rely on the pressure field, such as those which use material models that are dependent on the pressure (e.g. equation-of-state models), can generate erroneous results. Remeshing can also be strongly affected by these issues. The nodal-based test elements as they currently stand need to be used with caution to ensure that their numerical deficiencies do not adversely affect critical values of interest.

  20. A theoretical study on a convergence problem of nodal methods

    Energy Technology Data Exchange (ETDEWEB)

    Shaohong, Z.; Ziyong, L. [Shanghai Jiao Tong Univ., 1954 Hua Shan Road, Shanghai, 200030 (China); Chao, Y. A. [Westinghouse Electric Company, P. O. Box 355, Pittsburgh, PA 15230-0355 (United States)

    2006-07-01

    The effectiveness of modern nodal methods is largely due to its use of the information from the analytical flux solution inside a homogeneous node. As a result, the nodal coupling coefficients depend explicitly or implicitly on the evolving Eigen-value of a problem during its solution iteration process. This poses an inherently non-linear matrix Eigen-value iteration problem. This paper points out analytically that, whenever the half wave length of an evolving node interior analytic solution becomes smaller than the size of that node, this non-linear iteration problem can become inherently unstable and theoretically can always be non-convergent or converge to higher order harmonics. This phenomenon is confirmed, demonstrated and analyzed via the simplest 1-D problem solved by the simplest analytic nodal method, the Analytic Coarse Mesh Finite Difference (ACMFD, [1]) method. (authors)

  1. Comparison of nodal staging with lean body mass based and with total body weight based in lung cancer

    International Nuclear Information System (INIS)

    Lee, H. Y.; Chung, J. K.; Kang, W. J.; So, Y.; Lee, D. S.; Lee, M. C.

    2004-01-01

    The standardized uptake (SUV) is semiquantitative evaluation parameter in positron emission tomography (PET). But there is no consensus about the application or process of SUV measurement. In this study, we used measured lean body mass (LBM) and total weight for application in SUV measurement. Also we compared the each nodal staging with SUV between measured LBM, and total weight, in non small cell lung cancer (NSCLC). Total 21 patients with lung cancer were enrolled (M:F=17:4, age 45[+-]8 years). PET-CT was done before operation with Gemini (Philips, Milpitas, U.S.). Each image was reconstructed twice with measured weight and lean body mass. Maximum SUVs of 103 dissected lymph nodes were measured and compared with histological result. For the deciding on the cut off value, receiver operating characteristic (ROC) analysis was done. 14 lymph nodes in the 103 dissected lymph nodes were metastatic lesions. From the ROC analysis, the cut off value of SUV was 1.7 with measured LBM and 2.3 with total weight. With measured LBM, Sensitivity and specificity were 92.5%. 78.2% and area under curve was 0.881. With total weight, sensitivity and specificity was 92.5% and 77%, Area under curve was 0.859. The normalization of SUV could be done with measured LBM. With the normalization of SUV with LBM, the nodal staging of NSCLC using SUV could be more accurate than using total weight in the reconstruction and measurement of SUV for lymph node lesions

  2. Super-nodal methods for space-time kinetics

    Science.gov (United States)

    Mertyurek, Ugur

    The purpose of this research has been to develop an advanced Super-Nodal method to reduce the run time of 3-D core neutronics models, such as in the NESTLE reactor core simulator and FORMOSA nuclear fuel management optimization codes. Computational performance of the neutronics model is increased by reducing the number of spatial nodes used in the core modeling. However, as the number of spatial nodes decreases, the error in the solution increases. The Super-Nodal method reduces the error associated with the use of coarse nodes in the analyses by providing a new set of cross sections and ADFs (Assembly Discontinuity Factors) for the new nodalization. These so called homogenization parameters are obtained by employing consistent collapsing technique. During this research a new type of singularity, namely "fundamental mode singularity", is addressed in the ANM (Analytical Nodal Method) solution. The "Coordinate Shifting" approach is developed as a method to address this singularity. Also, the "Buckling Shifting" approach is developed as an alternative and more accurate method to address the zero buckling singularity, which is a more common and well known singularity problem in the ANM solution. In the course of addressing the treatment of these singularities, an effort was made to provide better and more robust results from the Super-Nodal method by developing several new methods for determining the transverse leakage and collapsed diffusion coefficient, which generally are the two main approximations in the ANM methodology. Unfortunately, the proposed new transverse leakage and diffusion coefficient approximations failed to provide a consistent improvement to the current methodology. However, improvement in the Super-Nodal solution is achieved by updating the homogenization parameters at several time points during a transient. The update is achieved by employing a refinement technique similar to pin-power reconstruction. A simple error analysis based on the relative

  3. A comparison of Nodal methods in neutron diffusion calculations

    Energy Technology Data Exchange (ETDEWEB)

    Tavron, Barak [Israel Electric Company, Haifa (Israel) Nuclear Engineering Dept. Research and Development Div.

    1996-12-01

    The nuclear engineering department at IEC uses in the reactor analysis three neutron diffusion codes based on nodal methods. The codes, GNOMERl, ADMARC2 and NOXER3 solve the neutron diffusion equation to obtain flux and power distributions in the core. The resulting flux distributions are used for the furl cycle analysis and for fuel reload optimization. This work presents a comparison of the various nodal methods employed in the above codes. Nodal methods (also called Coarse-mesh methods) have been designed to solve problems that contain relatively coarse areas of homogeneous composition. In the nodal method parts of the equation that present the state in the homogeneous area are solved analytically while, according to various assumptions and continuity requirements, a general solution is sought out. Thus efficiency of the method for this kind of problems, is very high compared with the finite element and finite difference methods. On the other hand, using this method one can get only approximate information about the node vicinity (or coarse-mesh area, usually a feel assembly of a 20 cm size). These characteristics of the nodal method make it suitable for feel cycle analysis and reload optimization. This analysis requires many subsequent calculations of the flux and power distributions for the feel assemblies while there is no need for detailed distribution within the assembly. For obtaining detailed distribution within the assembly methods of power reconstruction may be applied. However homogenization of feel assembly properties, required for the nodal method, may cause difficulties when applied to fuel assemblies with many absorber rods, due to exciting strong neutron properties heterogeneity within the assembly. (author).

  4. Nodal spectrum method for solving neutron diffusion equation

    International Nuclear Information System (INIS)

    Sanchez, D.; Garcia, C. R.; Barros, R. C. de; Milian, D.E.

    1999-01-01

    Presented here is a new numerical nodal method for solving static multidimensional neutron diffusion equation in rectangular geometry. Our method is based on a spectral analysis of the nodal diffusion equations. These equations are obtained by integrating the diffusion equation in X, Y directions and then considering flat approximations for the current. These flat approximations are the only approximations that are considered in this method, as a result the numerical solutions are completely free from truncation errors. We show numerical results to illustrate the methods accuracy for coarse mesh calculations

  5. Oddness of least energy nodal solutions on radial domains

    Directory of Open Access Journals (Sweden)

    Christopher Grumiau

    2010-07-01

    Full Text Available In this article, we consider the Lane-Emden problem $$displaylines{ Delta u(x + |{u(x}mathclose|^{p-2}u(x=0, quad hbox{for } xinOmega,cr u(x=0, quad hbox{for } xinpartialOmega, }$$ where $2 < p < 2^{*}$ and $Omega$ is a ball or an annulus in $mathbb{R}^{N}$, $Ngeq 2$. We show that, for p close to 2, least energy nodal solutions are odd with respect to an hyperplane -- which is their nodal surface. The proof ingredients are a constrained implicit function theorem and the fact that the second eigenvalue is simple up to rotations.

  6. Development and validation of a nodal code for core calculation

    International Nuclear Information System (INIS)

    Nowakowski, Pedro Mariano

    2004-01-01

    The code RHENO solves the multigroup three-dimensional diffusion equation using a nodal method of polynomial expansion.A comparative study has been made between this code and present internationals nodal diffusion codes, resulting that the RHENO is up to date.The RHENO has been integrated to a calculation line and has been extend to make burnup calculations.Two methods for pin power reconstruction were developed: modulation and imbedded. The modulation method has been implemented in a program, while the implementation of the imbedded method will be concluded shortly.The validation carried out (that includes experimental data of a MPR) show very good results and calculation efficiency

  7. Nodal algorithm derived from a new variational principle

    International Nuclear Information System (INIS)

    Watson, Fernando V.

    1995-01-01

    As a by-product of the research being carried on by the author on methods of recovering pin power distribution of PWR cores, a nodal algorithm based on a modified variational principle for the two group diffusion equations has been obtained. The main feature of the new algorithm is the low dimensionality achieved by the reduction of the original diffusion equations to a system of algebraic Eigen equations involving the average sources only, instead of sources and interface group currents used in conventional nodal methods. The advantage of this procedure is discussed and results generated by the new algorithm and by a finite difference code are compared. (author). 2 refs, 7 tabs

  8. Nodal approximations in space and time for neutron kinetics

    International Nuclear Information System (INIS)

    Grossman, L.M.; Hennart, J.P.

    2005-01-01

    A general formalism is described of the nodal type in time and space for the neutron kinetics equations. In space, several nodal methods are given of the Raviart-Thomas type (RT0 and RT1), of the Brezzi-Douglas-Marini type (BDM0 and BDM1) and of the Brezzi-Douglas-Fortin-Marini type (BDFM 1). In time, polynomial and analytical approximations are derived. In the analytical case, they are based on the inclusion of an exponential term in the basis function. They can be continuous or discontinuous in time, leading in particular to the well-known Crank-Nicolson, Backward Euler and θ schemes

  9. Regional Nodal Irradiation in Early-Stage Breast Cancer.

    Science.gov (United States)

    Whelan, Timothy J; Olivotto, Ivo A; Parulekar, Wendy R; Ackerman, Ida; Chua, Boon H; Nabid, Abdenour; Vallis, Katherine A; White, Julia R; Rousseau, Pierre; Fortin, Andre; Pierce, Lori J; Manchul, Lee; Chafe, Susan; Nolan, Maureen C; Craighead, Peter; Bowen, Julie; McCready, David R; Pritchard, Kathleen I; Gelmon, Karen; Murray, Yvonne; Chapman, Judy-Anne W; Chen, Bingshu E; Levine, Mark N

    2015-07-23

    Most women with breast cancer who undergo breast-conserving surgery receive whole-breast irradiation. We examined whether the addition of regional nodal irradiation to whole-breast irradiation improved outcomes. We randomly assigned women with node-positive or high-risk node-negative breast cancer who were treated with breast-conserving surgery and adjuvant systemic therapy to undergo either whole-breast irradiation plus regional nodal irradiation (including internal mammary, supraclavicular, and axillary lymph nodes) (nodal-irradiation group) or whole-breast irradiation alone (control group). The primary outcome was overall survival. Secondary outcomes were disease-free survival, isolated locoregional disease-free survival, and distant disease-free survival. Between March 2000 and February 2007, a total of 1832 women were assigned to the nodal-irradiation group or the control group (916 women in each group). The median follow-up was 9.5 years. At the 10-year follow-up, there was no significant between-group difference in survival, with a rate of 82.8% in the nodal-irradiation group and 81.8% in the control group (hazard ratio, 0.91; 95% confidence interval [CI], 0.72 to 1.13; P=0.38). The rates of disease-free survival were 82.0% in the nodal-irradiation group and 77.0% in the control group (hazard ratio, 0.76; 95% CI, 0.61 to 0.94; P=0.01). Patients in the nodal-irradiation group had higher rates of grade 2 or greater acute pneumonitis (1.2% vs. 0.2%, P=0.01) and lymphedema (8.4% vs. 4.5%, P=0.001). Among women with node-positive or high-risk node-negative breast cancer, the addition of regional nodal irradiation to whole-breast irradiation did not improve overall survival but reduced the rate of breast-cancer recurrence. (Funded by the Canadian Cancer Society Research Institute and others; MA.20 ClinicalTrials.gov number, NCT00005957.).

  10. Discontinuous nodal schemes applied to the bidimensional neutron transport equation

    International Nuclear Information System (INIS)

    Delfin L, A.; Valle G, E. Del; Hennart B, J.P.

    1996-01-01

    In this paper several strong discontinuous nodal schemes are described, starting from the one that has only two interpolation parameters per cell to the one having ten. Their application to the spatial discretization of the neutron transport equation in X-Y geometry is also described, giving, for each one of the nodal schemes, the approximation for the angular neutron flux that includes the set of interpolation parameters and the corresponding polynomial space. Numerical results were obtained for several test problems presenting here the problem with the highest degree of difficulty and their comparison with published results 1,2 . (Author)

  11. Spontaneous coronary dissection: case report

    OpenAIRE

    Couto, Gustavo J. Ventura; Deslandes, Alexandre de O.; Santos, Paulo César de Souza; Cruz, Alexandre de Araújo; Saraiva, Roberto Santos

    2007-01-01

    O objetivo do trabalho é demonstrar o caso de um homem de 62 anos, com quadro de dissecção coronariana espontânea, localizada em 1/3 inicial de coronária circunflexa esquerda, tratado cirurgicamente com revascularização miocárdica. A operação realizada com sucesso demonstra, nesse caso, ser o único meio possível de cura.The purpose of the paper is to demonstrate the case of a 62-year-old man, with spontaneous coronary dissection of the left circumflex artery, treated surgically by myocardial ...

  12. Tuberculous Lymphadenitis Mimicking Nodal Metastasis in Follicular Variant Papillary Thyroid Carcinoma.

    Science.gov (United States)

    Yu, Marc Gregory; Atun, Jenny Maureen

    2016-01-01

    Tuberculous (TB) lymphadenitis can mimic cervical node metastasis from papillary thyroid carcinoma (PTC) since the distribution and appearance of affected lymph nodes are similar. We present the case of an asymptomatic 50-year-old Filipino who sought consult for a gradually enlarging anterior neck mass and a single palpable cervical lymph node. Preoperative workup suggested a thyroid malignancy with nodal metastasis. He underwent total thyroidectomy with node dissection where histopathology confirmed follicular variant- (FV-) PTC. Lymph node examination, however, revealed TB lymphadenitis, and the patient was given standard antimycobacterial therapy. This is the first documented case in Southeast Asia, a high TB burden region. This is also the first report involving FV-PTC, which has features between those of conventional PTC and follicular thyroid carcinoma. The case suggests that, in endemic areas, TB should be a differential in the etiology of cervical lymphadenopathy in PTC patients. In developed countries, this differential diagnosis is also valuable because of the increasing incidence of HIV and TB coinfection. Proper preoperative evaluation is important and needs to be highlighted in the formulation of local guidelines.

  13. Tuberculous Lymphadenitis Mimicking Nodal Metastasis in Follicular Variant Papillary Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Marc Gregory Yu

    2016-01-01

    Full Text Available Tuberculous (TB lymphadenitis can mimic cervical node metastasis from papillary thyroid carcinoma (PTC since the distribution and appearance of affected lymph nodes are similar. We present the case of an asymptomatic 50-year-old Filipino who sought consult for a gradually enlarging anterior neck mass and a single palpable cervical lymph node. Preoperative workup suggested a thyroid malignancy with nodal metastasis. He underwent total thyroidectomy with node dissection where histopathology confirmed follicular variant- (FV- PTC. Lymph node examination, however, revealed TB lymphadenitis, and the patient was given standard antimycobacterial therapy. This is the first documented case in Southeast Asia, a high TB burden region. This is also the first report involving FV-PTC, which has features between those of conventional PTC and follicular thyroid carcinoma. The case suggests that, in endemic areas, TB should be a differential in the etiology of cervical lymphadenopathy in PTC patients. In developed countries, this differential diagnosis is also valuable because of the increasing incidence of HIV and TB coinfection. Proper preoperative evaluation is important and needs to be highlighted in the formulation of local guidelines.

  14. Extension of the linear nodal method to large concrete building calculations

    International Nuclear Information System (INIS)

    Childs, R.L.; Rhoades, W.A.

    1985-01-01

    The implementation of the linear nodal method in the TORT code is described, and the results of a mesh refinement study to test the effectiveness of the linear nodal and weighted diamond difference methods available in TORT are presented

  15. The Nodal Location of Metastases in Melanoma Sentinel Lymph Nodes

    DEFF Research Database (Denmark)

    Riber-Hansen, Rikke; Nyengaard, Jens; Hamilton-Dutoit, Stephen

    2009-01-01

    BACKGROUND: The design of melanoma sentinel lymph node (SLN) histologic protocols is based on the premise that most metastases are found in the central parts of the nodes, but the evidence for this belief has never been thoroughly tested. METHODS: The nodal location of melanoma metastases in 149...

  16. Real-time control of power systems using nodal prices

    NARCIS (Netherlands)

    Jokic, A.; Lazar, M.; Bosch, van den P.P.J.

    2009-01-01

    This article presents a novel control scheme for achieving optimal power balancing and congestion management in electrical power systems via nodal prices. We develop a dynamic controller that guarantees economically optimal steady-state operation while respecting all line flow constraints in

  17. Topological transport in Dirac nodal-line semimetals

    Science.gov (United States)

    Rui, W. B.; Zhao, Y. X.; Schnyder, Andreas P.

    2018-04-01

    Topological nodal-line semimetals are characterized by one-dimensional Dirac nodal rings that are protected by the combined symmetry of inversion P and time-reversal T . The stability of these Dirac rings is guaranteed by a quantized ±π Berry phase and their low-energy physics is described by a one-parameter family of (2+1)-dimensional quantum field theories exhibiting the parity anomaly. Here we study the Berry-phase supported topological transport of P T -invariant nodal-line semimetals. We find that small inversion breaking allows for an electric-field-induced anomalous transverse current, whose universal component originates from the parity anomaly. Due to this Hall-like current, carriers at opposite sides of the Dirac nodal ring flow to opposite surfaces when an electric field is applied. To detect the topological currents, we propose a dumbbell device, which uses surface states to filter charges based on their momenta. Suggestions for experiments and device applications are discussed.

  18. Hyoid bone chondrosarcoma with cervical nodal metastasis: A case ...

    African Journals Online (AJOL)

    Background: Hyoid bone chondrosarcoma is a very rare condition. This study presents a case report of low-grade chondrosarcoma of hyoid bone with cervical nodal metastasis. The study also presents preoperative radiological investigations, pathological examination and the follow-up of the case. Case presentation: A 42 ...

  19. Note on the nodal line of the p-Laplacian

    Directory of Open Access Journals (Sweden)

    Abdel R. El Amrouss

    2006-09-01

    Full Text Available In this paper, we prove that the length of the nodal line of the eigenfunctions associated to the second eigenvalue of the problem $$ -Delta_p u = lambda ho (x |u|^{p-2}u quad hbox{in } Omega $$ with the Dirichlet conditions is not bounded uniformly with respect to the weight.

  20. A nodal method based on the response-matrix method

    International Nuclear Information System (INIS)

    Cunha Menezes Filho, A. da; Rocamora Junior, F.D.

    1983-02-01

    A nodal approach based on the Response-Matrix method is presented with the purpose of investigating the possibility of mixing two different allocations in the same problem. It is found that the use of allocation of albedo combined with allocation of direct reflection produces good results for homogeneous fast reactor configurations. (Author) [pt

  1. CRY 1AB trangenic cowpea obtained by nodal electroporation ...

    African Journals Online (AJOL)

    Electroporation-mediated genetic transformation was used to introduce Cry 1 Ab insecticidal gene into cowpea. Nodal buds were electroporated in planta with a plasmid carrying the Cry 1Ab and antibiotic resistance npt II genes driven by a 35S CaMV promoter. T1 seeds derived from electroporated branches were selected ...

  2. Evaluation of Educator & Student Use of & Attitudes toward Dissection & Dissection Alternatives

    Science.gov (United States)

    Osenkowski, Pamela; Green, Che; Tjaden, Anne; Cunniff, Peggy

    2015-01-01

    Animal dissection has been routinely practiced in American biology classrooms for decades. With technological advancements, more states adopting student choice measures, and increased awareness about ethical concerns surrounding dissection, many useful dissection alternatives have been developed. To understand the current use of animal dissection…

  3. 47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

    Science.gov (United States)

    2010-10-01

    ... Service § 101.503 Digital Electronic Message Service Nodal Stations. 10.6 GHz DEMS Nodal Stations may be... 47 Telecommunication 5 2010-10-01 2010-10-01 false Digital Electronic Message Service Nodal Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY...

  4. Medical Students' Attitudinal Changes towards Cadaver Dissection ...

    African Journals Online (AJOL)

    Background: Recently, not only the medical school curriculum but also medical students' attitude towards cadaver-based learning of anatomy has changed. This investigation is therefore designed to analyse students' attitudes towards human cadaveric dissection before and after exposure to dissection. Methods: A ...

  5. Aortic Dissection Type A in Alpine Skiers

    Directory of Open Access Journals (Sweden)

    Thomas Schachner

    2013-01-01

    Full Text Available Patients and Methods. 140 patients with aortic dissection type A were admitted for cardiac surgery. Seventy-seven patients experienced their dissection in the winter season (from November to April. We analyzed cases of ascending aortic dissection associated with alpine skiing. Results. In 17 patients we found skiing-related aortic dissections. Skiers were taller (180 (172–200 cm versus 175 (157–191 cm, and heavier (90 (68–125 kg versus 80 (45–110 kg, than nonskiers. An extension of aortic dissection into the aortic arch, the descending thoracic aorta, and the abdominal aorta was found in 91%, 74%, and 69%, respectively, with no significant difference between skiers and nonskiers. Skiers experienced RCA ostium dissection requiring CABG in 17.6% while this was true for 5% of nonskiers (. Hospital mortality of skiers was 6% versus 13% in nonskiers (. The skiers live at an altitude of 170 (0–853 m.a.s.l. and experience their dissection at 1602 (1185–3105; m.a.s.l. In 82% symptom start was during recreational skiing without any trauma. Conclusion. Skiing associated aortic dissection type A is usually nontraumatic. The persons affected live at low altitudes and practice an outdoor sport at unusual high altitude at cold temperatures. Postoperative outcome is good.

  6. Aortic Dissection Type A in Alpine Skiers

    Science.gov (United States)

    Schachner, Thomas; Fischler, Nikolaus; Dumfarth, Julia; Bonaros, Nikolaos; Krapf, Christoph; Schobersberger, Wolfgang; Grimm, Michael

    2013-01-01

    Patients and Methods. 140 patients with aortic dissection type A were admitted for cardiac surgery. Seventy-seven patients experienced their dissection in the winter season (from November to April). We analyzed cases of ascending aortic dissection associated with alpine skiing. Results. In 17 patients we found skiing-related aortic dissections. Skiers were taller (180 (172–200) cm versus 175 (157–191) cm, P = 0.008) and heavier (90 (68–125) kg versus 80 (45–110) kg, P = 0.002) than nonskiers. An extension of aortic dissection into the aortic arch, the descending thoracic aorta, and the abdominal aorta was found in 91%, 74%, and 69%, respectively, with no significant difference between skiers and nonskiers. Skiers experienced RCA ostium dissection requiring CABG in 17.6% while this was true for 5% of nonskiers (P = 0.086). Hospital mortality of skiers was 6% versus 13% in nonskiers (P = 0.399). The skiers live at an altitude of 170 (0–853) m.a.s.l. and experience their dissection at 1602 (1185–3105; P < 0.001) m.a.s.l. In 82% symptom start was during recreational skiing without any trauma. Conclusion. Skiing associated aortic dissection type A is usually nontraumatic. The persons affected live at low altitudes and practice an outdoor sport at unusual high altitude at cold temperatures. Postoperative outcome is good. PMID:23971024

  7. Beyond Dissection: Innovative Tools for Biology Education.

    Science.gov (United States)

    Larson, Sandra, Ed.

    This catalog lists resources available for classroom use in teaching about anatomy and physiology which are alternatives to dissection. The entries are provided under three main categories: (1) Whole Animal Dissection/Vivisection; (2) Animal Organ or System Anatomy and Physiology; and (3) Other, including animal behavior, biotechnology,…

  8. Squamous cell carcinomas of the soft palate treated with radiation therapy alone or followed by planned neck dissection

    International Nuclear Information System (INIS)

    Erkal, Haldun S.; Serin, Meltem; Amdur, Robert J.; Villaret, Douglas B.; Stringer, Scott P.; Mendenhall, William M.

    2001-01-01

    Purpose: The present study presents the experience at the University of Florida with treatment of unselected patients with carcinomas of the soft palate with radiation therapy (RT) alone or followed by planned neck dissection. Methods and Materials: One hundred seven patients treated with curative intent with RT alone or followed by neck dissection from 1965 to 1996 were included in the study. All patients had follow-up for at least 2 years. No patients were lost to follow-up. Results: Local control rates at 5 years were 86% for T1, 91% for T2, 67% for T3, and 36% for T4 carcinomas. T-stage and overall treatment time significantly affected local control in multivariate analysis. Nodal control rates at 5 years were 86% for N0, 76% for N1, 61% for N2, and 67% for N3 carcinomas. Overall treatment time and planned neck dissection significantly affected nodal control in multivariate analysis. Ultimate local-regional control rates at 5 years were 90% for Stage I, 92% for Stage II, 84% for Stage III, and 60% for Stage IV disease. Overall treatment time and planned neck dissection significantly affected ultimate local-regional control in multivariate analysis. The overall survival rate at 5 years was 42% for all patients. Overall stage, overall treatment time, and planned neck dissection significantly affected overall survival in multivariate analysis. The cause-specific survival rate at 5 years was 70% for all patients. Overall treatment time and planned neck dissection significantly affected cause-specific survival in multivariate analysis. Three patients sustained severe postoperative complications and 3 patients sustained severe late complications. Sixteen patients had synchronous and 14 patients had metachronous carcinomas of the head and neck mucosal sites. Conclusion: For limited carcinomas of the soft palate, RT (alone or followed by planned neck dissection) results in relatively high local-regional control and survival rates. For advanced carcinomas of the soft

  9. Quality of life after planned neck dissection

    International Nuclear Information System (INIS)

    Iwae, Shigemichi; Hirayama, Yuji; Komatsu, Hirokazu

    2009-01-01

    We evaluated the effect of planned neck dissection (PND) after concurrent chemoradiotherapy (CCRT) on quality of life (QOL) by using a self-administered neck dissection questionnaire and an arm abduction test. Subjects are fourteen patients who had undergone CCRT followed by planned selective neck dissection for the treatment of mesopharyngeal and hypopharyngeal cancer. The findings of the survey were compared with thirty-two patients who had undergone CCRT alone. Patients without PND had better scores on measures of pain, constriction, numbness and appearance of the neck, but had no advantage about arm abduction. After PND, the patients who had dissected dominant hand side had lower satisfaction compared with those who had dissected non-dominant hand side. (author)

  10. [Ultrasound dissection in laparoscopic cholecystectomy].

    Science.gov (United States)

    Horstmann, R; Kern, M; Joosten, U; Hohlbach, G

    1993-01-01

    An ultrasound dissector especially developed for laparoscopic surgery was used during laparoscopic cholecystectomy on 34 patients. The ultrasound power, the volume of suction and irrigation could be determined individually at the generator and activated during the operation with a foot pedal. With the dissector it was possible to fragmentate, emulgate and aspirate simultaneously fat tissue as well as infected edematous structures. The cystic artery and cystic duct, small vessels, lymphatic and connective tissue were not damaged. Therefore this system seems to be excellent for the preparation of Calot's trigonum and blunt dissection of the gallbladder out of its bed, particularly in fatty, acute or chronic infected tissue. No complications were observed within the peri- and postoperative period.

  11. Impact of axillary nodal metastases on lymphatic mapping and sentinel lymph node identification rate in patients with early stage breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pelosi, Ettore [Ospedale S. Giovanni Battista, S.C.D.U. Medicina Nucleare 2, Turin (Italy); Universita Torino, Dottorato di Ricerca Radioimmunolocalizzazione dei Tumori Umani, Turin (Italy); Ala, Ada; Bussone, Riccardo [Ospedale S. Giovanni Battista, Reparto di Chirurgia Oncologica 10, Turin (Italy); Bello, Marilena; Douroukas, Anastasios; Varetto, Teresio [Ospedale S. Giovanni Battista, S.C.D.U. Medicina Nucleare 2, Turin (Italy); Migliaretti, Giuseppe [Universita di Torino, Dipartimento di Sanita Pubblica e Microbiologia, Turin (Italy); Berardengo, Ester [Ospedale S. Giovanni Battista, Servizio di Anatomia Patologica 4, Turin (Italy); Bisi, Gianni [Ospedale S. Giovanni Battista, S.C.D.U. Medicina Nucleare 2, Turin (Italy); Universita di Torino, Dipartimento di Medicina Interna, SCDU Medicina Nucleare 2, Turin (Italy)

    2005-08-01

    The aim of this study was to define the impact of the presence of axillary nodal metastases on lymphatic mapping and sentinel lymph node (SLN) identification rate in patients with early breast cancer. Two hundred and forty-six lymphatic mapping procedures were performed with both labelled nanocolloid and blue dye, followed by SLN biopsy and/or complete axillary dissection. The following parameters were recorded: patient's age, tumour laterality and location, tumour size, tumour histology, tumour stage, tumour grade, lymphovascular invasion, radiotracer injection site (subdermal-peritumoural/peri-areolar), SLN visualisation at lymphoscintigraphy, SLN metastases (presence/absence, size) and other axillary metastases (presence/absence, number). Discriminant analysis was used to analyse the data. SLNs were identified by labelled nanocolloid alone in 94.7% of tumours, by blue dye alone in 93.5% and by the combined technique in 99.2%. Discriminant analysis showed the gamma probe SLN identification rate to be significantly limited by the presence of axillary nodal metastases. In particular, the size of SLN metastases and the number of other axillary metastases were the most important variables in reducing the gamma probe SLN identification rate (p=0.004 and p=0.002, respectively). On the other hand, high tumour grade was the only parameter limiting the blue dye SLN identification rate. The accuracy of lymphatic mapping with labelled nanocolloid is limited by the presence of axillary nodal metastases, and particularly by the degree of SLN tumoural invasion and the presence and number of other axillary nodal metastases. Neither of these elements seems to interfere with the blue dye identification rate. The combination of the two tracers maximises the SLN identification rate. (orig.)

  12. Impact of axillary nodal metastases on lymphatic mapping and sentinel lymph node identification rate in patients with early stage breast cancer

    International Nuclear Information System (INIS)

    Pelosi, Ettore; Ala, Ada; Bussone, Riccardo; Bello, Marilena; Douroukas, Anastasios; Varetto, Teresio; Migliaretti, Giuseppe; Berardengo, Ester; Bisi, Gianni

    2005-01-01

    The aim of this study was to define the impact of the presence of axillary nodal metastases on lymphatic mapping and sentinel lymph node (SLN) identification rate in patients with early breast cancer. Two hundred and forty-six lymphatic mapping procedures were performed with both labelled nanocolloid and blue dye, followed by SLN biopsy and/or complete axillary dissection. The following parameters were recorded: patient's age, tumour laterality and location, tumour size, tumour histology, tumour stage, tumour grade, lymphovascular invasion, radiotracer injection site (subdermal-peritumoural/peri-areolar), SLN visualisation at lymphoscintigraphy, SLN metastases (presence/absence, size) and other axillary metastases (presence/absence, number). Discriminant analysis was used to analyse the data. SLNs were identified by labelled nanocolloid alone in 94.7% of tumours, by blue dye alone in 93.5% and by the combined technique in 99.2%. Discriminant analysis showed the gamma probe SLN identification rate to be significantly limited by the presence of axillary nodal metastases. In particular, the size of SLN metastases and the number of other axillary metastases were the most important variables in reducing the gamma probe SLN identification rate (p=0.004 and p=0.002, respectively). On the other hand, high tumour grade was the only parameter limiting the blue dye SLN identification rate. The accuracy of lymphatic mapping with labelled nanocolloid is limited by the presence of axillary nodal metastases, and particularly by the degree of SLN tumoural invasion and the presence and number of other axillary nodal metastases. Neither of these elements seems to interfere with the blue dye identification rate. The combination of the two tracers maximises the SLN identification rate. (orig.)

  13. Nodal Clearance Rate and Long-Term Efficacy of Individualized Sentinel Node–Based Pelvic Intensity Modulated Radiation Therapy for High-Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Müller, Arndt-Christian, E-mail: arndt-christian.mueller@med.uni-tuebingen.de [Department of Radiation Oncology, Eberhard Karls University, Tübingen (Germany); Eckert, Franziska; Paulsen, Frank; Zips, Daniel [Department of Radiation Oncology, Eberhard Karls University, Tübingen (Germany); Stenzl, Arnulf; Schilling, David [Department of Urology, Eberhard Karls University, Tübingen (Germany); Alber, Markus [Department of Oncology, Aarhus University, Aarhus (Denmark); Bares, Roland [Department of Nuclear Medicine and Clinical Molecular Imaging, Eberhard Karls University, Tübingen (Germany); Martus, Peter [Institute for Clinical Epidemiology and Applied Biometry, Eberhard Karls University, Tübingen (Germany); Weckermann, Dorothea [Department of Urology, Klinikum Augsburg, Augsburg (Germany); Belka, Claus; Ganswindt, Ute [Department of Radiation Oncology, Ludwig-Maximilians-University, Munich (Germany)

    2016-02-01

    Purpose: To assess the efficacy of individual sentinel node (SN)-guided pelvic intensity modulated radiation therapy (IMRT) by determining nodal clearance rate [(n expected nodal involvement − n observed regional recurrences)/n expected nodal involvement] in comparison with surgically staged patients. Methods and Materials: Data on 475 high-risk prostate cancer patients were examined. Sixty-one consecutive patients received pelvic SN-based IMRT (5 × 1.8 Gy/wk to 50.4 Gy [pelvic nodes + individual SN] and an integrated boost with 5 × 2.0 Gy/wk to 70.0 Gy to prostate + [base of] seminal vesicles) and neo-/adjuvant long-term androgen deprivation therapy; 414 patients after SN–pelvic lymph node dissection were used to calculate the expected nodal involvement rate for the radiation therapy sample. Biochemical control and overall survival were estimated for the SN-IMRT patients using the Kaplan-Meier method. The expected frequency of nodal involvement in the radiation therapy group was estimated by imputing frequencies of node-positive patients in the surgical sample to the pattern of Gleason, prostate-specific antigen, and T category in the radiation therapy sample. Results: After a median follow-up of 61 months, 5-year OS after SN-guided IMRT reached 84.4%. Biochemical control according to the Phoenix definition was 73.8%. The nodal clearance rate of SN-IMRT reached 94%. Retrospective follow-up evaluation is the main limitation. Conclusions: Radiation treatment of pelvic nodes individualized by inclusion of SNs is an effective regional treatment modality in high-risk prostate cancer patients. The pattern of relapse indicates that the SN-based target volume concept correctly covers individual pelvic nodes. Thus, this SN-based approach justifies further evaluation, including current dose-escalation strategies to the prostate in a larger prospective series.

  14. Perceptions of cadaveric dissection in anatomy teaching.

    Science.gov (United States)

    Naz, Saima; Nazir, Ghazala; Iram, Samia; Mohammad, Malik; Umair; Qari, Iftikhar Hussain; Mohammad, Shaheen

    2011-01-01

    Anatomy professors world over are lamenting about medical students' lack of interest in dissections and its diminishing utilisation in medical studies. The objective of our study was to find out the reasons why some of the Pakistani medical students were avoiding dissections. We conducted this study in 5 medical colleges of Pakistan from Dec 2010-Oct 2011. Questionnaires were prepared and administered to more than 500 Pakistani medical students, at least 6 months after their first cadaver dissecting session. Mostly 1st and 2nd year medical students participated in this study. Around 43% students have actually performed dissections in some form, whereas around 57% had never touched the cadaver. Further evaluation of these results revealed that out of 57% of students, 45% avoided dissection due to bad smell of formaldehyde, 37% due to moral/ethical grounds, 22% due to low motivation and respect of human body, 19.4% due to anxiety, 18.6% due to religious reason, 16% due to fear, asthma and emotional reaction, 9.4% due to toxic chemical, 8.6% due to laziness and 7% due to nightmares. In spite of availability of required number of cadavers in all 5 medical colleges and a clear realisation amongst the students that dissecting cadaver is an effective way of learning anatomy; majority of students were not very keen and had therefore not performed dissection even once.

  15. New procedure for criticality search using coarse mesh nodal methods

    International Nuclear Information System (INIS)

    Pereira, Wanderson F.; Silva, Fernando C. da; Martinez, Aquilino S.

    2011-01-01

    The coarse mesh nodal methods have as their primary goal to calculate the neutron flux inside the reactor core. Many computer systems use a specific form of calculation, which is called nodal method. In classical computing systems that use the criticality search is made after the complete convergence of the iterative process of calculating the neutron flux. In this paper, we proposed a new method for the calculation of criticality, condition which will be over very iterative process of calculating the neutron flux. Thus, the processing time for calculating the neutron flux was reduced by half compared with the procedure developed by the Nuclear Engineering Program of COPPE/UFRJ (PEN/COPPE/UFRJ). (author)

  16. New procedure for criticality search using coarse mesh nodal methods

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wanderson F.; Silva, Fernando C. da; Martinez, Aquilino S., E-mail: wneto@con.ufrj.b, E-mail: fernando@con.ufrj.b, E-mail: Aquilino@lmp.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2011-07-01

    The coarse mesh nodal methods have as their primary goal to calculate the neutron flux inside the reactor core. Many computer systems use a specific form of calculation, which is called nodal method. In classical computing systems that use the criticality search is made after the complete convergence of the iterative process of calculating the neutron flux. In this paper, we proposed a new method for the calculation of criticality, condition which will be over very iterative process of calculating the neutron flux. Thus, the processing time for calculating the neutron flux was reduced by half compared with the procedure developed by the Nuclear Engineering Program of COPPE/UFRJ (PEN/COPPE/UFRJ). (author)

  17. The variational nodal method: history and recent accomplishments

    International Nuclear Information System (INIS)

    Lewis, E.E.

    2004-01-01

    The variational nodal method combines spherical harmonics expansions in angle with hybrid finite element techniques is space to obtain multigroup transport response matrix algorithms applicable to both deep penetration and reactor core physics problems. This survey briefly recounts the method's history and reviews its capabilities. The variational basis for the approach is presented and two methods for obtaining discretized equations in the form of response matrices are detailed. The first is that contained the widely used VARIANT code, while the second incorporates newly developed integral transport techniques into the variational nodal framework. The two approaches are combined with a finite sub element formulation to treat heterogeneous nodes. Applications are presented for both a deep penetration problem and to an OECD benchmark consisting of LWR MOX fuel assemblies. Ongoing work is discussed. (Author)

  18. Radiological signs of extra nodal abdominal involvements in lymphoma

    International Nuclear Information System (INIS)

    Carro, A.I.; Alegre, N.; Cervera, J.L.; Montero, A.I.

    1998-01-01

    To assess abdominal CT images in lymphoma patients for the study of extra nodal abdominal involvement. Ninety-two patients diagnosed as having lymphoma were studied retrospectively. All the patients underwent abdominopelvic CT with oral and intravenous contrast (except in one patient who was allergic). In every case, the diagnosis was confirmed by biopsy or radiological follow-up after treatment had been completed. Fifty-two patients (56.5%) presented infiltration of extra nodal organs. The organs most frequently involved were liver and spleen, followed by the gastrointestinal tract, the musculoskeletal system and the genitourinary tract. The findings in this study coincide with those reported elsewhere with the exception of the splenic involvement the incidence of which was lower in the present series. (Author) 17 refs

  19. On the nodal structure of atomic and molecular Wigner functions

    International Nuclear Information System (INIS)

    Dahl, J.P.; Schmider, H.

    1996-01-01

    In previous work on the phase-space representation of quantum mechanics, we have presented detailed pictures of the electronic one-particle reduced Wigner function for atoms and small molecules. In this communication, we focus upon the nodal structure of the function. On the basis of the simplest systems, we present an expression which relates the oscillatory decay of the Wigner function solely to the dot product of the position and momentum vector, if both arguments are large. We then demonstrate the regular behavior of nodal patterns for the larger systems. For the molecular systems, an argument analogous to the open-quotes bond-oscillatory principleclose quotes for momentum densities links the nuclear framework to an additional oscillatory term in momenta parallel to bonds. It is shown that these are visible in the Wigner function in terms of characteristic nodes

  20. An alternative solver for the nodal expansion method equations - 106

    International Nuclear Information System (INIS)

    Carvalho da Silva, F.; Carlos Marques Alvim, A.; Senra Martinez, A.

    2010-01-01

    An automated procedure for nuclear reactor core design is accomplished by using a quick and accurate 3D nodal code, aiming at solving the diffusion equation, which describes the spatial neutron distribution in the reactor. This paper deals with an alternative solver for nodal expansion method (NEM), with only two inner iterations (mesh sweeps) per outer iteration, thus having the potential to reduce the time required to calculate the power distribution in nuclear reactors, but with accuracy similar to the ones found in conventional NEM. The proposed solver was implemented into a computational system which, besides solving the diffusion equation, also solves the burnup equations governing the gradual changes in material compositions of the core due to fuel depletion. Results confirm the effectiveness of the method for practical purposes. (authors)

  1. Topological and trivial magnetic oscillations in nodal loop semimetals

    Science.gov (United States)

    Oroszlány, László; Dóra, Balázs; Cserti, József; Cortijo, Alberto

    2018-05-01

    Nodal loop semimetals are close descendants of Weyl semimetals and possess a topologically dressed band structure. We argue by combining the conventional theory of magnetic oscillation with topological arguments that nodal loop semimetals host coexisting topological and trivial magnetic oscillations. These originate from mapping the topological properties of the extremal Fermi surface cross sections onto the physics of two dimensional semi-Dirac systems, stemming from merging two massless Dirac cones. By tuning the chemical potential and the direction of magnetic field, a sharp transition is identified from purely trivial oscillations, arising from the Landau levels of a normal two dimensional (2D) electron gas, to a phase where oscillations of topological and trivial origin coexist, originating from 2D massless Dirac and semi-Dirac points, respectively. These could in principle be directly identified in current experiments.

  2. Ischemic stroke associated with radio frequency ablation for nodal reentry

    International Nuclear Information System (INIS)

    Diaz M, Juan C; Duran R, Carlos E; Perafan B, Pablo; Pava M, Luis F

    2010-01-01

    Atrioventricular nodal reentry tachycardia is the most common type of paroxysmal supraventricular tachycardia. In those patients in whom drug therapy is not effective or not desired, radio frequency ablation is an excellent therapeutic method. Although overall these procedures are fast and safe, several complications among which ischemic stroke stands out, have been reported. We present the case of a 41 year old female patient with repetitive episodes of tachycardia due to nodal reentry who was treated with radiofrequency ablation. Immediately after the procedure she presented focal neurologic deficit consistent with ischemic stroke in the right medial cerebral artery territory. Angiography with angioplastia and abxicimab was performed and then tissue plasminogen activator (rtPA) was locally infused, with appropriate clinical and angiographic outcome.

  3. RELAP 4/MOD 6 boiling water nodalization study

    International Nuclear Information System (INIS)

    Sonneck, G.; Pfau, H.

    1985-09-01

    The risk of nuclear steam supply systems is dominated by the core melt accidents. The first step to a realistic assessment of these sequences is the successful prediction of a loss of coolant event in a test loop. One of the codes for that is RELAP 4/MOD 6 and one of the important options in this code is the nodalization. The base of this work is the test LOCA No. 1 FIX II in Studsvik (Sweden) which also served as the OECD International Standard Problem 15. This report discusses the influence of different nodalizations, of different distributions of pressure, water and structural heat as well as of different bubble rise options, break flow coefficients, and heat transfer time steps. The most important result is that a simple RELAP 4/MOD6 model with less than 10 volumes is able to predict an experiment as LOCA No. 1 in FIX II successfully using only a fraction of the usual computing time. (Author)

  4. A nodal model for the simulation of a PWR core

    International Nuclear Information System (INIS)

    Souza Pinto, R. de.

    1981-06-01

    A computer program FORTRAN language was developed to simulate the neutronic and thermal-hydraulic transient behaviour of a PWR reactor core. The reator power is calculated using a point kinectics model with six groups of delayed neutron precursors. The fission product decay heat was considered assuming three effective decay heat groups. A nodal model was employed for the treatment of heat transfer in the fuel rod, with integration of the heat equation by the lumped parameter technique. Axial conduction was neglected. A single-channel nodal model was developed for the thermo-hydrodynamic simulation using mass and energy conservation equations for the control volumes. The effect of the axial pressure variation was neglected. The computer program was tested, with good results, through the simulation of the transient behaviour of postulated accidents in a typical PWR. (Author) [pt

  5. The variational nodal method: some history and recent activity

    International Nuclear Information System (INIS)

    Lewis, E.E.; Smith, M.A.; Palmiotti, G.

    2005-01-01

    The variational nodal method combines spherical harmonics expansions in angle with hybrid finite element techniques in space to obtain multigroup transport response matrix algorithms applicable to a wide variety of reactor physics problems. This survey briefly recounts the method's history and reviews its capabilities. Two methods for obtaining discretized equations in the form of response matrices are compared. The first is that contained the widely used VARIANT code, while the second incorporates more recently developed integral transport techniques into the variational nodal framework. The two approaches are combined with a finite sub-element formulation to treat heterogeneous nodes. Results are presented for application to a deep penetration problem and to an OECD benchmark consisting of LWR Mox fuel assemblies. Ongoing work is discussed. (authors)

  6. Hybrid microscopic depletion model in nodal code DYN3D

    International Nuclear Information System (INIS)

    Bilodid, Y.; Kotlyar, D.; Shwageraus, E.; Fridman, E.; Kliem, S.

    2016-01-01

    Highlights: • A new hybrid method of accounting for spectral history effects is proposed. • Local concentrations of over 1000 nuclides are calculated using micro depletion. • The new method is implemented in nodal code DYN3D and verified. - Abstract: The paper presents a general hybrid method that combines the micro-depletion technique with correction of micro- and macro-diffusion parameters to account for the spectral history effects. The fuel in a core is subjected to time- and space-dependent operational conditions (e.g. coolant density), which cannot be predicted in advance. However, lattice codes assume some average conditions to generate cross sections (XS) for nodal diffusion codes such as DYN3D. Deviation of local operational history from average conditions leads to accumulation of errors in XS, which is referred as spectral history effects. Various methods to account for the spectral history effects, such as spectral index, burnup-averaged operational parameters and micro-depletion, were implemented in some nodal codes. Recently, an alternative method, which characterizes fuel depletion state by burnup and 239 Pu concentration (denoted as Pu-correction) was proposed, implemented in nodal code DYN3D and verified for a wide range of history effects. The method is computationally efficient, however, it has applicability limitations. The current study seeks to improve the accuracy and applicability range of Pu-correction method. The proposed hybrid method combines the micro-depletion method with a XS characterization technique similar to the Pu-correction method. The method was implemented in DYN3D and verified on multiple test cases. The results obtained with DYN3D were compared to those obtained with Monte Carlo code Serpent, which was also used to generate the XS. The observed differences are within the statistical uncertainties.

  7. SPANDOM - source projection analytic nodal discrete ordinates method

    International Nuclear Information System (INIS)

    Kim, Tae Hyeong; Cho, Nam Zin

    1994-01-01

    We describe a new discrete ordinates nodal method for the two-dimensional transport equation. We solve the discrete ordinates equation analytically after the source term is projected and represented in polynomials. The method is applied to two fast reactor benchmark problems and compared with the TWOHEX code. The results indicate that the present method accurately predicts not only multiplication factor but also flux distribution

  8. HEXAN - a hexagonal nodal code for solving the diffusion equation

    International Nuclear Information System (INIS)

    Makai, M.

    1982-07-01

    This report describes the theory of and provides a user's manual for the HEXAN program, which is a nodal program for the solution of the few-group diffusion equation in hexagonal geometry. Based upon symmetry considerations, the theory provides an analytical solution in a homogeneous node. WWER and HTGR test problem solutions are presented. The equivalence of the finite-difference scheme and the response matrix method is proven. The properties of a symmetric node's response matrix are investigated. (author)

  9. Predictors of health-related quality of life in patients treated with neck dissection for head and neck cancer.

    Science.gov (United States)

    Gane, Elise M; McPhail, Steven M; Hatton, Anna L; Panizza, Benedict J; O'Leary, Shaun P

    2017-12-01

    Patients with head and neck cancer can report reduced health-related quality of life several years after treatment. The aim of this study was to identify risk factors for reduced quality of life in patients up to 5 years following neck dissection. This cross-sectional study was conducted at two hospitals in Brisbane, Australia. Patients completed two measures of quality of life: the Neck Dissection Impairment Index (NDII), a region- and disease-specific tool, and the Assessment of Quality of Life-4 Domains, a general tool. Generalised linear modelling was used to determine which demographic and clinical variables were associated with quality of life. The cohort included n = 129 patients (71% male, median age 61, median 3 years since surgery). Positive nodal disease was associated with better quality of life on the NDII [e.g. N2 vs N0 coeff (95% CI) = 22.84 (7.33, 38.37)]. Worse quality of life was associated with adjuvant treatment [e.g. Independent Living domain model: surgery with chemoradiation vs surgery only coeff (95% CI) = -0.11 (-0.22, -0.01)]. Positive nodal disease was associated with better quality of life, which may be a reflection of response shift. Multimodality treatment leads to worse quality of life compared with surgery only.

  10. NOMAD: a nodal microscopic analysis method for nuclear fuel depletion

    International Nuclear Information System (INIS)

    Rajic, H.L.; Ougouag, A.M.

    1987-01-01

    Recently developed assembly homogenization techniques made possible very efficient global burnup calculations based on modern nodal methods. There are two possible ways of modeling the global depletion process: macroscopic and microscopic depletion models. Using a microscopic global depletion approach NOMAD (NOdal Microscopic Analysis Method for Nuclear Fuel Depletion), a multigroup, two- and three-dimensional, multicycle depletion code was devised. The code uses the ILLICO nodal diffusion model. The formalism of the ILLICO methodology is extended to treat changes in the macroscopic cross sections during a depletion cycle without recomputing the coupling coefficients. This results in a computationally very efficient method. The code was tested against a well-known depletion benchmark problem. In this problem a two-dimensional pressurized water reactor is depleted through two cycles. Both cycles were run with 1 x 1 and 2 x 2 nodes per assembly. It is obvious that the one node per assembly solution gives unacceptable results while the 2 x 2 solution gives relative power errors consistently below 2%

  11. Applications of a systematic homogenization theory for nodal diffusion methods

    International Nuclear Information System (INIS)

    Zhang, Hong-bin; Dorning, J.J.

    1992-01-01

    The authors recently have developed a self-consistent and systematic lattice cell and fuel bundle homogenization theory based on a multiple spatial scales asymptotic expansion of the transport equation in the ratio of the mean free path to the reactor characteristics dimension for use with nodal diffusion methods. The mathematical development leads naturally to self-consistent analytical expressions for homogenized diffusion coefficients and cross sections and flux discontinuity factors to be used in nodal diffusion calculations. The expressions for the homogenized nuclear parameters that follow from the systematic homogenization theory (SHT) are different from those for the traditional flux and volume-weighted (FVW) parameters. The calculations summarized here show that the systematic homogenization theory developed recently for nodal diffusion methods yields accurate values for k eff and assembly powers even when compared with the results of a fine mesh transport calculation. Thus, it provides a practical alternative to equivalence theory and GET (Ref. 3) and to simplified equivalence theory, which requires auxiliary fine-mesh calculations for assemblies embedded in a typical environment to determine the discontinuity factors and the equivalent diffusion coefficient for a homogenized assembly

  12. Flow-based market coupling. Stepping stone towards nodal pricing?

    International Nuclear Information System (INIS)

    Van der Welle, A.J.

    2012-07-01

    For achieving one internal energy market for electricity by 2014, market coupling is deployed to integrate national markets into regional markets and ultimately one European electricity market. The extent to which markets can be coupled depends on the available transmission capacities between countries. Since interconnections are congested from time to time, congestion management methods are deployed to divide the scarce available transmission capacities over market participants. For further optimization of the use of available transmission capacities while maintaining current security of supply levels, flow-based market coupling (FBMC) will be implemented in the CWE region by 2013. Although this is an important step forward, important hurdles for efficient congestion management remain. Hence, flow based market coupling is compared to nodal pricing, which is often considered as the most optimal solution from theoretical perspective. In the context of decarbonised power systems it is concluded that advantages of nodal pricing are likely to exceed its disadvantages, warranting further development of FBMC in the direction of nodal pricing.

  13. Combined neck dissection and postoperative radiation therapy in the management of the high-risk neck: a matched-pair analysis

    International Nuclear Information System (INIS)

    Lundahl, Robert E.; Foote, Robert L.; Bonner, James A.; Suman, Vera J.; Lewis, Jean E.; Kasperbauer, Jan L.; McCaffrey, Thomas V.; Olsen, Kerry D.

    1998-01-01

    Purpose: The purpose of this study was to determine the efficacy of postoperative adjuvant radiation therapy with regard to reducing the rate of recurrence in the neck, cancer-related death, and death from any cause in patients with squamous cell carcinoma of the head and neck region metastatic to neck nodes. Methods: This was a retrospective review of patients with pathologically confirmed nodal metastases who underwent neck dissection and postoperative adjuvant radiation therapy for squamous cell carcinoma of the head and neck region. Time to recurrence in the dissected area of the neck, any recurrence in the neck, cancer-related death, and death from any cause were estimated with the Kaplan-Meier method. A matched-pair analysis was performed utilizing a cohort of patients who underwent neck dissection without postoperative radiation therapy. The patients from the two cohorts were matched according to previously reported high-risk features for cancer recurrence and death. Cox hazards models for the matched pairs were used to evaluate the relative risk of subsequent recurrence in the dissected side of the neck, any neck recurrence, cancer-related death, and overall survival. Materials: The medical records and pathologic slides of 95 consecutive patients with pathologically confirmed nodal metastases from squamous cell carcinoma of the head and neck region who underwent neck dissection and postoperative adjuvant radiation therapy between January 1974 and December 1990 were reviewed. Previously published data from 284 patients with squamous cell carcinoma of the head and neck region treated with neck dissection alone between January 1970 and December 1980 were used for a matched-pair analysis. Results: The relative risks for recurrence in the dissected side of the neck, any neck recurrence (dissected neck or delayed undissected neck metastasis), cancer-related death, and death from any cause for patients treated with operation alone relative to those treated with

  14. Animal Rights Groups Target High School Dissection.

    Science.gov (United States)

    Trotter, Andrew

    1992-01-01

    Two groups leading the charge against dissection are People for the Ethical Treatment of Animals (PETA) and the Student Action Corps for Animals (SACA). Protests by student and community members remain the movement's strongest weapon. (MLF)

  15. Dissecting aortic aneurysm in maintenance hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Ounissi M

    2009-01-01

    Full Text Available The dissecting aortic aneurysm (DAA is a rare pathology that may result in fatal outcome. We report follow up of three cases of DAA patients undergoing maintenance hemo-dialysis who were managed conservatively.

  16. Cervical artery dissection following a turbulent flight.

    LENUS (Irish Health Repository)

    Quinn, Colin

    2012-01-31

    BACKGROUND: Cervical artery dissection is a common cause of stroke in young patients without vascular risk factors and may affect the carotid or vertebral arteries. The risk of spontaneous dissection is higher in those with genetic predisposing factors while other cases may be precipitated by an event involving head or neck movement or associated with direct neck trauma. CASE REPORT: We present the case of a previously well young woman with a history of migraine who developed internal carotid artery dissection following a turbulent short-haul commercial flight while restrained using a seatbelt. DISCUSSION: We propose that repetitive flexion-hyperextension neck movements encountered during the flight were the most likely precipitant of carotid artery dissection in this case and review the therapeutic options available.

  17. Spontaneous aortic dissecting hematoma in two dogs.

    Science.gov (United States)

    Boulineau, Theresa Marie; Andrews-Jones, Lydia; Van Alstine, William

    2005-09-01

    This report describes 2 cases of spontaneous aortic dissecting hematoma in young Border Collie and Border Collie crossbred dogs. Histology was performed in one of the cases involving an unusual splitting of the elastin present within the wall of the aorta, consistent with elastin dysplasia as described in Marfan syndrome in humans. The first case involved a young purebred Border Collie that died suddenly and the second case involved a Border Collie crossbred dog that died after a 1-month history of seizures. Gross lesions included pericardial tamponade with dissection of the ascending aorta in the former case and thoracic cavity hemorrhage, mediastinal hematoma, and aortic dissection in the latter. Histologic lesions in the case of the Border Collie crossbred dog included a dissecting hematoma of the ascending aorta with elastin dysplasia and right axillary arterial intimal proliferation.

  18. CT diagnosis of acute aortic dissection

    International Nuclear Information System (INIS)

    Ogawa, Noriko; Kobayashi, Takeshi

    1989-01-01

    Sixteen (47.5%) of 35 patients with acute aortic dissection showed a non-opacified crescent in the aorta on an initial contrast CT. Seven of these 16 patients underwent cineangiography soon after the initial CT, and in all 7 patients, neither an intimal tear nor an intimal flap was obtained. All but one of above 16 patients were followed by CT. Mean duration of follow-up was 9.6 months. In 10 of 15 patients with non-opacified false lumen, the false lumen remained non-opacified until the last examination. Moreover, in 6 of these 10 patients, the false lumen shrunk, and in the other 3, it disappeared completely on follow-up CT. On the other hand, in remaining 5 of these 15 patients who were initially diagnosed to have non-opacified false lumen, the false lumen became opacified and enlarged in size on follow-up CT performed in the first 14 weeks. Moreover, in 4 of these 5 patients, the false lumen became opacified in the only first 6 weeks. No matter how intensive care should be paid at least for the first 6 weeks, it seems that patients with aortic dissection which have non-opacified false lumen had good prognosis in comparison to patients with ordinary aortic dissections which have opacified false lumen. We believe aortic dissection with non-opacified false lumen may consist of two type of aortic dissection, one has no intimal tear, the other has some intimal tears and a thrombosed false lumen. In conclusion, CT is the most useful modality in diagnosing acute aortic dissection. The reasons are the incidence of acute aortic dissection with non-opacified false lumen was high, patients with non-opacified false lumen had good prognosis, and it was difficult to diagnose aortic dissection with non-opacified false lumen by conventional cineangiography and/or DSA. (author)

  19. Counter Traction Makes Endoscopic Submucosal Dissection Easier

    OpenAIRE

    Oyama, Tsuneo

    2012-01-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable co...

  20. Defining the target volume for post-operative radiotherapy after D2 dissection in gastric cancer by CT-based vessel-guided delineation

    International Nuclear Information System (INIS)

    Yoon, Hong In; Chang, Jee Suk; Lim, Joon Seok; Noh, Sung Hoon; Hyung, Woo Jin; An, Ji Yeong; Lee, Yong Chan; Rha, Sun Young; Kim, Kyung Hwan; Koom, Woong Sub

    2013-01-01

    Purpose: To determine the recurrent nodal gross tumor volume (rnGTV) based on CT-guided vascular structure to refine the clinical target volume (CTV) delineation in postoperative radiotherapy for advanced gastric cancer following radical gastrectomy with D2 dissection. Materials and methods: We retrospectively reviewed follow-up images from 91 patients with their first regional recurrence after D2 dissection in stage III gastric cancer with N3 disease. We defined rnGTV as recurrent nodes shown in follow-up CT images, in which one diagnostic radiologist with specialty of gastrointestinal tract investigated. We drew rnGTVs at the equivalent location based on the same vessels of reference comparing CT images to recurrence CT images. Results: We propose vessel-based locations of rnGTVs on CT images with axial and coronal views. We show different patterns of regional recurrence according to the location of primary gastric cancer using CT and digitally reconstructed radiograph (DRR) images. Frequently recurred sites, overlapped by more than five rnGTVs, are depicted in a DRR image. Conclusions: This study suggests vessel-based delineations of rnGTVs on CT images depending on nodal recurrence sites from follow-up images after D2 lymphadenectomy. Our results could help reduce the inter-observer variation of CTV delineation after D2 dissection in gastric cancer

  1. Recurrent post-partum coronary artery dissection

    Directory of Open Access Journals (Sweden)

    Resnic Frederic S

    2010-10-01

    Full Text Available Abstract Coronary artery dissection is a rare but well-described cause for myocardial infarction during the post-partum period. Dissection of multiple coronary arteries is even less frequent. Here we present a case of recurrent post-partum coronary artery dissections. This unusual presentation poses unique problems for management. A 35 year-old female, gravida 3 para 2, presented with myocardial infarction 9 weeks and 3 days post-partum. Cardiac catheterization demonstrated left anterior descending (LAD dissection but an otherwise normal coronary anatomy. The lesion was treated with four everolimus eluting stents. Initially the patient made an unremarkable recovery until ventricular fibrillation arrest occurred on the following day. Unsynchronized cardioversion restored a normal sinus rhythm and repeat catheterization revealed new right coronary artery (RCA dissection. A wire was passed distally, but it was unclear whether this was through the true or false lumen and no stents could be placed. However, improvement of distal RCA perfusion was noted on angiogram. Despite failure of interventional therapy the patient was therefore treated conservatively. Early operation after myocardial infarction has a significantly elevated risk of mortality and the initial dissection had occurred within 24 hours. This strategy proved successful as follow-up transthoracic echocardiography after four months demonstrated a preserved left ventricular ejection fraction of 55-60% without regional wall motion abnormalities. The patient remained asymptomatic from a cardiac point of view.

  2. Magnetic resonance diagnosis of aortic dissection

    International Nuclear Information System (INIS)

    Mukohara, Nobuhiko; Yoshida, Yutaka; Nakamura, Kazuo

    1986-01-01

    Magnetic resonance imaging (MRI) was performed in thirty-one patients with aortic dissection to evaluate its usefulness in diagnosing the site of communicating orifice between the true and false lumens and the presence of retrograde dissection. 1. MRI revealed the site of the entry as a defect in the intimal flap in the images of 12 of 15 patients (80 %). 2. The site of the communicating orifice between the true and false lumens in the abdominal aorta could be determined in six of eight patients (75 %). 3. MRI diagnosis of retrograde dissection was successful in three patients. 4. Cross-sectional analysis of the abdominal aorta based on the location of the true lumen revealed that the celiac and superior mesenteric arteries tended to arise from the true lumen when the latter was situated in the anterior part of the abdominal aorta. The right and left renal arteries arose from the true lumen when it was positioned anterolaterally. In conclusion, MRI was a useful diagnostic method for aortic dissection, especially for determining the site of entry in the thoracic aorta. The changes in signal intensity in the false lumen provided useful information for locating the communicating orifice between the true and false lumens and for diagnosis of retrograde dissection. Cross-sectional analysis of dissection in the abdominal aorta was useful for predicting the branching of the main arteries from the true or false lumen. (author)

  3. The Effect of Animal Dissections on Student Acquisition of Knowledge of and Attitudes toward the Animals Dissected.

    Science.gov (United States)

    McCollum, Terry L.

    A conflict exists over the use of animals in the classroom. One aspect of this use involved the dissection of animals. Animal protection advocates report that dissections constitute abuse of the animals dissected. The advocates state that what is learned by dissection could be more effectively learned by other means. Some science educators state…

  4. Radiotherapy studies and extra-nodal non-Hodgkin lymphomas, progress and challenges

    DEFF Research Database (Denmark)

    Specht, L

    2012-01-01

    Extra-nodal lymphomas may arise in any organ, and different histological subtypes occur in distinct patterns. Prognosis and treatment depend not only on the histological subtype and disease extent, but also on the particular involved extra-nodal organ. The clinical course and response to treatment...... for the more common extra-nodal organs, e.g. stomach, Waldeyer's ring, skin and brain, are fairly well known and show significant variation. A few randomised trials have been carried out testing the role of radiotherapy in these lymphomas. However, for most extra-nodal lymphomas, randomised trials have...... not been carried out, and treatment decisions are made on small patient series and extrapolations from nodal lymphomas. Hopefully, wide international collaboration will make controlled clinical trials possible in the less common extra-nodal lymphomas. Modern highly conformal radiotherapy allows better...

  5. Solution and study of nodal neutron transport equation applying the LTSN-DiagExp method

    International Nuclear Information System (INIS)

    Hauser, Eliete Biasotto; Pazos, Ruben Panta; Vilhena, Marco Tullio de; Barros, Ricardo Carvalho de

    2003-01-01

    In this paper we report advances about the three-dimensional nodal discrete-ordinates approximations of neutron transport equation for Cartesian geometry. We use the combined collocation method of the angular variables and nodal approach for the spatial variables. By nodal approach we mean the iterated transverse integration of the S N equations. This procedure leads to the set of one-dimensional averages angular fluxes in each spatial variable. The resulting system of equations is solved with the LTS N method, first applying the Laplace transform to the set of the nodal S N equations and then obtained the solution by symbolic computation. We include the LTS N method by diagonalization to solve the nodal neutron transport equation and then we outline the convergence of these nodal-LTS N approximations with the help of a norm associated to the quadrature formula used to approximate the integral term of the neutron transport equation. (author)

  6. Five-point form of the nodal diffusion method and comparison with finite-difference

    International Nuclear Information System (INIS)

    Azmy, Y.Y.

    1988-01-01

    Nodal Methods have been derived, implemented and numerically tested for several problems in physics and engineering. In the field of nuclear engineering, many nodal formalisms have been used for the neutron diffusion equation, all yielding results which were far more computationally efficient than conventional Finite Difference (FD) and Finite Element (FE) methods. However, not much effort has been devoted to theoretically comparing nodal and FD methods in order to explain the very high accuracy of the former. In this summary we outline the derivation of a simple five-point form for the lowest order nodal method and compare it to the traditional five-point, edge-centered FD scheme. The effect of the observed differences on the accuracy of the respective methods is established by considering a simple test problem. It must be emphasized that the nodal five-point scheme derived here is mathematically equivalent to previously derived lowest order nodal methods. 7 refs., 1 tab

  7. A Nodal-independent and tissue-intrinsic mechanism controls heart-looping chirality

    Science.gov (United States)

    Noël, Emily S.; Verhoeven, Manon; Lagendijk, Anne Karine; Tessadori, Federico; Smith, Kelly; Choorapoikayil, Suma; den Hertog, Jeroen; Bakkers, Jeroen

    2013-11-01

    Breaking left-right symmetry in bilateria is a major event during embryo development that is required for asymmetric organ position, directional organ looping and lateralized organ function in the adult. Asymmetric expression of Nodal-related genes is hypothesized to be the driving force behind regulation of organ laterality. Here we identify a Nodal-independent mechanism that drives asymmetric heart looping in zebrafish embryos. In a unique mutant defective for the Nodal-related southpaw gene, preferential dextral looping in the heart is maintained, whereas gut and brain asymmetries are randomized. As genetic and pharmacological inhibition of Nodal signalling does not abolish heart asymmetry, a yet undiscovered mechanism controls heart chirality. This mechanism is tissue intrinsic, as explanted hearts maintain ex vivo retain chiral looping behaviour and require actin polymerization and myosin II activity. We find that Nodal signalling regulates actin gene expression, supporting a model in which Nodal signalling amplifies this tissue-intrinsic mechanism of heart looping.

  8. Elsevier Trophoblast Research Award lecture: The multifaceted role of Nodal signaling during mammalian reproduction.

    Science.gov (United States)

    Park, C B; Dufort, D

    2011-03-01

    Nodal, a secreted signaling protein in the transforming growth factor-beta (TGF-β) superfamily, has established roles in vertebrate development. However, components of the Nodal signaling pathway are also expressed at the maternal-fetal interface and have been implicated in many processes of mammalian reproduction. Emerging evidence indicates that Nodal and its extracellular inhibitor Lefty are expressed in the uterus and complex interactions between the two proteins mediate menstruation, decidualization and embryo implantation. Furthermore, several studies have shown that Nodal from both fetal and maternal sources may regulate trophoblast cell fate and facilitate placentation as both embryonic and uterine-specific Nodal knockout mouse strains exhibit disrupted placenta morphology. Here we review the established and prospective roles of Nodal signaling in facilitating successful pregnancy, including recent evidence supporting a potential link to parturition and preterm birth. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Evaluating dissection in the gross anatomy course: Correlation between quality of laboratory dissection and students outcomes.

    Science.gov (United States)

    Nwachukwu, Chika; Lachman, Nirusha; Pawlina, Wojciech

    2015-01-01

    Anatomy learned by active exploration through dissection has many proven benefits including improvement of anatomic knowledge. Decreased laboratory time may affect the quality of dissection and ultimately lower student performance in anatomy translating to lower knowledge acquisition. The aim of this study was to determine whether the quality of students' dissection in teams correlates with their performance in the gross anatomy course. Quality of dissections for each team enrolled in a gross anatomy course at Mayo Medical School was evaluated biweekly using a five-point rubric based on course learning objectives. Assessment of anatomic knowledge was based on sequential laboratory practice practical examination scores, achievements on daily audience response system (ARS) quizzes, and final practical, written, and National Board of Medical Examiners(®) (NBME(®) ) Gross Anatomy and Embryology Subject Examinations. Twelve teams comprising 48 students were included in the study. There was a positive correlation between dissection quality and practice practical examination score (R = 0.83) and a negative correlation between dissection quality and ARS quizzes (R = -0.985). Dissection teams with a passing score on their dissection evaluations (>70%) performed better on their final examinations. Based on an end of course survey, students agreed that dissection evaluations should continue to be a part of the course. This study showed that better quality of dissection was associated with higher scores on practice practical examinations, final practical, written, and NBME examinations. The study demonstrated a positive correlation between dissection evaluations, accompanied by formative feedback during the course, and higher scores on final course assessments. © 2014 American Association of Anatomists.

  10. [Pay attention to the selective lateral pelvic lymph node dissection in mid-low rectal cancer].

    Science.gov (United States)

    Meng, Wenjian; Wang, Ziqiang

    2017-03-25

    Lateral pelvic lymph node metastasis is an important metastatic mode and a major cause of locoregional recurrence of mid-low rectal cancer. Recently, there is an East-West discrepancy in regard to the diagnosis, clinical significance, treatment and prognosis of lateral pelvic lymph node metastasis. In the West, lateral nodal involvement may represent systemic disease and preoperative chemoradiotherapy can sterilize clinically suspected lateral nodes. Thus, in many Western countries, the standard therapy for lower rectal cancer is total mesorectal excision with chemoradiotherapy, and pelvic sidewall dissection is rarely performed. In the East, and Japan in particular, however, there is a positive attitude in regard to lateral pelvic lymph node dissection (LPND). They consider that lateral pelvic lymph node metastasis is as regional metastasis, and the clinically suspected lateral nodes can not be removed by neoadjuvant chemoradiotherapy. The selective LPND after neoadjuvant chemoradiotherapy may be found to be promising treatment for the improvement of therapeutic benefits in these patients. Therefore, the large-scale prospective studies are urgently required to improve selection criteria for LPND and neoadjuvant treatment to prevent overtreatment in the near future. Selective LPND after neoadjuvant treatment based on modern imaging techniques is expected to reduce locoregional recurrence and improve long-term survival in patients with mid-low rectal cancer.

  11. Nodal wear model: corrosion in carbon blast furnace hearths

    International Nuclear Information System (INIS)

    Verdeja, L. F.; Gonzalez, R.; Alfonso, A.; Barbes, M. F.

    2003-01-01

    Criteria developed for the Nodal Wear Model (NWM) were applied to estimate the shape of the corrosion profiles that a blast furnace hearth may acquire during its campaign. Taking into account design of the hearth, the boundary conditions, the characteristics of the refractory materials used and the operation conditions of the blast furnace, simulation of wear profiles with central well, mushroom and elephant foot shape were accomplished. The foundations of the NWM are constructed considering that the corrosion of the refractory is a function of the temperature present at each point (node) of the liquid metal-refractory interface and the corresponding physical and chemical characteristics of the corrosive fluid. (Author) 31 refs

  12. Mechanism of polyuria and natriuresis in atrioventricular nodal tachycardia.

    Science.gov (United States)

    Canepa-Anson, R; Williams, M; Marshall, J; Mitsuoka, T; Lightman, S; Sutton, R

    1984-01-01

    A woman with tachycardia associated with polyuria was investigated. Electrophysiological analysis showed that the tachycardia was an atrioventricular nodal re-entrant tachycardia. Programmed stimulation was then used to provoke and sustain the tachycardia for 40 minutes. Polyuria, with an appreciable increase in free water clearance, was observed. This was associated with reduction in plasma and urinary arginine vasopressin concentrations. Appreciable natriuresis also developed. These results support the hypothesis that the polyuria with increased free water clearance and the natriuresis occurring during sustained tachycardia in man are due to inhibition of secretion of vasopressin and the release of natriuretic factor. PMID:6434116

  13. Approximate Schur complement preconditioning of the lowest order nodal discretizations

    Energy Technology Data Exchange (ETDEWEB)

    Moulton, J.D.; Ascher, U.M. [Univ. of British Columbia, Vancouver, British Columbia (Canada); Morel, J.E. [Los Alamos National Lab., NM (United States)

    1996-12-31

    Particular classes of nodal methods and mixed hybrid finite element methods lead to equivalent, robust and accurate discretizations of 2nd order elliptic PDEs. However, widespread popularity of these discretizations has been hindered by the awkward linear systems which result. The present work exploits this awkwardness, which provides a natural partitioning of the linear system, by defining two optimal preconditioners based on approximate Schur complements. Central to the optimal performance of these preconditioners is their sparsity structure which is compatible with Dendy`s black box multigrid code.

  14. Evaluation of the use of nodal methods for MTR neutronic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Reitsma, F.; Mueller, E.Z.

    1997-08-01

    Although modern nodal methods are used extensively in the nuclear power industry, their use for research reactor analysis has been very limited. The suitability of nodal methods for material testing reactor analysis is investigated with the emphasis on the modelling of the core region (fuel assemblies). The nodal approach`s performance is compared with that of the traditional finite-difference fine mesh approach. The advantages of using nodal methods coupled with integrated cross section generation systems are highlighted, especially with respect to data preparation, simplicity of use and the possibility of performing a great variety of reactor calculations subject to strict time limitations such as are required for the RERTR program.

  15. Nodal line optimization and its application to violin top plate design

    Science.gov (United States)

    Yu, Yonggyun; Jang, In Gwun; Kim, In Kyum; Kwak, Byung Man

    2010-10-01

    In the literature, most problems of structural vibration have been formulated to adjust a specific natural frequency: for example, to maximize the first natural frequency. In musical instruments like a violin; however, mode shapes are equally important because they are related to sound quality in the way that natural frequencies are related to the octave. The shapes of nodal lines, which represent the natural mode shapes, are generally known to have a unique feature for good violins. Among the few studies on mode shape optimization, one typical study addresses the optimization of nodal point location for reducing vibration in a one-dimensional beam structure. However, nodal line optimization, which is required in violin plate design, has not yet been considered. In this paper, the central idea of controlling the shape of the nodal lines is proposed and then applied to violin top plate design. Finite element model for a violin top plate was constructed using shell elements. Then, optimization was performed to minimize the square sum of the displacement of selected nodes located along the target nodal lines by varying the thicknesses of the top plate. We conducted nodal line optimization for the second and the fifth modes together at the same time, and the results showed that the nodal lines obtained match well with the target nodal lines. The information on plate thickness distribution from nodal line optimization would be valuable for tailored trimming of a violin top plate for the given performances.

  16. Time-dependent patterning of the mesoderm and endoderm by Nodal signals in zebrafish

    Directory of Open Access Journals (Sweden)

    Dougan Scott T

    2007-03-01

    Full Text Available Abstract Background The vertebrate body plan is generated during gastrulation with the formation of the three germ layers. Members of the Nodal-related subclass of the TGF-β superfamily induce and pattern the mesoderm and endoderm in all vertebrates. In zebrafish, two nodal-related genes, called squint and cyclops, are required in a dosage-dependent manner for the formation of all derivatives of the mesoderm and endoderm. These genes are expressed dynamically during the blastula stages and may have different roles at different times. This question has been difficult to address because conditions that alter the timing of nodal-related gene expression also change Nodal levels. We utilized a pharmacological approach to conditionally inactivate the ALK 4, 5 and 7 receptors during the blastula stages without disturbing earlier signaling activity. This permitted us to directly examine when Nodal signals specify cell types independently of dosage effects. Results We show that two drugs, SB-431542 and SB-505124, completely block the response to Nodal signals when added to embryos after the mid-blastula transition. By blocking Nodal receptor activity at later stages, we demonstrate that Nodal signaling is required from the mid-to-late blastula period to specify sequentially, the somites, notochord, blood, Kupffer's vesicle, hatching gland, heart, and endoderm. Blocking Nodal signaling at late times prevents specification of cell types derived from the embryo margin, but not those from more animal regions. This suggests a linkage between cell fate and length of exposure to Nodal signals. Confirming this, cells exposed to a uniform Nodal dose adopt progressively more marginal fates with increasing lengths of exposure. Finally, cell fate specification is delayed in squint mutants and accelerated when Nodal levels are elevated. Conclusion We conclude that (1 Nodal signals are most active during the mid-to-late blastula stages, when nodal-related gene

  17. Identification and Management of Iatrogenic Aortocoronary Dissection

    Directory of Open Access Journals (Sweden)

    Shao-Ping Nie, MD, PhD, FESC, FSCAI

    2016-05-01

    Full Text Available Iatrogenic aortocoronary dissection (IACD is a rare but potentially life-threatening complication during coronary catheterizations. Although the incidence was relatively low, the dissection often leads to procedure failure with increased risk of myocardial infarction and death. IACD is mainly caused by disruption of intima at the ostia of left or right coronary artery during interventional procedures, and appears as luminal filling defects or persistence of contrast (“extraluminal cap” or intimal tear outside the coronary lumen. Dissection could disseminate antegradely and lead to subtotal or total occlusion of the coronary lumen. Similarly, it could extend retrogradely into the sinus of Valsalva and cusp, or even the ascending aorta, aortic arch, or descending aorta, leading to hemodynamic collapse. Early identification and prompt management is crucial to the prognosis of patients with IACD. Immediate bail-out stenting should be performed as rapidly as possible in most cases of severe dissection, even when significant propagation has already occurred. Surgery should only be considered when stenting failed to seal the dissection and the patients had hemodynamic compromise.

  18. Exact boundary controllability of nodal profile for quasilinear hyperbolic systems

    CERN Document Server

    Li, Tatsien; Gu, Qilong

    2016-01-01

    This book provides a comprehensive overview of the exact boundary controllability of nodal profile, a new kind of exact boundary controllability stimulated by some practical applications. This kind of controllability is useful in practice as it does not require any precisely given final state to be attained at a suitable time t=T by means of boundary controls, instead it requires the state to exactly fit any given demand (profile) on one or more nodes after a suitable time t=T by means of boundary controls. In this book we present a general discussion of this kind of controllability for general 1-D first order quasilinear hyperbolic systems and for general 1-D quasilinear wave equations on an interval as well as on a tree-like network using a modular-structure construtive method, suggested in LI Tatsien's monograph "Controllability and Observability for Quasilinear Hyperbolic Systems"(2010), and we establish a complete theory on the local exact boundary controllability of nodal profile for 1-D quasilinear hyp...

  19. Nodal Diffusion Burnable Poison Treatment for Prismatic Reactor Cores

    International Nuclear Information System (INIS)

    Ougouag, A.M.; Ferrer, R.M.

    2010-01-01

    The prismatic block version of the High Temperature Reactor (HTR) considered as a candidate Very High Temperature Reactor (VHTR)design may use burnable poison pins in locations at some corners of the fuel blocks (i.e., assembly equivalent structures). The presence of any highly absorbing materials, such as these burnable poisons, within fuel blocks for hexagonal geometry, graphite-moderated High Temperature Reactors (HTRs) causes a local inter-block flux depression that most nodal diffusion-based method have failed to properly model or otherwise represent. The location of these burnable poisons near vertices results in an asymmetry in the morphology of the assemblies (or blocks). Hence the resulting inadequacy of traditional homogenization methods, as these 'spread' the actually local effect of the burnable poisons throughout the assembly. Furthermore, the actual effect of the burnable poison is primarily local with influence in its immediate vicinity, which happens to include a small region within the same assembly as well as similar regions in the adjacent assemblies. Traditional homogenization methods miss this artifact entirely. This paper presents a novel method for treating the local effect of the burnable poison explicitly in the context of a modern nodal method.

  20. Hereditary bone dysplasia with pathological fractures and nodal osteoarthropathy

    International Nuclear Information System (INIS)

    Arendse, Regan; Brink, Paul; Beighton, Peter

    2009-01-01

    A father and daughter both had multiple pathological fractures and nodal osteoarthropathy. The father, aged 50 years, had at least 20 healed fractures of the axial and appendicular skeleton, sustained by minor trauma over his 50-year lifespan, many of which had been surgically fixed prior to his first presentation to us. Fractures of the clavicles, thoracic cage and long bones of the arms and legs, had healed with malalignment and deformity. Healed fractures were complicated by ankylosis of the cervical vertebrae and both elbows. He also had osteoarthritis of the hands, with exuberant osteophytosis, and profound perceptive deafness. His general health was good, his intellect and facies were normal, and his sclerae were white. The daughter, aged 27 years, had sustained at least seven fractures of the axial and appendicular skeleton following trivial injuries, in distribution similar to those of the father. She had also experienced painful swelling of the fingers, which preceded progressive development of nodal osteoarthropathy. Her hearing was normal. In both individuals, biochemical and immunological investigations yielded normal results. It was not possible for molecular studies to be undertaken. Pedigree data were consistent with autosomal dominant transmission, and this disorder appeared to be a previously undocumented heritable skeletal dysplasia. (orig.)

  1. Hereditary bone dysplasia with pathological fractures and nodal osteoarthropathy

    Energy Technology Data Exchange (ETDEWEB)

    Arendse, Regan [University of Stellenbosch, Department of Medicine, Tygerberg Hospital, Stellenbosch (South Africa); University of Cape Town, Division of Rheumatology, Groote Schuur Hospital, Cape Town (South Africa); Brink, Paul [University of Stellenbosch, Department of Medicine, Tygerberg Hospital, Stellenbosch (South Africa); Beighton, Peter [University of Cape Town, Division of Human Genetics, Faculty of Health Sciences, Cape Town (South Africa)

    2009-12-15

    A father and daughter both had multiple pathological fractures and nodal osteoarthropathy. The father, aged 50 years, had at least 20 healed fractures of the axial and appendicular skeleton, sustained by minor trauma over his 50-year lifespan, many of which had been surgically fixed prior to his first presentation to us. Fractures of the clavicles, thoracic cage and long bones of the arms and legs, had healed with malalignment and deformity. Healed fractures were complicated by ankylosis of the cervical vertebrae and both elbows. He also had osteoarthritis of the hands, with exuberant osteophytosis, and profound perceptive deafness. His general health was good, his intellect and facies were normal, and his sclerae were white. The daughter, aged 27 years, had sustained at least seven fractures of the axial and appendicular skeleton following trivial injuries, in distribution similar to those of the father. She had also experienced painful swelling of the fingers, which preceded progressive development of nodal osteoarthropathy. Her hearing was normal. In both individuals, biochemical and immunological investigations yielded normal results. It was not possible for molecular studies to be undertaken. Pedigree data were consistent with autosomal dominant transmission, and this disorder appeared to be a previously undocumented heritable skeletal dysplasia. (orig.)

  2. Dirac Magnon Nodal Loops in Quasi-2D Quantum Magnets.

    Science.gov (United States)

    Owerre, S A

    2017-07-31

    In this report, we propose a new concept of one-dimensional (1D) closed lines of Dirac magnon nodes in two-dimensional (2D) momentum space of quasi-2D quantum magnetic systems. They are termed "2D Dirac magnon nodal-line loops". We utilize the bilayer honeycomb ferromagnets with intralayer coupling J and interlayer coupling J L , which is realizable in the honeycomb chromium compounds CrX 3 (X ≡ Br, Cl, and I). However, our results can also exist in other layered quasi-2D quantum magnetic systems. Here, we show that the magnon bands of the bilayer honeycomb ferromagnets overlap for J L  ≠ 0 and form 1D closed lines of Dirac magnon nodes in 2D momentum space. The 2D Dirac magnon nodal-line loops are topologically protected by inversion and time-reversal symmetry. Furthermore, we show that they are robust against weak Dzyaloshinskii-Moriya interaction Δ DM  magnon edge modes.

  3. Renal Infarction from Type B Aortic Dissection

    Directory of Open Access Journals (Sweden)

    Marit Tweet

    2017-07-01

    Full Text Available History of present illness: A 69-year-old-female with a medical history of hypertension presented to the emergency department (ED complaining of sudden onset of lower back and abdominal pain. Eight hours prior to presentation she reported turning to grab something on another counter and felt a sudden onset sharp pain in her lower back. She began to notice ill-defined abdominal pain, although she denied any shortness of breath, chest pain, numbness, weakness, or urologic symptoms. Her vital signs on presentation to the ED were temperature 36.5˚C, blood pressure 143/88, heart rate 84, respiratory rate 14, and oxygen saturation 93% on room air. On arrival, the patient was in significant discomfort and was rolling on the bed due to pain. Although she appeared to be in moderate distress she had minimal, if any, tenderness on abdominal exam, and only mild left lower back tenderness to palpation. This disconnect between the patient’s apparent discomfort and the lack of physical exam findings prompted the ordering of a computed tomography angiography (CTA of the abdomen/pelvis with greatest suspicion for abdominal aortic aneurysm. Significant findings: Initial abdominal images demonstrated a dissection flap; therefore, a CTA of the chest was also obtained. These images revealed a Stanford type B aortic dissection beginning just distal to the left subclavian artery and extending to the origin of the inferior mesenteric artery. The right renal artery arose from the true lumen of the dissection while the left renal artery arose from the false lumen. This case is interesting as imaging shows the lack of perfusion to the left kidney, residing in the retroperitoneum, which correlates with her non-descript abdominal and left flank pain. Discussion: Aortic dissection is defined as a tear within the wall of the aorta that allows blood to track between intima and media layers. A dissection is classified as Stanford Type A if it involves any portion of the

  4. Diagnostic imaging of acute aortic dissection

    International Nuclear Information System (INIS)

    Ohya, Tohru; Kumazaki, Tatsuo

    1991-01-01

    One hundred and nineteen patients with aortic dissection who underwent diagnostic imaging were reviewed and angiographic findings as well as those of CT were analysed. Thirty eight cases (43.1%) had non-contrast opacified false lumen, the type of which we call 'thrombosed type aortic dissection'. A comparative study of the thrombosed type with the patent type of false lumens was made particularly from the stand point of the characteristic diagnostic imagings (CT and angiography). At the same time, the pitfalls of these imagings in thrombosed type aortic dissection were studied. At the onset the average age of thrombosed type was 62.3 years old, while that of the patent type was 57.3. A statistical significance between the two groups was p<0.05. Thrombosed type in all cases was caused by atherosclerosis, whereas patent type was caused by the Marfan's syndrome in 11 cases. Other clinical findings, such as initial symptoms and blood pressure revealed no significant differences between the two groups. Pre-contrast CT in acute thrombosed type aortic dissection showed 'hyperdense crescent sign' in 89.4%. However, in 3 cases with thrombosed type in which the pre-contrast CT showed 'hyperdense crescent sign' contrast-enhanced CT detected no clear evidence of aortic dissection in the same site. This was due to obscurity induced by contrast medium. Angiographic findings of thrombosed type were classified into 3 groups: normal type, stenosed true lumen type and ulcer-like projection type. The incidence of normal type was estimated to be 48.4%, whereas stenosed true lumen type was 24.2% and ulcer-like projection was 27.7%. The present study concluded that thrombosed type is not rare in acute aortic dissection and contrast-enhanced CT as well as pre-contrast CT, is of great value in diagnosing thrombosed type. 'Hyperdense crescent sign' in pre-contrast CT is characteristic of intramural hematoma. (author)

  5. An electronic instructor for gross anatomy dissection.

    Science.gov (United States)

    Josephson, Eleanor M; Moore, Larry J

    2006-01-01

    Gross anatomy is time consuming to teach and to learn. Because the process of dissection takes up so much student time, assistance in the form of an in-lab instructional DVD program might improve student performance. The DVD could be viewed with a portable device by individual dissection groups at their tables. Groups could dissect at their own pace, with access to step-by-step demonstrations and answers to frequently asked anatomical questions. We created an instructional DVD program demonstrating dissection of the canine ventral neck and thoracic limb. The effect on student exam scores of using the DVD versus not using it was measured in a controlled, two-sample study using incoming first-year veterinary students as volunteers. Volunteers were told the study was of two different dissection methods; the DVD was not specifically mentioned until after the students were separated into two groups (Blue/DVD group and Orange/No DVD group), and then only to volunteers in the Blue group. Except for the DVD, the two groups had the same resources. The difference in scores on an exam given after a single dissection period did not differ sufficiently to conclude that DVD use raised the mean score; however, 73% of the DVD group scored 60% or higher, while only 38% of the No DVD group scored 60% or higher. The difference in mean scores overall was 2.3 points out of a possible 49, suggesting that the DVD helped students, especially those with lower scores, to earn two to three more points than they would have otherwise.

  6. Cervical Artery Dissection and Choosing Appropriate Therapy.

    Science.gov (United States)

    Lau, Jonathan T; Hunt, John S; Bruner, David I; Austin, Andrea L

    2017-08-01

    Cervical artery dissection is a common cause of stroke in young adults. This may result from head and neck trauma; it can also occur spontaneously or secondary to genetic connective tissue or vascular disorders. Neurologic symptoms arise as a result of thromboembolism and hypoperfusion causing cerebral ischemia. We present a case of a previously healthy male who was found to have a cervical internal carotid artery dissection and the decision to use antiplatelet therapy instead of anticoagulation to prevent stroke. Data is lacking regarding the efficacy of one therapy over the other.

  7. Cervical Artery Dissection and Choosing Appropriate Therapy

    Directory of Open Access Journals (Sweden)

    Jonathan T. Lau

    2017-07-01

    Full Text Available Cervical artery dissection is a common cause of stroke in young adults. This may result from head and neck trauma; it can also occur spontaneously or secondary to genetic connective tissue or vascular disorders. Neurologic symptoms arise as a result of thromboembolism and hypoperfusion causing cerebral ischemia. We present a case of a previously healthy male who was found to have a cervical internal carotid artery dissection and the decision to use antiplatelet therapy instead of anticoagulation to prevent stroke. Data is lacking regarding the efficacy of one therapy over the other.

  8. Coronary artery dissection following chest trauma

    Directory of Open Access Journals (Sweden)

    Manoj K Agarwala

    2016-01-01

    Full Text Available Chest trauma has a high rate of mortality. Coronary dissection causing myocardial infarction (MI following blunt chest trauma is rare. We describe the case of an anterior MI following blunt chest trauma. A 39-year-old male was received in our hospital following a motorcycle accident. The patient was asymptomatic before the accident. The patient underwent craniotomy for evacuation of hematoma. He developed severe chest pain and an electrocardiogram (ECG revealed anterior ST segment elevation following surgery. Acute coronary event was medically managed; subsequently, coronary angiogram was performed that showed dissection in the left anterior coronary artery, which was stented.

  9. Assessment of Effect on LBLOCA PCT for Change in Upper Head Nodalization

    International Nuclear Information System (INIS)

    Kang, Dong Gu; Huh, Byung Gil; Yoo, Seung Hun; Bang, Youngseok; Seul, Kwangwon; Cho, Daehyung

    2014-01-01

    In this study, the best estimate plus uncertainty (BEPU) analysis of LBLOCA for original and modified nodalizations was performed, and the effect on LBLOCA PCT for change in upper head nodalization was assessed. In this study, the best estimate plus uncertainty (BEPU) analysis of LBLOCA for original and modified nodalizations was performed, and the effect on LBLOCA PCT for change in upper head nodalization was assessed. It is confirmed that modification of upper head nodalization influences PCT behavior, especially in the reflood phase. In conclusions, the modification of nodalization to reflect design characteristic of upper head temperature should be done to predict PCT behavior accurately in LBLOCA analysis. In the best estimate (BE) method with the uncertainty evaluation, the system nodalization is determined by the comparative studies of the experimental data. Up to now, it was assumed that the temperature of the upper dome in OPR-1000 was close to that of the cold leg. However, it was found that the temperature of the upper head/dome might be a little lower than or similar to that of the hot leg through the evaluation of the detailed design data. Since the higher upper head temperature affects blowdown quenching and peak cladding temperature in the reflood phase, the nodalization for upper head should be modified

  10. LOLA SYSTEM: A code block for nodal PWR simulation. Part. I - Simula-3 Code

    Energy Technology Data Exchange (ETDEWEB)

    Aragones, J M; Ahnert, C; Gomez Santamaria, J; Rodriguez Olabarria, I

    1985-07-01

    Description of the theory and users manual of the SIMULA-3 code, which is part of the core calculation system by nodal theory in one group, called LOLA SYSTEM. SIMULA-3 is the main module of the system, it uses a modified nodal theory, with interface leakages equivalent to the diffusion theory. (Author) 4 refs.

  11. Rules for Phase Shifts of Quantum Oscillations in Topological Nodal-Line Semimetals

    Science.gov (United States)

    Li, Cequn; Wang, C. M.; Wan, Bo; Wan, Xiangang; Lu, Hai-Zhou; Xie, X. C.

    2018-04-01

    Nodal-line semimetals are topological semimetals in which band touchings form nodal lines or rings. Around a loop that encloses a nodal line, an electron can accumulate a nontrivial π Berry phase, so the phase shift in the Shubnikov-de Haas (SdH) oscillation may give a transport signature for the nodal-line semimetals. However, different experiments have reported contradictory phase shifts, in particular, in the WHM nodal-line semimetals (W =Zr /Hf , H =Si /Ge , M =S /Se /Te ). For a generic model of nodal-line semimetals, we present a systematic calculation for the SdH oscillation of resistivity under a magnetic field normal to the nodal-line plane. From the analytical result of the resistivity, we extract general rules to determine the phase shifts for arbitrary cases and apply them to ZrSiS and Cu3 PdN systems. Depending on the magnetic field directions, carrier types, and cross sections of the Fermi surface, the phase shift shows rich results, quite different from those for normal electrons and Weyl fermions. Our results may help explore transport signatures of topological nodal-line semimetals and can be generalized to other topological phases of matter.

  12. Nodal integral method for the neutron diffusion equation in cylindrical geometry

    International Nuclear Information System (INIS)

    Azmy, Y.Y.

    1987-01-01

    The nodal methodology is based on retaining a higher a higher degree of analyticity in the process of deriving the discrete-variable equations compared to conventional numerical methods. As a result, extensive numerical testing of nodal methods developed for a wide variety of partial differential equations and comparison of the results to conventional methods have established the superior accuracy of nodal methods on coarse meshes. Moreover, these tests have shown that nodal methods are more computationally efficient than finite difference and finite-element methods in the sense that they require shorter CPU times to achieve comparable accuracy in the solutions. However, nodal formalisms and the final discrete-variable equations they produce are, in general, more complicated than their conventional counterparts. This, together with anticipated difficulties in applying the transverse-averaging procedure in curvilinear coordinates, has limited the applications of nodal methods, so far, to Cartesian geometry, and with additional approximations to hexagonal geometry. In this paper the authors report recent progress in deriving and numerically implementing a nodal integral method (NIM) for solving the neutron diffusion equation in cylindrical r-z geometry. Also, presented are comparisons of numerical solutions to two test problems with those obtained by the Exterminator-2 code, which indicate the superior accuracy of the nodal integral method solutions on much coarser meshes

  13. LOLA SYSTEM: A code block for nodal PWR simulation. Part. I - Simula-3 Code

    International Nuclear Information System (INIS)

    Aragones, J. M.; Ahnert, C.; Gomez Santamaria, J.; Rodriguez Olabarria, I.

    1985-01-01

    Description of the theory and users manual of the SIMULA-3 code, which is part of the core calculation system by nodal theory in one group, called LOLA SYSTEM. SIMULA-3 is the main module of the system, it uses a modified nodal theory, with interface leakages equivalent to the diffusion theory. (Author) 4 refs

  14. A practical implementation of the higher-order transverse-integrated nodal diffusion method

    International Nuclear Information System (INIS)

    Prinsloo, Rian H.; Tomašević, Djordje I.; Moraal, Harm

    2014-01-01

    Highlights: • A practical higher-order nodal method is developed for diffusion calculations. • The method resolves the issue of the transverse leakage approximation. • The method achieves much superior accuracy as compared to standard nodal methods. • The calculational cost is only about 50% greater than standard nodal methods. • The method is packaged in a module for connection to existing nodal codes. - Abstract: Transverse-integrated nodal diffusion methods currently represent the standard in full core neutronic simulation. The primary shortcoming of this approach is the utilization of the quadratic transverse leakage approximation. This approach, although proven to work well for typical LWR problems, is not consistent with the formulation of nodal methods and can cause accuracy and convergence problems. In this work, an improved, consistent quadratic leakage approximation is formulated, which derives from the class of higher-order nodal methods developed some years ago. Further, a number of iteration schemes are developed around this consistent quadratic leakage approximation which yields accurate node average results in much improved calculational times. The most promising of these iteration schemes results from utilizing the consistent leakage approximation as a correction method to the standard quadratic leakage approximation. Numerical results are demonstrated on a set of benchmark problems and further applied to a realistic reactor problem, particularly the SAFARI-1 reactor, operating at Necsa, South Africa. The final optimal solution strategy is packaged into a standalone module which may simply be coupled to existing nodal diffusion codes

  15. Acute Type II Aortic Dissection with Severe Aortic Regurgitation and Chronic Descending Aortic Dissection in Pregnant Patient with Marfan Syndrome.

    Science.gov (United States)

    Lee, Seok-Soo; Jung, Tae-Eun; Lee, Dong Hyup

    2012-12-01

    Aortic dilatation and dissection are severe complications during pregnancy that can be fatal to both the mother and the fetus. The risks of these complications are especially high in pregnant patients with Marfan syndrome; however, incidents of descending aortic dissection are very rare. This case report involves a successful Bentall procedure for and recovery from a rare aortic dissection in a pregnant Marfan patient who developed acute type II aortic dissection with severe aortic regurgitation and chronic descending aortic dissection immediately after Cesarean section. Regular follow-up will be needed to monitor the descending aortic dissection.

  16. Multidetector-row computed tomography for the preoperative evaluation of axillary nodal status in patients with breast cancer

    International Nuclear Information System (INIS)

    Ogasawara, Yutaka; Doihara, Hiroyoshi; Shiraiwa, Misaki; Ishihara, Setsuko

    2008-01-01

    We evaluated the effectiveness of multidetector-row computed tomography (MD-CT) for detecting axillary lymph nodal status (ALNS) in patients with breast cancer. We reviewed 42 patients with breast cancer. A metastatic lymph node on MD-CT was defined as oval or round, with more than 5 mm on the short axis. We evaluated ALNS preoperatively by both palpation and MD-CT findings and performed sentinel lymph node biopsy (SLNB) and complete axillary lymph node dissection (ALND). For establishing the ALNS, MD-CT showed a sensitivity of 76.9%, a specificity of 96.6%, and an accuracy of 90.5%. On the basis of the MD-CT findings, misdiagnosis was made in 4 of the 42 patients, only one of which was false positive. On the other hand, one patient with a histologically negative sentinel lymph node (SLN) result had metastasis only in a non-SLN. Preoperative MD-CT showed a positive node in this patient. Multidetector-row computed tomography assists in identifying women who require ALND without SLNB, with sufficient positive predictive value. False-negative detection by SLNB could be avoided with careful interpretation of the axillary lymph nodes shown by MD-CT. (author)

  17. Opposing nodal and BMP signals regulate left-right asymmetry in the sea urchin larva.

    Directory of Open Access Journals (Sweden)

    Yi-Jyun Luo

    Full Text Available Nodal and BMP signals are important for establishing left-right (LR asymmetry in vertebrates. In sea urchins, Nodal signaling prevents the formation of the rudiment on the right side. However, the opposing pathway to Nodal signaling during LR axis establishment is not clear. Here, we revealed that BMP signaling is activated in the left coelomic pouch, specifically in the veg2 lineage, but not in the small micromeres. By perturbing BMP activities, we demonstrated that BMP signaling is required for activating the expression of the left-sided genes and the formation of the left-sided structures. On the other hand, Nodal signals on the right side inhibit BMP signaling and control LR asymmetric separation and apoptosis of the small micromeres. Our findings show that BMP signaling is the positive signal for left-sided development in sea urchins, suggesting that the opposing roles of Nodal and BMP signals in establishing LR asymmetry are conserved in deuterostomes.

  18. A spectral nodal method for discrete ordinates problems in x,y geometry

    International Nuclear Information System (INIS)

    Barros, R.C. de; Larsen, E.W.

    1991-06-01

    A new nodal method is proposed for the solution of S N problems in x- y-geometry. This method uses the Spectral Green's Function (SGF) scheme for solving the one-dimensional transverse-integrated nodal transport equations with no spatial truncation error. Thus, the only approximations in the x, y-geometry nodal method occur in the transverse leakage terms, as in diffusion theory. We approximate these leakage terms using a flat or constant approximation, and we refer to the resulting method as the SGF-Constant Nodal (SGF-CN) method. We show in numerical calculations that the SGF-CN method is much more accurate than other well-known transport nodal methods for coarse-mesh deep-penetration S N problems, even though the transverse leakage terms are approximated rather simply. (author)

  19. Dual Atrioventricular Nodal Pathways Physiology: A Review of Relevant Anatomy, Electrophysiology, and Electrocardiographic Manifestations

    Directory of Open Access Journals (Sweden)

    Bhalaghuru Chokkalingam Mani, MD

    2014-01-01

    Full Text Available More than half a century has passed since the concept of dual atrioventricular (AV nodal pathways physiology was conceived. Dual AV nodal pathways have been shown to be responsible for many clinical arrhythmia syndromes, most notably AV nodal reentrant tachycardia. Although there has been a considerable amount of research on this topic, the subject of dual AV nodal pathways physiology remains heavily debated and discussed. Despite advances in understanding arrhythmia mechanisms and the widespread use of invasive electrophysiologic studies, there is still disagreement on the anatomy and physiology of the AV node that is the basis of discontinuous antegrade AV conduction. The purpose of this paper is to review the concept of dual AV nodal pathways physiology and its varied electrocardiographic manifestations.

  20. Global Distribution of Dissected Duricrust on Mars

    Science.gov (United States)

    Mustard, J. F.; Cooper, C. D.

    2000-01-01

    Evidence for dissected duricrust was identified in high resolution MOC images. Analysis of all available images was used to map the global distribution of this terrain. It is apparently restricted to two latitude bands: 30-60 deg. N and 30-60 deg. S.

  1. Partial axillary dissection in early breast cancer

    African Journals Online (AJOL)

    Tarek Abdel Halim El-Fayoumi

    ORIGINAL ARTICLE. Partial axillary dissection in early breast cancer. Tarek Abdel Halim El-Fayoumi *. Department of General Surgery, Faculty of Medicine, Alexandria University, Egypt. Received 16 October 2012; accepted 7 January 2013. Available online 7 March 2013. KEYWORDS. Breast cancer;. Axillary lymph nodes.

  2. Dissection in Pre-college Education

    OpenAIRE

    Buyukmihci, NC

    2017-01-01

    This paper discusses the educational and ethical issues surrounding dissection of non-human animals in pre-college education. It argues that this exercise has no benefits to students that could possibly be outweighed by the death of healthy animals killed for this purpose.

  3. Squid Dissection: From Pen to Ink.

    Science.gov (United States)

    Brown, Cindy; Kisiel, Jim

    2003-01-01

    Introduces students to dissection, which is an important part of scientific discovery. Students not only gain an understanding of the anatomy of a squid, but also develop a sense of responsibility and respect for the animal that they are using as a learning tool. (Author/SOE)

  4. Shoulder complaints after nerve sparing neck dissections

    NARCIS (Netherlands)

    van Wilgen, CP; Dijkstra, PU; van der Laan, BFAM; Plukker, JTM; Roodenburg, JLN

    The purpose of the study was to analyse the prevalence of shoulder complaints after nerve sparing neck dissection at least I year after surgery, and to analyse the influence of radiation therapy on shoulder complaints. Patients were interviewed for shoulder complaints, and patients filled out the

  5. Thrombosed false channel in acute aortic dissections

    International Nuclear Information System (INIS)

    Alerci, M.; Dore, R.; Kluzer, A.; Digiulio, G.; D'Andrea, F.; De Agostini, A.

    1987-01-01

    Three cases are reported of acute dissection with complete thrombosis of the false channel, which is a very uncommonevent in DeBakey's I and II type aortic dissections. The 3 patients entered hospital because of severe thoracic pain without any ECG sign of myocardial infarction. Emergency CT showed evidence of pericardial effusion suggesting hemopericardium, enlargement of the ascending aorta and a peripheral semilunar filling defect which caused a slight deformation of the true channel. On precontrast scans, only one case showed inward displacement of peripheral calcifications and high-density aortic wall. No tipical signs of aortic dissection were reported, expect in the first patient - where a double contrast filled lumen, separated by an intimal flap was seen. CT findings are individually discussed. It is emphasized that in all patients more than one CT sign was present at a time. The correct evaluation of these signs together with the clinacal data could lead to the right diagnosis of aortic dissection in spite of the lack of a f???

  6. Electrocautery causes more ischemic peritoneal tissue damage than ultrasonic dissection.

    NARCIS (Netherlands)

    Broek, R.P.G ten; Wilbers, J.; Goor, H. van

    2011-01-01

    BACKGROUND: Minimizing peritoneal tissue injury during abdominal surgery has the benefit of reducing postoperative inflammatory response, pain, and adhesion formation. Ultrasonic dissection seems to reduce tissue damage. This study aimed to compare electrocautery and ultrasonic dissection in terms

  7. Acute headache and persistent headache attributed to cervical artery dissection

    DEFF Research Database (Denmark)

    Schytz, Henrik W; Ashina, Messoud; Magyari, Melinda

    2014-01-01

    for Headache or facial or neck pain attributed to cervical carotid or vertebral artery dissection or Headache attributed to intracranial arterial dissection. Six months after dissection five of 19 patients still reported persistent headache attributed to dissection. The study demonstrates that the ICHD......The criteria for headache attributed to cervical artery dissection have been changed in the new third edition of the International Classification of Headache Disorders (ICHD-III beta). We have retrospectively investigated 19 patients diagnosed from 2001 to 2006 with cervical artery dissection......-III beta criteria for cervical artery dissection are useful for classifying patients at the first encounter. We show for the first time that persistent headache attributed to arterial dissection is frequent....

  8. An integral nodal variational method for multigroup criticality calculations

    International Nuclear Information System (INIS)

    Lewis, E.E.; Tsoulfanidis, N.

    2003-01-01

    An integral formulation of the variational nodal method is presented and applied to a series of benchmark critically problems. The method combines an integral transport treatment of the even-parity flux within the spatial node with an odd-parity spherical harmonics expansion of the Lagrange multipliers at the node interfaces. The response matrices that result from this formulation are compatible with those in the VARIANT code at Argonne National Laboratory. Either homogeneous or heterogeneous nodes may be employed. In general, for calculations requiring higher-order angular approximations, the integral method yields solutions with comparable accuracy while requiring substantially less CPU time and memory than the standard spherical harmonics expansion using the same spatial approximations. (author)

  9. An Adaptive Approach to Variational Nodal Diffusion Problems

    International Nuclear Information System (INIS)

    Zhang Hui; Lewis, E.E.

    2001-01-01

    An adaptive grid method is presented for the solution of neutron diffusion problems in two dimensions. The primal hybrid finite elements employed in the variational nodal method are used to reduce the diffusion equation to a coupled set of elemental response matrices. An a posteriori error estimator is developed to indicate the magnitude of local errors stemming from the low-order elemental interface approximations. An iterative procedure is implemented in which p refinement is applied locally by increasing the polynomial order of the interface approximations. The automated algorithm utilizes the a posteriori estimator to achieve local error reductions until an acceptable level of accuracy is reached throughout the problem domain. Application to a series of X-Y benchmark problems indicates the reduction of computational effort achievable by replacing uniform with adaptive refinement of the spatial approximations

  10. A nonlinear analytic function expansion nodal method for transient calculations

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Han Gyn; Park, Sang Yoon; Cho, Byung Oh; Zee, Sung Quun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    The nonlinear analytic function expansion nodal (AFEN) method is applied to the solution of the time-dependent neutron diffusion equation. Since the AFEN method requires both the particular solution and the homogeneous solution to the transient fixed source problem, the derivation of the solution method is focused on finding the particular solution efficiently. To avoid complicated particular solutions, the source distribution is approximated by quadratic polynomials and the transient source is constructed such that the error due to the quadratic approximation is minimized, In addition, this paper presents a new two-node solution scheme that is derived by imposing the constraint of current continuity at the interface corner points. The method is verified through a series of application to the NEACRP PWR rod ejection benchmark problems. 6 refs., 2 figs., 1 tab. (Author)

  11. On-line application of the PANTHER advanced nodal code

    International Nuclear Information System (INIS)

    Hutt, P.K.; Knight, M.P.

    1992-01-01

    Over the last few years, Nuclear Electric has developed an integrated core performance code package for both light water reactors (LWRs) and advanced gas-cooled reactors (AGRs) that can perform a comprehensive range of calculations for fuel cycle design, safety analysis, and on-line operational support for such plants. The package consists of the following codes: WIMS for lattice physics, PANTHER whole reactor nodal flux and AGR thermal hydraulics, VIPRE for LWR thermal hydraulics, and ENIGMA for fuel performance. These codes are integrated within a UNIX-based interactive system called the Reactor Physics Workbench (RPW), which provides an interactive graphic user interface and quality assurance records/data management. The RPW can also control calculational sequences and data flows. The package has been designed to run both off-line and on-line accessing plant data through the RPW

  12. Fourier-Accelerated Nodal Solvers (FANS) for homogenization problems

    Science.gov (United States)

    Leuschner, Matthias; Fritzen, Felix

    2017-11-01

    Fourier-based homogenization schemes are useful to analyze heterogeneous microstructures represented by 2D or 3D image data. These iterative schemes involve discrete periodic convolutions with global ansatz functions (mostly fundamental solutions). The convolutions are efficiently computed using the fast Fourier transform. FANS operates on nodal variables on regular grids and converges to finite element solutions. Compared to established Fourier-based methods, the number of convolutions is reduced by FANS. Additionally, fast iterations are possible by assembling the stiffness matrix. Due to the related memory requirement, the method is best suited for medium-sized problems. A comparative study involving established Fourier-based homogenization schemes is conducted for a thermal benchmark problem with a closed-form solution. Detailed technical and algorithmic descriptions are given for all methods considered in the comparison. Furthermore, many numerical examples focusing on convergence properties for both thermal and mechanical problems, including also plasticity, are presented.

  13. Nodal domains on isospectral quantum graphs: the resolution of isospectrality?

    International Nuclear Information System (INIS)

    Band, Ram; Shapira, Talia; Smilansky, Uzy

    2006-01-01

    We present and discuss isospectral quantum graphs which are not isometric. These graphs are the analogues of the isospectral domains in R 2 which were introduced recently in Gordon et al (1992 Bull. Am. Math. Soc. 27 134-8), Chapman (1995 Am. Math. Mon. 102 124), Buser et al (1994 Int. Math. Res. Not. 9 391-400), Okada and Shudo (2001 J. Phys. A: Math. Gen. 34 5911-22), Jakobson et al (2006 J. Comput. Appl. Math. 194 141-55) and Levitin et al (2006 J. Phys. A: Math. Gen. 39 2073-82)) all based on Sunada's construction of isospectral domains (Sunada T 1985 Ann. Math. 121 196-86). After presenting some of the properties of these graphs, we discuss a few examples which support the conjecture that by counting the nodal domains of the corresponding eigenfunctions one can resolve the isospectral ambiguity

  14. INTERMITTENT ANTIARYTHMIC THERAPY OF ARIOVENTICULAR NODAL REENTRY TACHYCARDIA IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Boris Djindjic

    2008-04-01

    Full Text Available Until recent advances in pharmacology and clinical cardiology regarding farmacodynamics of antiarrhythmic drugs and their efficiency in patients with refractory paroxysmal supraventricular tachycardia, chronic prophylactic therapy was the only treatment option for patients refusing catheter ablation. Another treatment option, also known by eponym “pill in pocket” have been shown to be equally useful and efficacious.The aim of our study was prospective examination of children with refractory atrioventricular nodal reentry tachycardia (AVNRT who were withdrawn from chronic antiarrhythmic prophylactic therapy and started with intermittent oral beta blocker treatment (propranolol at dosage 1 mg/kg - max 80 mg.Twelve children (8 boys and 4 girls with AVNRT were included in the study. Four children did not have arrhythmia during first six months after withdrawal and 7 were successfully treated without complication.Intermittent antiarrhythmic therapy in children with AVNRT could be very efficacious and useful treatment option which significantly improves their quality of life.

  15. CAISO flicks switch on nodal scheme and lights stay on

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-06-15

    In 2000-01, two years after introducing a competitive wholesale power auction in California - with a separate day-ahead zonal market operated by the California Power Exchange and a zonal market for ancillary services and balancing energy operated by the California Independent System Operator (CAISO) - the California market collapsed from exorbitant prices, flagrant gaming, and abuse of market power. Nine years later, CAISO introduced a nodal pricing auction for the wholesale market in April, replacing the zonal scheme, which was among many causes of the original market's demise. With nearly 3,000 nodes on the network, high prices in one region do not affect prices everywhere on the system. After investing some $200 million to upgrade the software, countless delays, and 18 months of market simulation and testing, the new auction was introduced and nothing unusual happened.

  16. Ultrasound beam characteristics of a symmetric nodal origami based array

    Science.gov (United States)

    Bilgunde, Prathamesh N.; Bond, Leonard J.

    2018-04-01

    Origami-the ancient art of paper folding-is being explored in acoustics for effective focusing of sound. In this short communication, we present a numerical investigation of beam characteristics for an origami based ultrasound array. A spatial re-configuration of array elements is performed based upon the symmetric nodal origami. The effect of fold angle on the ultrasound beam is evaluated using frequency domain and transient finite element analysis. It was found that increase in the fold angle reduces near field length by 58% and also doubles the beam intensity as compared to the linear array. Transient analysis also indicated 80% reduction in the -6dB beam width, which can improve the lateral resolution of phased array. Such a spatially re-configurable array could potentially be used in the future to reduce the cost of electronics in the phased array instrumentation.

  17. Space-angle approximations in the variational nodal method

    International Nuclear Information System (INIS)

    Lewis, E. E.; Palmiotti, G.; Taiwo, T.

    1999-01-01

    The variational nodal method is formulated such that the angular and spatial approximations maybe examined separately. Spherical harmonic, simplified spherical harmonic, and discrete ordinate approximations are coupled to the primal hybrid finite element treatment of the spatial variables. Within this framework, two classes of spatial trial functions are presented: (1) orthogonal polynomials for the treatment of homogeneous nodes and (2) bilinear finite subelement trial functions for the treatment of fuel assembly sized nodes in which fuel-pin cell cross sections are represented explicitly. Polynomial and subelement trial functions are applied to benchmark water-reactor problems containing MOX fuel using spherical harmonic and simplified spherical harmonic approximations. The resulting accuracy and computing costs are compared

  18. A nonlinear analytic function expansion nodal method for transient calculations

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Han Gyn; Park, Sang Yoon; Cho, Byung Oh; Zee, Sung Quun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-12-31

    The nonlinear analytic function expansion nodal (AFEN) method is applied to the solution of the time-dependent neutron diffusion equation. Since the AFEN method requires both the particular solution and the homogeneous solution to the transient fixed source problem, the derivation of the solution method is focused on finding the particular solution efficiently. To avoid complicated particular solutions, the source distribution is approximated by quadratic polynomials and the transient source is constructed such that the error due to the quadratic approximation is minimized, In addition, this paper presents a new two-node solution scheme that is derived by imposing the constraint of current continuity at the interface corner points. The method is verified through a series of application to the NEACRP PWR rod ejection benchmark problems. 6 refs., 2 figs., 1 tab. (Author)

  19. ANDREA: Advanced nodal diffusion code for reactor analysis

    International Nuclear Information System (INIS)

    Belac, J.; Josek, R.; Klecka, L.; Stary, V.; Vocka, R.

    2005-01-01

    A new macro code is being developed at NRI which will allow coupling of the advanced thermal-hydraulics model with neutronics calculations as well as efficient use in core loading pattern optimization process. This paper describes the current stage of the macro code development. The core simulator is based on the nodal expansion method, Helios lattice code is used for few group libraries preparation. Standard features such as pin wise power reconstruction and feedback iterations on critical control rod position, boron concentration and reactor power are implemented. A special attention is paid to the system and code modularity in order to enable flexible and easy implementation of new features in future. Precision of the methods used in the macro code has been verified on available benchmarks. Testing against Temelin PWR operational data is under way (Authors)

  20. Comparison of PANTHER nodal solutions in hexagonal-z geometry

    International Nuclear Information System (INIS)

    Knight, M.; Hutt, P.; Lewis, I.

    1995-01-01

    The reactor physics code PANTHER has been extended to hexagonal geometries. Steady-state, depletion, and transient calculations with feedback can all be performed. Two hexagonal nodal flux solutions have been developed. In the first method, transverse integration is performed exactly as in the rectangular case. The resulting transverse integrated equation has singular terms, which are simply ignored. The second approach applies a conformal mapping that transforms the hexagon onto a rectangle. Pin power reconstruction has also been developed with both methods. For a benchmark VVER-1000 reactor depletion problem, both methods give accurate results for standard depletion calculations. In the more extreme situation with all rods inserted, the simpler method breaks down. However, the accuracy of the conformal solution was found to be excellent in all cases studied

  1. Static benchmarking of the NESTLE advanced nodal code

    International Nuclear Information System (INIS)

    Mosteller, R.D.

    1997-01-01

    Results from the NESTLE advanced nodal code are presented for multidimensional numerical benchmarks representing four different types of reactors, and predictions from NESTLE are compared with measured data from pressurized water reactors (PWRs). The numerical benchmarks include cases representative of PWRs, boiling water reactors (BWRs), CANDU heavy water reactors (HWRs), and high-temperature gas-cooled reactors (HTGRs). The measured PWR data include critical soluble boron concentrations and isothermal temperature coefficients of reactivity. The results demonstrate that NESTLE correctly solves the multigroup diffusion equations for both Cartesian and hexagonal geometries, that it reliably calculates k eff and reactivity coefficients for PWRs, and that--subsequent to the incorporation of additional thermal-hydraulic models--it will be able to perform accurate calculations for the corresponding parameters in BWRs, HWRs, and HTGRs as well

  2. Contemporary Management of Recurrent Nodal Disease in Differentiated Thyroid Carcinoma

    Science.gov (United States)

    Na’ara, Shorook; Amit, Moran; Fridman, Eran; Gil, Ziv

    2016-01-01

    Differentiated thyroid carcinoma (DTC) comprises over 90% of thyroid tumors and includes papillary and follicular carcinomas. Patients with DTC have an excellent prognosis, with a 10-year survival rate of over 90%. However, the risk of recurrent tumor ranges between 5% and 30% within 10 years of the initial diagnosis. Cervical lymph node disease accounts for the majority of recurrences and in most cases is detected during follow-up by ultrasound or elevated levels of serum thyroglobulin. Recurrent disease is accompanied by increased morbidity. The mainstay of treatment of nodal recurrence is surgical management. We provide an overview of the literature addressing surgical management of recurrent or persistent lymph node disease in patients with DTC. PMID:26886954

  3. Error Estimation and Accuracy Improvements in Nodal Transport Methods

    International Nuclear Information System (INIS)

    Zamonsky, O.M.

    2000-01-01

    The accuracy of the solutions produced by the Discrete Ordinates neutron transport nodal methods is analyzed.The obtained new numerical methodologies increase the accuracy of the analyzed scheems and give a POSTERIORI error estimators. The accuracy improvement is obtained with new equations that make the numerical procedure free of truncation errors and proposing spatial reconstructions of the angular fluxes that are more accurate than those used until present. An a POSTERIORI error estimator is rigurously obtained for one dimensional systems that, in certain type of problems, allows to quantify the accuracy of the solutions. From comparisons with the one dimensional results, an a POSTERIORI error estimator is also obtained for multidimensional systems. LOCAL indicators, which quantify the spatial distribution of the errors, are obtained by the decomposition of the menctioned estimators. This makes the proposed methodology suitable to perform adaptive calculations. Some numerical examples are presented to validate the theoretical developements and to illustrate the ranges where the proposed approximations are valid

  4. Nodal wear model: corrosion in carbon blast furnace hearths

    Directory of Open Access Journals (Sweden)

    Verdeja, L. F.

    2003-06-01

    Full Text Available Criterions developed for the Nodal Wear Model (NWM were applied to estimate the shape of the corrosion profiles that a blast furnace hearth may acquire during its campaign. Taking into account design of the hearth, the boundary conditions, the characteristics of the refractory materials used and the operation conditions of the blast furnace, simulation of wear profiles with central well, mushroom and elephant foot shape were accomplished. The foundations of the NWM are constructed considering that the corrosion of the refractory is a function of the temperature present at each point (node of the liquid metal-refractory interface and the corresponding physical and chemical characteristics of the corrosive fluid.

    Se aplican los criterios del Modelo de Desgaste Nodal (MDN para la estimación de los perfiles de corrosión que podría ir adquiriendo el crisol de un homo alto durante su campaña. Atendiendo al propio diseño del crisol, a las condiciones límites de contorno, a las características del material refractario utilizado y a las condiciones de operación del horno, se consiguen simular perfiles de desgaste con "pozo central", con "forma de seta" ó de "pie de elefante". Los fundamentos del MDN se apoyan en la idea de considerar que la corrosión del refractario es función de la temperatura que el sistema pueda presentar en cada punto (nodo de la intercara refractario-fundido y de las correspondientes características físico-químicas del fluido corrosivo.

  5. DISSECT: a new mnemonic-based approach to the categorization of aortic dissection.

    Science.gov (United States)

    Dake, M D; Thompson, M; van Sambeek, M; Vermassen, F; Morales, J P

    2013-08-01

    Classification systems for aortic dissection provide important guides to clinical decision-making, but the relevance of traditional categorization schemes is being questioned in an era when endovascular techniques are assuming a growing role in the management of this frequently complex and catastrophic entity. In recognition of the expanding range of interventional therapies now used as alternatives to conventional treatment approaches, the Working Group on Aortic Diseases of the DEFINE Project developed a categorization system that features the specific anatomic and clinical manifestations of the disease process that are most relevant to contemporary decision-making. The DISSECT classification system is a mnemonic-based approach to the evaluation of aortic dissection. It guides clinicians through an assessment of six critical characteristics that facilitate optimal communication of the most salient details that currently influence the selection of a therapeutic option, including those findings that are key when considering an endovascular procedure, but are not taken into account by the DeBakey or Stanford categorization schemes. The six features of aortic dissection include: duration of disease; intimal tear location; size of the dissected aorta; segmental extent of aortic involvement; clinical complications of the dissection, and thrombus within the aortic false lumen. In current clinical practice, endovascular therapy is increasingly considered as an alternative to medical management or open surgical repair in select cases of type B aortic dissection. Currently, endovascular aortic repair is not used for patients with type A aortic dissection, but catheter-based techniques directed at peripheral branch vessel ischemia that may complicate type A dissection are considered valuable adjunctive interventions, when indicated. The use of a new system for categorization of aortic dissection, DISSECT, addresses the shortcomings of well-known established schemes devised

  6. Partial axillary dissection in early breast cancer

    Directory of Open Access Journals (Sweden)

    Tarek Abdel Halim El-Fayoumi

    2013-09-01

    Full Text Available Background: In order to reduce the probability of later clinical involvement of the axilla and at establishing a sound basis for adjuvant treatment planning axillary dissection is an important operative procedure. So, partial axillary dissection has been applied to decrease the morbidity and postoperative axillary complications.Aim of the work was to study the reliability of partial axillary lymph node dissection in patients with breast carcinoma with clinically negative axilla. Methods: Eighteen patients underwent modified radical mastectomy, while the other two patients who were fulfilling the criteria for conservative breast surgery underwent lumpectomy. All patients did complete axillary lymph nodes dissection. Intraoperative leveling of the axilla was performed and level I axillary lymph nodes were identified according to their relation to pectoralis minor muscle; then they were subjected to intraoperative pathological examination by frozen section examination followed by complete axillary clearance. Then post operative histopathological examination of the tumor and all lymph nodes was done. Results: By intraoperative pathological examination; five patients (25% were found positive for malignant invasion, while 15 patients (75% were pathologically free. While paraffin section showed six patients (30% with malignant invasion, and 14 patients (70% were pathologically free. There was a false negative rate of 5% in level I axillary lymph nodes by intraoperative pathological examination which was positive for metastasis by paraffin section that revealed microinvasion in one lymph node out of 8 in level I. Only two cases out of 20 were found positive for metastasis in level II and III. Conclusion: Partial axillary lymph node dissection is a minimally invasive, feasible and sufficient technique that can predict the axillary lymph node status. KEYWORDS: Breast cancer, Axillary lymph nodes clearance

  7. Emotional response of undergraduates to cadaver dissection.

    Science.gov (United States)

    Wisenden, Patricia A; Budke, Katherine J; Klemetson, Chelsea J; Kurtti, Tana R; Patel, Chandi M; Schwantz, Trenda L; Wisenden, Brian D

    2018-03-01

    The most effective way to learn human anatomy is through cadaver dissection. Historically, cadaver dissection has been the provenance of professional schools. Increasingly, cadaver-based courses in human anatomy are shifting to the undergraduate level, which creates both problems and opportunities because of differences between undergraduate and graduate student populations. Anxiety associated with dissecting cadavers can create a barrier to learning, and ultimately, entry into the health and medical sciences for some demographic subpopulations of undergraduates. We surveyed 76 students in 2007 and 51 students in 2009 at four times in the semester to investigate the timing and sociodemographic predictors of anxiety over cadaver dissection. We followed this with a second survey of 44 students in 2014 to test the effect of humanization of cadaver donors (providing information about donor occupation and cause of death) to reduce student anxiety. Students experienced anxiety upon first exposure to cadaver dissection. Female students experienced greater anxiety than male students upon first exposure to cadavers but this effect was short-lived. Self-identified non-white, non-Christian students experienced sustained anxiety throughout the semester, likely because cadaver stress compounded social and financial stressors unique to international students. Humanization was effective in reducing anxiety in non-white, non-Christian students but had the unexpected effect of increasing anxiety in female students. We recommend that humanizing information be offered to students who seek it out, but not forced upon students for whom the information would only add to their stress. Clin. Anat. 31:224-230, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. Positive family history of aortic dissection dramatically increases dissection risk in family members.

    Science.gov (United States)

    Ma, Wei-Guo; Chou, Alan S; Mok, Salvior C M; Ziganshin, Bulat A; Charilaou, Paris; Zafar, Mohammad A; Sieller, Richard S; Tranquilli, Maryann; Rizzo, John A; Elefteriades, John A

    2017-08-01

    Although family members of patients with aortic dissection (AoD) are believed to be at higher risk of AoD, the prognostic value of family history (FH) of aortic dissection (FHAD) in family members of patients with AoD has not been studied rigorously. We seek examine how much a positive FHAD increases the risk of developing new aortic dissection (AoD) among first-degree relatives. Patients with AoD at our institution were analyzed for information of FHAD. Positive FHAD referred to that AoD occurred in index patient and one or more first-degree relatives. Negative FHAD was defined as the condition in which only one case of AoD (the index patient) occurred in the family. The age at AoD, exposure years in adulthood before AoD, and annual probability of AoD among first-degree relatives were compared between patients with negative and positive FHADs. FHAD was positive in 32 and negative in 68 among the 100 AoD patients with detailed family history information. Mean age at dissection was 59.9±14.7years. Compared to negative FHAD, patients with positive FHAD dissected at significantly younger age (54.7±16.8 vs 62.4±13.0years, p=0.013), had more AoD events in first-degree relatives (2.3±0.6 vs 1.0±0.0, pfamily members, with a higher annual probability of aortic dissection, a shorter duration of "exposure time" before dissection occurs and a lower mean age at time of dissection. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  9. Acute Type II Aortic Dissection with Severe Aortic Regurgitation and Chronic Descending Aortic Dissection in Pregnant Patient with Marfan Syndrome

    OpenAIRE

    Lee, Seok-Soo; Jung, Tae-Eun; Lee, Dong Hyup

    2012-01-01

    Aortic dilatation and dissection are severe complications during pregnancy that can be fatal to both the mother and the fetus. The risks of these complications are especially high in pregnant patients with Marfan syndrome; however, incidents of descending aortic dissection are very rare. This case report involves a successful Bentall procedure for and recovery from a rare aortic dissection in a pregnant Marfan patient who developed acute type II aortic dissection with severe aortic regurgitat...

  10. Anatomical Variations in the Sinoatrial Nodal Artery: A Meta-Analysis and Clinical Considerations.

    Directory of Open Access Journals (Sweden)

    Jens Vikse

    Full Text Available The sinoatrial nodal artery (SANa is a highly variable vessel which supplies blood to the sinoatrial node (SAN. Due to its variability and susceptibility to iatrogenic injury, our study aimed to assess the anatomy of the SANa and determine the prevalence of its anatomical variations.An extensive search of major electronic databases was performed to identify all articles reporting anatomical data on the SANa. No lower date limit or language restrictions were applied. Anatomical data regarding the artery were extracted and pooled into a meta-analysis.Sixty-six studies (n = 21455 hearts were included in the meta-analysis. The SANa usually arose as a single vessel with a pooled prevalence of 95.5% (95%CI:93.6-96.9. Duplication and triplication of the artery were also observed with pooled prevalence of 4.3% (95%CI:2.8-6.0 and 0.3% (95%CI:0-0.7, respectively. The most common origin of the SANa was from the right coronary artery (RCA, found in 68.0% (95%CI:55.6-68.9 of cases, followed by origin from the left circumflex artery, and origin from the left coronary artery with pooled prevalence of 22.1% (95%CI:15.0-26.2 and 2.7 (95%CI:0.7-5.2, respectively. A retrocaval course of the SANa was the most common course of the artery with a pooled prevalence of 47.1% (95%CI:36.0-55.5. The pooled prevalence of an S-shaped SANa was 7.6% (95%CI:2.9-14.1.The SANa is most commonly reported as a single vessel, originating from the RCA, and taking a retrocaval course to reach the SAN. Knowledge of high risk anatomical variants of the SANa, such as an S-shaped artery, must be taken into account by surgeons to prevent iatrogenic injuries. Specifically, interventional or cardiosurgical procedures, such as the Cox maze procedure for atrial fibrillation, open heart surgeries through the right atrium or intraoperative cross-clamping or dissection procedures during mitral valve surgery using the septal approach can all potentiate the risk for injury in the setting of high

  11. Role of Neck Dissection in Clinical T3N0M0 Lesion of Oral Cavity: Changing Trend.

    Science.gov (United States)

    Dass, Arjun; Singhal, Surinder K; Punia, Rps; Gupta, Nitin; Verma, Hitesh; Budhiraja, Shilpi; Salaria, Minakshi

    2017-08-01

    Neck dissection is an important part in the management of head and neck malignancies especially in terms of control of nodal metastasis. The study is focused on evaluating the profile of lymph nodes in T 3 N 0 M 0 lesion of different subsides of oral cavity. To evaluate the utility of neck dissection in T 3 N 0 M 0 stage of carcinomas of the different region of oral cavity. Ninety patients aged 20 to 70 years underwent treatment for carcinoma of the oral cavity at our center between 2005 and 2013. Of these, 39 patients were stage T 3 N 0 M 0 and underwent excision of the primary lesion with neck dissection. The data were collected retrospectively from hospital record library. These patients were evaluated clinically, radiologically and compared with intra operative finding. Addition of radiotherapy was decided on final histopathology. Out of 39 patients, the site of primary tumour in 21 patients was tongue, in 13 patients was Buccal Mucosa (BM), in 2 patients was lip and in 3 patients was Floor of Mouth (FOM) with tongue. In patients with clinically negative neck nodes, ultrasonography and intra-operative examination revealed the presence of suspicious nodes in 35.9% and 30.7% cases respectively. Occult metastasis in the nodes was identified on histopathological examination in 15 patients (38.5%). A total of 14 patients of carcinoma of tongue and one patient of BM showed positive nodes on histopathology. These patients with positive neck nodes on histopathology, were sent for postoperative radiotherapy. At follow up examination, four patients showed local and distal recurrence and they were managed accordingly. Out of 39 patients, 11 patients of BM, 2 patients of lip, 1 patient of FOM and 6 patients of tongue were disease free in last follow up. Selective neck dissection is an effective therapeutic intervention in patients without clinically involved neck nodes. It can upstage the tumour and additional treatment may be advised. In patients with carcinoma of buccal

  12. A simple nodal force distribution method in refined finite element meshes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jai Hak [Chungbuk National University, Chungju (Korea, Republic of); Shin, Kyu In [Gentec Co., Daejeon (Korea, Republic of); Lee, Dong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2017-05-15

    In finite element analyses, mesh refinement is frequently performed to obtain accurate stress or strain values or to accurately define the geometry. After mesh refinement, equivalent nodal forces should be calculated at the nodes in the refined mesh. If field variables and material properties are available at the integration points in each element, then the accurate equivalent nodal forces can be calculated using an adequate numerical integration. However, in certain circumstances, equivalent nodal forces cannot be calculated because field variable data are not available. In this study, a very simple nodal force distribution method was proposed. Nodal forces of the original finite element mesh are distributed to the nodes of refined meshes to satisfy the equilibrium conditions. The effect of element size should also be considered in determining the magnitude of the distributing nodal forces. A program was developed based on the proposed method, and several example problems were solved to verify the accuracy and effectiveness of the proposed method. From the results, accurate stress field can be recognized to be obtained from refined meshes using the proposed nodal force distribution method. In example problems, the difference between the obtained maximum stress and target stress value was less than 6 % in models with 8-node hexahedral elements and less than 1 % in models with 20-node hexahedral elements or 10-node tetrahedral elements.

  13. A polygonal nodal SP3 method for whole core Pin-by-Pin neutronics calculation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yunzhao; Wu, Hongchun; Cao, Liangzhi, E-mail: xjtulyz@gmail.com, E-mail: hongchun@mail.xjtu.edu.cn, E-mail: caolz@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi' an Jiaotong University, Shaanxi (China)

    2011-07-01

    In this polygonal nodal-SP3 method, neutron transport equation is transformed by employing an isotropic SP3 method into two coupled equations that are both in the same mathematic form with the diffusion equation, and then a polygonal nodal method is proposed to solve the two coupled equations. In the polygonal nodal method, adjacent nodes are coupled through partial currents, and a nodal response matrix between incoming and outgoing currents is obtained by expanding detailed nodal flux distribution into a sum of exponential functions. This method avoids the transverse integral technique, which is widely used in regular nodal method and can not be used in triangular geometry because of the mathematical singularity. It is demonstrated by the numerical results of the test problems that the k{sub eff} and power distribution agree well with other codes, the triangular nodal-SP3 method appears faster, and that whole core pin-by-pin transport calculation with fine meshes is feasible after parallelization and acceleration. (author)

  14. Nodal price volatility reduction and reliability enhancement of restructured power systems considering demand-price elasticity

    International Nuclear Information System (INIS)

    Goel, L.; Wu, Qiuwei; Wang, Peng

    2008-01-01

    With the development of restructured power systems, the conventional 'same for all customers' electricity price is getting replaced by nodal prices. Electricity prices will fluctuate with time and nodes. In restructured power systems, electricity demands will interact mutually with prices. Customers may shift some of their electricity consumption from time slots of high electricity prices to those of low electricity prices if there is a commensurate price incentive. The demand side load shift will influence nodal prices in return. This interaction between demand and price can be depicted using demand-price elasticity. This paper proposes an evaluation technique incorporating the impact of the demand-price elasticity on nodal prices, system reliability and nodal reliabilities of restructured power systems. In this technique, demand and price correlations are represented using the demand-price elasticity matrix which consists of self/cross-elasticity coefficients. Nodal prices are determined using optimal power flow (OPF). The OPF and customer damage functions (CDFs) are combined in the proposed reliability evaluation technique to assess the reliability enhancement of restructured power systems considering demand-price elasticity. The IEEE reliability test system (RTS) is simulated to illustrate the developed techniques. The simulation results show that demand-price elasticity reduces the nodal price volatility and improves both the system reliability and nodal reliabilities of restructured power systems. Demand-price elasticity can therefore be utilized as a possible efficient tool to reduce price volatility and to enhance the reliability of restructured power systems. (author)

  15. Type-I and type-II topological nodal superconductors with s -wave interaction

    Science.gov (United States)

    Huang, Beibing; Yang, Xiaosen; Xu, Ning; Gong, Ming

    2018-01-01

    Topological nodal superconductors with protected gapless points in momentum space are generally realized based on unconventional pairings. In this work we propose a minimal model to realize these topological nodal phases with only s -wave interaction. In our model the linear and quadratic spin-orbit couplings along the two orthogonal directions introduce anisotropic effective unconventional pairings in momentum space. This model may support different nodal superconducting phases characterized by either an integer winding number in BDI class or a Z2 index in D class at the particle-hole invariant axes. In the vicinity of the nodal points the effective Hamiltonian can be described by either type-I or type-II Dirac equations, and the Lifshitz transition from type-I nodal phases to type-II nodal phases can be driven by external in-plane magnetic fields. We show that these nodal phases are robust against weak impurities, which only slightly renormalizes the momentum-independent parameters in the impurity-averaged Hamiltonian, thus these phases are possible to be realized in experiments with real semi-Dirac materials. The smoking-gun evidences to verify these phases based on scanning tunneling spectroscopy method are also briefly discussed.

  16. Detection of lymph node metastasis in patients with nodal prostate cancer relapse using (18)F/(11)C-choline positron emission tomography/computerized tomography.

    Science.gov (United States)

    Jilg, Cordula A; Schultze-Seemann, Wolfgang; Drendel, Vanessa; Vach, Werner; Wieser, Gesche; Krauss, Tobias; Jandausch, Anett; Hölz, Stefanie; Henne, Karl; Reske, Sven N; Grosu, Anca-L; Weber, Wolfgang A; Rischke, H Christian

    2014-07-01

    We evaluated the diagnostic accuracy of choline positron emission tomography/computerized tomography for nodal relapse of prostate cancer according to topographical site and tumor infiltration size in lymph nodes. A total of 72 patients with nodal prostate cancer relapse after primary therapy underwent pelvic and/or retroperitoneal salvage lymph node dissection. Salvage was done after whole body positron emission tomography/computerized tomography with (11)C-choline or (18)F-fluoroethylcholine showed positron emission tomography positive lymph nodes but no other detectable metastasis. Diagnostic accuracy was evaluated in 160 dissected lymph node regions (pelvic left/right and retroperitoneal), 498 subregions (common, external and internal iliac, obturator, presacral, aortic bifurcation, aortal, vena caval and interaortocaval) and 2,122 lymph nodes. Lymph node metastasis was present in 32% of resected lymph nodes (681 of 2,122), resulting in 238 positive subregions and 111 positive regions. Positron emission tomography/computerized tomography was positive for 110 regions and 209 subregions. Sensitivity, specificity, positive and negative predictive values, and accuracy were 91.9%, 83.7%, 92.7%, 82.0% and 89.4% (region based), 80.7%, 93.5%, 91.9%, 84.1% and 87.3% (subregion based), and 57.0%, 98.4%, 94.5%, 82.6% and 84.9% (lesion based), respectively. Of 393 positive lymph node metastases detected by this method 278 (70.7%) were in lymph nodes with a less than 10 mm short axis diameter. Imaging sensitivity was 13.3%, 57.4% and 82.8% for a tumor infiltration depth of 2 or greater to less than 3 mm, 5 or greater to less than 6 mm and 10 or greater to less than 11 mm, respectively. Lymph node metastasis site and the radiotracer ((11)C-choline/(18)F-fluoroethylcholine) had no substantial impact on diagnostic accuracy. Choline positron emission tomography/computerized tomography detects affected lymph node regions (pelvic left/right and retroperitoneal) in patients with

  17. Nodal-dependent mesendoderm specification requires the combinatorial activities of FoxH1 and Eomesodermin.

    Directory of Open Access Journals (Sweden)

    Christopher E Slagle

    2011-05-01

    Full Text Available Vertebrate mesendoderm specification requires the Nodal signaling pathway and its transcriptional effector FoxH1. However, loss of FoxH1 in several species does not reliably cause the full range of loss-of-Nodal phenotypes, indicating that Nodal signals through additional transcription factors during early development. We investigated the FoxH1-dependent and -independent roles of Nodal signaling during mesendoderm patterning using a novel recessive zebrafish FoxH1 mutation called midway, which produces a C-terminally truncated FoxH1 protein lacking the Smad-interaction domain but retaining DNA-binding capability. Using a combination of gel shift assays, Nodal overexpression experiments, and genetic epistasis analyses, we demonstrate that midway more accurately represents a complete loss of FoxH1-dependent Nodal signaling than the existing zebrafish FoxH1 mutant schmalspur. Maternal-zygotic midway mutants lack notochords, in agreement with FoxH1 loss in other organisms, but retain near wild-type expression of markers of endoderm and various nonaxial mesoderm fates, including paraxial and intermediate mesoderm and blood precursors. We found that the activity of the T-box transcription factor Eomesodermin accounts for specification of these tissues in midway embryos. Inhibition of Eomesodermin in midway mutants severely reduces the specification of these tissues and effectively phenocopies the defects seen upon complete loss of Nodal signaling. Our results indicate that the specific combinations of transcription factors available for signal transduction play critical and separable roles in determining Nodal pathway output during mesendoderm patterning. Our findings also offer novel insights into the co-evolution of the Nodal signaling pathway, the notochord specification program, and the chordate branch of the deuterostome family of animals.

  18. Prophylactic dissection of level V in primary mucosal SCC in the clinically N positive neck: A systematic review.

    Science.gov (United States)

    McLean, Timothy; Kerr, Stephen J; Giddings, Charles E B

    2017-09-01

    To review the evidence for level V dissection in the management of previously untreated mucosal squamous cell carcinoma (SCC) of the head and neck presenting with nodal metastasis when level V is clinically uninvolved. The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) were used to conduct a systematic review of the current literature, including all English language articles published after 1990. A literature search was performed on November 29, 2015, of Medline, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Library. The search yielded a total of 270 papers. Strict inclusion and exclusion criteria were applied, leaving 20 eligible papers. Overall prevalence was calculated using random effect meta-analysis. The overall prevalence of level V occult disease in the node (N)-positive neck, irrespective of subsite, was 2.56% (95% confidence interval 1.29-3.84) (2,368 patients and 2,533 necks). The prevalence of occult level V metastasis was up to 7.7% for oral cavity and 8.3% for oropharyngeal tumors. Five studies reported regional recurrence rates over variable time periods. There is exceedingly limited data on outcomes, such as spinal accessory nerve function, quality of life, and perioperative complications. Mucosal head and neck SCC presenting with nodal metastasis but with level V clinically uninvolved has a low prevalence of occult level V disease. Routine dissection of level V does not appear to be warranted; however, a definitive conclusion is unable to be drawn due to limited data on morbidity and oncological outcomes. Laryngoscope, 127:2074-2080, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  19. Face centered cubic SnSe as a Z2 trivial Dirac nodal line material

    OpenAIRE

    Tateishi, Ikuma; Matsuura, Hiroyasu

    2018-01-01

    The presence of Dirac nodal line in the time-reversal and inversion symmetric system is dictated by Z2 index when spin-orbit interaction is absent. With the first principles calculation, we show that the Dirac nodal line can emerge in Z2 trivial material by calculating the band structure of SnSe of face centered cubic lattice as an example and it becomes a topological crystalline insulator when spin-orbit interaction is taken into account. We clarify the origin of the Dirac nodal line by obta...

  20. NUMERICAL SOLUTION OF SINGULAR INVERSE NODAL PROBLEM BY USING CHEBYSHEV POLYNOMIALS

    OpenAIRE

    NEAMATY, ABDOLALI; YILMAZ, EMRAH; AKBARPOOR, SHAHRBANOO; DABBAGHIAN, ABDOLHADI

    2017-01-01

    In this study, we consider Sturm-Liouville problem in two cases: the first case having no singularity and the second case having a singularity at zero. Then, we calculate the eigenvalues and the nodal points and present the uniqueness theorem for the solution of the inverse problem by using a dense subset of the nodal points in two given cases. Also, we use Chebyshev polynomials of the first kind for calculating the approximate solution of the inverse nodal problem in these cases. Finally, we...

  1. Using nodal expansion method in calculation of reactor core with square fuel assemblies

    International Nuclear Information System (INIS)

    Abdollahzadeh, M. Y.; Boroushaki, M.

    2009-01-01

    A polynomial nodal method is developed to solve few-group neutron diffusion equations in cartesian geometry. In this article, the effective multiplication factor, group flux and power distribution based on the nodal polynomial expansion procedure is presented. In addition, by comparison of the results the superiority of nodal expansion method on finite-difference and finite-element are fully demonstrated. The comparison of the results obtained by these method with those of the well known benchmark problems have shown that they are in very good agreement.

  2. [Method for optimal sensor placement in water distribution systems with nodal demand uncertainties].

    Science.gov (United States)

    Liu, Shu-Ming; Wu, Xue; Ouyang, Le-Yan

    2013-08-01

    The notion of identification fitness was proposed for optimizing sensor placement in water distribution systems. Nondominated Sorting Genetic Algorithm II was used to find the Pareto front between minimum overlap of possible detection times of two events and the best probability of detection, taking nodal demand uncertainties into account. This methodology was applied to an example network. The solutions show that the probability of detection and the number of possible locations are not remarkably affected by nodal demand uncertainties, but the sources identification accuracy declines with nodal demand uncertainties.

  3. The application of modern nodal methods to PWR reactor physics analysis

    International Nuclear Information System (INIS)

    Knight, M.P.

    1988-06-01

    The objective of this research is to develop efficient computational procedures for PWR reactor calculations, based on modern nodal methods. The analytic nodal method, which is characterised by the use of exact exponential expansions in transverse-integrated equations, is implemented within an existing finite-difference code. This shows considerable accuracy and efficiency on standard benchmark problems, very much in line with existing experience with nodal methods., Assembly powers can be calculated to within 2.0% with just one mesh per assembly. (author)

  4. A variational nodal diffusion method of high accuracy; Varijaciona nodalna difuziona metoda visoke tachnosti

    Energy Technology Data Exchange (ETDEWEB)

    Tomasevic, Dj; Altiparmarkov, D [Institut za Nuklearne Nauke Boris Kidric, Belgrade (Yugoslavia)

    1988-07-01

    A variational nodal diffusion method with accurate treatment of transverse leakage shape is developed and presented in this paper. Using Legendre expansion in transverse coordinates higher order quasi-one-dimensional nodal equations are formulated. Numerical solution has been carried out using analytical solutions in alternating directions assuming Legendre expansion of the RHS term. The method has been tested against 2D and 3D IAEA benchmark problem, as well as 2D CANDU benchmark problem. The results are highly accurate. The first order approximation yields to the same order of accuracy as the standard nodal methods with quadratic leakage approximation, while the second order reaches reference solution. (author)

  5. Counter traction makes endoscopic submucosal dissection easier.

    Science.gov (United States)

    Oyama, Tsuneo

    2012-11-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.

  6. Effective imaging of carotid artery dissection

    International Nuclear Information System (INIS)

    Obradovis, G.

    1997-01-01

    Angiography has been the gold standard in the diagnosis of arterial dissection for many years. With recent advances in techniques, particularly in MRI it may be worthy to re-evaluate the imaging methods available in obtaining the most information to maxims the patients' level of management. Assessing the imaging methods used in four patients with clinically suspected carotid artery dissection may reveal the most appropriate clinical pathway in managing these types of patients. In today's economic environment, we are striving for the most cost-effective imaging methods combined with the least invasive and safest. We must also review the cost benefit analysis of CT, angiography (DSA), Doppler Ultrasound and MRI/MRA. It is not within the scope of this paper to argue the merits of each imaging method, but purely to present some of the benefits in using non-invasive techniques if the clinical indications warrant them and they are available. (author)

  7. Regional nodal relapse in surgically staged Merkel cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Hoeller, Ulrike; Mueller, Thomas; Schubert, Tina; Budach, Volker; Ghadjar, Pirus [Charite Universitaetsmedizin Berlin, Department of Radiation Oncology, Berlin (Germany); Brenner, Winfried [Charite Universitaetsmedizin Berlin, Department of Nuclear Medicine, Berlin (Germany); Kiecker, Felix [Charite Universitaetsmedizin Berlin, Department of Dermatology, Berlin (Germany); Schicke, Bernd [Tumor Center Berlin, Berlin (Germany); Haase, Oliver [Charite Universitaetsmedizin Berlin, Department of Surgery, Berlin (Germany)

    2014-10-08

    The nodal relapse pattern of surgically staged Merkel cell carcinoma (MCC) with/without elective nodal radiotherapy (RT) was studied in a single institution. A total of 51 patients with MCC, 33 % UICC stage I, 14 % II, 53 % III (4 lymph node metastases of unknown primary) were eligible. All patients had surgical staging: 23 patients sentinel node biopsy (SNB), 22 patients SNB followed by lymphadenectomy (LAD) and 6 patients LAD. In all, 94 % of the primary tumors (PT) were completely resected; 57 % of patients received RT, 51 % of known PT sites, 33 % (8/24 patients) regional RT to snN0 nodes and 68 % (17/27 patients) to pN+ nodes, mean reference dose 51.5 and 50 Gy, respectively. Mean follow-up was 6 years (range 2-14 years). A total of 22 % (11/51) patients developed regional relapses (RR); the 5-year RR rate was 27 %. In snN0 sites (stage I/II), relapse occurred in 5 of 14 nonirradiated vs. none of 8 irradiated sites (p = 0.054), resulting in a 5-year RR rate of 33 % versus 0 % (p = 0.16). The crude RR rate was lower in stage I (12 %, 2/17 patients) than for stage II (43 %, 3/7 patients). In stage III (pN+), RR appeared to be less frequent in irradiated sites (18 %, 3/14 patients) compared with nonirradiated sites (33 %, 3/10 patients, p = 0.45) with 5-year RR rates of 23 % vs. 34 %, respectively. Our data suggest that adjuvant nodal RT plays a major role even if the sentinel nodes were negative. Adjuvant RT of the lymph nodes in patients with stage IIa tumors and RT after LAD in stage III tumors is proposed and should be evaluated prospectively. (orig.) [German] Untersucht wurde das regionaere Rezidivmuster des Merkelzell-Karzinoms (MCC) nach chirurgischem Staging und stadienadaptierter Therapie. Eingeschlossen wurden 51 Patienten mit lokalisiertem MCC: 33 % hatten UICC-Stadium-I-, 14 % -II-, 53 % -III-Tumoren (davon 4 Lymphknotenmetastasen eines unbekannten Primaertumors). Alle Patienten erhielten ein chirurgisches Staging: 23 Waechterlymphknotenbiopsien (SNB

  8. Whole vitreous humor dissection for vitreodynamic analysis.

    Science.gov (United States)

    Murali, Karthik; Kashani, Amir H; Humayun, Mark S

    2015-05-24

    The authors propose an effective technique to isolate whole, intact vitreous core and cortex from post mortem enucleated porcine eyes. While previous studies have shown the results of such dissections, the detailed steps have not been described, precluding researchers outside the field from replicating their methods. Other studies harvest vitreous either through aspiration, which does not maintain the vitreous structure anatomy, or through partial dissection, which only isolates the vitreous core. The proposed method isolates the whole vitreous body, with the vitreous core and cortex intact, while maintaining vitreous anatomy and structural integrity. In this method, a full thickness scleral flap in an enucleated porcine eye is first created and through this, the choroid tissue can be separated from the sclera. The scleral flap is then expanded and the choroid is completely separated from the sclera. Finally the choroid-retina tissue is peeled off the vitreous to leave an isolated intact vitreous body. The proposed vitreous dissection technique can be used to study physical properties of the vitreous humor. In particular, this method has significance for experimental studies involving drug delivery, vitreo-retinal oxygen transport, and intraocular convection.

  9. Acute aortic dissection: be aware of misdiagnosis

    Directory of Open Access Journals (Sweden)

    Asteri Theodora

    2009-02-01

    Full Text Available Abstract Background Acute aortic dissection (AAD is a life-threatening condition requiring immediate assessment and therapy. A patient suffering from AAD often presents with an insignificant or irrelevant medical history, giving rise to possible misdiagnosis. The aim of this retrospective study is to address the problem of misdiagnosing AD and the different imaging studies used. Methods From January 2000 to December 2004, 49 patients (41 men and 8 women, aged from 18–75 years old presented to the Emergency Department of our hospital for different reasons and finally diagnosed with AAD. Fifteen of those patients suffered from arterial hypertension, one from giant cell arteritis and another patient from Marfan's syndrome. The diagnosis of AAD was made by chest X-ray, contrast enhanced computed tomography (CT, transthoracic echocardiography (TTE and coronary angiography. Results Initial misdiagnosis occurred in fifteen patients (31% later found to be suffering from AAD. The misdiagnosis was myocardial infarction in 12 patients and cerebral infarction in another three patients. Conclusion Aortic dissection may present with a variety of clinical manifestations, like syncope, chest pain, anuria, pulse deficits, abdominal pain, back pain, or acute congestive heart failure. Nearly a third of the patients found to be suffering from AD, were initially otherwise diagnosed. Key in the management of acute aortic dissection is to maintain a high level of suspicion for this diagnosis.

  10. Assessment of stent edge dissections by fractional flow reserve.

    Science.gov (United States)

    Chung, Ju-Hyun; Ann, Soe Hee; Koo, Bon-Kwon; Nam, Chang-Wook; Doh, Joon-Hyung; Singh, Gillian Balbir; Kim, Hyung Il; Shin, Eun-Seok

    2015-04-15

    Edge dissections after intervention have been studied with imaging techniques, however, functional assessment has not been studied yet. We investigated the relationship between fractional flow reserve (FFR) and the angiographic type of stent edge dissections and tried to assess the use of FFR-guided management for edge dissection. 51 edge dissections assessed by FFR were included in this prospective observational study. FFR was measured for each type of edge dissection and compared with quantitative coronary angiographic findings. Clinical outcomes were evaluated based on FFR measurements. Edge dissections were classified as type A (47.1%; 24/51), type B (41.2%; 21/51), type C (2.0%; 1/51) and type D (9.8%; 5/51). Mean FFR in type A dissection was 0.87 ± 0.09, in type B 0.86 ± 0.07, in type C 0.72 and in type D 0.57 ± 0.08. All type C and D dissections (6/51) had FFR ≤ 0.8 and were treated with additional stents. Among the 45 type A and B dissections, 8 had a FFR ≤ 0.8 (17.8%), and 50% received additional stenting. All dissections with FFR >0.8 were left untreated except one long dissection case. There was no death, myocardial infarction or target lesion revascularization during hospitalization or the follow-up period (median 152 days; IQR 42-352 days). FFR correlates well with an angiographic type of edge dissection. Angiographic findings are sufficient for deciding the treatment of severe dissections such as types C and D, while FFR-guided management may be safe and effective for mild edge dissections such as types A and B. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. MRI and MR angiography of vertebral artery dissection

    International Nuclear Information System (INIS)

    Mascalchi, M.; Bianchi, M.C.; Mangiafico, S.; Ferrito, G.; Puglioli, M.; Marin, E.; Mugnai, S.; Canapicchi, R.; Quilici, N.; Inzitari, D.

    1997-01-01

    A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3-20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients. (orig.). With 7 figs., 3 tabs

  12. Hybrid nodal methods in the solution of the diffusion equations in X Y geometry; Metodos nodales hibridos en la solucion de las ecuaciones de difusion en geometria XY

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, N. [CFE, Carretera Cardel-Nautla Km. 43.5, 91680 Veracruz (Mexico); Alonso V, G.; Valle G, E. del [IPN-ESFM, 07738 Mexico D.F. (Mexico)]. e-mail: nhmiranda@mexico.com

    2003-07-01

    In 1979, Hennart and collaborators applied several schemes of classic finite element in the numerical solution of the diffusion equations in X Y geometry and stationary state. Almost two decades then, in 1996, himself and other collaborators carried out a similar work but using nodal schemes type finite element. Continuing in this last direction, in this work a group it is described a set of several Hybrid Nodal schemes denominated (NH) as well as their application to solve the diffusion equations in multigroup in stationary state and X Y geometry. The term hybrid nodal it means that such schemes interpolate not only Legendre moments of face and of cell but also the values of the scalar flow of neutrons in the four corners of each cell or element of the spatial discretization of the domain of interest. All the schemes here considered are polynomials like they were it their predecessors. Particularly, its have developed and applied eight different hybrid nodal schemes that its are very nearby related with those developed by Hennart and collaborators in the past. It is treated of schemes in those that nevertheless that decreases the number of interpolation parameters it is conserved the accurate in relation to the bi-quadratic and bi-cubic schemes. Of these eight, three were described and applied in a previous work. It is the bi-lineal classic scheme as well as the hybrid nodal schemes, bi-quadratic and bi-cubic for that here only are described the other 5 hybrid nodal schemes although they are provided numerical results for several test problems with all them. (Author)

  13. Molecular pathogenesis of splenic and nodal marginal zone lymphoma.

    Science.gov (United States)

    Spina, Valeria; Rossi, Davide

    Genomic studies have improved our understanding of the biological basis of splenic (SMZL) and nodal (NMZL) marginal zone lymphoma by providing a comprehensive and unbiased view of the genes/pathways that are deregulated in these diseases. Consistent with the physiological involvement of NOTCH, NF-κB, B-cell receptor and toll-like receptor signaling in mature B-cells differentiation into the marginal zone B-cells, many oncogenic mutations of genes involved in these pathways have been identified in SMZL and NMZL. Beside genetic lesions, also epigenetic and post-transcriptional modifications contribute to the deregulation of marginal zone B-cell differentiation pathways in SMZL and NMZL. This review describes the progress in understanding the molecular mechanism underlying SMZL and NMZL, including molecular and post-transcriptional modifications, and discusses how information gained from these efforts has provided new insights on potential targets of diagnostic, prognostic and therapeutic relevance in SMZL and NMZL. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Micropropagation of Calophyllum brasiliense (Cambess.) from nodal segments.

    Science.gov (United States)

    Silveira, S S; Cordeiro-Silva, R; Degenhardt-Goldbach, J; Quoirin, M

    2016-05-03

    Micropropagation of Calophyllum brasiliense Cambess. (Clusiaceae) is a way to overcome difficulties in achieving large-scale plant production, given the recalcitrant nature of the seeds, irregular fructification and absence of natural vegetative propagation of the species. Cultures were established using nodal segments 2 cm in length, obtained from 1-2 year old seedlings, maintained in a greenhouse. Mercury chloride and Plant Preservative Mixture™ were used in the surface sterilizing stage, better results being achieved with Plant Preservative Mixture™ incorporation in culture medium, at any concentration. Polyvinylpyrrolidone, activated charcoal, cysteine, ascorbic acid or citric acid were added to the culture medium to avoid oxidation. After 30 days of culture, polyvinylpirrolidone and ascorbic acid gave better results, eliminating oxidation in most explants. For shoot multiplication, benzylaminopurine was used in concentrations of 4.4 and 8.8 µM in Woody Plant Medium, resulting in an average of 4.43 and 4.68 shoots per explant, respectively, after 90 days. Indole-3-butyric acid and α-naphthalene acetic acid were used to induce root formation, reaching a maximum rooting rate of 24% with 20µM α-naphthalene acetic acid. For acclimatization. the rooted plants were transferred to Plantmax® substrate and cultured in a greenhouse, reaching 79% of survival after 30 days and 60% after one year.

  15. Relevance of regional nodal management in multimodality esophageal cancer treatment

    International Nuclear Information System (INIS)

    Wong, J.; Perez-Tamayo, C.; Takasugi, B.; Orringer, M.B.; Flint, A.; Lichter, A.S.

    1986-01-01

    A prospective study has been undertaken at the University of Michigan Hospital, where patients with distal esophageal carcinoma receive concurrent radiation therapy (3,750 cGy delivered in 15 fractions) and systemic chemotherapy (cisplatin, Velban, 5-FU), followed by blunt esophagectomy with exploration and lymph node sampling. Strict pathologic screening and handling of nodal tissue and esophagectomy specimens were analyzed. Eighteen patients with distal esophageal lesions ranging from 5 to 12 cm (average, 7 cm) detected on the initial barium swallow study have been seen to date. In three of these patients celiac axis involvement has been demonstrated on CT. All primary lesions were confirmed by biopsy. Five were found to be squamous cell carcinoma and thirteen were adenocarcinomas. One of 15 of the presently evaluable patients (5%) had microscopic involvement of a celiac node at surgery. Celiac, lesser curvature, and superior gastric nodes where all encompassed in the radiation therapy portals to the aforementioned dose. CT scan planning was done in all patients. This added volume was well tolerated by the patients without morbidity

  16. Topological Nodal Cooper Pairing in Doped Weyl Metals

    Science.gov (United States)

    Li, Yi; Haldane, F. D. M.

    2018-02-01

    We generalize the concept of Berry connection of the single-electron band structure to that of a two-particle Cooper pairing state between two Fermi surfaces with opposite Chern numbers. Because of underlying Fermi surface topology, the pairing Berry phase acquires nontrivial monopole structure. Consequently, pairing gap functions have topologically protected nodal structure as vortices in the momentum space with the total vorticity solely determined by the pair monopole charge qp. The nodes of gap function behave as the Weyl-Majorana points of the Bogoliubov-de Gennes pairing Hamiltonian. Their relation with the connection patterns of the surface modes from the Weyl band structure and the Majorana surface modes inside the pairing gap is also discussed. Under the approximation of spherical Fermi surfaces, the pairing symmetry are represented by monopole harmonic functions. The lowest possible pairing channel carries angular momentum number j =|qp|, and the corresponding gap functions are holomorphic or antiholomorphic functions on Fermi surfaces. After projected on the Fermi surfaces with nontrivial topology, all the partial-wave channels of pairing interactions acquire the monopole charge qp independent of concrete pairing mechanism.

  17. Application of the SPH method in nodal diffusion analyses of SFR cores

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Evgeny; Fridman, Emil [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Reactor Safety; Mikityuk, K. [Paul Scherrer Institut, Villigen (Switzerland)

    2016-07-01

    The current study investigated the potential of the SPH method, applied to correct the few-group XS produced by Serpent, to further improve the accuracy of the nodal diffusion solutions. The procedure for the generation of SPH-corrected few-group XS is presented in the paper. The performance of the SPH method was tested on a large oxide SFR core from the OECD/NEA SFR benchmark. The reference SFR core was modeled with the DYN3D and PARCS nodal diffusion codes using the SPH-corrected few-group XS generated by Serpent. The nodal diffusion results obtained with and without SPH correction were compared to the reference full-core Serpent MC solution. It was demonstrated that the application of the SPH method improves the accuracy of the nodal diffusion solutions, particularly for the rodded core state.

  18. A Hybrid Interpolation Method for Geometric Nonlinear Spatial Beam Elements with Explicit Nodal Force

    Directory of Open Access Journals (Sweden)

    Huiqing Fang

    2016-01-01

    Full Text Available Based on geometrically exact beam theory, a hybrid interpolation is proposed for geometric nonlinear spatial Euler-Bernoulli beam elements. First, the Hermitian interpolation of the beam centerline was used for calculating nodal curvatures for two ends. Then, internal curvatures of the beam were interpolated with a second interpolation. At this point, C1 continuity was satisfied and nodal strain measures could be consistently derived from nodal displacement and rotation parameters. The explicit expression of nodal force without integration, as a function of global parameters, was founded by using the hybrid interpolation. Furthermore, the proposed beam element can be degenerated into linear beam element under the condition of small deformation. Objectivity of strain measures and patch tests are also discussed. Finally, four numerical examples are discussed to prove the validity and effectivity of the proposed beam element.

  19. ANOVA-HDMR structure of the higher order nodal diffusion solution

    International Nuclear Information System (INIS)

    Bokov, P. M.; Prinsloo, R. H.; Tomasevic, D. I.

    2013-01-01

    Nodal diffusion methods still represent a standard in global reactor calculations, but employ some ad-hoc approximations (such as the quadratic leakage approximation) which limit their accuracy in cases where reference quality solutions are sought. In this work we solve the nodal diffusion equations utilizing the so-called higher-order nodal methods to generate reference quality solutions and to decompose the obtained solutions via a technique known as High Dimensional Model Representation (HDMR). This representation and associated decomposition of the solution provides a new formulation of the transverse leakage term. The HDMR structure is investigated via the technique of Analysis of Variance (ANOVA), which indicates why the existing class of transversely-integrated nodal methods prove to be so successful. Furthermore, the analysis leads to a potential solution method for generating reference quality solutions at a much reduced calculational cost, by applying the ANOVA technique to the full higher order solution. (authors)

  20. Concomitant occurrence of sinus histiocytosis with massive lymphadenopathy and nodal marginal zone lymphoma.

    Science.gov (United States)

    Pang, Changlee S; Grier, David D; Beaty, Michael W

    2011-03-01

    Sinus histiocytosis with massive lymphadenopathy (SHML), also known as Rosai-Dorfman disease, is a rare self-limiting disorder of histiocytes with unknown etiology. Sinus histiocytosis with massive lymphadenopathy is most common in children and young adults and is characterized by painless lymphadenopathy. Histologically there is a proliferation of sinus histiocytes with lymphophagocytosis or emperipolesis. On rare occasions, SHML has been associated with lymphoma, usually involving different anatomic sites and developing at different times. We report a case of concomitant SHML and nodal marginal zone lymphoma involving the same lymph node without involvement of other nodal or extranodal sites. The presence of concomitant SHML within the lymph node involved by nodal marginal zone lymphoma may represent the responsiveness of SHML histiocytes to B-cell-derived cytokines in lymphoproliferative disorders. To our knowledge, this is the first description of concomitant occurrence of SHML and nodal marginal zone lymphoma.

  1. MicroRNA expression in nodal and extranodal Diffuse Large B-cell Lymphoma

    DEFF Research Database (Denmark)

    Mandrup, Charlotte; Petersen, Anders; Højfeldt, Anne Dirks

    MicroRNA expression in nodal and extranodal Diffuse Large B-cell Lymphoma   C. Mandrup1, A. Petersen1, A. D. Hoejfeldt1, H. F. Thomsen1, J. Madsen1, J. Dahlgaard1, P. Johansen2, A. Bukh1, K. Dybkaer1 and H. E Johnsen1. 1Department of Hematology, 2Pathological Institute, Aalborg Hospital, Aarhus...... University Hospital, Aalborg, Denmark Introduction: The aim of this project was to analyse microRNA (miRNA) expression in nodal and extranodal diffuse large B-cell lymphoma (DLBCL). Manifestation at diagnosis may be nodal and/or extranodal. At present, there are no known determinants for none...... of the manifestations, and no way to predict the potential progression from nodal to extranodal disease. miRNA are small regulatory RNA molecules with core function to repress/cleave sequence complementary mRNA targets. Abnormalities in miRNA genetics and expression are known to affect initiation and development...

  2. Exclusion of elective nodal irradiation is associated with minimal elective nodal failure in non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Cox James D

    2009-01-01

    Full Text Available Abstract Background Controversy still exists regarding the long-term outcome of patients whose uninvolved lymph node stations are not prophylactically irradiated for non-small cell lung cancer (NSCLC treated with definitive radiotherapy. To determine the frequency of elective nodal failure (ENF and in-field failure (IFF, we examined a large cohort of patients with NSCLC staged with positron emission tomography (PET/computed tomography (CT and treated with 3-dimensional conformal radiotherapy (3D-CRT that excluded uninvolved lymph node stations. Methods We retrospectively reviewed the records of 115 patients with non-small cell lung cancer treated at our institution with definitive radiation therapy with or without concurrent chemotherapy (CHT. All patients were treated with 3D-CRT, including nodal regions determined by CT or PET to be disease involved. Concurrent platinum-based CHT was administered for locally advanced disease. Patients were analyzed in follow-up for survival, local regional recurrence, and distant metastases (DM. Results The median follow-up time was 18 months (3 to 44 months among all patients and 27 months (6 to 44 months among survivors. The median overall survival, 2-year actuarial overall survival and disease-free survival were 19 months, 38%, and 28%, respectively. The majority of patients died from DM, the overall rate of which was 36%. Of the 31 patients with local regional failure, 26 (22.6% had IFF, 5 (4.3% had ENF and 2 (1.7% had isolated ENF. For 88 patients with stage IIIA/B, the frequencies of IFF, any ENF, isolated ENF, and DM were 23 (26%, 3 (9%, 1 (1.1% and 36 (40.9%, respectively. The comparable rates for the 22 patients with early stage node-negative disease (stage IA/IB were 3 (13.6%, 1(4.5%, 0 (0%, and 5 (22.7%, respectively. Conclusion We observed only a 4.3% recurrence of any ENF and a 1.7% recurrence of isolated ENF in patients with NSCLC treated with definitive 3D-CRT without prophylactic irradiation of

  3. Exclusion of elective nodal irradiation is associated with minimal elective nodal failure in non-small cell lung cancer

    International Nuclear Information System (INIS)

    Sulman, Erik P; Komaki, Ritsuko; Klopp, Ann H; Cox, James D; Chang, Joe Y

    2009-01-01

    Controversy still exists regarding the long-term outcome of patients whose uninvolved lymph node stations are not prophylactically irradiated for non-small cell lung cancer (NSCLC) treated with definitive radiotherapy. To determine the frequency of elective nodal failure (ENF) and in-field failure (IFF), we examined a large cohort of patients with NSCLC staged with positron emission tomography (PET)/computed tomography (CT) and treated with 3-dimensional conformal radiotherapy (3D-CRT) that excluded uninvolved lymph node stations. We retrospectively reviewed the records of 115 patients with non-small cell lung cancer treated at our institution with definitive radiation therapy with or without concurrent chemotherapy (CHT). All patients were treated with 3D-CRT, including nodal regions determined by CT or PET to be disease involved. Concurrent platinum-based CHT was administered for locally advanced disease. Patients were analyzed in follow-up for survival, local regional recurrence, and distant metastases (DM). The median follow-up time was 18 months (3 to 44 months) among all patients and 27 months (6 to 44 months) among survivors. The median overall survival, 2-year actuarial overall survival and disease-free survival were 19 months, 38%, and 28%, respectively. The majority of patients died from DM, the overall rate of which was 36%. Of the 31 patients with local regional failure, 26 (22.6%) had IFF, 5 (4.3%) had ENF and 2 (1.7%) had isolated ENF. For 88 patients with stage IIIA/B, the frequencies of IFF, any ENF, isolated ENF, and DM were 23 (26%), 3 (9%), 1 (1.1%) and 36 (40.9%), respectively. The comparable rates for the 22 patients with early stage node-negative disease (stage IA/IB) were 3 (13.6%), 1(4.5%), 0 (0%), and 5 (22.7%), respectively. We observed only a 4.3% recurrence of any ENF and a 1.7% recurrence of isolated ENF in patients with NSCLC treated with definitive 3D-CRT without prophylactic irradiation of uninvolved lymph node stations. Thus

  4. Intra nodal reconstruction of the numerical solution generated by the spectro nodal constant for Sn problems of eigenvalues in two-dimensional rectangular geometry

    International Nuclear Information System (INIS)

    Menezes, Welton Alves de

    2009-01-01

    In this dissertation the spectral nodal method SD-SGF-CN, cf. spectral diamond - spectral Green's function - constant nodal, is used to determine the angular fluxes averaged along the edges of the homogenized nodes in heterogeneous domains. Using these results, we developed an algorithm for the reconstruction of the node-edge average angular fluxes within the nodes of the spatial grid set up on the domain, since more localized numerical solutions are not generated by coarse-mesh numerical methods. Numerical results are presented to illustrate the accuracy of the algorithm we offer. (author)

  5. A study of the literature on nodal methods in reactor physics calculations

    International Nuclear Information System (INIS)

    Van de Wetering, T.F.H.

    1993-01-01

    During the last few decades several calculation methods have been developed for the three-dimensional analysis of a reactor core. A literature survey was carried out to gain insights in the starting points and method of operation of the advanced nodal methods. These methods are applied in reactor core analyses of large nuclear power reactors, because of their high computing speed. The so-called Nodal-Expansion method is described in detail

  6. Late sequelae of whiplash injury with dissection of cervical arteries.

    Science.gov (United States)

    Hauser, Vital; Zangger, Peter; Winter, Yaroslav; Oertel, Wolfgang; Kesselring, Jürg

    2010-01-01

    The objective of our study was to estimate the incidence of posttraumatic dissections of cervical arteries in patients with whiplash injury acquired in a car accident. We performed a retrospective analysis of medical records of 500 patients with whiplash injury acquired in car accidents between 1996 and 2005 and searched for dissections of cervical arteries occurring within 12 months after injury. Eight cases of cervical arterial dissection occurred within 12 months following whiplash injury. In 7 cases (87.5%), the dissection was complicated by brain infarction. The incidence of posttraumatic dissections after whiplash injuries was much higher than the overall incidence of cervical arterial dissections in the general population (1.6 vs. 0.0041%). The risk of cerebrovascular events was still increased 4-12 months after whiplash injury (0.6 vs. 0.003075% in the general population). There is an increased risk of posttraumatic dissection and cerebrovascular events within 12 months after whiplash injury. Car accident is an important risk factor for arterial dissections. The victims of car accidents should be screened for arterial dissections. The results of this study should be more thoroughly investigated in a prospective trial of car accident victims as a risk factor for arterial dissections. Copyright © 2010 S. Karger AG, Basel.

  7. MR imaging of the entry, the abdominal communicating orifice, and the retrograde dissection in aortic dissections

    International Nuclear Information System (INIS)

    Yoshida, Y.; Mukohara, N.; Nakamura, K.; Sugimura, K.; Kono, M.

    1986-01-01

    MR imaging (1.5 T) was performed on 41 patients with aortic dissection. Entries were clearly visualized on the MR images as partial defects of the intimal flap in 18 of 21 patients (85.7%). In eight of ten patients, the locations of abdominal communicating orifices corresponded to the lowest signal intensities of the false lumina. Retrograde disections were diagnosed in all six patients from gradual increases in signal intensities of the false lumina toward the heart. MR imaging was very useful in diagnosing entries of the thoracic aorta, abdominal communicating orifices between true and false lumina, and retrograde dissections

  8. Cilia are required for asymmetric nodal induction in the sea urchin embryo.

    Science.gov (United States)

    Tisler, Matthias; Wetzel, Franziska; Mantino, Sabrina; Kremnyov, Stanislav; Thumberger, Thomas; Schweickert, Axel; Blum, Martin; Vick, Philipp

    2016-08-23

    Left-right (LR) organ asymmetries are a common feature of metazoan animals. In many cases, laterality is established by a conserved asymmetric Nodal signaling cascade during embryogenesis. In most vertebrates, asymmetric nodal induction results from a cilia-driven leftward fluid flow at the left-right organizer (LRO), a ciliated epithelium present during gastrula/neurula stages. Conservation of LRO and flow beyond the vertebrates has not been reported yet. Here we study sea urchin embryos, which use nodal to establish larval LR asymmetry as well. Cilia were found in the archenteron of embryos undergoing gastrulation. Expression of foxj1 and dnah9 suggested that archenteron cilia were motile. Cilia were polarized to the posterior pole of cells, a prerequisite of directed flow. High-speed videography revealed rotating cilia in the archenteron slightly before asymmetric nodal induction. Removal of cilia through brief high salt treatments resulted in aberrant patterns of nodal expression. Our data demonstrate that cilia - like in vertebrates - are required for asymmetric nodal induction in sea urchin embryos. Based on these results we argue that the anterior archenteron represents a bona fide LRO and propose that cilia-based symmetry breakage is a synapomorphy of the deuterostomes.

  9. Solution and Study of the Two-Dimensional Nodal Neutron Transport Equation

    International Nuclear Information System (INIS)

    Panta Pazos, Ruben; Biasotto Hauser, Eliete; Tullio de Vilhena, Marco

    2002-01-01

    In the last decade Vilhena and coworkers reported an analytical solution to the two-dimensional nodal discrete-ordinates approximations of the neutron transport equation in a convex domain. The key feature of these works was the application of the combined collocation method of the angular variable and nodal approach in the spatial variables. By nodal approach we mean the transverse integration of the SN equations. This procedure leads to a set of one-dimensional S N equations for the average angular fluxes in the variables x and y. These equations were solved by the old version of the LTS N method, which consists in the application of the Laplace transform to the set of nodal S N equations and solution of the resulting linear system by symbolic computation. It is important to recall that this procedure allow us to increase N the order of S N up to 16. To overcome this drawback we step forward performing a spectral painstaking analysis of the nodal S N equations for N up to 16 and we begin the convergence of the S N nodal equations defining an error for the angular flux and estimating the error in terms of the truncation error of the quadrature approximations of the integral term. Furthermore, we compare numerical results of this approach with those of other techniques used to solve the two-dimensional discrete approximations of the neutron transport equation. (authors)

  10. Advances in the solution of three-dimensional nodal neutron transport equation

    International Nuclear Information System (INIS)

    Pazos, Ruben Panta; Hauser, Eliete Biasotto; Vilhena, Marco Tullio de

    2003-01-01

    In this paper we study the three-dimensional nodal discrete-ordinates approximations of neutron transport equation in a convex domain with piecewise smooth boundaries. We use the combined collocation method of the angular variables and nodal approach for the spatial variables. By nodal approach we mean the iterated transverse integration of the S N equations. This procedure leads to the set of one-dimensional averages angular fluxes in each spatial variable. The resulting system of equations is solved with the LTS N method, first applying the Laplace transform to the set of the nodal S N equations and then obtaining the solution by symbolic computation. We include the LTS N method by diagonalization to solve the nodal neutron transport equation and then we outline the convergence of these nodal-LTS N approximations with the help of a norm associated to the quadrature formula used to approximate the integral term of the neutron transport equation. We give numerical results obtained with an algebraic computer system (for N up to 8) and with a code for higher values of N. We compare our results for the geometry of a box with a source in a vertex and a leakage zone in the opposite with others techniques used in this problem. (author)

  11. The implementation of a simplified spherical harmonics semi-analytic nodal method in PANTHER

    International Nuclear Information System (INIS)

    Hall, S.K.; Eaton, M.D.; Knight, M.P.

    2013-01-01

    Highlights: ► An SP N nodal method is proposed. ► Consistent CMFD derived and tested. ► Mark vacuum boundary conditions applied. ► Benchmarked against other diffusions and transport codes. - Abstract: In this paper an SP N nodal method is proposed which can utilise existing multi-group neutron diffusion solvers to obtain the solution. The semi-analytic nodal method is used in conjunction with a coarse mesh finite difference (CMFD) scheme to solve the resulting set of equations. This is compared against various nuclear benchmarks to show that the method is capable of computing an accurate solution for practical cases. A few different CMFD formulations are implemented and their performance compared. It is found that the effective diffusion coefficent (EDC) can provide additional stability and require less power iterations on a coarse mesh. A re-arrangement of the EDC is proposed that allows the iteration matrix to be computed at the beginning of a calculation. Successive nodal updates only modify the source term unlike existing CMFD methods which update the iteration matrix. A set of Mark vacuum boundary conditions are also derived which can be applied to the SP N nodal method extending its validity. This is possible due to a similarity transformation of the angular coupling matrix, which is used when applying the nodal method. It is found that the Marshak vacuum condition can also be derived, but would require the significant modification of existing neutron diffusion codes to implement it

  12. Multiarea Transmission Cost Allocation in Large Power Systems Using the Nodal Pricing Control Approach

    Directory of Open Access Journals (Sweden)

    M. Ghayeni

    2010-12-01

    Full Text Available This paper proposes an algorithm for transmission cost allocation (TCA in a large power system based on nodal pricing approach using the multi-area scheme. The nodal pricing approach is introduced to allocate the transmission costs by the control of nodal prices in a single area network. As the number of equations is dependent on the number of buses and generators, this method will be very time consuming for large power systems. To solve this problem, the present paper proposes a new algorithm based on multi-area approach for regulating the nodal prices, so that the simulation time is greatly reduced and therefore the TCA problem with nodal pricing approach will be applicable for large power systems. In addition, in this method the transmission costs are allocated to users more equitable. Since the higher transmission costs in an area having a higher reliability are paid only by users of that area in contrast with the single area method, in which these costs are allocated to all users regardless of their locations. The proposed method is implemented on the IEEE 118 bus test system which comprises three areas. Results show that with application of multi-area approach, the simulation time is greatly reduced and the transmission costs are also allocated to users with less variation in new nodal prices with respect to the single area approach.

  13. A quasi-static polynomial nodal method for nuclear reactor analysis

    International Nuclear Information System (INIS)

    Gehin, J.C.

    1992-09-01

    Modern nodal methods are currently available which can accurately and efficiently solve the static and transient neutron diffusion equations. Most of the methods, however, are limited to two energy groups for practical application. The objective of this research is the development of a static and transient, multidimensional nodal method which allows more than two energy groups and uses a non-linear iterative method for efficient solution of the nodal equations. For both the static and transient methods, finite-difference equations which are corrected by the use of discontinuity factors are derived. The discontinuity factors are computed from a polynomial nodal method using a non-linear iteration technique. The polynomial nodal method is based upon a quartic approximation and utilizes a quadratic transverse-leakage approximation. The solution of the time-dependent equations is performed by the use of a quasi-static method in which the node-averaged fluxes are factored into shape and amplitude functions. The application of the quasi-static polynomial method to several benchmark problems demonstrates that the accuracy is consistent with that of other nodal methods. The use of the quasi-static method is shown to substantially reduce the computation time over the traditional fully-implicit time-integration method. Problems involving thermal-hydraulic feedback are accurately, and efficiently, solved by performing several reactivity/thermal-hydraulic updates per shape calculation

  14. A quasi-static polynomial nodal method for nuclear reactor analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gehin, Jess C. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1992-09-01

    Modern nodal methods are currently available which can accurately and efficiently solve the static and transient neutron diffusion equations. Most of the methods, however, are limited to two energy groups for practical application. The objective of this research is the development of a static and transient, multidimensional nodal method which allows more than two energy groups and uses a non-linear iterative method for efficient solution of the nodal equations. For both the static and transient methods, finite-difference equations which are corrected by the use of discontinuity factors are derived. The discontinuity factors are computed from a polynomial nodal method using a non-linear iteration technique. The polynomial nodal method is based upon a quartic approximation and utilizes a quadratic transverse-leakage approximation. The solution of the time-dependent equations is performed by the use of a quasi-static method in which the node-averaged fluxes are factored into shape and amplitude functions. The application of the quasi-static polynomial method to several benchmark problems demonstrates that the accuracy is consistent with that of other nodal methods. The use of the quasi-static method is shown to substantially reduce the computation time over the traditional fully-implicit time-integration method. Problems involving thermal-hydraulic feedback are accurately, and efficiently, solved by performing several reactivity/thermal-hydraulic updates per shape calculation.

  15. Topological crystalline superconductivity and second-order topological superconductivity in nodal-loop materials

    Science.gov (United States)

    Shapourian, Hassan; Wang, Yuxuan; Ryu, Shinsei

    2018-03-01

    We study the intrinsic fully gapped odd-parity superconducting order in doped nodal-loop materials with a torus-shaped Fermi surface. We show that the mirror symmetry, which protects the nodal loop in the normal state, also protects the superconducting state as a topological crystalline superconductor. As a result, the surfaces preserving the mirror symmetry host gapless Majorana cones. Moreover, for a Weyl-loop system (twofold degenerate at the nodal loop), the surfaces that break the mirror symmetry (those parallel to the bulk nodal loop) contribute a Chern (winding) number to the quasi-two-dimensional system in a slab geometry, which leads to a quantized thermal Hall effect and a single Majorana zero mode bound at a vortex line penetrating the system. This Chern number can be viewed as a higher-order topological invariant, which supports hinge modes in a cubic sample when mirror symmetry is broken. For a Dirac-loop system (fourfold degenerate at the nodal loop), the fully gapped odd-parity state can be either time-reversal symmetry-breaking or symmetric, similar to the A and B phases of 3He. In a slab geometry, the A phase has a Chern number two, while the B phase carries a nontrivial Z2 invariant. We discuss the experimental relevance of our results to nodal-loop materials such as CaAgAs.

  16. Optical conductivity of three and two dimensional topological nodal-line semimetals

    Science.gov (United States)

    Barati, Shahin; Abedinpour, Saeed H.

    2017-10-01

    The peculiar shape of the Fermi surface of topological nodal-line semimetals at low carrier concentrations results in their unusual optical and transport properties. We analytically investigate the linear optical responses of three- and two-dimensional nodal-line semimetals using the Kubo formula. The optical conductivity of a three-dimensional nodal-line semimetal is anisotropic. Along the axial direction (i.e., the direction perpendicular to the nodal-ring plane), the Drude weight has a linear dependence on the chemical potential at both low and high carrier dopings. For the radial direction (i.e., the direction parallel to the nodal-ring plane), this dependence changes from linear into quadratic in the transition from low into high carrier concentration. The interband contribution into optical conductivity is also anisotropic. In particular, at large frequencies, it saturates to a constant value for the axial direction and linearly increases with frequency along the radial direction. In two-dimensional nodal-line semimetals, no interband optical transition could be induced and the only contribution to the optical conductivity arises from the intraband excitations. The corresponding Drude weight is independent of the carrier density at low carrier concentrations and linearly increases with chemical potential at high carrier doping.

  17. Squamous cell carcinomas metastatic to cervical lymph nodes from an unknown head-and-neck mucosal site treated with radiation therapy alone or in combination with neck dissection

    International Nuclear Information System (INIS)

    Erkal, Haldun S.; Mendenhall, William M.; Amdur, Robert J.; Villaret, Douglas B.; Stringer, Scott P.

    2001-01-01

    Purpose: The present study presents the experience at the University of Florida with treatment of patients with squamous cell carcinomas (SCC) metastatic to cervical lymph nodes from an unknown head-and-neck mucosal (H and NM) site with radiotherapy (RT) alone or in combination with neck dissection (ND). Methods and Materials: The study included 126 patients treated with curative intent from 1964 to 1997. All patients had follow-up for at least 2 years. No patients were lost to follow-up. Results: Twelve patients (10%) developed SCC in H and NM sites at 0.5 to 10.9 years (median, 1.8 years). The rate of developing carcinomas in H and NM sites at 5 years was 13%. Histologic differentiation significantly affected the rate of developing carcinomas in H and NM sites in multivariate analysis. Sixteen patients (13%) had persistent nodal disease and 12 patients (10%) developed recurrent nodal disease at 0.5 to 10.9 years (median, 1.1 years). The nodal control rate at 5 years was 78%. Nodal size, N stage, and planned ND significantly affected the rate of nodal control in multivariate analysis. Nineteen patients (15%) developed distant metastasis at 0.2-5.1 years (median, 0.9 years). The distant metastases rate at 5 years was 14%. Extracapsular extension and RT dose significantly affected the risk of distant metastases in multivariate analysis. The overall absolute survival rate at 5 years was 47%. Extracapsular extension, N stage, RT dose for H and NM sites, and planned ND significantly affected absolute survival in multivariate analysis. The rate of cause-specific survival at 5 years was 67%. Extracapsular extension, nodal size, N stage, overall treatment time, and planned ND significantly affected cause-specific survival in multivariate analysis. Eight patients (6%) had severe postoperative complications and 6 patients (5%) had severe late complications. Conclusion: The present study supports the effectiveness of RT in lowering the rate of developing carcinomas in the H

  18. Pelvic lymph node dissection during robot-assisted radical prostatectomy: efficacy, limitations, and complications-a systematic review of the literature.

    Science.gov (United States)

    Ploussard, Guillaume; Briganti, Alberto; de la Taille, Alexandre; Haese, Alexander; Heidenreich, Axel; Menon, Mani; Sulser, Tullio; Tewari, Ashutosh K; Eastham, James A

    2014-01-01

    Pelvic lymph node dissection (PLND) in prostate cancer is the most effective method for detecting lymph node metastases. However, a decline in the rate of PLND during radical prostatectomy (RP) has been noted. This is likely the result of prostate cancer stage migration in the prostate-specific antigen-screening era, and the introduction of minimally invasive approaches such as robot-assisted radical prostatectomy (RARP). To assess the efficacy, limitations, and complications of PLND during RARP. A review of the literature was performed using the Medline, Scopus, and Web of Science databases with no restriction of language from January 1990 to December 2012. The literature search used the following terms: prostate cancer, radical prostatectomy, robot-assisted, and lymph node dissection. The median value of nodal yield at PLND during RARP ranged from 3 to 24 nodes. As seen in open and laparoscopic RP series, the lymph node positivity rate increased with the extent of dissection during RARP. Overall, PLND-only related complications are rare. The most frequent complication after PLND is symptomatic pelvic lymphocele, with occurrence ranging from 0% to 8% of cases. The rate of PLND-associated grade 3-4 complications ranged from 0% to 5%. PLND is associated with increased operative time. Available data suggest equivalence of PLND between RARP and other surgical approaches in terms of nodal yield, node positivity, and intraoperative and postoperative complications. PLND during RARP can be performed effectively and safely. The overall number of nodes removed, the likelihood of node positivity, and the types and rates of complications of PLND are similar to pure laparoscopic and open retropubic procedures. Copyright © 2013 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  19. TGF-β promotes glioma cell growth via activating Nodal expression through Smad and ERK1/2 pathways

    International Nuclear Information System (INIS)

    Sun, Jing; Liu, Su-zhi; Lin, Yan; Cao, Xiao-pan; Liu, Jia-ming

    2014-01-01

    Highlights: •TGF-β promoted Nodal expression in glioma cells. •TGF-β promoted Nodal expression via activating Smad and ERK1/2 pathways. •TGF-β promotes glioma cell growth via activating Nodal expression. -- Abstract: While there were certain studies focusing on the mechanism of TGF-β promoting the growth of glioma cells, the present work revealed another novel mechanism that TGF-β may promote glioma cell growth via enhancing Nodal expression. Our results showed that Nodal expression was significantly upregulated in glioma cells when TGF-β was added, whereas the TGF-β-induced Nodal expression was evidently inhibited by transfection Smad2 or Smad3 siRNAs, and the suppression was especially significant when the Smad3 was downregulated. Another, the attenuation of TGF-β-induced Nodal expression was observed with blockade of the ERK1/2 pathway also. Further detection of the proliferation, apoptosis, and invasion of glioma cells indicated that Nodal overexpression promoted the proliferation and invasion of tumor cells and inhibited their apoptosis, resembling the effect of TGF-β addition. Downregulation of Nodal expression via transfection Nodal-specific siRNA in the presence of TGF-β weakened the promoting effect of the latter on glioma cells growth, and transfecting Nodal siRNA alone in the absence of exogenous TGF-β more profoundly inhibited the growth of glioma cells. These results demonstrated that while both TGF-β and Nodal promoted glioma cells growth, the former might exert such effect by enhancing Nodal expression, which may form a new target for glioma therapy

  20. The orphan receptor ALK7 and the Activin receptor ALK4 mediate signaling by Nodal proteins during vertebrate development

    Science.gov (United States)

    Reissmann, Eva; Jörnvall, Henrik; Blokzijl, Andries; Andersson, Olov; Chang, Chenbei; Minchiotti, Gabriella; Persico, M. Graziella; Ibáñez, Carlos F.; Brivanlou, Ali H.

    2001-01-01

    Nodal proteins have crucial roles in mesendoderm formation and left–right patterning during vertebrate development. The molecular mechanisms of signal transduction by Nodal and related ligands, however, are not fully understood. In this paper, we present biochemical and functional evidence that the orphan type I serine/threonine kinase receptor ALK7 acts as a receptor for mouse Nodal and Xenopus Nodal-related 1 (Xnr1). Receptor reconstitution experiments indicate that ALK7 collaborates with ActRIIB to confer responsiveness to Xnr1 and Nodal. Both receptors can independently bind Xnr1. In addition, Cripto, an extracellular protein genetically implicated in Nodal signaling, can independently interact with both Xnr1 and ALK7, and its expression greatly enhances the ability of ALK7 and ActRIIB to respond to Nodal ligands. The Activin receptor ALK4 is also able to mediate Nodal signaling but only in the presence of Cripto, with which it can also interact directly. A constitutively activated form of ALK7 mimics the mesendoderm-inducing activity of Xnr1 in Xenopus embryos, whereas a dominant-negative ALK7 specifically blocks the activities of Nodal and Xnr1 but has little effect on other related ligands. In contrast, a dominant-negative ALK4 blocks all mesoderm-inducing ligands tested, including Nodal, Xnr1, Xnr2, Xnr4, and Activin. In agreement with a role in Nodal signaling, ALK7 mRNA is localized to the ectodermal and organizer regions of Xenopus gastrula embryos and is expressed during early stages of mouse embryonic development. Therefore, our results indicate that both ALK4 and ALK7 can mediate signal transduction by Nodal proteins, although ALK7 appears to be a receptor more specifically dedicated to Nodal signaling. PMID:11485994

  1. CT and MR angiographic findings in dissection of cervical vessels

    International Nuclear Information System (INIS)

    Link, J.; Brinkmann, G.; Heuser, K.; Heller, M.

    1996-01-01

    Purpose: To determine the usefulness of CT angiography (CTA) and MR angiography (MRA) for evaluation of dissection in cervical vessels. Material and methods: Dissection of cervical vessels was revealed by conventional angiography in 4 patients (two female, two male) of 30-62 years of age. Dissection was located in the carotid artery (n=3) and in the vertebral artery (n=1). In two patients CTA and in two patients MRA was performed. Results: Diagnosis of dissection was possible by CTA (internal carotid artery: n=2) and by MRA (internal carotid artery and vertebral artery). Imaging of the dissection membrane of the vessel wall was possible in one case with MRA. Conclusion: CT and MR angiography was successful for detection of typical morphology of dissection in all cases. If results in a greater number can be obtained it seems to be conceivable that both methods can be used in primary diagnosis. (orig.) [de

  2. Spontaneous Coronary Artery Dissection following Topical Hormone Replacement Therapy

    Directory of Open Access Journals (Sweden)

    Alexander L. Pan

    2012-01-01

    Full Text Available Spontaneous coronary artery dissection is a rare condition, usually presenting as an acute coronary syndrome, and is often seen in states associated with high systemic estrogen levels such as pregnancy or oral contraceptive use. While topical hormonal replacement therapy may result in increased estrogen levels similar to those documented with oral contraceptive use, there are no reported cases of spontaneous coronary dissection with topical hormonal replacement therapy. We describe a 53-year-old female who developed two spontaneous coronary dissections while on topical hormonal replacement therapy. The patient had no other risk factors for coronary dissection. After withdrawal from topical hormonal therapy, our patient has done well and has not had recurrent coronary artery dissections over a one-year follow-up period. The potential contributory role of topical hormonal therapy as a cause of spontaneous coronary dissection should be recognized.

  3. Aortic dissection. Basic aspects and endovascular management

    International Nuclear Information System (INIS)

    Jaramillo, Nicolas I; Alviar, Carlos I

    2005-01-01

    Treatment of thoracic aortic pathology is complicated by the morbidity associated to the surgical procedure and to the frailty of an elderly and difficult population. Surgical operation in this kind of population frequently bears a significant incidence of death and long-term disability. In an effort to reduce the incidence of negative outcomes, minimally invasive techniques in the form of endovascular stenting have been introduced during the past decade. The technology, originally described by Parodi, and initially designed for its use in abdominal aortic aneurysms, has been adapted for the treatment of thoracic aortic aneurysms. Furthermore, an improved understanding of the pathophysiology and the natural history of thoracic aortic disease as well as the analysis of the outcomes have facilitated our treatment decisions in terms of the timing for an appropriate intervention. Treatment of thoracic aortic dissection using endovascular Stent is one of the more recent advances in this condition and is receiving increasing attention, as it is a less invasive alternative to an open surgical repair. Although this technology is still innovative, significant improvements have been made lately in the design and deployment of the endovascular Stent-grafts. These prostheses have been increasingly used to treat aneurysms, dissections and traumatic ruptures, as well as giant penetrating ulcers and intramural hematomas of the descending thoracic aorta with good early and mid-term outcomes. The rareness, complexity and severity of the pathology and the theoretically high risk of complications should render the surgeon extremely cautious especially with young patients. Conceptually, the endo luminal treatment in the acute phase seems to be the solution and will probably become a preferred therapy while technical refinement is under way. Worldwide experience is growing and with this a better understanding of the indications and limitations of this innovative therapy will be

  4. Contemporary Management of Acute Type B Dissection.

    Science.gov (United States)

    Scott, A J; Bicknell, C D

    2016-03-01

    Growing confidence in thoracic endovascular aortic repair (TEVAR) for the management of acute type B aortic dissection has resulted in controversies regarding optimum patient selection and the timing of intervention. In this review a clinical vignette to present a practical perspective on the contemporary management of acute type B dissection (ABAD) in a specialist vascular centre with particular focus on areas of debate is used. This is a narrative clinical review. Aggressive anti-impulse therapy is the cornerstone of management of all patients with ABAD. However, 20-30% of patients develop complicated ABAD defined by the presence of malperfusion syndromes, acute aortic dilatation, dissection extension, or persistent pain and hypotension. These complicated patients typically require intervention, and non-randomised series suggest TEVAR to be an effective alternative to open repair with a lower morbidity. There is considerable interest and controversy surrounding the use of TEVAR in uncomplicated ABAD patients for whom the intervention-free survival at 6 years is less than 50% for patients managed with anti-impulse therapy. Data regarding this question are sparse, but two randomised trials (ADSORB and INSTEAD) both demonstrated a higher rate of favourable aortic remodelling in patients managed with TEVAR than medical therapy alone. However, it is unclear whether this positive remodelling translates into a reduction in long-term mortality sufficient to balance the early perioperative hazards of endografting. Despite increasing adeptness at endovascular stenting, the long-term outcomes of patients with ABAD leave significant room for improvement. In particular, the optimum management of patients with uncomplicated disease is unclear and guidance from trials powered for long-term mortality is awaited. Until then, the principals of management of ABAD remain aggressive medical therapy for all patients, with TEVAR primarily reserved for those who develop complications

  5. Aortic dissection presenting as a febrile disease and atrial fibrillation

    OpenAIRE

    Blas-Macedo, Jorge; Márquez-Ramírez, Dolores; Gómez-Dominguez, José de Jesús

    2007-01-01

    Aortic dissection is a cardiovascular emergency. Its main manifestation is severe chest pain, and approximately 50% of patients present with an elevated systemic blood pressure. Rare reported physical findings include a pulsatile sterno-clavicular joint, dysphagia or testicular tenderness. The absence of sudden onset of pain lowers the likelihood of aortic dissection. We describe a patient in whom aortic dissection was accompanied by fever, nightsweats, suprasternal pain and atrial fibrillati...

  6. The risk for type B aortic dissection in Marfan syndrome.

    Science.gov (United States)

    den Hartog, Alexander W; Franken, Romy; Zwinderman, Aeilko H; Timmermans, Janneke; Scholte, Arthur J; van den Berg, Maarten P; de Waard, Vivian; Pals, Gerard; Mulder, Barbara J M; Groenink, Maarten

    2015-01-27

    Aortic dissections involving the descending aorta are a major clinical problem in patients with Marfan syndrome. The purpose of this study was to identify clinical parameters associated with type B aortic dissection and to develop a risk model to predict type B aortic dissection in patients with Marfan syndrome. Patients with the diagnosis of Marfan syndrome and magnetic resonance imaging or computed tomographic imaging of the aorta were followed for a median of 6 years for the occurrence of type B dissection or the combined end point of type B aortic dissection, distal aortic surgery, and death. A model using various clinical parameters as well as genotyping was developed to predict the risk for type B dissection in patients with Marfan syndrome. Between 1998 and 2013, 54 type B aortic dissections occurred in 600 patients with Marfan syndrome (mean age 36 ± 14 years, 52% male). Independent variables associated with type B aortic dissection were prior prophylactic aortic surgery (hazard ratio: 2.1; 95% confidence interval: 1.2 to 3.8; p = 0.010) and a proximal descending aorta diameter ≥27 mm (hazard ratio: 2.2; 95% confidence interval: 1.1 to 4.3; p = 0.020). In the risk model, the 10-year occurrence of type B aortic dissection in low-, moderate-, and high-risk patients was 6%, 19%, and 34%, respectively. Angiotensin II receptor blocker therapy was associated with fewer type B aortic dissections (hazard ratio: 0.3; 95% confidence interval: 0.1 to 0.9; p = 0.030). Patients with Marfan syndrome with prior prophylactic aortic surgery are at substantial risk for type B aortic dissection, even when the descending aorta is only slightly dilated. Angiotensin II receptor blocker therapy may be protective in the prevention of type B aortic dissections. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  7. Doing Dissections Differently: A Structured, Peer-Assisted Learning Approach to Maximizing Learning in Dissections

    Science.gov (United States)

    Hall, Emma R.; Davis, Rachel C.; Weller, Renate; Powney, Sonya; Williams, Sarah B.

    2013-01-01

    Areas of difficulty faced by our veterinary medicine students, with respect to their learning in dissection classes, were identified. These challenges were both general adult-learning related and specific to the discipline of anatomy. Our aim was to design, implement, and evaluate a modified reciprocal peer-assisted/team-based learning…

  8. Background Music in the Dissection Laboratory: Impact on Stress Associated with the Dissection Experience

    Science.gov (United States)

    Anyanwu, Emeka G.

    2015-01-01

    Notable challenges, such as mental distress, boredom, negative moods, and attitudes, have been associated with learning in the cadaver dissection laboratory (CDL). The ability of background music (BM) to enhance the cognitive abilities of students is well documented. The present study was designed to investigate the impact of BM in the CDL and on…

  9. Accuracy of Computed Tomography for Predicting Pathologic Nodal Extracapsular Extension in Patients With Head-and-Neck Cancer Undergoing Initial Surgical Resection

    Energy Technology Data Exchange (ETDEWEB)

    Prabhu, Roshan S., E-mail: roshansprabhu@gmail.com [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Magliocca, Kelly R. [Department of Pathology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Hanasoge, Sheela [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Aiken, Ashley H.; Hudgins, Patricia A. [Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Hall, William A. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Chen, Susie A. [Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas (United States); Eaton, Bree R.; Higgins, Kristin A. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Saba, Nabil F. [Department of Hematology and Medical Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Beitler, Jonathan J. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States)

    2014-01-01

    Purpose: Nodal extracapsular extension (ECE) in patients with head-and-neck cancer increases the loco-regional failure risk and is an indication for adjuvant chemoradiation therapy (CRT). To reduce the risk of requiring trimodality therapy, patients with head-and-neck cancer who are surgical candidates are often treated with definitive CRT when preoperative computed tomographic imaging suggests radiographic ECE. The purpose of this study was to assess the accuracy of preoperative CT imaging for predicting pathologic nodal ECE (pECE). Methods and Materials: The study population consisted of 432 consecutive patients with oral cavity or locally advanced/nonfunctional laryngeal cancer who underwent preoperative CT imaging before initial surgical resection and neck dissection. Specimens with pECE had the extent of ECE graded on a scale from 1 to 4. Results: Radiographic ECE was documented in 46 patients (10.6%), and pECE was observed in 87 (20.1%). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 43.7%, 97.7%, 82.6%, and 87.3%, respectively. The sensitivity of radiographic ECE increased from 18.8% for grade 1 to 2 ECE, to 52.9% for grade 3, and 72.2% for grade 4. Radiographic ECE criteria of adjacent structure invasion was a better predictor than irregular borders/fat stranding for pECE. Conclusions: Radiographic ECE has poor sensitivity, but excellent specificity for pECE in patients who undergo initial surgical resection. PPV and NPV are reasonable for clinical decision making. The performance of preoperative CT imaging increased as pECE grade increased. Patients with resectable head-and-neck cancer with radiographic ECE based on adjacent structure invasion are at high risk for high-grade pECE requiring adjuvant CRT when treated with initial surgery; definitive CRT as an alternative should be considered where appropriate.

  10. Biology teachers' dissection practices and the influences that lead to their adoption: An exploratory research

    Science.gov (United States)

    Milano, Regina Nicole

    The lack of resolution in the on-going animal dissection debate inspired this mixed methods study to identify Connecticut secondary biology teachers' dissection practices and the influences that lead to their adoption. Qualitative findings indicate past experiences, managing objections to dissection, school culture, goals of biology teaching and ethics as major influences on dissection practices with 58.4% (n=7) of the sample dissecting and 41.6% not dissecting (n=5). Quantitative findings reveal gender, standards and curriculum, advantages of dissection and experiences as a student as major influences on dissection practices with 71.9% (n=92) of the sample dissecting and 28.1% (n=36) not dissecting. The study concludes that dissection policies are necessary and imminent in Connecticut school districts. Furthermore, it advises teacher-initiated, qualitative and quantitative assessments to expose disparities between student dissection perspectives and their own, prior to conducting dissection. Finally, it provides suggestions for addressing potential differences including administrative involvement.

  11. Group-decoupled multi-group pin power reconstruction utilizing nodal solution 1D flux profiles

    International Nuclear Information System (INIS)

    Yu, Lulin; Lu, Dong; Zhang, Shaohong; Wang, Dezhong

    2014-01-01

    Highlights: • A direct fitting multi-group pin power reconstruction method is developed. • The 1D nodal solution flux profiles are used as the condition. • The least square fit problem is analytically solved. • A slowing down source improvement method is applied. • The method shows good accuracy for even challenging problems. - Abstract: A group-decoupled direct fitting method is developed for multi-group pin power reconstruction, which avoids both the complication of obtaining 2D analytic multi-group flux solution and any group-coupled iteration. A unique feature of the method is that in addition to nodal volume and surface average fluxes and corner fluxes, transversely-integrated 1D nodal solution flux profiles are also used as the condition to determine the 2D intra-nodal flux distribution. For each energy group, a two-dimensional expansion with a nine-term polynomial and eight hyperbolic functions is used to perform a constrained least square fit to the 1D intra-nodal flux solution profiles. The constraints are on the conservation of nodal volume and surface average fluxes and corner fluxes. Instead of solving the constrained least square fit problem numerically, we solve it analytically by fully utilizing the symmetry property of the expansion functions. Each of the 17 unknown expansion coefficients is expressed in terms of nodal volume and surface average fluxes, corner fluxes and transversely-integrated flux values. To determine the unknown corner fluxes, a set of linear algebraic equations involving corner fluxes is established via using the current conservation condition on all corners. Moreover, an optional slowing down source improvement method is also developed to further enhance the accuracy of the reconstructed flux distribution if needed. Two test examples are shown with very good results. One is a four-group BWR mini-core problem with all control blades inserted and the other is the seven-group OECD NEA MOX benchmark, C5G7

  12. Churchill regulates cell movement and mesoderm specification by repressing Nodal signaling

    Directory of Open Access Journals (Sweden)

    Mentzer Laura

    2007-11-01

    Full Text Available Abstract Background Cell movements are essential to the determination of cell fates during development. The zinc-finger transcription factor, Churchill (ChCh has been proposed to regulate cell fate by regulating cell movements during gastrulation in the chick. However, the mechanism of action of ChCh is not understood. Results We demonstrate that ChCh acts to repress the response to Nodal-related signals in zebrafish. When ChCh function is abrogated the expression of mesodermal markers is enhanced while ectodermal markers are expressed at decreased levels. In cell transplant assays, we observed that ChCh-deficient cells are more motile than wild-type cells. When placed in wild-type hosts, ChCh-deficient cells often leave the epiblast, migrate to the germ ring and are later found in mesodermal structures. We demonstrate that both movement of ChCh-compromised cells to the germ ring and acquisition of mesodermal character depend on the ability of the donor cells to respond to Nodal signals. Blocking Nodal signaling in the donor cells at the levels of Oep, Alk receptors or Fast1 inhibited migration to the germ ring and mesodermal fate change in the donor cells. We also detect additional unusual movements of transplanted ChCh-deficient cells which suggests that movement and acquisition of mesodermal character can be uncoupled. Finally, we demonstrate that ChCh is required to limit the transcriptional response to Nodal. Conclusion These data establish a broad role for ChCh in regulating both cell movement and Nodal signaling during early zebrafish development. We show that chch is required to limit mesodermal gene expression, inhibit Nodal-dependant movement of presumptive ectodermal cells and repress the transcriptional response to Nodal signaling. These findings reveal a dynamic role for chch in regulating cell movement and fate during early development.

  13. Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma.

    Science.gov (United States)

    Seol, Ki Ho; Lee, Jeong Eun

    2016-03-01

    To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4-72 Gy (39.6-45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC.

  14. Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Ki Ho; Lee, Jeong Eun [Dept. of Radiation Oncology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

    2016-03-15

    To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4-72 Gy (39.6-45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC.

  15. Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Seol, Ki Ho; Lee, Jeong Eun

    2016-01-01

    To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4-72 Gy (39.6-45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC

  16. Ultrasound-guided core biopsy: an effective method of detecting axillary nodal metastases.

    LENUS (Irish Health Repository)

    Solon, Jacqueline G

    2012-02-01

    BACKGROUND: Axillary nodal status is an important prognostic predictor in patients with breast cancer. This study evaluated the sensitivity and specificity of ultrasound-guided core biopsy (Ax US-CB) at detecting axillary nodal metastases in patients with primary breast cancer, thereby determining how often sentinel lymph node biopsy could be avoided in node positive patients. STUDY DESIGN: Records of patients presenting to a breast unit between January 2007 and June 2010 were reviewed retrospectively. Patients who underwent axillary ultrasonography with or without preoperative core biopsy were identified. Sensitivity, specificity, positive predictive value, and negative predictive value for ultrasonography and percutaneous biopsy were evaluated. RESULTS: Records of 718 patients were reviewed, with 445 fulfilling inclusion criteria. Forty-seven percent (n = 210\\/445) had nodal metastases, with 110 detected by Ax US-CB (sensitivity 52.4%, specificity 100%, positive predictive value 100%, negative predictive value 70.1%). Axillary ultrasonography without biopsy had sensitivity and specificity of 54.3% and 97%, respectively. Lymphovascular invasion was an independent predictor of nodal metastases (sensitivity 60.8%, specificity 80%). Ultrasound-guided core biopsy detected more than half of all nodal metastases, sparing more than one-quarter of all breast cancer patients an unnecessary sentinel lymph node biopsy. CONCLUSIONS: Axillary ultrasonography, when combined with core biopsy, is a valuable component of the management of patients with primary breast cancer. Its ability to definitively identify nodal metastases before surgical intervention can greatly facilitate a patient\\'s preoperative integrated treatment plan. In this regard, we believe our study adds considerably to the increasing data, which indicate the benefit of Ax US-CB in the preoperative detection of nodal metastases.

  17. The effect of nodalization and temperature of reactor upper region: Sensitivity analysis for APR-1400 LBLOCA

    International Nuclear Information System (INIS)

    Kang, Dong Gu

    2017-01-01

    Highlights: • The nodalization of APR-1400 was modified to reflect the characteristic of upper region temperature. • The effect of nodalization and temperature of reactor upper region on LBLOCA consequence was evaluated. • The modification of nodalization is an essential prerequisite in APR-1400 LBLOCA analysis. - Abstract: In best estimate (BE) calculation, the definition of system nodalization is important step influencing the prediction accuracy for specific thermal-hydraulic phenomena. The upper region of reactor is defined as the region of the upper guide structure (UGS) and upper dome. It has been assumed that the temperature of upper region is close to average temperature in most large break loss of coolant accident (LBLOCA) analysis cases. However, it was recently found that the temperature of upper region of APR-1400 reactor might be little lower than or similar to hot leg temperature through the review of detailed design data. In this study, the nodalization of APR-1400 was modified to reflect the characteristic of upper region temperature, and the effect of nodalization and temperature of reactor upper region on LBLOCA consequence was evaluated by sensitivity analysis including best estimate plus uncertainty (BEPU) calculation. In basecase calculation, in case of modified version, the peak cladding temperature (PCT) in blowdown phase became higher and the blowdown quenching (or cooling) was significantly deteriorated as compared to original case, and as a result, the cladding temperature in reflood phase became higher and the final quenching was also delayed. In addition, thermal-hydraulic parameters were compared and analyzed to investigate the effect of change of upper region on cladding temperature. In BEPU analysis, the 95 percentile PCT used in current regulatory practice was increased due to the modification of upper region nodalization, and it occurred in the reflood phase unlike original case.

  18. Extra-nodal extension is a significant prognostic factor in lymph node positive breast cancer.

    Directory of Open Access Journals (Sweden)

    Sura Aziz

    Full Text Available Presence of lymph node (LN metastasis is a strong prognostic factor in breast cancer, whereas the importance of extra-nodal extension and other nodal tumor features have not yet been fully recognized. Here, we examined microscopic features of lymph node metastases and their prognostic value in a population-based cohort of node positive breast cancer (n = 218, as part of the prospective Norwegian Breast Cancer Screening Program NBCSP (1996-2009. Sections were reviewed for the largest metastatic tumor diameter (TD-MET, nodal afferent and efferent vascular invasion (AVI and EVI, extra-nodal extension (ENE, number of ENE foci, as well as circumferential (CD-ENE and perpendicular (PD-ENE diameter of extra-nodal growth. Number of positive lymph nodes, EVI, and PD-ENE were significantly increased with larger primary tumor (PT diameter. Univariate survival analysis showed that several features of nodal metastases were associated with disease-free (DFS or breast cancer specific survival (BCSS. Multivariate analysis demonstrated an independent prognostic value of PD-ENE (with 3 mm as cut-off value in predicting DFS and BCSS, along with number of positive nodes and histologic grade of the primary tumor (for DFS: P = 0.01, P = 0.02, P = 0.01, respectively; for BCSS: P = 0.02, P = 0.008, P = 0.02, respectively. To conclude, the extent of ENE by its perpendicular diameter was independently prognostic and should be considered in line with nodal tumor burden in treatment decisions of node positive breast cancer.

  19. Thoracic aortic aneurysms and dissections: endovascular treatment.

    Science.gov (United States)

    Baril, Donald T; Cho, Jae S; Chaer, Rabih A; Makaroun, Michel S

    2010-01-01

    The treatment of thoracic aortic disease has changed radically with the advances made in endovascular therapy since the concept of thoracic endovascular aortic repair was first described 15 years ago. Currently, there is a diverse array of endografts that are commercially available to treat the thoracic aorta. Multiple studies, including industry-sponsored and single-institution reports, have demonstrated excellent outcomes of thoracic endovascular aortic repair for the treatment of thoracic aortic aneurysms, with less reported perioperative morbidity and mortality in comparison with conventional open repair. Additionally, similar outcomes have been demonstrated for the treatment of type B dissections. However, the technology remains relatively novel, and larger studies with longer term outcomes are necessary to more fully evaluate the role of endovascular therapy for the treatment of thoracic aortic disease. This review examines the currently available thoracic endografts, preoperative planning for thoracic endovascular aortic repair, and outcomes of thoracic endovascular aortic repair for the treatment of both thoracic aortic aneurysms and type B aortic dissections. Mt Sinai J Med 77:256-269, 2010. (c) 2010 Mount Sinai School of Medicine.

  20. Development of an object oriented nodal code using the refined AFEN derived from the method of component decomposition

    International Nuclear Information System (INIS)

    Noh, J. M.; Yoo, J. W.; Joo, H. K.

    2004-01-01

    In this study, we invented a method of component decomposition to derive the systematic inter-nodal coupled equations of the refined AFEN method and developed an object oriented nodal code to solve the derived coupled equations. The method of component decomposition decomposes the intra-nodal flux expansion of a nodal method into even and odd components in three dimensions to reduce the large coupled linear system equation into several small single equations. This method requires no additional technique to accelerate the iteration process to solve the inter-nodal coupled equations, since the derived equations can automatically act as the coarse mesh re-balance equations. By utilizing the object oriented programming concepts such as abstraction, encapsulation, inheritance and polymorphism, dynamic memory allocation, and operator overloading, we developed an object oriented nodal code that can facilitate the input/output and the dynamic control of the memories, and can make the maintenance easy. (authors)

  1. Diagnosis of Aortic Dissection in Emergency Department Patients is Rare

    Directory of Open Access Journals (Sweden)

    Scott M. Alter

    2015-10-01

    Full Text Available Introduction: Aortic dissection is a rare event. While the most frequent symptom is chest pain, that is a common emergency department (ED chief complaint and other diseases causing chest pain occur much more often. Furthermore, 20% of dissections are without chest pain and 6% are painless. For these reasons, diagnosing dissections may be challenging. Our goal was to determine the number of total ED and atraumatic chest pain patients for every aortic dissection diagnosed by emergency physicians. Methods: Design: Retrospective cohort. Setting: 33 suburban and urban New York and New Jersey EDs with annual visits between 8,000 and 80,000. Participants: Consecutive patients seen by emergency physicians from 1-1-1996 through 12-31-2010. Observations: We identified aortic dissection and atraumatic chest pain patients using the International Classification of Diseases 9th Revision and Clinical Modification codes. We then calculated the number of total ED and atraumatic chest pain patients for every aortic dissection, along with 95% confidence intervals (CIs. Results: From a database of 9.5 million ED visits, we identified 782 aortic dissections or one for every 12,200 (95% CI [11,400-13,100] visits. The mean age of dissection patients was 66±16 years and 38% were female. There were 763,000 (8% with atraumatic chest pain diagnoses. Thus, there is one dissection for every 980 (95% CI [910-1,050] atraumatic chest pain patients. Conclusion: The diagnosis of aortic dissections by emergency physicians is rare and challenging. An emergency physician seeing 3,000 to 4,000 patients a year would diagnose an aortic dissection approximately every three to four years.

  2. Recognizing nodal marginal zone lymphoma: recent advances and pitfalls. A systematic review

    Science.gov (United States)

    van den Brand, Michiel; van Krieken, J. Han J.M.

    2013-01-01

    The diagnosis of nodal marginal zone lymphoma is one of the remaining problem areas in hematopathology. Because no established positive markers exist for this lymphoma, it is frequently a diagnosis of exclusion, making distinction from other low-grade B-cell lymphomas difficult or even impossible. This systematic review summarizes and discusses the current knowledge on nodal marginal zone lymphoma, including clinical features, epidemiology and etiology, histology, and cytogenetic and molecular features. In particular, recent advances in diagnostics and pathogenesis are discussed. New immunohistochemical markers have become available that could be used as positive markers for nodal marginal zone lymphoma. These markers could be used to ensure more homogeneous study groups in future research. Also, recent gene expression studies and studies describing specific gene mutations have provided clues to the pathogenesis of nodal marginal zone lymphoma, suggesting deregulation of the nuclear factor kappa B pathway. Nevertheless, nodal marginal zone lymphoma remains an enigmatic entity, requiring further study to define its pathogenesis to allow an accurate diagnosis and tailored treatment. However, recent data indicate that it is not related to splenic or extranodal lymphoma, and that it is also not related to lymphoplasmacytic lymphoma. Thus, even though the diagnosis is not always easy, it is clearly a separate entity. PMID:23813646

  3. A new diffusion nodal method based on analytic basis function expansion

    International Nuclear Information System (INIS)

    Noh, J.M.; Cho, N.Z.

    1993-01-01

    The transverse integration procedure commonly used in most advanced nodal methods results in some limitations. The first is that the transverse leakage term that appears in the transverse integration procedure must be appropriately approximated. In most advanced nodal methods, this term is expanded in a quadratic polynomial. The second arises when reconstructing the pinwise flux distribution within a node. The available one-dimensional flux shapes from nodal calculation in each spatial direction cannot be used directly in the flux reconstruction. Finally, the transverse leakage defined for a hexagonal node becomes so complicated as not to be easily handled and contains nonphysical singular terms. In this paper, a new nodal method called the analytic function expansion nodal (AFEN) method is described for both the rectangular geometry and the hexagonal geometry in order to overcome these limitations. This method does not solve the transverse-integrated one-dimensional diffusion equations but instead solves directly the original multidimensional diffusion equation within a node. This is a accomplished by expanding the solution (or the intranodal homogeneous flux distribution) in terms of nonseparable analytic basis functions satisfying the diffusion equation at any point in the node

  4. Status on development and verification of reactivity initiated accident analysis code for PWR (NODAL3)

    International Nuclear Information System (INIS)

    Peng Hong Liem; Surian Pinem; Tagor Malem Sembiring; Tran Hoai Nam

    2015-01-01

    A coupled neutronics thermal-hydraulics code NODAL3 has been developed based on the nodal few-group neutron diffusion theory in 3-dimensional Cartesian geometry for a typical pressurized water reactor (PWR) static and transient analyses, especially for reactivity initiated accidents (RIA). The spatial variables are treated by using a polynomial nodal method (PNM) while for the neutron dynamic solver the adiabatic and improved quasi-static methods are adopted. A simple single channel thermal-hydraulics module and its steam table is implemented into the code. Verification works on static and transient benchmarks are being conducting to assess the accuracy of the code. For the static benchmark verification, the IAEA-2D, IAEA-3D, BIBLIS and KOEBERG light water reactor (LWR) benchmark problems were selected, while for the transient benchmark verification, the OECD NEACRP 3-D LWR Core Transient Benchmark and NEA-NSC 3-D/1-D PWR Core Transient Benchmark (Uncontrolled Withdrawal of Control Rods at Zero Power). Excellent agreement of the NODAL3 results with the reference solutions and other validated nodal codes was confirmed. (author)

  5. Interplay between short-range correlated disorder and Coulomb interaction in nodal-line semimetals

    Science.gov (United States)

    Wang, Yuxuan; Nandkishore, Rahul M.

    2017-09-01

    In nodal-line semimetals, Coulomb interactions and short-range correlated disorder are both marginal perturbations to the clean noninteracting Hamiltonian. We analyze their interplay using a weak-coupling renormalization group approach. In the clean case, the Coulomb interaction has been found to be marginally irrelevant, leading to Fermi liquid behavior. We extend the analysis to incorporate the effects of disorder. The nodal line structure gives rise to kinematical constraints similar to that for a two-dimensional Fermi surface, which plays a crucial role in the one-loop renormalization of the disorder couplings. For a twofold degenerate nodal loop (Weyl loop), we show that disorder flows to strong coupling along a unique fixed trajectory in the space of symmetry inequivalent disorder couplings. Along this fixed trajectory, all symmetry inequivalent disorder strengths become equal. For a fourfold degenerate nodal loop (Dirac loop), disorder also flows to strong coupling, however, the strengths of symmetry inequivalent disorder couplings remain different. We show that feedback from disorder reverses the sign of the beta function for the Coulomb interaction, causing the Coulomb interaction to flow to strong coupling as well. However, the Coulomb interaction flows to strong coupling asymptotically more slowly than disorder. Extrapolating our results to strong coupling, we conjecture that at low energies nodal line semimetals should be described by a noninteracting nonlinear sigma model. We discuss the relation of our results with possible many-body localization at zero temperatures in such materials.

  6. Tumor microvessel density–associated mast cells in canine nodal lymphoma

    Directory of Open Access Journals (Sweden)

    Moges Woldemeskel

    2014-11-01

    Full Text Available Objective: Mast cells are associated in angiogenesis in various human and animal neoplasms. However, association of mast cells with tumor microvessel density in canine lymphoma was not previously documented. The objective of the study is to determine if mast cells are increased in canine nodal lymphomas and to evaluate their correlation with tumor microvessel density and grading of lymphomas. Methods: Nodal lymphomas from 33 dogs were studied and compared with nonneoplastic lymph nodes from 6 dogs as control. Mast cell count was made on Toluidine blue stained sections. Immunohistochemistry using antibody against Factor VIII was employed to visualize and determine microvessel density. Results: The mast cell count in lymphoma (2.95 ± 2.4 was significantly higher (p < 0.05 than that in the control (0.83 ± 0.3 and was positively correlated with tumor microvessel density (r = 0.44, p = 0.009. Significant difference was not observed in mast cell count and tumor microvessel density among different gradings of lymphomas. Conclusions: Mast cells are associated with tumor microvessel density in canine nodal lymphoma with no significant difference among gradings of lymphomas. Mast cells may play an important role in development of canine nodal lymphomas. Further detailed investigation on the role of mast cells as important part of tumor microenvironment in canine nodal lymphomas is recommended.

  7. Sensitivity analysis of MIDAS tests using SPACE code. Effect of nodalization

    International Nuclear Information System (INIS)

    Eom, Shin; Oh, Seung-Jong; Diab, Aya

    2018-01-01

    The nodalization sensitivity analysis for the ECCS (Emergency Core Cooling System) bypass phe�nomena was performed using the SPACE (Safety and Performance Analysis CodE) thermal hydraulic analysis computer code. The results of MIDAS (Multi-�dimensional Investigation in Downcomer Annulus Simulation) test were used. The MIDAS test was conducted by the KAERI (Korea Atomic Energy Research Institute) for the performance evaluation of the ECC (Emergency Core Cooling) bypass phenomenon in the DVI (Direct Vessel Injection) system. The main aim of this study is to examine the sensitivity of the SPACE code results to the number of thermal hydraulic channels used to model the annulus region in the MIDAS experiment. The numerical model involves three nodalization cases (4, 6, and 12 channels) and the result show that the effect of nodalization on the bypass fraction for the high steam flow rate MIDAS tests is minimal. For computational efficiency, a 4 channel representation is recommended for the SPACE code nodalization. For the low steam flow rate tests, the SPACE code over-�predicts the bypass fraction irrespective of the nodalization finesse. The over-�prediction at low steam flow may be attributed to the difficulty to accurately represent the flow regime in the vicinity of the broken cold leg.

  8. Nodalization effects on RELAP5 results related to MTR research reactor transient scenarios

    Directory of Open Access Journals (Sweden)

    Khedr Ahmed

    2005-01-01

    Full Text Available The present work deals with the anal y sis of RELAP5 results obtained from the evaluation study of the total loss of flow transient with the deficiency of the heat removal system in a research reactor using two different nodalizations. It focuses on the effect of nodalization on the thermal-hydraulic evaluation of the re search reactor. The analysis of RELAP5 results has shown that nodalization has a big effect on the predicted scenario of the postulated transient. There fore, great care should be taken during the nodalization of the reactor, especially when the avail able experimental or measured data are insufficient for making a complete qualification of the nodalization. Our analysis also shows that the research reactor pool simulation has a great effect on the evaluation of natural circulation flow and on other thermal-hydraulic parameters during the loss of flow transient. For example, the on set time of core boiling changes from less than 2000 s to 15000 s, starting from the beginning of the transient. This occurs if the pool is simulated by two vertical volumes in stead of one vertical volume.

  9. Tumor microvessel density–associated mast cells in canine nodal lymphoma

    Science.gov (United States)

    Mann, Elizabeth; Whittington, Lisa

    2014-01-01

    Objective: Mast cells are associated in angiogenesis in various human and animal neoplasms. However, association of mast cells with tumor microvessel density in canine lymphoma was not previously documented. The objective of the study is to determine if mast cells are increased in canine nodal lymphomas and to evaluate their correlation with tumor microvessel density and grading of lymphomas. Methods: Nodal lymphomas from 33 dogs were studied and compared with nonneoplastic lymph nodes from 6 dogs as control. Mast cell count was made on Toluidine blue stained sections. Immunohistochemistry using antibody against Factor VIII was employed to visualize and determine microvessel density. Results: The mast cell count in lymphoma (2.95 ± 2.4) was significantly higher (p < 0.05) than that in the control (0.83 ± 0.3) and was positively correlated with tumor microvessel density (r = 0.44, p = 0.009). Significant difference was not observed in mast cell count and tumor microvessel density among different gradings of lymphomas. Conclusions: Mast cells are associated with tumor microvessel density in canine nodal lymphoma with no significant difference among gradings of lymphomas. Mast cells may play an important role in development of canine nodal lymphomas. Further detailed investigation on the role of mast cells as important part of tumor microenvironment in canine nodal lymphomas is recommended. PMID:26770752

  10. Sensitivity analysis of MIDAS tests using SPACE code. Effect of nodalization

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Shin; Oh, Seung-Jong; Diab, Aya [KEPCO International Nuclear Graduate School (KINGS), Ulsan (Korea, Republic of). Dept. of NPP Engineering

    2018-02-15

    The nodalization sensitivity analysis for the ECCS (Emergency Core Cooling System) bypass phe�nomena was performed using the SPACE (Safety and Performance Analysis CodE) thermal hydraulic analysis computer code. The results of MIDAS (Multi-�dimensional Investigation in Downcomer Annulus Simulation) test were used. The MIDAS test was conducted by the KAERI (Korea Atomic Energy Research Institute) for the performance evaluation of the ECC (Emergency Core Cooling) bypass phenomenon in the DVI (Direct Vessel Injection) system. The main aim of this study is to examine the sensitivity of the SPACE code results to the number of thermal hydraulic channels used to model the annulus region in the MIDAS experiment. The numerical model involves three nodalization cases (4, 6, and 12 channels) and the result show that the effect of nodalization on the bypass fraction for the high steam flow rate MIDAS tests is minimal. For computational efficiency, a 4 channel representation is recommended for the SPACE code nodalization. For the low steam flow rate tests, the SPACE code over-�predicts the bypass fraction irrespective of the nodalization finesse. The over-�prediction at low steam flow may be attributed to the difficulty to accurately represent the flow regime in the vicinity of the broken cold leg.

  11. Diagnostic imaging of acute aortic dissection; Evaluation of thrombosed type aortic dissection by CT and angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ohya, Tohru; Kumazaki, Tatsuo (Nippon Medical School, Tokyo (Japan))

    1991-01-01

    One hundred and nineteen patients with aortic dissection who underwent diagnostic imaging were reviewed and angiographic findings as well as those of CT were analysed. Thirty eight cases (43.1%) had non-contrast opacified false lumen, the type of which we call 'thrombosed type aortic dissection'. A comparative study of the thrombosed type with the patent type of false lumens was made particularly from the stand point of the characteristic diagnostic imagings (CT and angiography). At the same time, the pitfalls of these imagings in thrombosed type aortic dissection were studied. At the onset the average age of thrombosed type was 62.3 years old, while that of the patent type was 57.3. A statistical significance between the two groups was p<0.05. Thrombosed type in all cases was caused by atherosclerosis, whereas patent type was caused by the Marfan's syndrome in 11 cases. Other clinical findings, such as initial symptoms and blood pressure revealed no significant differences between the two groups. Pre-contrast CT in acute thrombosed type aortic dissection showed 'hyperdense crescent sign' in 89.4%. However, in 3 cases with thrombosed type in which the pre-contrast CT showed 'hyperdense crescent sign' contrast-enhanced CT detected no clear evidence of aortic dissection in the same site. This was due to obscurity induced by contrast medium. Angiographic findings of thrombosed type were classified into 3 groups: normal type, stenosed true lumen type and ulcer-like projection type. The incidence of normal type was estimated to be 48.4%, whereas stenosed true lumen type was 24.2% and ulcer-like projection was 27.7%. The present study concluded that thrombosed type is not rare in acute aortic dissection and contrast-enhanced CT as well as pre-contrast CT, is of great value in diagnosing thrombosed type. 'Hyperdense crescent sign' in pre-contrast CT is characteristic of intramural hematoma. (author).

  12. Spontaneous carotid artery dissection causing a juvenile cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Trattnig, S.; Huebsch, P.; Schindler, E.

    1988-11-01

    The case of a 19-year-old patient is presented who was admitted with aphasia and hemiparesis due to basal ganglia infarction as a result of spontaneous dissection of the internal carotid artery. The difficulties in diagnosing this disease with CT and MRI in the acute stage are demonstrated. Angiography is still imperative in order to ascertain that a carotid dissection has occurred.

  13. Reaction of Medical Students to Experiences in Dissection Room ...

    African Journals Online (AJOL)

    Conclusion: The present study findings show that smell of the dissection room, touch and fear of cadaver were the commonest cause of their symptoms experienced while study in dissection room for the majority of students. Thus, instructors are should give awareness raising education before the commencement of the ...

  14. THE IMPACT OF DIAGNOSTIC DISCREPANCIES IN AORTIC DISSECTION MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Abdalla Hassan

    2016-01-01

    Full Text Available Aortic dissection is uncommon with high mortality rate if untreated. We report a challenging case of long segment aortic dissection in which the dissection type was very difficult to identify due to limitations of the available imaging studies. 66-year-old male presented to us with 3 days history of chest pain and difficulty breathing. He is known to be hypertensive. In the emergency room, patient has systolic blood pressure >190. Chest X-ray showed widening of mediastinum. CT angiography of chest and abdomen showed an acute dissection of the thoracic aorta extending from the mid ascending aorta to the infra-renal aorta suggestive of Stanford type A aortic dissection. Transthoracic and Trans-esophageal echocardiography revealed a partially calcified intimal flap in the distal portion of the arch and in the descending thoracic aorta suggestive of Stanford type B aortic dissection. Medical treatment started, and repeated CT angiography was obtained and it confirmed type B aortic dissection. One week after discharge, patient was readmitted with severe neck pain and difficulty breathing. CT chest without contrast showed grossly stable appearance of type A dissection consistent with the first CT angiography. Cardiothoracic surgery immediately reevaluated the situation and recommended surgical intervention.

  15. Arterial occlusion to treat basilar artery dissecting aneurysm

    NARCIS (Netherlands)

    Cui, Qing Ke; Liu, Wei Dong; Liu, Peng; Li, Xue Yuan; Zhang, Lian Qun; Ma, Long Jia; Ren, Yun Fei; Wu, Ya Ping; Wang, Zhi Gang

    2015-01-01

    Object: To explore the clinical feasibility of employing occlusion to treat basilar artery dissecting aneurysm. Methods: One patient, male and 46 years old, suffered transient numbness and weakness on the right limbs. Cerebral angiography indicated basilar artery dissecting aneurysm. The patient

  16. Intramural Esophageal Dissection after Endoscopy: A Case Report

    International Nuclear Information System (INIS)

    Han, Ki Tae; Kim, Song Soo; Kim, Jin Hwan

    2011-01-01

    Intramural esophageal dissection (IED) is an uncommon disorder characterized by a separation between the esophageal mucosa and submucosa with or without perforation. IED is usually related with an abrupt increase in intraesophageal pressure, history of recent instrumentation, and a coagulation disorder. We report a case of IED showing extensive dissection into the wall of the stomach, which successfully subsided by conservative treatment.

  17. CrossFit-related cervical internal carotid artery dissection.

    Science.gov (United States)

    Lu, Albert; Shen, Peter; Lee, Paul; Dahlin, Brian; Waldau, Ben; Nidecker, Anna E; Nundkumar, Anoop; Bobinski, Matthew

    2015-08-01

    CrossFit is a high-intensity strength and conditioning program that has gained popularity over the past decade. Potential injuries associated with CrossFit training have been suggested in past reports. We report three cases of cervical carotid dissection that are associated with CrossFit workouts. Patient 1 suffered a distal cervical internal carotid artery (ICA) dissection near the skull base and a small infarct in Wernicke's area. He was placed on anticoagulation and on follow-up has near complete recovery. Patient 2 suffered a proximal cervical ICA dissection that led to arterial occlusion and recurrent middle cerebral artery territory infarcts and significant neurological sequelae. Patient 3 had a skull base ICA dissection that led to a partial Horner's syndrome but no cerebral infarct. While direct causality cannot be proven, intense CrossFit workouts may have led to the ICA dissections in these patients.

  18. Immunostaining of dissected zebrafish embryonic heart.

    Science.gov (United States)

    Yang, Jingchun; Xu, Xiaolei

    2012-01-10

    Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects. The expression of any gene can be manipulated via morpholino technology or RNA injection. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis. Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals. Copyright © 2012 Journal of Visualized Experiments

  19. A simplified presentation of the multigroup analytic nodal method in 2-D Cartesian geometry

    International Nuclear Information System (INIS)

    Hebert, Alain

    2008-01-01

    The nodal diffusion algorithms used in many production reactor simulation codes are originating from a common ancestry developed in the 1970s, the analytic nodal method (ANM) of the QUANDRY code. However, this original presentation of the ANM is complex and makes difficult the calculation of the nodal coupling matrices. Moreover, QUANDRY is limited to two-energy groups and its generalization to more groups appears laborious. We are presenting a simplified implementation of the ANM requiring only limited programming work. This formulation is consistent with the initial QUANDRY implementation and is easily generalizable to arbitrary G-group problems. A Matlab script is provided to highlight the simplicity of our presentation. For the sake of clarity, our implementation is limited to G-group, 2-D Cartesian geometry

  20. Cryopreservation of in vitro grown nodal segments of Rauvolfia serpentina by PVS2 vitrification.

    Science.gov (United States)

    Ray, Avik; Bhattacharya, Sabita

    2008-01-01

    This paper describes the cryopreservation by PVS2 vitrification of Rauvolfia serpentina (L.) Benth ex kurz, an important tropical medicinal plant. The effects of type and size of explants, sucrose preculture (duration and concentration) and vitrification treatment were tested. Preliminary experiments with PVS1, 2 and 3 produced shoot growth only for PVS2. When optimizing the PVS2 vitrification of nodal segments, those of 0.31 - 0.39 cm in size were better than other nodal sizes and or apices. Sucrose preculture had a positive role in survival and subsequent regrowth of the cryopreserved explants. Seven days on 0.5 M sucrose solution significantly improved the viability of nodal segments. PVS2 incubation for 45 minutes combined with a 7-day preculture gave the optimum result of 66 percent. Plantlets derived after cryopreservation resumed growth and regenerated normally.

  1. cmpXLatt: Westinghouse automated testing tool for nodal cross section models

    International Nuclear Information System (INIS)

    Guimaraes, Petri Forslund; Rönnberg, Kristian

    2011-01-01

    The procedure for evaluating the merits of different nodal cross section representation models is normally both cumbersome and time consuming, and includes many manual steps when preparing appropriate benchmark problems. Therefore, a computer tool called cmpXLatt has been developed at Westinghouse in order to facilitate the process of performing comparisons between nodal diffusion theory results and corresponding transport theory results on a single node basis. Due to the large number of state points that can be evaluated by cmpXLatt, a systematic and comprehensive way of performing verification and validation of nodal cross section models is provided. This paper presents the main features of cmpXLatt and demonstrates the benefits of using cmpXLatt in a real life application. (author)

  2. Higher order polynomial expansion nodal method for hexagonal core neutronics analysis

    International Nuclear Information System (INIS)

    Jin, Young Cho; Chang, Hyo Kim

    1998-01-01

    A higher-order polynomial expansion nodal(PEN) method is newly formulated as a means to improve the accuracy of the conventional PEN method solutions to multi-group diffusion equations in hexagonal core geometry. The new method is applied to solving various hexagonal core neutronics benchmark problems. The computational accuracy of the higher order PEN method is then compared with that of the conventional PEN method, the analytic function expansion nodal (AFEN) method, and the ANC-H method. It is demonstrated that the higher order PEN method improves the accuracy of the conventional PEN method and that it compares very well with the other nodal methods like the AFEN and ANC-H methods in accuracy

  3. Isospectral discrete and quantum graphs with the same flip counts and nodal counts

    Science.gov (United States)

    Juul, Jonas S.; Joyner, Christopher H.

    2018-06-01

    The existence of non-isomorphic graphs which share the same Laplace spectrum (to be referred to as isospectral graphs) leads naturally to the following question: what additional information is required in order to resolve isospectral graphs? It was suggested by Band, Shapira and Smilansky that this might be achieved by either counting the number of nodal domains or the number of times the eigenfunctions change sign (the so-called flip count) (Band et al 2006 J. Phys. A: Math. Gen. 39 13999–4014 Band and Smilansky 2007 Eur. Phys. J. Spec. Top. 145 171–9). Recent examples of (discrete) isospectral graphs with the same flip count and nodal count have been constructed by Ammann by utilising Godsil–McKay switching (Ammann private communication). Here, we provide a simple alternative mechanism that produces systematic examples of both discrete and quantum isospectral graphs with the same flip and nodal counts.

  4. SIRIUS - A one-dimensional multigroup analytic nodal diffusion theory code

    Energy Technology Data Exchange (ETDEWEB)

    Forslund, P. [Westinghouse Atom AB, Vaesteraas (Sweden)

    2000-09-01

    In order to evaluate relative merits of some proposed intranodal cross sections models, a computer code called Sirius has been developed. Sirius is a one-dimensional, multigroup analytic nodal diffusion theory code with microscopic depletion capability. Sirius provides the possibility of performing a spatial homogenization and energy collapsing of cross sections. In addition a so called pin power reconstruction method is available for the purpose of reconstructing 'heterogeneous' pin qualities. consequently, Sirius has the capability of performing all the calculations (incl. depletion calculations) which are an integral part of the nodal calculation procedure. In this way, an unambiguous numerical analysis of intranodal cross section models is made possible. In this report, the theory of the nodal models implemented in sirius as well as the verification of the most important features of these models are addressed.

  5. Discrete rod burnup analysis capability in the Westinghouse advanced nodal code

    International Nuclear Information System (INIS)

    Buechel, R.J.; Fetterman, R.J.; Petrunyak, M.A.

    1992-01-01

    Core design analysis in the last several years has evolved toward the adoption of nodal-based methods to replace traditional fine-mesh models as the standard neutronic tool for first core and reload design applications throughout the nuclear industry. The accuracy, speed, and reduction in computation requirements associated with the nodal methods have made three-dimensional modeling the preferred approach to obtain the most realistic core model. These methods incorporate detailed rod power reconstruction as well. Certain design applications such as confirmation of fuel rod design limits and fuel reconstitution considerations, for example, require knowledge of the rodwise burnup distribution to avoid unnecessary conservatism in design analyses. The Westinghouse Advanced Nodal Code (ANC) incorporates the capability to generate the intra-assembly pin burnup distribution using an efficient algorithm

  6. Aortic dissection presenting with secondary pulmonary hypertension caused by compression of the pulmonary artery by dissecting hematoma: a case report

    International Nuclear Information System (INIS)

    Kim, Dong Hun; Ryu, Sang Wan; Choi, Yong Sun; Ahn, Byoung Hee

    2004-01-01

    The rupture of an acute dissection of the ascending aorta into the space surrounding the pulmonary artery is an uncommon occurrence. No previous cases of transient pulmonary hypertension caused by a hematoma surrounding the pulmonary artery have been documented in the literature. Herein, we report a case of acute aortic dissection presenting as secondary pulmonary hypertension

  7. A transient, Hex-Z nodal code corrected by discontinuity factors

    International Nuclear Information System (INIS)

    Shatilla, Y.A.M.; Henry, A.F.

    1993-01-01

    This document constitutes Volume 1 of the Final Report of a three-year study supported by the special Research Grant Program for Nuclear Energy Research set up by the US Department of Energy. The original motivation for the work was to provide a fast and accurate computer program for the analysis of transients in heavy water or graphite-moderated reactors being considered as candidates for the New Production Reactor. Thus, part of the funding was by way of pass-through money from the Savannah River Laboratory. With this intent in mind, a three-dimensional (Hex-Z), general-energy-group transient, nodal code was created, programmed, and tested. In order to improve accuracy, correction terms, called open-quotes discontinuity factors,close quotes were incorporated into the nodal equations. Ideal values of these factors force the nodal equations to provide node-integrated reaction rates and leakage rates across nodal surfaces that match exactly those edited from a more exact reference calculation. Since the exact reference solution is needed to compute the ideal discontinuity factors, the fact that they result in exact nodal equations would be of little practical interest were it not that approximate discontinuity factors, found at a greatly reduced cost, often yield very accurate results. For example, for light-water reactors, discontinuity factors found from two-dimensional, fine-mesh, multigroup transport solutions for two-dimensional cuts of a fuel assembly provide very accurate predictions of three-dimensional, full-core power distributions. The present document (volume 1) deals primarily with the specification, programming and testing of the three-dimensional, Hex-Z computer program. The program solves both the static (eigenvalue) and transient, general-energy-group, nodal equations corrected by user-supplied discontinuity factors

  8. Fluorine-18-Fluorodeoxyglucose PET in the mediastinal nodal staging of bronchogenic carcinoma.

    Energy Technology Data Exchange (ETDEWEB)

    Berlangieri, S.U.; Scott, A.M.; Knight, S.; Pointon, O.; Thomas, D.L.; O``Keefe, G.; Chan, J.G.; Egen, G.F.; Tochon-Danguy, H.J.; Clarke, C.P.; McKay, W.J. [Austin Hospital, Melbourne, VIC (Australia). Centre for Positron Emission Tomography and the Departments of Nuclear Medicine and Thoracic Surgery

    1998-03-01

    Full text: Non-invasive methods of pre-operative staging of non-small cell bronchogenic carcinoma are inaccurate. To determine the clinical role of positron emission tomography (PET) in the mediastinal staging of lung carcinoma, {sup 18}F-fluorodeoxyglucose (FDG) studies were performed in 25 patients with suspected non-small cell bronchogenic carcinoma and correlated with pathology. The patients comprised 20 men and 5 women (mean age 63; range 43-78 y). All patients had proven non-small cell lung carcinoma, except two, one patient with benign inflammatory disease and the other with small cell carcinoma. The FDG PET studies were acquired on a Siemens 951131R body tomography over 2-3 bed positions to include the thorax and mediastinum. The PET images were interpreted for tumour involvement of mediastinal nodes according to the American Thoracic Society classification and scored for confidence of tumour presence on a 5 point scale. The intensity of glucose metabolism was compared to mediastinal blood pool activity and graded on a 4 point scale. FDG PET correctly excluded ipsilateral mediastinal nodal (N2) disease in 16 of 16 patients. Six of nine patients with N2 disease were correctly identified by FDG PET. Of the three patients with N2 nodal involvement not detected by PET, each had single station nodal disease, and in two patients the primary lesions abutted the involved nodal group. A total of 104 nodal stations were sampled or examined at surgery. FDG PET correctly excluded disease in 83/83 (100% specificity) negative nodal stations. FDG PET is a promising non-invasive functional imaging modality for the mediastinal staging of bronchogenic carcinoma.

  9. Hybrid nodal methods in the solution of the diffusion equations in X Y geometry

    International Nuclear Information System (INIS)

    Hernandez M, N.; Alonso V, G.; Valle G, E. del

    2003-01-01

    In 1979, Hennart and collaborators applied several schemes of classic finite element in the numerical solution of the diffusion equations in X Y geometry and stationary state. Almost two decades then, in 1996, himself and other collaborators carried out a similar work but using nodal schemes type finite element. Continuing in this last direction, in this work a group it is described a set of several Hybrid Nodal schemes denominated (NH) as well as their application to solve the diffusion equations in multigroup in stationary state and X Y geometry. The term hybrid nodal it means that such schemes interpolate not only Legendre moments of face and of cell but also the values of the scalar flow of neutrons in the four corners of each cell or element of the spatial discretization of the domain of interest. All the schemes here considered are polynomials like they were it their predecessors. Particularly, its have developed and applied eight different hybrid nodal schemes that its are very nearby related with those developed by Hennart and collaborators in the past. It is treated of schemes in those that nevertheless that decreases the number of interpolation parameters it is conserved the accurate in relation to the bi-quadratic and bi-cubic schemes. Of these eight, three were described and applied in a previous work. It is the bi-lineal classic scheme as well as the hybrid nodal schemes, bi-quadratic and bi-cubic for that here only are described the other 5 hybrid nodal schemes although they are provided numerical results for several test problems with all them. (Author)

  10. A geometrically exact beam element based on the absolute nodal coordinate formulation

    International Nuclear Information System (INIS)

    Gerstmayr, Johannes; Matikainen, Marko K.; Mikkola, Aki M.

    2008-01-01

    In this study, Reissner's classical nonlinear rod formulation, as implemented by Simo and Vu-Quoc by means of the large rotation vector approach, is implemented into the framework of the absolute nodal coordinate formulation. The implementation is accomplished in the planar case accounting for coupled axial, bending, and shear deformation. By employing the virtual work of elastic forces similarly to Simo and Vu-Quoc in the absolute nodal coordinate formulation, the numerical results of the formulation are identical to those of the large rotation vector formulation. It is noteworthy, however, that the material definition in the absolute nodal coordinate formulation can differ from the material definition used in Reissner's beam formulation. Based on an analytical eigenvalue analysis, it turns out that the high frequencies of cross section deformation modes in the absolute nodal coordinate formulation are only slightly higher than frequencies of common shear modes, which are present in the classical large rotation vector formulation of Simo and Vu-Quoc, as well. Thus, previous claims that the absolute nodal coordinate formulation is inefficient or would lead to ill-conditioned finite element matrices, as compared to classical approaches, could be refuted. In the introduced beam element, locking is prevented by means of reduced integration of certain parts of the elastic forces. Several classical large deformation static and dynamic examples as well as an eigenvalue analysis document the equivalence of classical nonlinear rod theories and the absolute nodal coordinate formulation for the case of appropriate material definitions. The results also agree highly with those computed in commercial finite element codes

  11. On the treatment of nonlinear local feedbacks within advanced nodal generalized perturbation theory

    International Nuclear Information System (INIS)

    Maldonado, G.I.; Turinsky, P.J.; Kropaczek, D.J.

    1993-01-01

    Recent efforts to upgrade the underlying neutronics formulations within the in-core nuclear fuel management optimization code FORMOSA (Ref. 1) have produced two important developments; first, a computationally efficient and second-order-accurate advanced nodal generalized perturbation theory (GPT) model [derived from the nonlinear iterative nodal expansion method (NEM)] for evaluating core attributes (i.e., k eff and power distribution versus cycle burnup), and second, an equally efficient and accurate treatment of local thermal-hydraulic and fission product feedbacks embedded within NEM GPT. The latter development is the focus of this paper

  12. Segregated nodal domains of two-dimensional multispecies Bose-Einstein condensates

    Science.gov (United States)

    Chang, Shu-Ming; Lin, Chang-Shou; Lin, Tai-Chia; Lin, Wen-Wei

    2004-09-01

    In this paper, we study the distribution of m segregated nodal domains of the m-mixture of Bose-Einstein condensates under positive and large repulsive scattering lengths. It is shown that components of positive bound states may repel each other and form segregated nodal domains as the repulsive scattering lengths go to infinity. Efficient numerical schemes are created to confirm our theoretical results and discover a new phenomenon called verticillate multiplying, i.e., the generation of multiple verticillate structures. In addition, our proposed Gauss-Seidel-type iteration method is very effective in that it converges linearly in 10-20 steps.

  13. [Does nodal irradiation (clavicular and internal mammary chains) increase the toxicity of adjuvant breast radiotherapy?].

    Science.gov (United States)

    Riou, O; Bourgier, C; Fenoglietto, P; Azria, D

    2015-06-01

    Treatment volume is a major risk factor of radiation-induced toxicity. As nodal irradiation increases treatment volume, radiation toxicity should be greater. Nevertheless, scientific randomised data do not support this fact. However, a radiation-induced toxicity is possible outside tangential fields in the nodal volumes not related to breast-only treatment. Treatment should not be adapted only to the disease but personalized to the individual risk of toxicity for each patient. Copyright © 2015 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  14. A self-consistent nodal method in response matrix formalism for the multigroup diffusion equations

    International Nuclear Information System (INIS)

    Malambu, E.M.; Mund, E.H.

    1996-01-01

    We develop a nodal method for the multigroup diffusion equations, based on the transverse integration procedure (TIP). The efficiency of the method rests upon the convergence properties of a high-order multidimensional nodal expansion and upon numerical implementation aspects. The discrete 1D equations are cast in response matrix formalism. The derivation of the transverse leakage moments is self-consistent i.e. does not require additional assumptions. An outstanding feature of the method lies in the linear spatial shape of the local transverse leakage for the first-order scheme. The method is described in the two-dimensional case. The method is validated on some classical benchmark problems. (author)

  15. Nodal signals mediate interactions between the extra-embryonic and embryonic tissues in zebrafish

    OpenAIRE

    Xiang, Fan; Hagos, Engda G.; Xu, Bo; Sias, Christina; Kawakami, Koichi; Burdine, Rebecca D.; Dougan, Scott T.

    2007-01-01

    In many vertebrates, extra-embryonic tissues are important signaling centers that induce and pattern the germ layers. In teleosts, the mechanism by which the extra-embryonic yolk syncytial layer (YSL) patterns the embryo is not understood. Although the Nodal-related protein Squint is expressed in the YSL, its role in this tissue is not known. We generated a series of stable transgenic lines with GFP under the control of squint genomic sequences. In all species, nodal-related genes induce thei...

  16. Spectral nodal method for one-speed X,Y-geometry Eigenvalue diffusion problems

    International Nuclear Information System (INIS)

    Dominguez, Dany S.; Lorenzo, Daniel M.; Hernandez, Carlos G.; Barros, Ricardo C.; Silva, Fernando C. da

    2001-01-01

    Presented here is a new numerical nodal method for steady-state multidimensional neutron diffusion equation in rectangular geometry. Our method is based on a spectral analysis of the transverse-integrated nodal diffusion equations. These equations are obtained by integrating the diffusion equation in X and Y directions, and then considering flat approximations for the transverse leakage terms. These flat approximations are the only approximations that we consider in this method; as a result the numerical solutions are completely free from truncation errors in slab geometry. We show numerical results to illustrate the method's accuracy for coarse mesh calculations in a heterogeneous medium. (author)

  17. One-dimensional nodal neutronics routines for the TRAC-BD1 thermal-hydraulics program

    International Nuclear Information System (INIS)

    Nigg, D.W.

    1983-09-01

    Nuclear reactor core transient neutronic behavior is currently modeled in the TRAC-BD1 code using a point-reactor kinetics formulation. This report describes a set of subroutines based on the Analytic Nodal Method that were written to provide TRAC-BD1 with a one-dimensional space-dependent neutronics capability. Use of the routines is illustrated with several test problems. The results of these problems show that the Analytic Nodal neutronics routines have desirable accuracy and computing time characteristics and should be a useful addition to TRAC-BD1

  18. Incidental Prophylactic Nodal Irradiation and Patterns of Nodal Relapse in Inoperable Early Stage NSCLC Patients Treated With SBRT: A Case-Matched Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lao, Louis [Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Auckland City Hospital, Auckland (New Zealand); Hope, Andrew J. [Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario (Canada); Maganti, Manjula [Department of Biostatistics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario (Canada); Brade, Anthony; Bezjak, Andrea; Saibishkumar, Elantholi P.; Giuliani, Meredith; Sun, Alexander [Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario (Canada); Cho, B. C. John, E-mail: john.cho@rmp.uhn.on.ca [Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario (Canada)

    2014-09-01

    Purpose: Reported rates of non-small cell lung cancer (NSCLC) nodal failure following stereotactic body radiation therapy (SBRT) are lower than those reported in the surgical series when matched for stage. We hypothesized that this effect was due to incidental prophylactic nodal irradiation. Methods and Materials: A prospectively collected group of medically inoperable early stage NSCLC patients from 2004 to 2010 was used to identify cases with nodal relapses. Controls were matched to cases, 2:1, controlling for tumor volume (ie, same or greater) and tumor location (ie, same lobe). Reference (normalized to equivalent dose for 2-Gy fractions [EQD2]) point doses at the ipsilateral hilum and carina, demographic data, and clinical outcomes were extracted from the medical records. Univariate conditional logistical regression analyses were performed with variables of interest. Results: Cases and controls were well matched except for size. The controls, as expected, had larger gross tumor volumes (P=.02). The mean ipsilateral hilar doses were 9.6 Gy and 22.4 Gy for cases and controls, respectively (P=.014). The mean carinal doses were 7.0 Gy and 9.2 Gy, respectively (P=.13). Mediastinal nodal relapses, with and without ipsilateral hilar relapse, were associated with mean ipsilateral hilar doses of 3.6 Gy and 19.8 Gy, respectively (P=.01). The conditional density plot appears to demonstrate an inverse dose-effect relationship between ipsilateral hilar normalized total dose and risk of ipsilateral hilar relapse. Conclusions: Incidental hilar dose greater than 20 Gy is significantly associated with fewer ipsilateral hilar relapses in inoperable early stage NSCLC patients treated with SBRT.

  19. Incidental Prophylactic Nodal Irradiation and Patterns of Nodal Relapse in Inoperable Early Stage NSCLC Patients Treated With SBRT: A Case-Matched Analysis

    International Nuclear Information System (INIS)

    Lao, Louis; Hope, Andrew J.; Maganti, Manjula; Brade, Anthony; Bezjak, Andrea; Saibishkumar, Elantholi P.; Giuliani, Meredith; Sun, Alexander; Cho, B. C. John

    2014-01-01

    Purpose: Reported rates of non-small cell lung cancer (NSCLC) nodal failure following stereotactic body radiation therapy (SBRT) are lower than those reported in the surgical series when matched for stage. We hypothesized that this effect was due to incidental prophylactic nodal irradiation. Methods and Materials: A prospectively collected group of medically inoperable early stage NSCLC patients from 2004 to 2010 was used to identify cases with nodal relapses. Controls were matched to cases, 2:1, controlling for tumor volume (ie, same or greater) and tumor location (ie, same lobe). Reference (normalized to equivalent dose for 2-Gy fractions [EQD2]) point doses at the ipsilateral hilum and carina, demographic data, and clinical outcomes were extracted from the medical records. Univariate conditional logistical regression analyses were performed with variables of interest. Results: Cases and controls were well matched except for size. The controls, as expected, had larger gross tumor volumes (P=.02). The mean ipsilateral hilar doses were 9.6 Gy and 22.4 Gy for cases and controls, respectively (P=.014). The mean carinal doses were 7.0 Gy and 9.2 Gy, respectively (P=.13). Mediastinal nodal relapses, with and without ipsilateral hilar relapse, were associated with mean ipsilateral hilar doses of 3.6 Gy and 19.8 Gy, respectively (P=.01). The conditional density plot appears to demonstrate an inverse dose-effect relationship between ipsilateral hilar normalized total dose and risk of ipsilateral hilar relapse. Conclusions: Incidental hilar dose greater than 20 Gy is significantly associated with fewer ipsilateral hilar relapses in inoperable early stage NSCLC patients treated with SBRT

  20. IV DSA in the diagnosis and follow-up of dissection of the thoracic aorta

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickx, P.; Luska, G.; Laas, J.; Haverich, A.

    1986-05-01

    Intravenous DSA was performed in 53 patients with suspected dissection of the thoracic aorta and in 13 patients following surgery for aortic dissection. In 36 patients, the suspected diagnosis could be excluded definitely and, in 14 cases out of 17, a dissection was correctly diagnosed. All 11 type B dissections were correctly diagnosed. Of six type A dissections, only three were adequately demonstrated by IV DSA. In type B dissections, IV DSA is reliable, but in type A dissection with massive aortic insufficiency or pericardial tamponade the findings are not reliable. In all 13 patients who had surgery for dissection, IV DSA proved suitable for showing the anastomosis and progress of the disease.

  1. Case report of lymph nodal, hepatic and splenic tuberculosis in an HIV-positive patient

    Directory of Open Access Journals (Sweden)

    Bianca Barone

    Full Text Available We describe a case of a male patient, 38 years old, HIV-positive (most recent CD4 count about 259/mm³, with abdominal pain, nausea, vomiting, anorexia, weight loss, and vespertine high fever with chills. His hemogram showed normocytic and normochromic anemia, with a high erythrocyte sedimentation rate (ESR and gross granulations in the neutrophils. Transaminases were normal. Bone marrow biopsy evidenced a chronic disease anemia pattern and a lack of infectious agents. Abdominal ultrasound examination showed a normal-size spleen, which exhibited heterogeneous parenchyma and multiple small hypoechoic images, together with small ascites, peripancreatic and para-aortic lymphadenopathy. These findings were confirmed by abdominal CT. The liver was normal in size, but had a hyperechoic image, which was not visualized on CT. Histopathological analysis of one of the multiple abdominal lymph nodes obtained by laparoscopic biopsy exhibited a chronic granulomatous inflammatory process, with caseous necrosis. Tissue sections were positive for BAAR (acid-alcohol-resistant bacillus, and the cultures were positive for Mycobacterium tuberculosis. Anti-tuberculosis treatment was begun, and the patient evolved with improvement of his general state, fever remission and weight gain. Splenic tuberculosis is a rare disease, occurring predominantly in patients in late stages of AIDS and/or disseminated tuberculosis. It is a difficult diagnosis, since there are no specific findings. Hence, complementary examinations, such as abdominal ultrasound/ CT, or fine needle aspiration, are usually necessary for investigation and differential diagnosis. Often, lesion regression after anti-tuberculosis regimens can be seen, and splenectomy is restricted to complicated or refractory disease.

  2. Clinical value and indication for the dissection of lymph nodes posterior to the right recurrent laryngeal nerve in papillary thyroid carcinoma.

    Science.gov (United States)

    Luo, Ding-Cun; Xu, Xiao-Cheng; Ding, Jin-Wang; Zhang, Yu; Peng, You; Pan, Gang; Zhang, Wo

    2017-10-03

    Lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) are common sites of nodal recurrence after the resection of papillary thyroid carcinoma (PTC). However, the indication for LN-prRLN dissection remains debatable. We therefore studied the relationships between LN-prRLN metastasis and the clinicopathological characteristics in 306 patients with right or bilateral PTC who underwent LN-prRLN dissection. We found that LN-prRLN metastasis occurred in 16.67% of PTC and was associated with a number of the clinicopathological features. The receiver-operator characteristic (ROC) analysis showed that the areas under the ROC curves for the prediction of LN-prRLN metastasis by the risk factors age right tumor size > 0.85 cm, lymph node (right cervical central VI-1) number > 1.5, metastatic lymph node (right cervical central VI-1) size > 0.45 cm, and lymph node number in the right cervical lateral compartment > 0.5 were 0.601, 0.815, 0.813, 0.725, and 0.743, respectively. In conclusion, the risk factors for LN-prRLN metastasis in patients suffering right thyroid lobe or bilateral PTC include age ≤ 35.5 years, right tumor size ≥ 0.85 cm, capsular invasion, metastatic lymph node (right cervical central VI-1) number ≥ 2, metastatic lymph node (right cervical central VI-1) size ≥ 0.45 cm, and metastatic lymph node number in the right cervical lateral compartment ≥ 1. In patients whose risk factors can be identified pre-operatively or intraoperatively, the dissection of LN-pr-RLN should be considered during right cervical central compartment dissection.

  3. Amplification and protein overexpression of cyclin D1: Predictor of occult nodal metastasis in early oral cancer.

    Science.gov (United States)

    Noorlag, Rob; Boeve, Koos; Witjes, Max J H; Koole, Ronald; Peeters, Ton L M; Schuuring, Ed; Willems, Stefan M; van Es, Robert J J

    2017-02-01

    Accurate nodal staging is pivotal for treatment planning in early (stage I-II) oral cancer. Unfortunately, current imaging modalities lack sensitivity to detect occult nodal metastases. Chromosomal region 11q13, including genes CCND1, Fas-associated death domain (FADD), and CTTN, is often amplified in oral cancer with nodal metastases. However, evidence in predicting occult nodal metastases is limited. In 158 patients with early tongue and floor of mouth (FOM) squamous cell carcinomas, both CCND1 amplification and cyclin D1, FADD, and cortactin protein expression were correlated with occult nodal metastases. CCND1 amplification and cyclin D1 expression correlated with occult nodal metastases. Cyclin D1 expression was validated in an independent multicenter cohort, confirming the correlation with occult nodal metastases in early FOM cancers. Cyclin D1 is a predictive biomarker for occult nodal metastases in early FOM cancers. Prospective research on biopsy material should confirm these results before implementing its use in routine clinical practice. © 2016 Wiley Periodicals, Inc. Head Neck 39: 326-333, 2017. © 2016 Wiley Periodicals, Inc.

  4. Pulmonary artery dissection in eight dogs with patent ductus arteriosus.

    Science.gov (United States)

    Scansen, Brian A; Simpson, Elaine M; López-Alvarez, Jordi; Thomas, William P; Bright, Janice M; Eason, Bryan D; Rush, John E; Dukes-McEwan, Joanna; Green, Henry W; Cunningham, Suzanne M; Visser, Lance C; Kent, Agnieszka M; Schober, Karsten E

    2015-06-01

    To describe a series of dogs with pulmonary artery dissection and patent ductus arteriosus (PDA). Eight dogs. Retrospective case series. Pulmonary artery dissection was diagnosed in 8 dogs, 3 were Weimaraners. Four dogs presented in left-sided congestive heart failure, 4 presented for murmur evaluation and without clinical signs, and 1 presented in right-sided congestive heart failure. In 7 dogs the dissection was first documented concurrent with a diagnosis of uncorrected PDA. In the other dog, with pulmonary valve stenosis and PDA, the dissection was observed on autopsy examination 17 months after balloon pulmonary valvuloplasty and ductal closure. Median age at presentation for the 7 dogs with antemortem diagnosis of pulmonary artery dissection was 3.5 years (range, 1.5-4 years). Three dogs had the PDA surgically ligated, 2 dogs did not undergo PDA closure, 1 dog failed transcatheter occlusion of the PDA with subsequent surgical ligation, 1 dog underwent successful transcatheter device occlusion of the PDA, and 1 dog had the PDA closed by transcatheter coil delivery 17 months prior to the diagnosis of pulmonary artery dissection. The 2 dogs that did not have the PDA closed died 1 and 3 years after diagnosis due to heart failure. Pulmonary artery dissection is a potential complication of PDA in dogs, the Weimaraner breed may be at increased risk, presentation is often in mature dogs, and closure of the PDA can be performed and appears to improve outcome. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Review of patients with dysphasia after a neck dissection

    International Nuclear Information System (INIS)

    Yokoyama, Junkichi

    2007-01-01

    The most useful modality for treating neck metastasis is a neck dissection. A neck dissection was previously performed as a radical neck dissection. However, disabilities in shoulder movement and swallowing function often occur after this procedure. Recently, a functional neck dissection has therefore been performed in order to avoid such postoperative complications. The current study for dysphasia after a neck dissection investigates patients with primary unknown neck metastasis and neck recurrence after chemoradiation. Eleven cases of dysphasia occurred after a neck dissection between 2003 and 2006. These cases resected the lower cranial nerves (IX, X, XII), or paralysis of these nerves occurred despite their preservation after surgery. Patients with dysphasia underwent rehabilitation to regain their swallowing function. However, rehabilitation was unsuccessful and the patients were thus required to undergo further surgery. A neck dissection with resection of the lower cranial nerves (IX, X, XII) may sometimes result in dysphasia. Consequently, surgery to prevent dysphasia should be performed simultaneously so that timely postoperative therapy can be carried out. (author)

  6. Neurorehabilitation in stroke produced by vertebral artery dissection: case presentation

    Directory of Open Access Journals (Sweden)

    Stanescu Ioana

    2018-02-01

    Full Text Available Arterial dissections are a common cause of stroke in the young (mean age 44 to 46 years. Primary lesion is a tear of the arterial intima, which promotes platelet aggregation, thrombus formation, which further produced vessel stenosis / occlusion, distal embolism or vessel wall rupture. Vertebral artery (VA dissection appear most commonly in extracranial segments V2 and V3, and could be spontaneous (with underlying predispositions or triggered by various traumatisms. Clinicaly, VA dissection produces an ischemic stroke or transient ischemic attack , preceded by local symptoms such as neck pain or headache. The diagnosis is confirmed by neurovascular imaging. Treatment of symptomatic VA dissections respect indications of treatment in ischemic strokes. Prognosis is mostly favorable in extracranial dissections. We present the case of a left VA dissection in V2 segment, produced by physical effort (swimming, which causes 2 ischemic lesions, one in the territory of the left posterior cerebral artery and the other in the territory of the left posterolateral chorroidal artery. Patient’s treatment included antiplatelet agents, statines, and an adapted physical rehabilitation program. At three months he showed significant clinical improvement with regain of autonomy and partial recanalisation at angio-MRI of the V2 segment of the dissected artery.

  7. Pulmonary Artery Dissection: A Fatal Complication of Pulmonary Hypertension

    Directory of Open Access Journals (Sweden)

    Chuanchen Zhang

    2016-01-01

    Full Text Available Pulmonary artery dissection is extremely rare but it is a really life-threatening condition when it happens. Most patients die suddenly from major bleeding or tamponade caused by direct rupture into mediastinum or retrograde into the pericardial sac. What we are reporting is a rare case of a 46-year-old female patient whose pulmonary artery dissection involves both the pulmonary valve and right pulmonary artery. The patient had acute chest pain and severe dyspnea, and the diagnosis of pulmonary artery dissection was confirmed by ultrasonography and CT angiography. Moreover, its etiology, clinical manifestations, and management are also discussed in this article.

  8. Pseudo-dissection of ascending aorta in inferior myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Grahame K. Goode

    2011-06-01

    Full Text Available Acute aortic dissection is a cardiac emergency which can present as inferior myocardial infarction. It has high morbidity and mortality requiring prompt diagnosis and treatment. Rapid advances in noninvasive imaging modalities have facilitated the early diagnosis of this condition and in ruling out this potentially catastrophic illness. We report an interesting case of a 57 year- old -man who presented with inferior myocardial infarction requiring thrombolysis and temporary pacing wire for complete heart block. An echocardiogram was highly suspicious of aortic dissection. CT scan confirmed that the malposition of the temporary pacing wire through the aorta mimicked aortic dissection.

  9. Selective neck dissection: a review of the evidence.

    Science.gov (United States)

    Pagedar, Nitin A; Gilbert, Ralph W

    2009-01-01

    The management of regional metastatic disease in patients with oral cancer is a topic of controversy. Comprehensive neck dissection has been the mainstay of treatment historically, but clinicians have sought alternatives to limit the morbidity of the classic radical neck dissection. This article will review evidence on the applicability of selective neck dissection in two settings: as primary treatment of the clinically positive neck and as salvage treatment of recurrent neck disease after radiotherapy. In the text, for each article cited we supply the level of evidence thereof according to the Oxford Centre for Evidence-based medicine.

  10. Intraoperative validation of CT-based lymph nodal levels, sublevels IIa and IIb: Is it of clinical relevance in selective radiation therapy?

    International Nuclear Information System (INIS)

    Levendag, Peter; Gregoire, Vincent; Hamoir, Marc; Voet, Peter; Est, Henrie van der; Heijmen, Ben; Kerrebijn, Jeroen

    2005-01-01

    Purpose: The objectives of this study are to discuss the intraoperative validation of CT-based boundaries of lymph nodal levels in the neck, and in particular the clinical relevance of the delineation of sublevels IIa and IIb in case of selective radiation therapy (RT). Methods and Materials: To validate the radiologically defined level contours, clips were positioned intraoperatively at the level boundaries defined by surgical anatomy. In 10 consecutive patients, clips were placed, at the time of a neck dissection being performed, at the most cranial border of the neck. Anterior-posterior and lateral X-ray films were obtained intraoperatively. Next, in 3 patients, neck levels were contoured on preoperative contrast-enhanced CT scans according to the international consensus guidelines. From each of these 3 patients, an intraoperative CT scan was also obtained, with clips placed at the surgical-anatomy-based level boundaries. The preoperative (CT-based) and intraoperative (surgery-defined) CT scans were matched. Results: Clips placed at the most cranial part of the neck lined up at the caudal part of the transverse process of the cervical vertebra C-I. The posterior border of surgical level IIa (spinal accessory nerve [SAN]) did not match with the posterior border of CT-based level IIa (internal jugular vein [IJV]). Other surgical boundaries and CT-based contours were in good agreement. Conclusions: The cranial border of the neck, i.e., the cranial border of level IIa/IIb, corresponds to the caudal edge of the lateral process of C-I. Except for the posterior border between level IIa and level IIb, a perfect match was observed between the other surgical-clip-identified levels II-V boundaries (surgical-anatomy) and the CT-based delineation contours. It is argued that (1) because of the parotid gland overlapping part of level II, and (2) the frequent infestation of occult metastatic cells in the lymph channels around the IJV, the division of level II into radiologic

  11. Nodal involvement in Hodgkin disease and non-Hodgkin lymphoma assessed by magnetic resonance

    International Nuclear Information System (INIS)

    Tesoro Tess, J.D.; Balzarini, L.; Ceglia, E.; Petrillo, R.; Musumeci, R.

    1990-01-01

    Magnetic Resonance Imaging (MRI) demonstrates a good capability in distinguishing nodal involvement in hodgkin disease and nonhodgkin lymphoma both in the chest and in the retroperitoneal areas the initial presentation of the disease. However CT and lymphangiography demonstrated comparable or superior values of accuracy and sensitivity. (H.W.) 4 refs.; 2 tabs

  12. A nodal Grean's function method of reactor core fuel management code, NGCFM2D

    International Nuclear Information System (INIS)

    Li Dongsheng; Yao Dong.

    1987-01-01

    This paper presents the mathematical model and program structure of the nodal Green's function method of reactor core fuel management code, NGCFM2D. Computing results of some reactor cores by NGCFM2D are analysed and compared with other codes

  13. Unbounded planar domains whose second nodal line does not touch the boundary

    Czech Academy of Sciences Publication Activity Database

    Freitas, P.; Krejčiřík, David

    2007-01-01

    Roč. 14, č. 1 (2007), s. 107-111 ISSN 1073-2780 R&D Projects: GA MŠk LC06002 Institutional research plan: CEZ:AV0Z10480505 Keywords : Dirichlet Laplacian * eigenfunctions * nodal line Subject RIV: BA - General Mathematics Impact factor: 0.702, year: 2007

  14. Computation of Steady State Nodal Voltages for Fast Security Assessment in Power Systems

    DEFF Research Database (Denmark)

    Møller, Jakob Glarbo; Jóhannsson, Hjörtur; Østergaard, Jacob

    2014-01-01

    Development of a method for real-time assess-ment of post-contingency nodal voltages is introduced. Linear network theory is applied in an algorithm that utilizes Thevenin equivalent representation of power systems as seen from every voltage-controlled node in a network. The method is evaluated b...

  15. Short-term displacement and reproducibility of the breast and nodal targets under active breathing control

    NARCIS (Netherlands)

    Moran, Jean M.; Balter, James M.; Ben-David, Merav A.; Marsh, Robin B.; van Herk, Marcel; Pierce, Lori J.

    2007-01-01

    PURPOSE: The short-term displacement and reproducibility of the breast or chest wall, and the internal mammary (IM), infraclavicular (ICV), and supraclavicular (SCV) nodal regions have been assessed as a function of breath-hold state using an active breathing control (ABC) device for patients

  16. An error bound estimate and convergence of the Nodal-LTS N solution in a rectangle

    International Nuclear Information System (INIS)

    Hauser, Eliete Biasotto; Pazos, Ruben Panta; Tullio de Vilhena, Marco

    2005-01-01

    In this work, we report the mathematical analysis concerning error bound estimate and convergence of the Nodal-LTS N solution in a rectangle. For such we present an efficient algorithm, called LTS N 2D-Diag solution for Cartesian geometry

  17. Lymphoma no Hodgkin extra nodal in head and neck: value of CT

    International Nuclear Information System (INIS)

    Ramos Aguilar, A.; Romance Garcia, A.; Fuentes Lupianez, J.J.; Sanchez Lafuente, J.; Rodriguez Sanpedro, F.

    1994-01-01

    The head and neck regions is one of the most common sites of extra nodal non-Hodgkin's lymphoma (NHL). We studied 7 cases of NHL of head and neck using CT enhanced with intravenous contrast medium, analyzing the important role it plays in diagnosis, treatment planning and evaluation of the recurrence of these tumors. (Author)

  18. VARIANT: VARIational anisotropic nodal transport for multidimensional Cartesian and hexadgonal geometry calculation

    International Nuclear Information System (INIS)

    Palmiotti, G.; Carrico, C.B.; Lewis, E.E.

    1995-10-01

    The theoretical basis, implementation information and numerical results are presented for VARIANT (VARIational Anisotropic Neutron Transport), a FORTRAN module of the DIF3D code system at Argonne National Laboratory. VARIANT employs the variational nodal method to solve multigroup steady-state neutron diffusion and transport problems. The variational nodal method is a hybrid finite element method that guarantees nodal balance and permits spatial refinement through the use of hierarchical complete polynomial trial functions. Angular variables are expanded with complete or simplified P 1 , P 3 or P 5 5 spherical harmonics approximations with full anisotropic scattering capability. Nodal response matrices are obtained, and the within-group equations are solved by red-black or four-color iteration, accelerated by a partitioned matrix algorithm. Fission source and upscatter iterations strategies follow those of DIF3D. Two- and three-dimensional Cartesian and hexagonal geometries are implemented. Forward and adjoint eigenvalue, fixed source, gamma heating, and criticality (concentration) search problems may be performed

  19. A new communication scheme for the neutron diffusion nodal method in a distributed computing environment

    International Nuclear Information System (INIS)

    Kirk, B.L.; Azmy, Y.

    1994-01-01

    A modified scheme is developed for solving the two-dimensional nodal diffusion equations on distributed memory computers. The scheme is aimed at minimizing the volume of communication among processors while maximizing the tasks in parallel. Results show a significant improvement in parallel efficiency on the Intel iPSC/860 hypercube compared to previous algorithms

  20. Encapsulation of nodal cuttings and shoot tips for storage and exchange of cassava germplasm.

    Science.gov (United States)

    Danso, K E; Ford-Lloyd, B V

    2003-04-01

    We report the encapsulation of in vitro-derived nodal cuttings or shoot tips of cassava in 3% calcium alginate for storage and germplasm exchange purposes. Shoot regrowth was not significantly affected by the concentration of sucrose in the alginate matrix while root formation was. In contrast, increasing the sucrose concentration in the calcium chloride polymerisation medium significantly reduced regrowth from encapsulated nodal cuttings of accession TME 60444. Supplementing the alginate matrix with increased concentrations of 6-benzylaminopurine and alpha-naphthaleneacetic acid enhanced complete plant regrowth within 2 weeks. Furthermore, plant regrowth by encapsulated nodal cuttings and shoot tips was significantly affected by the duration of the storage period as shoot recovery decreased from almost 100% to 73.3% for encapsulated nodal cuttings and 94.4% to 60% for shoot tips after 28 days of storage. The high frequency of plant regrowth from alginate-coated micropropagules coupled with high viability percentage after 28 days of storage is highly encouraging for the exchange of cassava genetic resources. Such encapsulated micropropagules could be used as an alternative to synthetic seeds derived from somatic embryos.

  1. GDF3 is a BMP inhibitor that can activate Nodal signaling only at very high doses

    Science.gov (United States)

    Levine, Ariel J.; Levine, Zachary J.; Brivanlou, Ali H.

    2013-01-01

    Within the TGF-β superfamily, there are approximately forty ligands divided into two major branches: the TGF-β/Activin/Nodal ligands and the BMP/GDF ligands. We studied the ligand GDF3 and found that it inhibits signaling by its co-family members, the BMPs; however, GDF3 has been described by others to have Nodal-like activity. Here, we show that GDF3 can activate Nodal signaling, but only at very high doses and only upon mRNA over-expression. In contrast, GDF3 inhibits BMP signaling upon over-expression of GDF3 mRNA, as recombinant protein, and regardless of its dose. We therefore further characterized the mechanism through which GDF3 protein acts as a specific BMP inhibitor and found that the BMP inhibitory activity of GDF3 resides redundantly in the unprocessed, predominant form and in the mature form of the protein. These results confirm and extend the activity that we described for GDF3 and illuminate the experimental basis for the different observations of others. We suggest that GDF3 is either a bi-functional TGF-β ligand, or, more likely, that it is a BMP inhibitor that can artificially activate Nodal signaling under non-physiological conditions. PMID:18823971

  2. Barrier tunneling of the loop-nodal semimetal in the hyperhoneycomb lattice

    Science.gov (United States)

    Guan, Ji-Huan; Zhang, Yan-Yang; Lu, Wei-Er; Xia, Yang; Li, Shu-Shen

    2018-05-01

    We theoretically investigate the barrier tunneling in the 3D model of the hyperhoneycomb lattice, which is a nodal-line semimetal with a Dirac loop at zero energy. In the presence of a rectangular potential, the scattering amplitudes for different injecting states around the nodal loop are calculated, by using analytical treatments of the effective model, as well as numerical simulations of the tight binding model. In the low energy regime, states with remarkable transmissions are only concentrated in a small range around the loop plane. When the momentum of the injecting electron is coplanar with the nodal loop, nearly perfect transmissions can occur for a large range of injecting azimuthal angles if the potential is not high. For higher potential energies, the transmission shows a resonant oscillation with the potential, but still with peaks being perfect transmissions that do not decay with the potential width. These strikingly robust transports of the loop-nodal semimetal can be approximately explained by a momentum dependent Dirac Hamiltonian.

  3. Error quantification of the axial nodal diffusion kernel of the DeCART code

    International Nuclear Information System (INIS)

    Cho, J. Y.; Kim, K. S.; Lee, C. C.

    2006-01-01

    This paper is to quantify the transport effects involved in the axial nodal diffusion kernel of the DeCART code. The transport effects are itemized into three effects, the homogenization, the diffusion, and the nodal effects. A five pin model consisting of four fuel pins and one non-fuel pin is demonstrated to quantify the transport effects. The transport effects are analyzed for three problems, the single pin (SP), guide tube (GT) and control rod (CR) problems by replacing the non-fuel pin with the fuel pin, a guide-tube and a control rod pins, respectively. The homogenization and diffusion effects are estimated to be about -4 and -50 pcm for the eigenvalue, and less than 2 % for the node power. The nodal effect on the eigenvalue is evaluated to be about -50 pcm in the SP and GT problems, and +350 pcm in the CR problem. Regarding the node power, this effect induces about a 3 % error in the SP and GT problems, and about a 20 % error in the CR problem. The large power error in the CR problem is due to the plane thickness, and it can be decreased by using the adaptive plane size. From the error quantification, it is concluded that the homogenization and the diffusion effects are not controllable if DeCART maintains the diffusion kernel for the axial solution, but the nodal effect is controllable by introducing the adaptive plane size scheme. (authors)

  4. Depletion Calculations for MTR Core Using MCNPX and Multi-Group Nodal Diffusion Methods

    International Nuclear Information System (INIS)

    Jaradata, Mustafa K.; Park, Chang Je; Lee, Byungchul

    2013-01-01

    In order to maintain a self-sustaining steady-state chain reaction, more fuel than is necessary in order to maintain a steady state chain reaction must be loaded. The introduction of this excess fuel increases the net multiplication capability of the system. In this paper MCNPX and multi-group nodal diffusion theory will be used for depletion calculations for MTR core. The eigenvalue and power distribution in the core will be compared for different burnup. Multi-group nodal diffusion theory with combination of NEWT-TRITON system was used to perform depletion calculations for 3Χ3 MTR core. 2G and 6G approximations were used and compared with MCNPX results for 2G approximation the maximum difference from MCNPX was 40 mk and for 6G approximation was 6 mk which is comparable to the MCNPX results. The calculated power using nodal code was almost the same MCNPX results. Finally the results of the multi-group nodal theory were acceptable and comparable to the calculated using MCNPX

  5. Atrial activation during atrioventricular nodal reentrant tachycardia: studies on retrograde fast pathway conduction

    NARCIS (Netherlands)

    Katritsis, Demosthenes G.; Ellenbogen, Kenneth A.; Becker, Anton E.

    2006-01-01

    Detailed right and left septal mapping of retrograde atrial activation during typical atrioventricular nodal reentrant tachycardia (AVNRT) has not been undertaken and may provide insight into the complex physiology of AVNRT, especially the anatomic localization of the fast and slow pathways. The

  6. A Nodal-independent and tissue-intrinsic mechanism controls heart-looping chirality

    NARCIS (Netherlands)

    Noel, E.S.; Verhoeven, M.; Lagendijk, A.K.; Tessadori, F.; Smith, K.; Choorapoikayil, S.; den Hertog, J.; Bakkers, J.

    2013-01-01

    Breaking left-right symmetry in bilateria is a major event during embryo development that is required for asymmetric organ position, directional organ looping and lateralized organ function in the adult. Asymmetric expression of Nodal-related genes is hypothesized to be the driving force behind

  7. On the relationship between some nodal schemes and the finite element method in static diffusion calculations

    International Nuclear Information System (INIS)

    Fedon-Magnaud, C.; Hennart, J.P.; Lautard, J.J.

    1983-03-01

    An unified formulation of non conforming finite elements with quadrature formula and simple nodal scheme is presented. The theoretical convergence is obtained for the previous scheme when the mesh is refined. Numerical tests are provided in order to bear out the theorical results

  8. A nodal method applied to a diffusion problem with generalized coefficients

    International Nuclear Information System (INIS)

    Laazizi, A.; Guessous, N.

    1999-01-01

    In this paper, we consider second order neutrons diffusion problem with coefficients in L ∞ (Ω). Nodal method of the lowest order is applied to approximate the problem's solution. The approximation uses special basis functions in which the coefficients appear. The rate of convergence obtained is O(h 2 ) in L 2 (Ω), with a free rectangular triangulation. (authors)

  9. A difference-equation formalism for the nodal domains of separable billiards

    Energy Technology Data Exchange (ETDEWEB)

    Manjunath, Naren; Samajdar, Rhine [Indian Institute of Science, Bangalore 560012 (India); Jain, Sudhir R., E-mail: srjain@barc.gov.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-09-15

    Recently, the nodal domain counts of planar, integrable billiards with Dirichlet boundary conditions were shown to satisfy certain difference equations in Samajdar and Jain (2014). The exact solutions of these equations give the number of domains explicitly. For complete generality, we demonstrate this novel formulation for three additional separable systems and thus extend the statement to all integrable billiards.

  10. The statistics of the points where nodal lines intersect a reference curve

    International Nuclear Information System (INIS)

    Aronovitch, Amit; Smilansky, Uzy

    2007-01-01

    We study the intersection points of a fixed planar curve Γ with the nodal set of a translationally invariant and isotropic Gaussian random field Ψ(r) and the zeros of its normal derivative across the curve. The intersection points form a discrete random process which is the object of this study. The field probability distribution function is completely specified by the correlation G(|r - r'|) = (Ψ(r)Ψ(r')). Given an arbitrary G(|r - r'|), we compute the two-point correlation function of the point process on the line, and derive other statistical measures (repulsion, rigidity) which characterize the short- and long-range correlations of the intersection points. We use these statistical measures to quantitatively characterize the complex patterns displayed by various kinds of nodal networks. We apply these statistics in particular to nodal patterns of random waves and of eigenfunctions of chaotic billiards. Of special interest is the observation that for monochromatic random waves, the number variance of the intersections with long straight segments grows like Lln L, as opposed to the linear growth predicted by the percolation model, which was successfully used to predict other long-range nodal properties of that field

  11. [Parahisian atrial tachycardia or atrioventricular nodal reentrant tachycardia with tendon of Todaro breakthrough?].

    Science.gov (United States)

    Orczykowski, Michał; Jaworska-Wilczyńska, Maria; Urbanek, Piotr; Bodalski, Robert; Derejko, Paweł; Gajek, Jacek; Hryniewiecki, Tomasz; Szumowski, Lukasz; Walczak, Franciszek

    2010-08-01

    We present a case of a 61 year-old woman with tachycardia originating close to the His bundle where radiofrequency (RF) ablation may bear potential risk of atrioventricular (AV) block. In this case report we discuss the possibility of a AV nodal reciprocating tachycardia with tendon of Todaro breakthrough. Patient was safely and effectively treated with RF catheter ablation.

  12. Prognostic value of nodal micrometastases in patients with cancer of the gastro-oesophageal junction

    NARCIS (Netherlands)

    Heeren, PAM; Kelder, W; Blondeel, [No Value; van Westreenen, HL; Hollema, H; Plukker, JT

    Aims. Aim of this study was to examine the presence and the prognostic impact of immunohistochemically identified nodal micrometastases in patients with astro-oesophageal junction (GEJ) carcinomas. Methods. Between January 1988 and December 2000, 148 patients underwent a radical (R0) resection with

  13. Bifurcation from infinity and nodal solutions of quasilinear elliptic differential equations

    Directory of Open Access Journals (Sweden)

    Bian-Xia Yang

    2014-01-01

    Full Text Available In this article, we establish a unilateral global bifurcation theorem from infinity for a class of $N$-dimensional p-Laplacian problems. As an application, we study the global behavior of the components of nodal solutions of the problem $$\\displaylines{ \\operatorname{div}(\\varphi_p(\

  14. Nodalization qualification process of the PSBVVER facility for the Cathare2 thermal-hydraulic code

    International Nuclear Information System (INIS)

    Del Nevo, A.; Araneo, D.; D'Auria, F.; Galassi, G.

    2004-01-01

    The present document deals with the nodalization qualification process of the PSB-VVER test facility for Cathare2 code. PSB-VVER facility is a 1/300 volume scale model of a VVER-1000, reactor installed at Electrogorsk Research and Engineering Centre in 1998. The version V1.5b of the Cathare2 code has been used. In order to evaluate the nodalization performance, the qualifying procedure set up at the DIMNP of Pisa University (UNIPI) has been applied that foresees two qualification levels: a 'steady state' level and an 'on transient' level. After the steady state behavior check of the nodalization, it has been preformed the on transient qualification the PSB-VVER test 2. It is a 11% equivalent break in Upper Plenum with the actuation of one high pressure injection system, connected to the hot leg of the loop 4, and 4 passive systems (ECCS hydro-accumulators), connected to the outlet plenum and to the inlet chamber of the downcomer. The low-pressure injection system is not available in the test. The goal of this paper is to demonstrate that the first step of the nodalization qualification adopted for the PSB test analyses is achieved and the PSB facility input deck is available and ready to use. The quantitative accuracy of the performed calculation has been evaluated by using the FFT-BM tool developed at the University of Pisa.(author)

  15. Clinical implementation of coverage probability planning for nodal boosting in locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Ramlov, Anne; Assenholt, Marianne S; Jensen, Maria F

    2017-01-01

    PURPOSE: To implement coverage probability (CovP) for dose planning of simultaneous integrated boost (SIB) of pathologic lymph nodes in locally advanced cervical cancer (LACC). MATERIAL AND METHODS: CovP constraints for SIB of the pathological nodal target (PTV-N) with a central dose peak...

  16. A new nodal kinetics method for analyzing fast control rod motions in nuclear reactor cores

    International Nuclear Information System (INIS)

    Kaya, S.; Yavuz, H.

    2001-01-01

    A new nodal kinetics approach is developed for analyzing large reactivity accidents in nuclear reactor cores. This method shows promising that it has capability of inspecting promt criticality transients and it gives comparable results with respect to those of other techniques. (orig.)

  17. Esophageal Stricture Prevention after Endoscopic Submucosal Dissection

    Directory of Open Access Journals (Sweden)

    Deepanshu Jain

    2016-05-01

    Full Text Available Advances in diagnostic modalities and improvement in surveillance programs for Barrett esophagus has resulted in an increase in the incidence of superficial esophageal cancers (SECs. SEC, due to their limited metastatic potential, are amenable to non-invasive treatment modalities. Endoscopic ultrasound, endoscopic mucosal resection, and endoscopic submucosal dissection (ESD are some of the new modalities that gastroenterologists have used over the last decade to diagnose and treat SEC. However, esophageal stricture (ES is a very common complication and a major cause of morbidity post-ESD. In the past few years, there has been a tremendous effort to reduce the incidence of ES among patients undergoing ESD. Steroids have shown the most consistent results over time with minimal complications although the preferred mode of delivery is debatable, with both systemic and local therapy having pros and cons for specific subgroups of patients. Newer modalities such as esophageal stents, autologous cell sheet transplantation, polyglycolic acid, and tranilast have shown promising results but the depth of experience with these methods is still limited. We have summarized case reports, prospective single center studies, and randomized controlled trials describing the various methods intended to reduce the incidence of ES after ESD. Indications, techniques, outcomes, limitations, and reported complications are discussed.

  18. Dissecting the risky-choice framing effect

    Directory of Open Access Journals (Sweden)

    Ellen Peters

    2008-08-01

    Full Text Available Using five variants of the Asian Disease Problem, we dissected the risky-choice framing effect by requiring each participant to provide preference ratings for the full decision problem and also to provide attractiveness ratings for each of the component parts, i.e., the sure-thing option and the risky option. Consistent with previous research, more risky choices were made by respondents receiving negatively framed versions of the decision problems than by those receiving positively framed versions. However, different processes were evident for those scoring high and low on numeracy. Whereas the choices of the less numerate showed a large effect of frame above and beyond any influence of their evaluations of the separate options, the choices of the highly numerate were almost completely accounted for by their attractiveness ratings of the separate options. These results are consistent with an increased tendency of the highly numerate to integrate complex numeric information in the construction of their preferences and a tendency for the less numerate to respond more superficially to non-numeric sources of information.

  19. Modification of atrioventricular nodal electrophysiology by selective radiofrequency delivery on the anterior or posterior approaches.

    Science.gov (United States)

    Chorro, F J; Sanchis, J; Such, L; Artal, L; Llavador, J J; Llavador, E; Monmeneu, J V; López-Merino, V

    1997-05-01

    An analysis was made in 14 isolated and perfused rabbit hearts of the electrophysiological effects of selective radiofrequency (RF) delivery in the anterior (group I, n = 7) or posterior zone (group II, n = 7) of the Koch triangle, with the aim of modifying atrioventricular nodal (AVN) conduction without suppressing 1:1 transmission. After opening the right atrium, RF was delivered (0.5 W) with a 1-mm diameter unipolar electrode positioned in the selected zone until a prolongation of no less than 15% was obtained in the Wenckebach cycle length (WCL). Before and after (30 min) RF, anterograde and retrograde AVN refractoriness and conduction were evaluated, stimulating from the crista terminalis (CT), the interatrial septum (IAS), and from the RV epicardium. After RF, the following percentage increments were observed in group I: AH(CT) = 36% +/- 9%, AH(IAS) = 38% +/- 11%, WCL(CT) = 28% +/- 8%, WCL(IAS) = 22% +/- 6%, functional refractory period (FRP) of the AVN(CT) = 13% +/- 11%, FRP-AVN(IAS) = 13% +/- 8%, retrograde WCL = 20% +/- 19%, and retrograde FRPVA = 13% +/- 16%. The increments observed in group II and the significances of the differences with respect to group I were: AH(CT) = 11% +/- 14% (P IAS) = 19% +/- 32% (NS), WCL(CT) = 42% +/- 14% (P IAS) = 42% +/- 16% (P < 0.01), FRP-AVN(CT) = 28% +/- 28% (NS), FRP-AVN(LAS) = 21% +/- 19% (NS), retrograde WCL = 35% +/- 24% (NS), and retrograde FRP = 16% +/- 13% (NS). In both groups, the AH interval variations were not correlated with those of the rest of the parameters analyzed. Truncated nodal function curves suggestive of a dual AV nodal pathway were obtained in three experiments, though in only one of them was this observed under basal conditions. In the other two experiments, with dual AV nodal physiology only after RF (one from each group), AV nodal reentrant tachycardias were triggered with atrial extrastimulus at coupling intervals equal to or shorter than at those that cause a sudden lengthening of the AH

  20. Analysis of nodal coverage utilizing image guided radiation therapy for primary gynecologic tumor volumes

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Faisal [University of Utah School of Medicine, Salt Lake City, UT (United States); Loma Linda University Medical Center, Department of Radiation Oncology, Loma Linda, CA (United States); Sarkar, Vikren; Gaffney, David K.; Salter, Bill [Department of Radiation Oncology, University of Utah, Salt Lake City, UT (United States); Poppe, Matthew M., E-mail: matthew.poppe@hci.utah.edu [Department of Radiation Oncology, University of Utah, Salt Lake City, UT (United States)

    2016-10-01

    Purpose: To evaluate radiation dose delivered to pelvic lymph nodes, if daily Image Guided Radiation Therapy (IGRT) was implemented with treatment shifts based on the primary site (primary clinical target volume [CTV]). Our secondary goal was to compare dosimetric coverage with patient outcomes. Materials and methods: A total of 10 female patients with gynecologic malignancies were evaluated retrospectively after completion of definitive intensity-modulated radiation therapy (IMRT) to their pelvic lymph nodes and primary tumor site. IGRT consisted of daily kilovoltage computed tomography (CT)-on-rails imaging fused with initial planning scans for position verification. The initial plan was created using Varian's Eclipse treatment planning software. Patients were treated with a median radiation dose of 45 Gy (range: 37.5 to 50 Gy) to the primary volume and 45 Gy (range: 45 to 64.8 Gy) to nodal structures. One IGRT scan per week was randomly selected from each patient's treatment course and re-planned on the Eclipse treatment planning station. CTVs were recreated by fusion on the IGRT image series, and the patient's treatment plan was applied to the new image set to calculate delivered dose. We evaluated the minimum, maximum, and 95% dose coverage for primary and nodal structures. Reconstructed primary tumor volumes were recreated within 4.7% of initial planning volume (0.9% to 8.6%), and reconstructed nodal volumes were recreated to within 2.9% of initial planning volume (0.01% to 5.5%). Results: Dosimetric parameters averaged less than 10% (range: 1% to 9%) of the original planned dose (45 Gy) for primary and nodal volumes on all patients (n = 10). For all patients, ≥99.3% of the primary tumor volume received ≥ 95% the prescribed dose (V95%) and the average minimum dose was 96.1% of the prescribed dose. In evaluating nodal CTV coverage, ≥ 99.8% of the volume received ≥ 95% the prescribed dose and the average minimum dose was 93%. In

  1. VALIDATION OF FULL CORE GEOMETRY MODEL OF THE NODAL3 CODE IN THE PWR TRANSIENT BENCHMARK PROBLEMS

    Directory of Open Access Journals (Sweden)

    Tagor Malem Sembiring

    2015-10-01

    Full Text Available ABSTRACT VALIDATION OF FULL CORE GEOMETRY MODEL OF THE NODAL3 CODE IN THE PWR TRANSIENT BENCHMARK PROBLEMS. The coupled neutronic and thermal-hydraulic (T/H code, NODAL3 code, has been validated in some PWR static benchmark and the NEACRP PWR transient benchmark cases. However, the NODAL3 code have not yet validated in the transient benchmark cases of a control rod assembly (CR ejection at peripheral core using a full core geometry model, the C1 and C2 cases.  By this research work, the accuracy of the NODAL3 code for one CR ejection or the unsymmetrical group of CRs ejection case can be validated. The calculations by the NODAL3 code have been carried out by the adiabatic method (AM and the improved quasistatic method (IQS. All calculated transient parameters by the NODAL3 code were compared with the reference results by the PANTHER code. The maximum relative difference of 16% occurs in the calculated time of power maximum parameter by using the IQS method, while the relative difference of the AM method is 4% for C2 case.  All calculation results by the NODAL3 code shows there is no systematic difference, it means the neutronic and T/H modules are adopted in the code are considered correct. Therefore, all calculation results by using the NODAL3 code are very good agreement with the reference results. Keywords: nodal method, coupled neutronic and thermal-hydraulic code, PWR, transient case, control rod ejection.   ABSTRAK VALIDASI MODEL GEOMETRI TERAS PENUH PAKET PROGRAM NODAL3 DALAM PROBLEM BENCHMARK GAYUT WAKTU PWR. Paket program kopel neutronik dan termohidraulika (T/H, NODAL3, telah divalidasi dengan beberapa kasus benchmark statis PWR dan kasus benchmark gayut waktu PWR NEACRP.  Akan tetapi, paket program NODAL3 belum divalidasi dalam kasus benchmark gayut waktu akibat penarikan sebuah perangkat batang kendali (CR di tepi teras menggunakan model geometri teras penuh, yaitu kasus C1 dan C2. Dengan penelitian ini, akurasi paket program

  2. [Thoracic aortic dissection revealed by systemic cholesterol embolism].

    Science.gov (United States)

    Braem, L; Paule, P; Héno, P; Morand, J J; Mafart, B; La Folie, T; Varlet, P; Mioulet, D; Fourcade, L

    2006-10-01

    Systemic cholesterol embolism is a rare complication of atherosclerosis, and has various presentations. Arterial catheterisms are a common cause. However, the association with an aortic dissection has been exceptionally reported. We report the observation of a 70 year-old man, with coronary artery disease, hypertension, diabetes and dyslipidemia. Six months before hospitalization, a coronary angioplasty was performed due to recurrent angina. The association of purpuric lesions on the feet, with acute renal failure confirmed cholesterol embolism syndrome. Transoesophageal echocardiography showed a dissection of the descending thoracic aorta associated with complex atheroma. The evolution was marked by the pulpar necrosis of a toe and by a worsening of the renal failure, requiring definitive hemodialysis. Further echographic control highlighted the rupture of the intimal veil of the dissection. Cholesterol embolism syndrome may reveal an aortic dissection in patients without thoracic symptoms. In such cases, transoesophageal echocardiography is a useful and non-invasive examination.

  3. Perception to Cadaver Dissection and Views on Anatomy as a ...

    African Journals Online (AJOL)

    However, literature on medical students' perceptions on cadaver dissection and their ... Bachelor of Medicine and Bachelor of Surgery at the new school of Medicine, Kenya ... training and counseling to make the experience better for students.

  4. An interesting case report of vertebral artery dissection following polytrauma

    Directory of Open Access Journals (Sweden)

    Vikas Acharya

    2016-01-01

    Conclusion: Our report displays select images related to this case report and emphasizes the consideration of routine imaging in head and neck traumatic injuries to diagnose internal carotid and/or vertebral artery dissections much earlier.

  5. The impact of nodal tumour burden on lymphoscintigraphic imaging in patients with melanomas

    Energy Technology Data Exchange (ETDEWEB)

    Kretschmer, Lutz; Bertsch, Hans Peter; Hellriegel, Simin; Thoms, Kai-Martin; Schoen, Michael Peter [Georg August University of Goettingen, Department of Dermatology, Venereology and Allergology, Goettingen (Germany); Bardzik, Pawel; Meller, Johannes; Sahlmann, Carsten Oliver [Georg-August-University of Goettingen, Department of Nuclear Medicine, Goettingen (Germany)

    2014-10-15

    To retrospectively study the influence of nodal tumour burden on lymphoscintigraphic imaging in 509 consecutive patients with melanomas. Bidirectional lymphatic drainage, the clear depiction of an afferent lymphatic vessel, time to depiction of the first sentinel lymph node (SLN) and number of depicted and excised nodes were recorded. Nodal tumour load was classified as SLN-negative, SLN micrometastases or macrometastases. In the overall population, using multivariate regression analysis, a short SLN depiction time was significantly associated with the depiction of a greater number of radioactive nodes, a short distance between the primary tumour site and the nodal basin, younger age and lower nodal tumour burden. The proportion of patients with clear depiction of an afferent lymphatic vessel depended on the nodal tumour load (46 % in SLN-negative patients, 57 % in SLN positive patients, and 69 % in patients with macrometastases; P = 0.009). Macrometastasis was significantly associated with delayed depiction of the first radioactive node and a greater number of depicted hotspots. In patients with clinically nonsuspicious nodes, i.e. the classical target group for SLN biopsy, clear depiction of an afferent vessel was significantly associated with a higher number of SLNs during dynamic acquisition, SLN micrometastasis and a higher overall number of metastatic lymph nodes after SLN biopsy plus completion lymphadenectomy. The excision of more than two SLNs did not increase the metastasis detection rate. In patients with bidirectional or tridirectional lymphatic drainage, the SLN positivity rates for the first, second and third basin were 25.4 %, 11.7 % and 0.0 %, respectively (P = 0.002). In patients with clinically nonsuspicious lymph nodes, clear depiction of an afferent lymph vessel may be a sign of micrometastasis. Macrometastasis is associated with prominent afferent vessels, delayed depiction of the first radioactive node and a higher number of depicted hotspots

  6. An approach to model reactor core nodalization for deterministic safety analysis

    Science.gov (United States)

    Salim, Mohd Faiz; Samsudin, Mohd Rafie; Mamat @ Ibrahim, Mohd Rizal; Roslan, Ridha; Sadri, Abd Aziz; Farid, Mohd Fairus Abd

    2016-01-01

    Adopting good nodalization strategy is essential to produce an accurate and high quality input model for Deterministic Safety Analysis (DSA) using System Thermal-Hydraulic (SYS-TH) computer code. The purpose of such analysis is to demonstrate the compliance against regulatory requirements and to verify the behavior of the reactor during normal and accident conditions as it was originally designed. Numerous studies in the past have been devoted to the development of the nodalization strategy for small research reactor (e.g. 250kW) up to the bigger research reactor (e.g. 30MW). As such, this paper aims to discuss the state-of-arts thermal hydraulics channel to be employed in the nodalization for RTP-TRIGA Research Reactor specifically for the reactor core. At present, the required thermal-hydraulic parameters for reactor core, such as core geometrical data (length, coolant flow area, hydraulic diameters, and axial power profile) and material properties (including the UZrH1.6, stainless steel clad, graphite reflector) have been collected, analyzed and consolidated in the Reference Database of RTP using standardized methodology, mainly derived from the available technical documentations. Based on the available information in the database, assumptions made on the nodalization approach and calculations performed will be discussed and presented. The development and identification of the thermal hydraulics channel for the reactor core will be implemented during the SYS-TH calculation using RELAP5-3D® computer code. This activity presented in this paper is part of the development of overall nodalization description for RTP-TRIGA Research Reactor under the IAEA Norwegian Extra-Budgetary Programme (NOKEBP) mentoring project on Expertise Development through the Analysis of Reactor Thermal-Hydraulics for Malaysia, denoted as EARTH-M.

  7. An approach to model reactor core nodalization for deterministic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Salim, Mohd Faiz, E-mail: mohdfaizs@tnb.com.my; Samsudin, Mohd Rafie, E-mail: rafies@tnb.com.my [Nuclear Energy Department, Regulatory Economics & Planning Division, Tenaga Nasional Berhad (Malaysia); Mamat Ibrahim, Mohd Rizal, E-mail: m-rizal@nuclearmalaysia.gov.my [Prototypes & Plant Development Center, Malaysian Nuclear Agency (Malaysia); Roslan, Ridha, E-mail: ridha@aelb.gov.my; Sadri, Abd Aziz [Nuclear Installation Divisions, Atomic Energy Licensing Board (Malaysia); Farid, Mohd Fairus Abd [Reactor Technology Center, Malaysian Nuclear Agency (Malaysia)

    2016-01-22

    Adopting good nodalization strategy is essential to produce an accurate and high quality input model for Deterministic Safety Analysis (DSA) using System Thermal-Hydraulic (SYS-TH) computer code. The purpose of such analysis is to demonstrate the compliance against regulatory requirements and to verify the behavior of the reactor during normal and accident conditions as it was originally designed. Numerous studies in the past have been devoted to the development of the nodalization strategy for small research reactor (e.g. 250kW) up to the bigger research reactor (e.g. 30MW). As such, this paper aims to discuss the state-of-arts thermal hydraulics channel to be employed in the nodalization for RTP-TRIGA Research Reactor specifically for the reactor core. At present, the required thermal-hydraulic parameters for reactor core, such as core geometrical data (length, coolant flow area, hydraulic diameters, and axial power profile) and material properties (including the UZrH{sub 1.6}, stainless steel clad, graphite reflector) have been collected, analyzed and consolidated in the Reference Database of RTP using standardized methodology, mainly derived from the available technical documentations. Based on the available information in the database, assumptions made on the nodalization approach and calculations performed will be discussed and presented. The development and identification of the thermal hydraulics channel for the reactor core will be implemented during the SYS-TH calculation using RELAP5-3D{sup ®} computer code. This activity presented in this paper is part of the development of overall nodalization description for RTP-TRIGA Research Reactor under the IAEA Norwegian Extra-Budgetary Programme (NOKEBP) mentoring project on Expertise Development through the Analysis of Reactor Thermal-Hydraulics for Malaysia, denoted as EARTH-M.

  8. An approach to model reactor core nodalization for deterministic safety analysis

    International Nuclear Information System (INIS)

    Salim, Mohd Faiz; Samsudin, Mohd Rafie; Mamat Ibrahim, Mohd Rizal; Roslan, Ridha; Sadri, Abd Aziz; Farid, Mohd Fairus Abd

    2016-01-01

    Adopting good nodalization strategy is essential to produce an accurate and high quality input model for Deterministic Safety Analysis (DSA) using System Thermal-Hydraulic (SYS-TH) computer code. The purpose of such analysis is to demonstrate the compliance against regulatory requirements and to verify the behavior of the reactor during normal and accident conditions as it was originally designed. Numerous studies in the past have been devoted to the development of the nodalization strategy for small research reactor (e.g. 250kW) up to the bigger research reactor (e.g. 30MW). As such, this paper aims to discuss the state-of-arts thermal hydraulics channel to be employed in the nodalization for RTP-TRIGA Research Reactor specifically for the reactor core. At present, the required thermal-hydraulic parameters for reactor core, such as core geometrical data (length, coolant flow area, hydraulic diameters, and axial power profile) and material properties (including the UZrH 1.6 , stainless steel clad, graphite reflector) have been collected, analyzed and consolidated in the Reference Database of RTP using standardized methodology, mainly derived from the available technical documentations. Based on the available information in the database, assumptions made on the nodalization approach and calculations performed will be discussed and presented. The development and identification of the thermal hydraulics channel for the reactor core will be implemented during the SYS-TH calculation using RELAP5-3D ® computer code. This activity presented in this paper is part of the development of overall nodalization description for RTP-TRIGA Research Reactor under the IAEA Norwegian Extra-Budgetary Programme (NOKEBP) mentoring project on Expertise Development through the Analysis of Reactor Thermal-Hydraulics for Malaysia, denoted as EARTH-M

  9. Combined-modality therapy for patients with regional nodal metastases from melanoma

    International Nuclear Information System (INIS)

    Ballo, Matthew T.; Ross, Merrick I.; Cormier, Janice N.; Myers, Jeffrey N.; Lee, Jeffrey E.; Gershenwald, Jeffrey E.; Hwu, Patrick; Zagars, Gunar K.

    2006-01-01

    Purpose: To evaluate the outcome and patterns of failure for patients with nodal metastases from melanoma treated with combined-modality therapy. Methods and Materials: Between 1983 and 2003, 466 patients with nodal metastases from melanoma were managed with lymphadenectomy and radiation, with or without systemic therapy. Surgery was a therapeutic procedure for clinically apparent nodal disease in 434 patients (regionally advanced nodal disease). Adjuvant radiation was generally delivered with a hypofractionated regimen. Adjuvant systemic therapy was delivered to 154 patients. Results: With a median follow-up of 4.2 years, 252 patients relapsed and 203 patients died of progressive disease. The actuarial 5-year disease-specific, disease-free, and distant metastasis-free survival rates were 49%, 42%, and 44%, respectively. By multivariate analysis, increasing number of involved lymph nodes and primary ulceration were associated with an inferior 5-year actuarial disease-specific and distant metastasis-free survival. Also, the number of involved lymph nodes was associated with the development of brain metastases, whereas thickness was associated with lung metastases, and primary ulceration was associated with liver metastases. The actuarial 5-year regional (in-basin) control rate for all patients was 89%, and on multivariate analysis there were no patient or disease characteristics associated with inferior regional control. The risk of lymphedema was highest for those patients with groin lymph node metastases. Conclusions: Although regional nodal disease can be satisfactorily controlled with lymphadenectomy and radiation, the risk of distant metastases and melanoma death remains high. A management approach to these patients that accounts for the competing risks of distant metastases, regional failure, and long-term toxicity is needed

  10. Application of nonlinear nodal diffusion method for a small research reactor

    International Nuclear Information System (INIS)

    Jaradat, Mustafa K.; Alawneh, Luay M.; Park, Chang Je; Lee, Byungchul

    2014-01-01

    Highlights: • We applied nonlinear unified nodal method for 10 MW IAEA MTR benchmark problem. • TRITION–NEWT system was used to obtain two-group burnup dependent cross sections. • The criticality and power distribution compared with reference (IAEA-TECDOC-233). • Comparison between different fuel materials was conducted. • Satisfactory results were provided using UNM for MTR core calculations. - Abstract: Nodal diffusion methods are usually used for LWR calculations and rarely used for research reactor calculations. A unified nodal method with an implementation of the coarse mesh finite difference acceleration was developed for use in plate type research reactor calculations. It was validated for two PWR benchmark problems and then applied for IAEA MTR benchmark problem for static calculations to check the validity and accuracy of the method. This work was conducted to investigate the unified nodal method capability to treat material testing reactor cores. A 10 MW research reactor core is considered with three calculation cases for low enriched uranium fuel depending on the core burnup status of fresh, beginning-of-life, and end-of-life cores. The validation work included criticality calculations, flux distribution, and power distribution; in addition, a comparison between different fuel materials with the same uranium content was conducted. The homogenized two-group cross sections were generated using the TRITON–NEWT system. The results were compared with a reference, which was taken from IAEA-TECDOC-233. The unified nodal method provides satisfactory results for an all-rod out case, and the three-dimensional, two-group diffusion model can be considered accurate enough for MTR core calculations

  11. An adaptive mesh refinement approach for average current nodal expansion method in 2-D rectangular geometry

    International Nuclear Information System (INIS)

    Poursalehi, N.; Zolfaghari, A.; Minuchehr, A.

    2013-01-01

    Highlights: ► A new adaptive h-refinement approach has been developed for a class of nodal method. ► The resulting system of nodal equations is more amenable to efficient numerical solution. ► The benefit of the approach is reducing computational efforts relative to the uniform fine mesh modeling. ► Spatially adaptive approach greatly enhances the accuracy of the solution. - Abstract: The aim of this work is to develop a spatially adaptive coarse mesh strategy that progressively refines the nodes in appropriate regions of domain to solve the neutron balance equation by zeroth order nodal expansion method. A flux gradient based a posteriori estimation scheme has been utilized for checking the approximate solutions for various nodes. The relative surface net leakage of nodes has been considered as an assessment criterion. In this approach, the core module is called in by adaptive mesh generator to determine gradients of node surfaces flux to explore the possibility of node refinements in appropriate regions and directions of the problem. The benefit of the approach is reducing computational efforts relative to the uniform fine mesh modeling. For this purpose, a computer program ANRNE-2D, Adaptive Node Refinement Nodal Expansion, has been developed to solve neutron diffusion equation using average current nodal expansion method for 2D rectangular geometries. Implementing the adaptive algorithm confirms its superiority in enhancing the accuracy of the solution without using fine nodes throughout the domain and increasing the number of unknown solution. Some well-known benchmarks have been investigated and improvements are reported

  12. An unusual case of uterine cotyledonoid dissecting leiomyoma with adenomyosis.

    Science.gov (United States)

    Shimizu, Ai; Tanaka, Hoshihito; Iwasaki, Sari; Wakui, Yukio; Ikeda, Hitoshi; Suzuki, Akira

    2016-08-04

    Cotyledonoid dissecting leiomyoma is a rare variant of uterine smooth muscle tumor with an unusual growth pattern that shows intramural dissection within uterine myometrium and often a placenta-like appearance in its extrauterine components. We present a unique case of cotyledonoid dissecting leiomyoma with adenomyosis. A 40-year-old Japanese female presented with prolonged menorrhagia and severe anemia. She had a pelvic mass followed-up for 6 years with a diagnosis of leiomyoma. However, increase in tumor size and cystic changes with hemorrhage were found by magnetic resonance imaging, and total abdominal hysterectomy with bilateral salpingectomy was performed. Macroscopically, the placenta-like exophytic mass protruding from the posterior uterine wall was composed of multiple nodules containing numerous hemorrhagic cysts. The mass showed continuity as a white multinodular dissecting mass infiltrating the posterolateral myometrium. Microscopically, both extra-and intrauterine portions of the mass were composed of nodules that contained swirled neoplastic smooth muscle cells with marked hyalinized degeneration, as observed in cotyledonoid dissecting leiomyomas of conventional type. In addition, numerous non-neoplastic glands of endometrial type surrounded by abundant endometrium-like stromal cells and non-neoplastic smooth muscle cells were found in the tumor, suggesting that it involved a part of concomitant adenomyosis originating from the nontumoral myometrium. Thus far, over 30 cases of cotyledonoid dissecting leiomyoma have been reported, none of which have described the presence of adenomyosis within the tumor. The present case suggested that cotyledonoid dissecting leiomyoma might have a unique clinical presentation involving concomitant uterine adenomyosis. It is critical for pathologists, gynecologists, and radiologists to be cognizant of cotyledonoid dissecting leiomyoma variants for timely and appropriate diagnosis and treatment.

  13. Spontaneous carotid artery dissection causing a juvenile cerebral infarction

    International Nuclear Information System (INIS)

    Trattnig, S.; Huebsch, P.; Schindler, E.

    1988-01-01

    The case of a 19-year-old patient is presented who was admitted with aphasia and hemiparesis due to basal ganglia infarction as a result of spontaneous dissection of the internal carotid artery. The difficulties in diagnosing this disease with CT and MRI in the acute stage are demonstrated. Angiography is still imperative in order to ascertain that a carotid dissection has occurred. (orig.) [de

  14. Cerebral Ischemia Due to Traumatic Carotid Artery Dissection: Case Report

    OpenAIRE

    Deniz Kamacı Şener; Özlem Taşkapılıoğlu; Nermin Kelebek Girgin; Bahattin Hakyemez; Mustafa Bakar; Yakup Tomak

    2012-01-01

    Blunt injury to the neck region may lead to carotid artery dissection and cerebral ischemia. Blunt injury to carotid artery is not frequent but determination of the presence of trauma in the history of stroke patients will provide early diagnosis and treatment of them. In this article, a case with cerebral ischemia resulting from traumatic carotid artery dissection is presented and clinical findings, diagnostic procedures and choice of treatment are discussed in the light of the literature.

  15. Cerebral Ischemia Due to Traumatic Carotid Artery Dissection: Case Report

    Directory of Open Access Journals (Sweden)

    Deniz Kamacı Şener

    2012-12-01

    Full Text Available Blunt injury to the neck region may lead to carotid artery dissection and cerebral ischemia. Blunt injury to carotid artery is not frequent but determination of the presence of trauma in the history of stroke patients will provide early diagnosis and treatment of them. In this article, a case with cerebral ischemia resulting from traumatic carotid artery dissection is presented and clinical findings, diagnostic procedures and choice of treatment are discussed in the light of the literature.

  16. Descending thoracic aorta dissection associated with esophageal carcinoma

    Directory of Open Access Journals (Sweden)

    Kaushik Saha

    2013-01-01

    Full Text Available The association of aortic dissection with a malignancy is a rare finding and previous reports are usually those of primary aortic sarcomas. A 45-year-old male presented to us with chest pain and dysphagia for 1 month with a background history of obstructive airway disease and uncontrolled hypertension. In this report we present a case of typical descending aorta dissection with associated esophageal carcinoma.

  17. False coronary dissection with the new Monorail angioplasty balloon catheter.

    Science.gov (United States)

    Esplugas, E; Cequier, A R; Sabaté, X; Jara, F

    1990-01-01

    During percutaneous transluminal coronary angioplasty, the appearance of persistent staining in the vessel by contrast media suggests coronary dissection. We report seven patients in whom a false image of severe coronary dissection was observed during angioplasty performed with the new Monorail balloon catheter. This image emerges at the moment of balloon inflation, is distally located to the balloon, and disappears with balloon catheter deflation. No complications were associated with the appearance of this image.

  18. Intraoperative monitoring of marginal mandibular nerve during neck dissection.

    Science.gov (United States)

    Tirelli, Giancarlo; Bergamini, Pier Riccardo; Scardoni, Alessandro; Gatto, Annalisa; Boscolo Nata, Francesca; Marcuzzo, Alberto Vito

    2018-05-01

    The purpose of this study was to assess the efficacy of intraoperative nerve integrity monitoring (NIM) to prevent marginal mandibular nerve injuries during neck dissection. This prospective study compared 36 patients undergoing NIM-assisted neck dissection from July 2014 to March 2015 to a cohort of 35 patients subjected to neck dissection over an identical period of time before the technique was introduced. We also assessed possible correlations between marginal mandibular nerve injuries and other factors, such as anthropometric measurements, presence of clinical neck metastases, type of neck dissection, and site of primary tumor. The incidence of marginal mandibular nerve paralyses was significantly lower among the group of patients undergoing NIM-assisted neck dissection (P = .021). There was no significant difference in the duration of the procedure, and the technique resulted in a limited increase of cost. No other factor seemed to influence the onset of marginal mandibular nerve palsy. In our opinion, NIM is a valuable aid for preventing marginal mandibular nerve injuries during neck dissection. © 2018 Wiley Periodicals, Inc.

  19. The outcome of laparoscopic cholecystectomy by ultrasonic dissection.

    LENUS (Irish Health Repository)

    Sasi, Walid

    2010-04-01

    Electrocautery remains the main energy form used for dissection in laparoscopic cholecystectomy. However, due to its many risks the search continues for safer and more efficient forms of energy. This chapter assesses the outcomes of dissection using ultrasonic energy as compared to monopolar electrocautery during laparoscopic cholecystectomy. Studies included are trials of prospectively randomized adult patients with symptomatic gallstone disease subject either ultrasonic or monopolar electrocautery dissection during laparoscopic cholecystectomy. Seven trials were included in this review, with a total patient number of 695 randomized to two dissection methods: 340 in the electrocautery group and 355 in the ultrasonic group. Ultrasonic dissection is shown to be superior to monopolar electrocautery in laparoscopic cholecystectomy. Disadvantages include a difficult maneuvering technique and overall cost. Appropriate training programs may be implemented to overcome the first disadvantage, and it might be argued that given the combined cost of factors associated with standard clip and cautery technique, cost issues may be outweighed by the benefits of ultrasonic dissection. However, this necessitates further cost-benefit analysis.

  20. Rare Presentation of Left Lower Lobe Pulmonary Artery Dissection

    Directory of Open Access Journals (Sweden)

    René Hako

    2017-01-01

    Full Text Available Background. Pulmonary arterial dissection with chronic pulmonary arterial hypertension as its major cause is a very rare but life-threatening condition. In most cases the main pulmonary trunk is the affected site usually without involvement of its branches. Segmental or lobar pulmonary artery dissection is extremely rare. Case Presentation. We report a unique case of left lower lobe pulmonary artery dissection in a 70-year-old male, with confirmed chronic pulmonary hypertension. To confirm dissection MDCT pulmonary angiography was used. Multiplanar reformation (MPR images in sagittal, coronal, oblique sagittal, and curved projections were generated. This case report presents morphologic CT features of rare chronic left lobar pulmonary artery dissection associated with chronic pulmonary hypertension at a place of localised pulmonary artery calcification. CT pulmonary angiography excluded signs of thromboembolism and potential motion or flow artefacts. Conclusion. To the best of our knowledge, no case of lower lobe pulmonary artery dissection with flap calcification has been reported yet. CT imaging of the chest is a key diagnostic tool that is able to detect an intimal flap and a false lumen within the pulmonary arterial tree and is preferred in differential diagnosis of rare complications of sustained pulmonary arterial hypertension.

  1. Symptomatic isolated middle cerebral artery dissection: High resolution MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Byon, Jung Hee; Kwak, Hyo Sung; Chung, Gyung Ho; Hwang, Seung Bae [Dept. of Radiology, Chonbuk National University Medical School, Jeonju (Korea, Republic of)

    2015-11-15

    To perform high-resolution magnetic resonance imaging (HRMRI) and determine clinical features of patients with acute symptomatic middle cerebral artery (MCA) dissection. Thirteen patients with acute symptomatic MCA dissection underwent HRMRI within 3 days after initial clinical onset. They also underwent routine brain MR imaging. HRMRI examinations included time-of-flight MR angiography (MRA), T2-weighted, T1-weighted, proton-density-weighted, and three-dimensional magnetization-prepared rapid acquisition gradient-echo (MPRAGE) sequences. Conventional angiography and MRA were used as reference standard to establish the diagnosis of MCA dissection. The angiographic findings and HRMRI findings such as intimal flap, double lumen, and intramural hematoma were analyzed in this study. All patients presented cerebral ischemia (median National Institutes of Health Stroke Scale score = 4, range = 0-18). String sign was seen on MRA in seven patients. However, double lumen was seen in all patients on HRMRI by intimal flap. High signal lesion on MPRAGE sequences around the dissection lumen due to intramural hematoma was seen in three patients. HRMRI can be used to easily detect the wall structure of MCA such as the intimal flap and double lumen in patients with acute symptomatic MCA dissection. MPRAGE can detect hemorrhage in false lumen of MCA dissection.

  2. Silent Aortic Dissection Presenting as Transient Locked-In Syndrome

    Science.gov (United States)

    Nadour, Wadih; Goldwasser, Brian; Biederman, Robert W.; Taffe, Kevin

    2008-01-01

    Acute aortic dissection is a medical emergency. Without prompt recognition and treatment, the mortality rate is high. An atypical presentation makes timely diagnosis difficult, especially if the patient is experiencing no characteristic pain. Many patients with aortic dissection are reported to have presented with various neurologic manifestations, but none with only a presentation of transient locked-in syndrome. Herein, we report a case of completely painless aortic dissection in a woman who presented with a transient episode of anarthria, quadriplegia, and preserved consciousness. On physical examination, she had a 40-point difference in blood pressure between her left and right arms, and a loud diastolic murmur. The diagnosis of acute aortic dissection was reached via a combination of radiography, computed tomography, echocardiography, and a high index of clinical suspicion. The patient underwent emergency surgery and ultimately experienced a successful outcome. To our knowledge, this is the 1st report of aortic dissection that presented solely as locked-in syndrome. We suggest that silent aortic dissection be added to the differential diagnosis for transient locked-in syndrome. PMID:18941610

  3. Consumption coagulopathy in acute aortic dissection: principles of management.

    Science.gov (United States)

    Liu, Yuyong; Han, Lu; Li, Jiachen; Gong, Ming; Zhang, Hongjia; Guan, Xinliang

    2017-06-12

    The effect of acute aortic dissection itself on coagulopathy or surgery-related coagulopathy has never been specifically studied. The aim of the present study was to perioperatively describe consumption coagulopathy in patients with acute aortic dissection. Sixty-six patients with acute type A aortic dissection were enrolled in this study from January 2015 to September 2016. Thirty-six patients with thoracic aortic aneurysms were used as a control group during the same period. Consumption coagulopathy was evaluated using standard laboratory tests, enzyme-linked immunosorbent assay and thromboelastograghy at five perioperative time-points. A significant reduction in clotting factors and fibrinogen was observed at the onset of acute aortic dissection. Enzyme-linked immunosorbent assay and thromboelastograghy also revealed a persistent systemic activation of the coagulation system and the consumption of clotting factors. In contrast, although platelet counts were consistently low, we did not find that platelet function was more impaired in the acute aortic dissection group than the control group. After surgery, clotting factors and fibrinogen were more impaired than platelet function. Thus, we proposed that hemostatic therapy should focus on the rapid and sufficient supplementation of clotting factors and fibrinogen to improve consumption coagulopathy in patients with acute aortic dissection.

  4. Development of an environment-insensitive PWR radial reflector model applicable to modern nodal reactor analysis method

    International Nuclear Information System (INIS)

    Mueller, E.M.

    1989-05-01

    This research is concerned with the development and analysis of methods for generating equivalent nodal diffusion parameters for the radial reflector of a PWR. The requirement that the equivalent reflector data be insensitive to changing core conditions is set as a principle objective. Hence, the environment dependence of the currently most reputable nodal reflector models, almost all of which are based on the nodal equivalence theory homgenization methods of Koebke and Smith, is investigated in detail. For this purpose, a special 1-D nodal equivalence theory reflector model, called the NGET model, is developed and used in 1-D and 2-D numerical experiments. The results demonstrate that these modern radial reflector models exhibit sufficient sensitivity to core conditions to warrant the development of alternative models. A new 1-D nodal reflector model, which is based on a novel combination of the nodal equivalence theory and the response matrix homogenization methods, is developed. Numerical results varify that this homogenized baffle/reflector model, which is called the NGET-RM model, is highly insensitive to changing core conditions. It is also shown that the NGET-RM model is not inferior to any of the existing 1-D nodal reflector models and that it has features which makes it an attractive alternative model for multi-dimensional reactor analysis. 61 refs., 40 figs., 36 tabs

  5. Validation of full core geometry model of the NODAL3 code in the PWR transient Benchmark problems

    International Nuclear Information System (INIS)

    T-M Sembiring; S-Pinem; P-H Liem

    2015-01-01

    The coupled neutronic and thermal-hydraulic (T/H) code, NODAL3 code, has been validated in some PWR static benchmark and the NEACRP PWR transient benchmark cases. However, the NODAL3 code have not yet validated in the transient benchmark cases of a control rod assembly (CR) ejection at peripheral core using a full core geometry model, the C1 and C2 cases. By this research work, the accuracy of the NODAL3 code for one CR ejection or the unsymmetrical group of CRs ejection case can be validated. The calculations by the NODAL3 code have been carried out by the adiabatic method (AM) and the improved quasistatic method (IQS). All calculated transient parameters by the NODAL3 code were compared with the reference results by the PANTHER code. The maximum relative difference of 16 % occurs in the calculated time of power maximum parameter by using the IQS method, while the relative difference of the AM method is 4 % for C2 case. All calculation results by the NODAL3 code shows there is no systematic difference, it means the neutronic and T/H modules are adopted in the code are considered correct. Therefore, all calculation results by using the NODAL3 code are very good agreement with the reference results. (author)

  6. Development and qualification of a thermal-hydraulic nodalization for modeling station blackout accident in PSB-VVER test facility

    Energy Technology Data Exchange (ETDEWEB)

    Saghafi, Mahdi [Department of Energy Engineering, Sharif University of Technology, Azadi Avenue, Tehran (Iran, Islamic Republic of); Ghofrani, Mohammad Bagher, E-mail: ghofrani@sharif.edu [Department of Energy Engineering, Sharif University of Technology, Azadi Avenue, Tehran (Iran, Islamic Republic of); D’Auria, Francesco [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, San Piero a Grado, Pisa (Italy)

    2016-07-15

    Highlights: • A thermal-hydraulic nodalization for PSB-VVER test facility has been developed. • Station blackout accident is modeled with the developed nodalization in MELCOR code. • The developed nodalization is qualified at both steady state and transient levels. • MELCOR predictions are qualitatively and quantitatively in acceptable range. • Fast Fourier Transform Base Method is used to quantify accuracy of code predictions. - Abstract: This paper deals with the development of a qualified thermal-hydraulic nodalization for modeling Station Black-Out (SBO) accident in PSB-VVER Integral Test Facility (ITF). This study has been performed in the framework of a research project, aiming to develop an appropriate accident management support tool for Bushehr nuclear power plant. In this regard, a nodalization has been developed for thermal-hydraulic modeling of the PSB-VVER ITF by MELCOR integrated code. The nodalization is qualitatively and quantitatively qualified at both steady-state and transient levels. The accuracy of the MELCOR predictions is quantified in the transient level using the Fast Fourier Transform Base Method (FFTBM). FFTBM provides an integral representation for quantification of the code accuracy in the frequency domain. It was observed that MELCOR predictions are qualitatively and quantitatively in the acceptable range. In addition, the influence of different nodalizations on MELCOR predictions was evaluated and quantified using FFTBM by developing 8 sensitivity cases with different numbers of control volumes and heat structures in the core region and steam generator U-tubes. The most appropriate case, which provided results with minimum deviations from the experimental data, was then considered as the qualified nodalization for analysis of SBO accident in the PSB-VVER ITF. This qualified nodalization can be used for modeling of VVER-1000 nuclear power plants when performing SBO accident analysis by MELCOR code.

  7. Accidente cerebrovascular isquémico asociado con ablación por radiofrecuencia de reentrada nodal Ischemic stroke associated with radio frequency ablation for nodal reentry

    Directory of Open Access Journals (Sweden)

    Juan C Díaz Martínez

    2010-04-01

    Full Text Available La taquicardia por reentrada nodal es la causa más común de taquicardia supraventricular paroxística; en aquellos pacientes en quienes el manejo farmacológico no es efectivo o deseado la ablación por radiofrecuencia es un excelente método terapéutico dada su alta tasa de curación. Aunque en términos generales dichos procedimientos son rápidos y seguros, se han descrito varias complicaciones entre las que sobresale el accidente cerebrovascular isquémico. Se presenta el caso de una paciente de 41 años con episodios de taquicardia por reentrada nodal a repetición, que fue llevada a ablación por radiofrecuencia. En el post-operatorio inmediato se evidenció déficit neurológico focal con isquemia en el territorio de la arteria cerebral media derecha, tras lo cual se realizó angiografía con intento de angioplastia y abxicimab y posteriormente infusión local de activador de plasminógeno tisular (rtPA con adecuado resultado clínico y angiográfico.Atrioventricular nodal reentry tachycardia is the most common type of paroxismal supraventricular tachycardia. In those patients in whom drug therapy is not effective or not desired, radio frequency ablation is an excellent therapeutic method. Although overall these procedures are fast and safe, several complications among which ischemic stroke stands out, have been reported. We present the case of a 41 year old female patient with repetitive episodes of tachycardia due to nodal reentry who was treated with radiofrequency ablation. Immediately after the procedure she presented focal neurologic deficit consistent with ischemic stroke in the right medial cerebral artery territory. Angiography with angioplastia and abxicimab was performed and then tissue plasminogen activator (rtPA was locally infused, with appropriate clinical and angiographic outcome.

  8. Medical Student Dissection of CadaversImproves Performance on Practical Exams, but not Dissection-Relevant Questions in the NBME Gross Anatomy and Embryology Final Exam

    Directory of Open Access Journals (Sweden)

    Leslie Sargent Jones

    2001-03-01

    Full Text Available We have examined whether cadaver dissection by first year medical students (MIs affected their performance in two test measures: the NBME Gross Anatomy and Embryology Subject Exam (dissection-relevant questions only, and practical exams given at the end of each major section within the course. The dissections for the entire course were divided into 18 regional dissection units and each student was assigned to dissect one third of the regional units; the other two-thirds of the material was learned from the partner-prosected cadavers. Performance for each student on the exams was then assessed as a function of the regions those students actually dissected. While the results indicated a small performance advantage for MIs answering questions on material they had dissected on the NBME Subject Exam questions relevant to dissection (78-88% of total exam, the results were not statistically significant. However, a similar, small performance advantage on the course practical exams was highly significant.

  9. Mapping of selected markets with Nodal pricing or similar systems. Australia, New Zealand and North American power markets

    Energy Technology Data Exchange (ETDEWEB)

    Mathiesen, Vivi (ed.)

    2011-07-01

    This report shows that the principals of nodal pricing can be implemented in different ways. A common denominator for markets with nodal pricing is a central market based nodal dispatch, where prices and flows are determined simultaneously close to real time. This stands apart from the European market design, which is based on a highly simplified version of the grid, and a physical point auction day ahead. Congestion management is handled by the TSO during the operational hour and not through the market as is the case in nodal pricing systems. Nodal pricing yields optimal dispatch and congestion management through the market, and as such an optimal utilisation of energy generation and network. However, whether this short term optimisation delivers the highest overall efficiency for the market in terms of competition in the wholesale and retail market, price discovery, possibilities for hedging, long term price signals etc. is difficult to determine. The markets investigated handle issues such as market power, risk management, investment signals and retail markets in very different ways. New Zealand and PJM are examples of markets with full nodal pricing, i.e. both generators and the demand side are exposed to nodal prices. The PJM market has more 'additional features' than the New Zealand market. Examples of these are separate capacity market to trigger investments in generation and generator price caps to deal with situations of market power. In addition PJM offers liquid and mature markets for risk management, such as aggregates of nodes where market participant can chose to be settled (rather than to be settled directly at the node). A general finding though, seems to be that risk management at peripheral nodes is challenging in nodal markets, particularly for independent retailers. In New Zealand generators and retailers were permitted to 'reintegrate' in order to cope with the nodal prices. The Australian market has central market based

  10. Pattern of Progression after Stereotactic Body Radiotherapy for Oligometastatic Prostate Cancer Nodal Recurrences.

    Science.gov (United States)

    Ost, P; Jereczek-Fossa, B A; Van As, N; Zilli, T; Tree, A; Henderson, D; Orecchia, R; Casamassima, F; Surgo, A; Miralbell, R; De Meerleer, G

    2016-09-01

    To report the relapse pattern of stereotactic body radiotherapy (SBRT) for oligorecurrent nodal prostate cancer (PCa). PCa patients with ≤3 lymph nodes (N1/M1a) at the time of recurrence were treated with SBRT. SBRT was defined as a radiotherapy dose of at least 5 Gy per fraction to a biological effective dose of at least 80 Gy to all metastatic sites. Distant progression-free survival was defined as the time interval between the first day of SBRT and appearance of new metastatic lesions, outside the high-dose region. Relapses after SBRT were recorded and compared with the initially treated site. Secondary end points were local control, time to palliative androgen deprivation therapy and toxicity scored using the Common Terminology Criteria for Adverse Events v4.0. Overall, 89 metastases were treated in 72 patients. The median distant progression-free survival was 21 months (95% confidence interval 16-25 months) with 88% of patients having ≤3 metastases at the time of progression. The median time from first SBRT to the start of palliative androgen deprivation therapy was 44 months (95% confidence interval 17-70 months). Most relapses (68%) occurred in nodal regions. Relapses after pelvic nodal SBRT (n = 36) were located in the pelvis (n = 14), retroperitoneum (n = 1), pelvis and retroperitoneum (n = 8) or in non-nodal regions (n = 13). Relapses after SBRT for extrapelvic nodes (n = 5) were located in the pelvis (n = 1) or the pelvis and retroperitoneum (n = 4). Late grade 1 and 2 toxicity was observed in 17% (n = 12) and 4% of patients (n = 3). SBRT for oligometastatic PCa nodal recurrences is safe. Most subsequent relapses are again nodal and oligometastatic. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  11. Regeneration of three sweet potato (Ipomea batatas (L.)) accessions via meristem, Nodal and callus induction

    International Nuclear Information System (INIS)

    Addae-Frimpomaah, F.

    2012-11-01

    In vitro regeneration of three sweet potato accessions UE007, UK-BNARI and SA-BNARI using meristem, nodal cuttings or callus induction was studied. Meristematic explants cultured on Murashige and Skoog (1962) basal medium supplemented with low concentration of benzylaminopurine (BAP) or kinetin resulted in callus with or without shoot development which delayed shoot emergence. The degree of callus development increased as the concentration of the cytokinin in the culture medium increased. Although, callus development was comparatively lower on kinetin amended medium than BAP amended medium, Murashige and Skoog medium supplemented with 0.25mg/1BAP had the highest shoot induction (80%). For further differentiation of callus or shoots into distinct stem and leaves, the culture were transferred into fresh MS medium supplemented with 0.25mg/1 BAP, 0.1 mg/1 NAA and 0.1 mg/1 Gibberellic acid (GA 3 . To overcome the delay in shoot initiation using meristem culture, nodal cuttings of sweet potato were used as explants and cultured on MS medium amended with 0.3 - 0.9mg/1 BAP. All explants cultured on 0.3 or 0.6mg/1 BAP developed shoots. Furthermore, liquid MS medium amended with 0.25mg/1 BAP, 0.1mg/I NAA, and 0.1mg/1 GA 3 also enhanced early shoot development from nodal cutting explants compared to solid culture. Post flask acclimatisation of meristem or nodal cutting-derived plantlets showed that meristem derived plantlets were better acclimatised than nodal cutting plants due to vigorous root development leading to higher percentage survival in pots and subsequent tuber production. Callusogenesis was achieved when leaf lobe explants were cultured on CLC/ Ipomoea medium supplemented with 1.0 - 4.0mg/1 2,4-D with 4.0mg/1 2,4-D being the optimal concentration. However, the calli were non-embryogenic and therefore could not produce embryos when transferred to 0.1mg/1 BAP amended medium but rather produced either single or multiple shoots. The highest percentage shoot (83

  12. Spontaneous vertebral dissection: Clinical, conventional angiographic, CT, and MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Provenzale, J.M.; Morgenlander, J.C. [Duke Univ. Medical Center, Durham, NC (United States); Gress, D. [Univ. of California, San Francisco, CA (United States)

    1996-03-01

    The purpose of this study was to determine if typical clinical and neuroradiologic patterns exist in patients with spontaneous vertebral artery (VA) dissection. The medical records and neuroradiologic examinations of 14 patients with spontaneous VA dissection were reviewed. The medical records were examined to exclude patients with a history of trauma and to record evidence of a nontratimatic precipitating event ({open_quotes}trivial trauma{close_quotes}) and presence of possible risk factors such as hypertension. All patients under-went conventional angiography, 13 either CT or MRI (II both CT and MRI), and 3 MRA. Conventional arteriograrris were evaluated for dissection site, evidence of fibromuscular dysplasia, luminal stenosis or occlusion, and pseudoaneurysm formation, CT examinations for the presence of infarction or subarachnoid hemorrhage, MR examinations for the presence of infarction or arterial signal abnormality, and MR angiograms for abnormality of the arterial signal column. Seven patients had precipitating events within 24 h of onset of symptoms that may have been causative of dissection and five had hypertension. At catheter angiography, two patients had dissections in two arteries (both VAs in one patient, VA and internal carotid artery in one patient), giving a total of 15 VAs with dissection. Dissection sites included V1 in four patients, V2 in one patient, V3 in three patients, V4 in six patients, and both V3 and V4 in one patient. Luminal stenosis was present in 13 VAs, occlusion in 2, pseudoaneurysm in 1, and evidence of fibromuscular dysplasia in 1. Posterior circulation infarcts were found on CT or MR in five patients. Subarachnoid hemorrhage was found on CT in two patients and by lumbar puncture alone in two patients. Abnormal periarterial signal on MRI was seen in three patients. MRA demonstrated absent VA signal in one patient, pseudoaneurysm in one, and a false-negative examination in one.

  13. Monopolar electrodissection versus cold dissection tonsillectomy among children

    International Nuclear Information System (INIS)

    Bukhari, Manal A.; Al-Ammar, Ahmed Y.

    2007-01-01

    To compare cold dissection to monopolar tonsillectomy in terms of operative time, intraoperative bleeding, post operative bleeding. The study included 100 children who underwent tonsillectomy between January 2002 and January 2004. This study was carried out at King Abdul-Aziz University Hospital, Riyadh, Kingdom of Saudi Arabia. Patients were randomly selected to have either the right or left tonsils removed by either technique (cold dissection or monopolar dissection technique). We compared both techniques in each side on the same patient. There was no significant difference in operative time between both sides by either technique, however, when the patients were grouped into 3 minute groups, the result showed that a greater number of patients were operated up on <-3 minutes by diathermy procedure compared to dissection method (44 versus 67) (p=0.0011). Blood loss was minimal with the diathermy technique, averaging 25.37 ml compared to 88.5 for cold dissection tonsillectomy. There was a significant increase in postoperative pain on the first postoperative day in the diathermy group compared to the cold dissection group (27% versus 12%) (p=0.0151). However, there was no significant difference in pain between both sides in the first 24 hours and from the 2nd to 10th postoperative days. Monopolar dissection tonsillectomy is a safe technique. It significantly reduces the operative time and intraoperative blood loss. However, it causes more pain on the 1st postoperative day, while on the rest of the days until the 10th postoperative day, there was no significant difference in pain between two sides. (author)

  14. Mutants dissecting development and behaviour in drosophila

    International Nuclear Information System (INIS)

    Joshi, Adita; Chandrashekaran, Shanti; Sharma, R.P.

    2005-01-01

    We have traced in this paper the progress in Drosophila genetics research from the 1960s, at the IARI, spearheaded by the visionary insight of M. S. Swaminathan. The work started with the study of indirect effect of radiation and the synergistic interaction of physical and chemical mutagens on chromosomal and genetic changes. This paved the way for the study of single gene mutants in dissecting developmental and behavioural processes. New genes discovered by us have been shown to encode conserved cell signalling molecules controlling developmental and behavioural pathways. With the complete sequencing of the Drosophila genome, in the year 2000, mounting evidence for the homology between Drosophila and human genes controlling genetic disorders became available. This has led to the fly becoming an indispensable tool for studying human diseases as well as a model to test for drugs and pharmaceuticals against human diseases and complex behavioural processes. For example wingless in Drosophila belongs to the conserved Wnt gene family and aberrant WNT signalling is linked to a range of human diseases, most notably cancer. Inhibition as well as activation of WNT signalling form the basis of an effective therapy for some cancers as well as several other clinical conditions. Recent experiments have shown that WNTs might also normally participate in self-renewal, proliferation or differentiation of stem cells and altering WNT signalling might be beneficial to the use of stem cells for therapeutic means. Likewise, the stambhA mutant of Drosophila which was discovered for its temperature-dependent paralytic behaviour is the fly homologue of Phospholipase Cβ. Phospholipase C mediated G protein signalling plays a central role in vital processes controlling epilepsy, vision, taste, and olfaction in animals. Proteins of the G-signalling pathway are of intense research interest since many human diseases involve defects in G-protein signalling pathways. In fact, approximately 50

  15. Endoscopic submucosal dissection for early Barrett's neoplasia.

    Science.gov (United States)

    Barret, Maximilien; Cao, Dalhia Thao; Beuvon, Frédéric; Leblanc, Sarah; Terris, Benoit; Camus, Marine; Coriat, Romain; Chaussade, Stanislas; Prat, Frédéric

    2016-04-01

    The possible benefit of endoscopic submucosal dissection (ESD) for early neoplasia arising in Barrett's esophagus remains controversial. We aimed to assess the efficacy and safety of ESD for the treatment of early Barrett's neoplasia. All consecutive patients undergoing ESD for the resection of a visible lesion in a Barrett's esophagus, either suspicious of submucosal infiltration or exceeding 10 mm in size, between February 2012 and January 2015 were prospectively included. The primary endpoint was the rate of curative resection of carcinoma, defined as histologically complete resection of adenocarcinomas without poor histoprognostic factors. Thirty-five patients (36 lesions) with a mean age of 66.2 ± 12 years, a mean ASA score of 2.1 ± 0.7, and a mean C4M6 Barrett's segment were included. The mean procedure time was 191 ± 79 mn, and the mean size of the resected specimen was 51.3 ± 23 mm. En bloc resection rate was 89%. Lesions were 12 ± 15 mm in size, and 81% (29/36) were invasive adenocarcinomas, six of which with submucosal invasion. Although R0 resection of carcinoma was 72.4%, the curative resection rate was 66% (19/29). After a mean follow-up of 12.9 ± 9 months, 16 (45.7%) patients had required additional treatment, among whom nine underwent surgical resection, and seven further endoscopic treatments. Metachronous lesions or recurrence of cancer developed during the follow-up period in 17.2% of the patients. The overall complication rate was 16.7%, including 8.3% perforations, all conservatively managed, and no bleeding. The 30-day mortality was 0%. In this early experience, ESD yielded a moderate curative resection rate in Barrett's neoplasia. At present, improvements are needed if ESD is to replace piecemeal endoscopic mucosal resection in the management of Barrett's neoplasia.

  16. Epidemiology of aortic disease - aneurysm, dissection, occlusion

    International Nuclear Information System (INIS)

    Steckmeier, B.

    2001-01-01

    The physiological infrarenal aortic diameter varies between 12.4 mm in women an 27.6 mm in men. As defined, an aneurysmatic dilatation begins with 29 mm. According to that, 9% of all people above the age of 65 are affected by an abdominal aortic aneurysm (AAA). Compared with the female sex, the male sex predominates at a rate of about 5:1. The disease is predominant in men of the white race. In black men, black and white women the incidence of AAA is identical. 38 to 50 percent of the AAA patients (patients) suffer from hypertension, 33 to 60% from coronary, 28% from cerebrovascular and 25% from peripheral occlusive disease. The AAA expansion rate varies between 0.2 and 0.8 cm per year and is exponential from a diameter of 5 cm on. In autopsy studies, the rupture rates with AAA diameters of 7 cm were below 5%, 39% and 65%, respecitvely. 70% of the AAA patients do not die of a rupture, but of a cardiac disease. Serum markers, such as metalloproteinases and procollagen peptides are significantly increased in AAA patients. Thoraco-abdominal aneurysms (TAA) make up only 2 to 5% of all degenerative aneurysms. 20 to 30% of the TAA patients are also affected by an AAA. 80% of the TAA are degenerative, 15 to 20% are a consequence of the chronic dissection - including 5% of Marfan patients -, 2% occur in case of infections and 1 to 2% in case of aortitis. The TAA incidence in 100,000 person-years is 5.9% during a monitoring period of 30 years. In case of TAA, an operation is indicated with a maximum diameter of 5.5 to 6 cm and more and, in case of a Marfan's syndrome (incidence of 1:10,000), with a maximum diameter of 5.5 cm and more. With regard to aorto-iliac occlusive diseases, there are defined 3 types of distribution. Type I refers to the region of the bifurcation itself. Type II defines the diffuse aortoiliac spread of the disease. Type III designates multiple-level occlusions also beyond the inguinal ligament. Type I patients in most cases are female and more

  17. "And afterwards your body to be given for public dissection": a history of the murderers dissected in Glasgow and the west of Scotland.

    Science.gov (United States)

    Kennedy, S S; McLeod, K J; McDonald, S W

    2001-02-01

    Between 1752 and 1832, the bodies of hanged murderers were dissected or gibbeted. During this period, 38 murderers were executed in the West of Scotland. The bodies of at least 23 were dissected in Glasgow. The stories of these murders are recounted. Insight is also given into the attitudes of the public and the anatomists to dissection of executed murderers.

  18. A comparison of retention of anatomical knowledge in an introductory college biology course: Traditional dissection vs. virtual dissection

    Science.gov (United States)

    Taeger, Kelli Rae

    Dissection has always played a crucial role in biology and anatomy courses at all levels of education. However, in recent years, ethical concerns, as well as improved technology, have brought to the forefront the issue of whether virtual dissection is as effective or whether it is more effective than traditional dissection. Most prior research indicated the two methods produced equal results. However, none of those studies examined retention of information past the initial test of knowledge. Two groups of college students currently enrolled in an introductory level college biology course were given one hour to complete a frog dissection. One group performed a traditional frog dissection, making cuts in an actual preserved frog specimen with scalpels and scissors. The other group performed a virtual frog dissection, using "The Digital Frog 2" software. Immediately after the dissections were completed, each group was given an examination consisting of questions on actual specimens, pictures generated from the computer software, and illustrations that neither group had seen. Two weeks later, unannounced, the groups took the same exam in order to test retention. The traditional dissection group scored significantly higher on two of the three sections, as well as the total score on the initial exam. However, with the exception of specimen questions (on which the traditional group retained significantly more information), there was no significant difference in the retention from exam 1 to exam 2 between the two groups. These results, along with the majority of prior studies, show that the two methods produce, for the most part, the same end results. Therefore, the decision of which method to employ should be based on the goals and preferences of the instructor(s) and the department. If that department's goals include: Being at the forefront of new technology, increasing time management, increasing student: teacher ratio for economic reasons, and/or ethical issues, then

  19. Standard of Care Versus Metastases-directed Therapy for PET-detected Nodal Oligorecurrent Prostate Cancer Following Multimodality Treatment: A Multi-institutional Case-control Study.

    Science.gov (United States)

    Steuber, T; Jilg, C; Tennstedt, P; De Bruycker, A; Tilki, D; Decaestecker, K; Zilli, T; Jereczek-Fossa, B A; Wetterauer, U; Grosu, A L; Schultze-Seemann, W; Heinzer, H; Graefen, M; Morlacco, A; Karnes, R J; Ost, P

    2018-03-10

    Most prostate cancer (PCa) patients with a biochemical failure following primary multimodality treatment (surgery and postoperative radiotherapy) relapse in the nodes. To perform a matched-case analysis in men with lymph node recurrent PCa comparing standard of care (SOC) with metastasis-directed therapy (MDT). PCa patients with a prostate-specific antigen (PSA) progression following multimodality treatment were included in this retrospective multi-institutional analysis. The SOC cohort (n=1816) received immediate or delayed androgen deprivation therapy administered at PSA progression. The MDT cohort (n=263) received either salvage lymph node dissection (n=166) or stereotactic body radiotherapy (n=97) at PSA progression to a positron emission tomography-detected nodal recurrence. The primary endpoint, cancer-specific survival (CSS), was analyzed using the Kaplan-Meier method, log-rank test, Cox proportional hazards models, and propensity score-matched analyses. At a median follow-up of 70 (interquartile range: 48-98) mo, MDT was associated with an improved CSS on univariate (p=0.029) and multivariate analysis (hazard ratio: 0.33, 95% confidence interval [CI]: 0.17-0.64) adjusted for the year of radical prostatectomy (RP), age at RP, PSA at RP, time from RP to PSA progression, Gleason score, surgical margin status, pT- and pN-stage. In total, 659 men were matched (3:1 ratio). The 5-yr CSS was 98.6% (95% CI: 94.3-99.6) and 95.7% (95% CI: 93.2-97.3) for MDT and SOC, respectively (p=0.005, log-rank). The main limitations of our study are its retrospective design and lack of standardization of systemic treatment in the SOC cohort. MDT for nodal oligorecurrent PCa improves CSS as compared with SOC. These retrospective data from a multi-institutional pooled analysis should be considered as hypothesis-generating and inform future randomized trials in this setting. Prostate cancer patients experiencing a lymph node recurrence might benefit from local treatments directed at

  20. Efficacy of 131I SPECT/CT in the initial nodal staging in patients with differentiated thyroid carcinoma at the first ablative radioiodine therapy

    International Nuclear Information System (INIS)

    Kisiel, N.; Garcia-Burillo, A.; Barios, M.; Dellepiane, F.; Castell-Conesa, J.

    2015-01-01

    Full text of publication follows. Background: after the first radioiodine ablative dose, planar Whole-Body Scanning (WBS) offers the possibility for detecting thyroid remnant, loco-regional node involvement and distant metastases. Nevertheless, available anatomic information is scarce and the high activity of thyroid remnants can interfere with the detection of cervical lymphatic nodes. Objective: to determine the additional value of the SPECT-CT over planar WBS, performed seven days after ablative treatment with 131 I, in patients who were operated on for Differentiated Thyroid Cancer (DTC). Methods: from January 2009 to December 2012, 132 patients with DTC were admitted for radio-ablation with 131 I after thyroidectomy. All of them underwent WBS seven days after ablation, and 91 had an additional SPECT-CT, 71 women and 20 men, with ages ranged from 15 to 89 years (mean, age 54 years). All patients had histological confirmed DTC (73 papillary, 17 follicular -2 cases with double tumour, papillary and follicular-, and 1 insular type). In addition to the thyroidectomy, lymph node dissection was performed in 54 patients (59%): 20 patients were classified as N0 and 29 as N1. The remaining 42 patients were classified as Nx. Planar and tomographic images were independently evaluated by two experienced nuclear medicine physicians. Results: 195 cervical focal uptake were observed in the 91 planar WBSs. No additional foci were observed in SPECT-CT. Findings: Planar WBS........... SPECT-CT........... Number of Foci Thyroid remnant...... Thyroid remnant..........51........... LNM...........0 Indeterminate.......... Thyroid remnant..........84............. LNM............5 LNM............ Thyroid remnant.........12............ Indeterminate.............0............ LNM..........43. Total Number of Foci............. 195. Compared to the nodal staging prior to ablation based on the histopathological diagnosis, we had an upstaging from N0 to N1 in 4 of 20 patients and from Nx to