WorldWideScience

Sample records for selective venous sampling

  1. Plasma metanephrine for assessing the selectivity of adrenal venous sampling

    NARCIS (Netherlands)

    Dekkers, T.; Deinum, J.; Schultze Kool, L.J.; Blondin, D.; Vonend, O.; Hermus, A.R.M.M.; Peitzsch, M.; Rump, L.C.; Antoch, G.; Sweep, F.C.; Bornstein, S.R.; Lenders, J.W.M.; Willenberg, H.S.; Eisenhofer, G.

    2013-01-01

    Adrenal vein sampling is used to establish the origins of excess production of adrenal hormones in primary aldosteronism. Correct catheter positioning is confirmed using adrenal vein measurements of cortisol, but this parameter is not always reliable. Plasma metanephrine represents an alternative

  2. Selective parathyroid venous sampling in primary hyperparathyroidism: A systematic review and meta-analysis.

    Science.gov (United States)

    Ibraheem, Kareem; Toraih, Eman A; Haddad, Antoine B; Farag, Mahmoud; Randolph, Gregory W; Kandil, Emad

    2018-05-14

    Minimally invasive parathyroidectomy requires accurate preoperative localization techniques. There is considerable controversy about the effectiveness of selective parathyroid venous sampling (sPVS) in primary hyperparathyroidism (PHPT) patients. The aim of this meta-analysis is to examine the diagnostic accuracy of sPVS as a preoperative localization modality in PHPT. Studies evaluating the diagnostic accuracy of sPVS for PHPT were electronically searched in the PubMed, EMBASE, Web of Science, and Cochrane Controlled Trials Register databases. Two independent authors reviewed the studies, and revised quality assessment of diagnostic accuracy study tool was used for the quality assessment. Study heterogeneity and pooled estimates were calculated. Two hundred and two unique studies were identified. Of those, 12 studies were included in the meta-analysis. Pooled sensitivity, specificity, and positive likelihood ratio (PLR) of sPVS were 74%, 41%, and 1.55, respectively. The area-under-the-receiver operating characteristic curve was 0.684, indicating an average discriminatory ability of sPVS. On comparison between sPVS and noninvasive imaging modalities, sensitivity, PLR, and positive posttest probability were significantly higher in sPVS compared to noninvasive imaging modalities. Interestingly, super-selective venous sampling had the highest sensitivity, accuracy, and positive posttest probability compared to other parathyroid venous sampling techniques. This is the first meta-analysis to examine the accuracy of sPVS in PHPT. sPVS had higher pooled sensitivity when compared to noninvasive modalities in revision parathyroid surgery. However, the invasiveness of this technique does not favor its routine use for preoperative localization. Super-selective venous sampling was the most accurate among all other parathyroid venous sampling techniques. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

  3. The diagnostic value of CT scan and selective venous sampling in Cushing's syndrome

    International Nuclear Information System (INIS)

    Negoro, Makoto; Kuwayama, Akio; Yamamoto, Naoto; Nakane, Toshichi; Yokoe, Toshio; Kageyama, Naoki; Ichihara, Kaoru; Ishiguchi, Tsuneo; Sakuma, Sadayuki

    1986-01-01

    We studied 24 patients with Cushing's syndrome in order to find the best way to confirm the pituitary adenoma preoperatively. At first, the sellar content was studied by means of a high-resolution CT scan in each patient. Second, by selective catheterization in the bilateral internal jugular vein and the inferior petrosal sinus, venous samples (c) were obtained for ACTH assay. Simultaneously, peripheral blood sampling (P) was made at the anterior cubital vein for the same purpose, and the C/P ratio was carefully calculated in each patient. If the C/P ratio exceeded 2, it was highly suggestive of the presence of pituitary adenoma. Even by an advanced high-resolution CT scan with a thickness of 2 mm, pituitary adenomas were detected in only 32 % of the patients studied. The result of image diagnosis in Cushing disease was discouraging. As for the chemical diagnosis, the results were as follows. At the early stage of this study, the catheterization was terminated in the jugular veins of nine patients. Among these, in five patients the presence of pituitary adenoma was predicted correctly in the preoperative stage. Later, by means of inferior petrosal sinus samplings, pituitary microadenomas were detected in ten patients among the twelve. Selective venous sampling for ACTH in the inferior petrosal sinus or jugular vein proved to be useful for the differential diagnosis of Cushing's syndrome when other diagnostic measures such as CT scan were inconclusive. (author)

  4. Selective inferior petrosal sinus sampling without venous outflow diversion in the detection of a pituitary adenoma in Cushing's syndrome

    International Nuclear Information System (INIS)

    Andereggen, Lukas; Schroth, Gerhard; Gralla, Jan; Ozdoba, Christoph; Seiler, Rolf; Mariani, Luigi; Beck, Juergen; Widmer, Hans-Rudolf; Andres, Robert H.; Christ, Emanuel

    2012-01-01

    Conventional MRI may still be an inaccurate method for the non-invasive detection of a microadenoma in adrenocorticotropin (ACTH)-dependent Cushing's syndrome (CS). Bilateral inferior petrosal sinus sampling (BIPSS) with ovine corticotropin-releasing hormone (oCRH) stimulation is an invasive, but accurate, intervention in the diagnostic armamentarium surrounding CS. Until now, there is a continuous controversial debate regarding lateralization data in detecting a microadenoma. Using BIPSS, we evaluated whether a highly selective placement of microcatheters without diversion of venous outflow might improve detection of pituitary microadenoma. We performed BIPSS in 23 patients that met clinical and biochemical criteria of CS and with equivocal MRI findings. For BIPSS, the femoral veins were catheterized bilaterally with a 6-F catheter and the inferior petrosal sinus bilaterally with a 2.7-F microcatheter. A third catheter was placed in the right femoral vein. Blood samples were collected from each catheter to determine ACTH blood concentration before and after oCRH stimulation. In 21 patients, a central-to-peripheral ACTH gradient was found and the affected side determined. In 18 of 20 patients where transsphenoidal partial hypophysectomy was performed based on BIPSS findings, microadenoma was histologically confirmed. BIPSS had a sensitivity of 94% and a specificity of 67% after oCRH stimulation in detecting a microadenoma. Correct localization of the adenoma was achieved in all Cushing's disease patients. BIPSS remains the gold standard in the detection of a microadenoma in CS. Our findings show that the selective placement of microcatheters without venous outflow diversion might further enhance better recognition to localize the pituitary tumor. (orig.)

  5. The Essentials of Parathyroid Hormone Venous Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Taslakian, Bedros, E-mail: btaslakian@gmail.com [NYU Langone Medical Center, Department of Radiology, NYU School of Medicine (United States); Trerotola, Scott O., E-mail: streroto@uphs.upenn.edu [Perelman School of Medicine of the University of Pennsylvania, Department of Radiology (United States); Sacks, Barry, E-mail: bsacks@bidmc.harvard.edu [Beth Israel Deaconess Medical Center, Department of Interventional Radiology (United States); Oklu, Rahmi, E-mail: oklu.rahmi@mayo.edu [Mayo Clinic, Department of Interventional Radiology (United States); Deipolyi, Amy, E-mail: deipolya@mskcc.org [Memorial Sloan Kettering Cancer Center, Department of Radiology (United States)

    2017-01-15

    Hyperparathyroidism is an excess of parathyroid hormone in the blood due to over-activity of one or more parathyroid gland. Localization of abnormal glands with noninvasive imaging modalities, such as technetium sestamibi scan and cross-sectional imaging, has a high success rate. Parathyroid venous sampling is performed for patients with persistent or recurrent disease after previous parathyroid surgery, when repeat noninvasive imaging studies are negative or discordant. The success of invasive localization studies and results interpretation is dependent on the interventional radiologist’s understanding of the normal and ectopic anatomic locations of parathyroid glands, as well as their blood supply and venous drainage. Anatomic and technical considerations for selective parathyroid venous sampling are reviewed.

  6. The Current Role of Venous Sampling in the Localization of Endocrine Disease

    International Nuclear Information System (INIS)

    Lau, Jeshen H. G.; Drake, William; Matson, Matthew

    2007-01-01

    Endocrine venous sampling plays a specific role in the diagnosis of endocrine disorders. In this article, we cover inferior petrosal sinus sampling, selective parathyroid venous sampling, hepatic venous sampling with arterial stimulation, adrenal venous sampling, and ovarian venous sampling. We review their indications and the scientific evidence justifying these indications in the diagnosis and management of Cushing's syndrome, hyperparathyroidism, pancreatic endocrine tumors, Conn's syndrome, primary hyperaldosteronism, pheochromocytomas, and androgen-secreting ovarian tumors. For each sampling technique, we compare its diagnostic accuracy with that of other imaging techniques and, where possible, look at how it impacts patient management. Finally, we incorporate venous sampling into diagnostic algorithms used at our institution

  7. Eleven-Year Retrospective Report of Super-Selective Venous Sampling for the Evaluation of Recurrent or Persistent Hyperparathyroidism in 32 Patients.

    Science.gov (United States)

    Habibollahi, Peiman; Shin, Benjamin; Shamchi, Sara P; Wachtel, Heather; Fraker, Douglas L; Trerotola, Scott O

    2018-01-01

    Parathyroid venous sampling (PAVS) is usually reserved for patients with persistent or recurrent hyperparathyroidism after parathyroidectomy with inconclusive noninvasive imaging studies. A retrospective study was performed to evaluate the diagnostic efficacy of super-selective PAVS (SSVS) in patients needing revision neck surgery with inconclusive imaging. Patients undergoing PAVS between 2005 and 2016 due to persistent or recurrent hyperparathyroidism following surgery were reviewed. PAVS was performed in all patients using super-selective technique. Single-value measurements within central neck veins performed as part of super-selective PAVS were used to simulate selective venous sampling (SVS) and allow for comparison to data, which might be obtained in a non-super-selective approach. 32 patients (mean age 51 ± 15 years; 8 men and 24 women) met inclusion and exclusion criteria. The sensitivity and positive predictive value (PPV) of SSVS for localizing the source of elevated PTH to a limited area in the neck or chest was 96 and 84%, respectively. Simulated SVS, on the other hand, had a sensitivity of 28% and a PPV of 89% based on the predefined gold standard. SSVS had a significantly higher sensitivity compared to simulated SVS (p localizing the source of hyperparathyroidism in patients undergoing revision surgery for hyperparathyroidism in whom noninvasive imaging studies are inconclusive. SSVS data had also markedly higher sensitivity for localizing disease in these patients compared to simulated SVS.

  8. Selective inferior petrosal sinus sampling without venous outflow diversion in the detection of a pituitary adenoma in Cushing's syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Andereggen, Lukas [Bern University Hospital, University Institute of Diagnostic and Interventional Neuroradiology, Bern (Switzerland); Bern University Hospital, Department of Neurosurgery, Bern (Switzerland); Schroth, Gerhard; Gralla, Jan; Ozdoba, Christoph [Bern University Hospital, University Institute of Diagnostic and Interventional Neuroradiology, Bern (Switzerland); Seiler, Rolf; Mariani, Luigi; Beck, Juergen; Widmer, Hans-Rudolf; Andres, Robert H. [Bern University Hospital, Department of Neurosurgery, Bern (Switzerland); Christ, Emanuel [Bern University Hospital, Division of Endocrinology, Diabetology and Clinical Nutrition, Bern (Switzerland)

    2012-05-15

    Conventional MRI may still be an inaccurate method for the non-invasive detection of a microadenoma in adrenocorticotropin (ACTH)-dependent Cushing's syndrome (CS). Bilateral inferior petrosal sinus sampling (BIPSS) with ovine corticotropin-releasing hormone (oCRH) stimulation is an invasive, but accurate, intervention in the diagnostic armamentarium surrounding CS. Until now, there is a continuous controversial debate regarding lateralization data in detecting a microadenoma. Using BIPSS, we evaluated whether a highly selective placement of microcatheters without diversion of venous outflow might improve detection of pituitary microadenoma. We performed BIPSS in 23 patients that met clinical and biochemical criteria of CS and with equivocal MRI findings. For BIPSS, the femoral veins were catheterized bilaterally with a 6-F catheter and the inferior petrosal sinus bilaterally with a 2.7-F microcatheter. A third catheter was placed in the right femoral vein. Blood samples were collected from each catheter to determine ACTH blood concentration before and after oCRH stimulation. In 21 patients, a central-to-peripheral ACTH gradient was found and the affected side determined. In 18 of 20 patients where transsphenoidal partial hypophysectomy was performed based on BIPSS findings, microadenoma was histologically confirmed. BIPSS had a sensitivity of 94% and a specificity of 67% after oCRH stimulation in detecting a microadenoma. Correct localization of the adenoma was achieved in all Cushing's disease patients. BIPSS remains the gold standard in the detection of a microadenoma in CS. Our findings show that the selective placement of microcatheters without venous outflow diversion might further enhance better recognition to localize the pituitary tumor. (orig.)

  9. 8D.04: CLINICAL BENEFITS OF ADMINISTERING SUPER-SELECTIVE SEGMENTAL ADRENAL VENOUS SAMPLING AND PERFORMING ADRENAL SPARING SURGERY IN THE PATIENTS WITH PRIMARY ALDOSTERONISM.

    Science.gov (United States)

    Satoh, F; Morimoto, R; Ono, Y; Iwakura, Y; Omata, K; Kudo, M; Satani, N; Ota, H; Seiji, K; Takase, K; Nakamura, Y; Sasano, H; Ito, S

    2015-06-01

    Adrenal venous sampling (AVS) has been well known to play pivotal roles in clinical differential diagnosis of unilateral aldosterone producing adenoma (APA) from bilateral idiopathic hyperaldosteronism (IHA). However, it is also true that a central vein AVS or c-AVS which collects the blood from right and left central adrenal veins can by no means discriminate bilateral APA from BHA. There have been no published studies reporting the reliable clinical differential diagnosis between bilateral APA and IHA, especially IHA cases with bilateral non-functioning adenomas (NFA), which has been considered practically impossible in clinical differential diagnosis. As an attempt to this clinical dilemma, segmental AVS (S-AVS), which could evaluate segmental effluents from adrenal tributary veins, has been recently developed. We have performed S-AVS in these patients above following C-AVS, via the insertion of a microcatheter in up to three intra-adrenal first-degree tributary veins on bilateral adrenals. S-AVS did enable us to evaluate the intra-adrenal localization of corticosteroidogenesis. These data did indicate that S-AVS should be performed in the PA patients who had increased aldosterone levels in bilateral central vein and demonstrated space occupying lesions in the bilateral adrenals in order to avoid bilateral adrenalectomy or long lasting medical treatment toward persistent PA. In addition to the situations above, we have administere S-AVS to the following patients; those who had clinically suspected APA but not sufficiently high lateralization indexes according to the results of C-AVS, very young ones with higher clinical probability of recurrence and those who could benefit from partial adrenalectomy by demonstrating the sites of specific steroidogenesis. However, it is also entirely true that S-AVS is more expensive, time-consuming and labor-intensive compared to C-AVS.(Figure is included in full-text article.)The angiography during S-AVS (A, B), the coronal CT

  10. Planar scintigraphy with 123I/99mTc-sestamibi, 99mTc-sestamibi SPECT/CT, 11C-methionine PET/CT, or selective venous sampling before reoperation of primary hyperparathyroidism?

    Science.gov (United States)

    Schalin-Jäntti, Camilla; Ryhänen, Eeva; Heiskanen, Ilkka; Seppänen, Marko; Arola, Johanna; Schildt, Jukka; Väisänen, Mika; Nelimarkka, Lassi; Lisinen, Irina; Aalto, Ville; Nuutila, Pirjo; Välimäki, Matti J

    2013-05-01

    All patients with primary hyperparathyroidism should undergo localization studies before reoperation, but it is not known which method is most accurate. The purpose of this prospective study was to compare the performance of planar scintigraphy with (123)I/(99m)Tc-sestamibi, (99m)Tc-sestamibi SPECT (SPECT/CT), (11)C-methionine PET/CT, and selective venous sampling (SVS) in persistent primary hyperparathyroidism. Twenty-one patients referred for reoperation of persistent hyperparathyroidism were included and investigated with (123)I/(99m)Tc-sestamibi, SPECT/CT (n = 19), (11)C-methionine PET/CT, and SVS (n = 18) before reoperation. All patients had been operated on 1-2 times previously because of hyperparathyroidism. The results of the localization studies were compared with operative findings, histology, and biochemical cure. Eighteen (86%) of 21 patients were biochemically cured. Nineteen parathyroid glands (9 adenomas, 1 atypical adenoma, and 9 hyperplastic glands) were removed from 17 patients, and 1 patient who was biochemically cured had an unclear histology result. The accuracy for localizing a pathologic parathyroid gland to the correct side of the neck was 59% (95% confidence interval [CI], 36%-79%) for (123)I/(99m)Tc-sestamibi, 19% (95% CI, 5%-42%) for SPECT/CT, 65% (95% CI, 43%-84%) for (11)C-methionine PET/CT, and 40% (95% CI, 19%-65%) for SVS (P hyperparathyroidism and is recommended as first-line imaging before reoperation. (11)C-methionine PET/CT provides valuable additional information if (123)I/(99m)Tc-sestamibi scan results remain negative. (99m)Tc-sestamibi SPECT/CT and SVS provide no additional information, compared with the combined results of (123)I/(99m)Tc-sestamibi and (11)C-methionine PET/CT imaging.

  11. Scintigraphy and venous sampling in endocrine adrenal diseases. Clinical results in 85 patients

    International Nuclear Information System (INIS)

    Feltrin, G.P.; Maffessanti, M.; Miotto, D.; Mantero, F.; Macri, G.; Romani, S.

    1979-01-01

    The results obtained by adrenal scanning and venous sampling in 85 patients affected by various forms of adrenal pathology are reported and discussed. Pheochromocytoma rarely needs venous catheterization and blood sampling, since arteriography is almost always capable to visualize it. Scintigraphy alone is generally accurate enough to distinguish between bilateral hyperplasia and tumors in Cushing's and adrenogenital syndromes (100% of personal observations); only a tumoral situation benefits by venous catheterization. Blood samples and venography must be preceded by scintigraphy in Conn's syndrome

  12. rCBF measurement by one-point venous sampling with the ARG method

    International Nuclear Information System (INIS)

    Yoshida, Nobuhiro; Okamoto, Toshiaki; Takahashi, Hidekado; Hattori, Teruo

    1997-01-01

    We investigated the possibility of using venous blood sampling instead of arterial blood sampling for the current method of ARG (autoradiography) used to determine regional cerebral blood flow (rCBF) on the basis of one session of arterial blood sampling and SPECT. For this purpose, the ratio of the arterial blood radioactivity count to the venous blood radioactivity count, the coefficient of variation, and the correlation and differences between arterial blood-based rCBF and venous blood-based rCBF were analyzed. The coefficient of variation was lowest (4.1%) 20 minutes after injection into the dorsum manus. When the relationship between venous and arterial blood counts was analyzed, arterial blood counts correlated well with venous blood counts collected at the dorsum manus 20 or 30 minutes after intravenous injection and with venous blood counts collected at the wrist 20 minutes after intravenous injection (r=0.97 or higher). The difference from rCBF determined on the basis of arterial blood was smallest (0.7) for rCBF determined on the basis of venous blood collected at the dorsum manus 20 minutes after intravenous injection. (author)

  13. Selective information sampling

    Directory of Open Access Journals (Sweden)

    Peter A. F. Fraser-Mackenzie

    2009-06-01

    Full Text Available This study investigates the amount and valence of information selected during single item evaluation. One hundred and thirty-five participants evaluated a cell phone by reading hypothetical customers reports. Some participants were first asked to provide a preliminary rating based on a picture of the phone and some technical specifications. The participants who were given the customer reports only after they made a preliminary rating exhibited valence bias in their selection of customers reports. In contrast, the participants that did not make an initial rating sought subsequent information in a more balanced, albeit still selective, manner. The preliminary raters used the least amount of information in their final decision, resulting in faster decision times. The study appears to support the notion that selective exposure is utilized in order to develop cognitive coherence.

  14. A content validated questionnaire for assessment of self reported venous blood sampling practices.

    Science.gov (United States)

    Bölenius, Karin; Brulin, Christine; Grankvist, Kjell; Lindkvist, Marie; Söderberg, Johan

    2012-01-19

    Venous blood sampling is a common procedure in health care. It is strictly regulated by national and international guidelines. Deviations from guidelines due to human mistakes can cause patient harm. Validated questionnaires for health care personnel can be used to assess preventable "near misses"--i.e. potential errors and nonconformities during venous blood sampling practices that could transform into adverse events. However, no validated questionnaire that assesses nonconformities in venous blood sampling has previously been presented. The aim was to test a recently developed questionnaire in self reported venous blood sampling practices for validity and reliability. We developed a questionnaire to assess deviations from best practices during venous blood sampling. The questionnaire contained questions about patient identification, test request management, test tube labeling, test tube handling, information search procedures and frequencies of error reporting. For content validity, the questionnaire was confirmed by experts on questionnaires and venous blood sampling. For reliability, test-retest statistics were used on the questionnaire answered twice. The final venous blood sampling questionnaire included 19 questions out of which 9 had in total 34 underlying items. It was found to have content validity. The test-retest analysis demonstrated that the items were generally stable. In total, 82% of the items fulfilled the reliability acceptance criteria. The questionnaire could be used for assessment of "near miss" practices that could jeopardize patient safety and gives several benefits instead of assessing rare adverse events only. The higher frequencies of "near miss" practices allows for quantitative analysis of the effect of corrective interventions and to benchmark preanalytical quality not only at the laboratory/hospital level but also at the health care unit/hospital ward.

  15. A content validated questionnaire for assessment of self reported venous blood sampling practices

    Directory of Open Access Journals (Sweden)

    Bölenius Karin

    2012-01-01

    Full Text Available Abstract Background Venous blood sampling is a common procedure in health care. It is strictly regulated by national and international guidelines. Deviations from guidelines due to human mistakes can cause patient harm. Validated questionnaires for health care personnel can be used to assess preventable "near misses"--i.e. potential errors and nonconformities during venous blood sampling practices that could transform into adverse events. However, no validated questionnaire that assesses nonconformities in venous blood sampling has previously been presented. The aim was to test a recently developed questionnaire in self reported venous blood sampling practices for validity and reliability. Findings We developed a questionnaire to assess deviations from best practices during venous blood sampling. The questionnaire contained questions about patient identification, test request management, test tube labeling, test tube handling, information search procedures and frequencies of error reporting. For content validity, the questionnaire was confirmed by experts on questionnaires and venous blood sampling. For reliability, test-retest statistics were used on the questionnaire answered twice. The final venous blood sampling questionnaire included 19 questions out of which 9 had in total 34 underlying items. It was found to have content validity. The test-retest analysis demonstrated that the items were generally stable. In total, 82% of the items fulfilled the reliability acceptance criteria. Conclusions The questionnaire could be used for assessment of "near miss" practices that could jeopardize patient safety and gives several benefits instead of assessing rare adverse events only. The higher frequencies of "near miss" practices allows for quantitative analysis of the effect of corrective interventions and to benchmark preanalytical quality not only at the laboratory/hospital level but also at the health care unit/hospital ward.

  16. VENOUS SAMPLING FOR CUSHING DISEASE: COMPARISON OF INTERNAL JUGULAR VEIN AND INFERIOR PETROSAL SINUS SAMPLING.

    Science.gov (United States)

    Radvany, Martin G; Quinones-Hinojosa, Alfredo; Gallia, Gary L; Wand, Gary S; Salvatori, Roberto

    2016-09-01

    Because magnetic resonance imaging (MRI) fails to detect many adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas, inferior petrosal sinus sampling (IPSS) is considered the gold standard to differentiate Cushing disease (CD) from ectopic ACTH secretion syndrome (EAS). Some authors have suggested internal jugular vein sampling (IJVS) as an alternative to IPSS. We simultaneously compared IJVS to IPSS in 30 consecutive patients referred for ACTH-dependent Cushing syndrome and equivocal MRI exams. Five sites were simultaneously sampled in each patient (right and left IPS, right and left IJV, and femoral vein) before and after the administration of corticotrophin-releasing hormone or desmopressin. The test was considered consistent with CD when the IPS to peripheral ratio was >2 at baseline or >3 after stimulus and the IJV to peripheral ratio was >1.7 at baseline or >2 after stimulus. In 27 of 30 patients, IPSS results were consistent with a central source of ACTH. Two of the other 3 patients had EAS (one lung carcinoid and one occult), and 1 patient had pathology-proven CD. The sensitivity of IPSS was 96.4%. Only 64.2% of these patients had results meeting criteria for a central source of ACTH by IJVS criteria. Twenty patients with centralizing IPPS have undergone pituitary surgery. Of these, the central origin of excessive ACTH was confirmed with certainty in 16 patients. Among these 16 patients, the IPSS sensitivity was 93.8%, whereas 5 patients had false-negative IJVS (68.7% sensitivity). These results do not support the routine use of IJVS in establishing if the pituitary is the source of excessive ACTH. ACTH = adrenocorticotropic hormone CD = Cushing disease CRH = corticotrophin-releasing hormone CS = Cushing syndrome DDAVP = desmopressin EAS = ectopic ACTH secretion IJVS = internal jugular vein sampling IPSS = inferior petrosal sinus sampling JVS = jugular venous sampling MRI = magnetic resonance imaging.

  17. Combined Ovarian and Adrenal Venous Sampling in the Localization of Adrenocorticotropic Hormone-Independent Ectopic Cushing Syndrome.

    Science.gov (United States)

    Chen, Shi; Li, Ran; Zhang, Xiaobo; Lu, Lin; Li, Ji; Pan, Hui; Zhu, Huijuan

    2018-03-01

    Cushing syndrome is rarely caused by the secretion of cortisol from ovarian tumors. In clinical decision-making, it is important to determine whether the ovarian tumor is capable of secreting cortisol. Selective ovarian and adrenal venous sampling is scarcely reported in the localization of ACTH-independent ectopic Cushing syndrome. We present a case of 40-year-old Chinese woman who had weight gain, hirsutism, hypertension, and menstrual disorder over 6 months. Her physical examination and biochemical assessment revealed adrenocorticotropic hormone-independent Cushing syndrome. Adrenal computed tomography scan indicated no abnormality. A mass of 5.7 cm × 4.2 cm × 3.4 cm was discovered by pelvic ultrasonography. Somatostatin receptor scintigraphy revealed no abnormal radioactivity intake. Combined ovarian and adrenal venous sampling together with a cortisol assay were conducted. Results revealed cortisol concentration of the right-side ovarian vein, left-side ovarian vein, and peripheral vein of 268.60, 29.00, and 35.18 μg/dL, respectively, suggesting a right-side ovarian origin. A right-side salpingo-oophorectomy was performed and the pathological diagnosis revealed ovarian steroid cell tumor, not otherwise specified. The cortisol level was substantially lower after the patient underwent surgery and symptoms of Cushing syndrome disappeared. At 3-year follow-up, the patient remained disease free, and no tumor was observed on pelvic ultrasonogram. Combined ovarian and adrenal venous sampling is valuable in the localization of adrenocorticotropic hormone-independent ectopic Cushing syndrome.

  18. What are the keys to successful adrenal venous sampling (AVS) in patients with primary aldosteronism?

    Science.gov (United States)

    Young, William F; Stanson, Anthony W

    2009-01-01

    Adrenal venous sampling (AVS) is the criterion standard to distinguish between unilateral and bilateral adrenal disease in patients with primary aldosteronism. The keys to successful AVS include appropriate patient selection, careful patient preparation, focused technical expertise, defined protocol, and accurate data interpretation. The use of AVS should be based on patient preferences, patient age, clinical comorbidities, and the clinical probability of finding an aldosterone-producing adenoma. AVS is optimally performed in the fasting state in the morning. AVS is an intricate procedure because the right adrenal vein is small and may be difficult to locate - the success rate depends on the proficiency of the angiographer. The key factors that determine the successful catheterization of both adrenal veins are experience, dedication and repetition. With experience, and focusing the expertise to 1 or 2 radiologists at a referral centre, the AVS success rate can be as high as 96%. A centre-specific, written protocol is mandatory. The protocol should be developed by an interested group of endocrinologists, radiologists and laboratory personnel. Safeguards should be in place to prevent mislabelling of the blood tubes in the radiology suite and to prevent sample mix-up in the laboratory.

  19. Order of draw practices in venous blood sampling at clinical biochemistry departments in the Danish health care system

    DEFF Research Database (Denmark)

    Jacobsen, Katja Kemp; Brandt, Ida; Christensen, Anne Vindahl

    2018-01-01

    the procedures in venous blood sampling among clinical biochemistry departments to assess the uniformity of order of blood draw and adherence to international guidelines in the Danish health care system. METHODS: We collected venous order of draw procedures from 49 clinical biochemistry departments at 22 public...... 15189:2012 accreditation (p = .57). CONCLUSIONS: Venous order of draw procedures is diverse at Danish clinical biochemistry departments and show moderate adherence to international guidelines....

  20. Selective digital venous hypertension: A rare complication of hemodialysis arteriovenous fistula

    Energy Technology Data Exchange (ETDEWEB)

    Swayne, L.C.; Manstein, C.; Somers, R.; Cope, C.

    1983-04-01

    We report and document angiographically a case of selective venous hypertension, masquerading as an infection, which involved the three middle digits of the right hand in a patient with an access arteriovenous (AV) fistula. This complication arose following hemodialysis and was resolved after resection of the right radial artery at the site of AV fistula and re-anastomosis.

  1. Malaria PCR Detection in Cambodian Low-Transmission Settings: Dried Blood Spots versus Venous Blood Samples

    Science.gov (United States)

    Canier, Lydie; Khim, Nimol; Kim, Saorin; Eam, Rotha; Khean, Chanra; Loch, Kaknika; Ken, Malen; Pannus, Pieter; Bosman, Philippe; Stassijns, Jorgen; Nackers, Fabienne; Alipon, SweetC; Char, Meng Chuor; Chea, Nguon; Etienne, William; De Smet, Martin; Kindermans, Jean-Marie; Ménard, Didier

    2015-01-01

    In the context of malaria elimination, novel strategies for detecting very low malaria parasite densities in asymptomatic individuals are needed. One of the major limitations of the malaria parasite detection methods is the volume of blood samples being analyzed. The objective of the study was to compare the diagnostic accuracy of a malaria polymerase chain reaction assay, from dried blood spots (DBS, 5 μL) and different volumes of venous blood (50 μL, 200 μL, and 1 mL). The limit of detection of the polymerase chain reaction assay, using calibrated Plasmodium falciparum blood dilutions, showed that venous blood samples (50 μL, 200 μL, 1 mL) combined with Qiagen extraction methods gave a similar threshold of 100 parasites/mL, ∼100-fold lower than 5 μL DBS/Instagene method. On a set of 521 field samples, collected in two different transmission areas in northern Cambodia, no significant difference in the proportion of parasite carriers, regardless of the methods used was found. The 5 μL DBS method missed 27% of the samples detected by the 1 mL venous blood method, but most of the missed parasites carriers were infected by Plasmodium vivax (84%). The remaining missed P. falciparum parasite carriers (N = 3) were only detected in high-transmission areas. PMID:25561570

  2. Venous Sampling

    Science.gov (United States)

    ... positioned on the examining table. You may be connected to monitors that track your heart rate, blood ... You should avoid strenuous exercise and lifting heavy objects for at least 24 hours. It is strongly ...

  3. Differential diagnosis of adrenocorticotropic hormone-independent Cushing syndrome: role of adrenal venous sampling.

    Science.gov (United States)

    Martins, Raquel G; Agrawal, Reshma; Berney, Daniel M; Reznek, Rodney; Matson, Matthew; Grossman, Ashley B; Druce, Maralyn R

    2012-01-01

    To outline the potential role for adrenal venous sampling in the diagnosis and management of adrenocorticotropic hormone (ACTH)-independent Cushing syndrome (CS). We present a case description and discuss the management of a 59-year-old woman with an 8-year history of weight gain, centripetal obesity, a round plethoric face, skin thinning, easy bruising, hirsutism, and progressive muscle weakness. The patient reported a prior personal history of asthma, type 2 diabetes mellitus, hypertension, dyslipidemia, and bilateral leg ulcers, but she denied having any personal or family history of endocrinopathy and was not taking any corticosteroid medication. Elevated midnight serum cortisol, failure to suppress cortisol levels with a low-dose dexamethasone suppression test, and undetectable plasma ACTH all indicated ACTH-independent CS. Additional investigations including dynamic tests and adrenal imaging were supported by adrenal venous sampling in order to make a diagnosis and formulate a management plan. She was ultimately noted to have bilateral functioning adrenal nodules (adenoma and adenolipoma) and underwent successful bilateral laparoscopic adrenalectomy, with postoperative glucocorticoid and mineralocorticoid replacement. Adrenal venous sampling may be an important step in the differential diagnosis of CS and localization of the source of cortisol excess. It may distinguish pheochromocytoma or benign nonfunctioning adrenal nodules from cortisol-secreting adenomas and may avoid unnecessary bilateral adrenalectomy. It can also ensure that the correct operation is completed, if required, and thus avoid the increased morbidity and mortality associated with repeated surgical interventions.

  4. Adrenal venous sampling: the learning curve of a single interventionalist with 282 consecutive procedures.

    Science.gov (United States)

    Jakobsson, Hugo; Farmaki, Katerina; Sakinis, Augustinas; Ehn, Olof; Johannsson, Gudmundur; Ragnarsson, Oskar

    2018-01-01

    Primary aldosteronism (PA) is a common cause of secondary hypertension. Adrenal venous sampling (AVS) is the gold standard for assessing laterality of PA, which is of paramount importance to decide adequate treatment. AVS is a technically complicated procedure with success rates ranging between 30% and 96%. The aim of this study was to investigate the success rate of AVS over time, performed by a single interventionalist. This was a retrospective study based on consecutive AVS procedures performed by a single operator between September 2005 and June 2016. Data on serum concentrations of aldosterone and cortisol from right and left adrenal vein, inferior vena cava, and peripheral vein were collected and selectivity index (SI) calculated. Successful AVS was defined as SI > 5. In total, 282 AVS procedures were performed on 269 patients, 168 men (62%) and 101 women (38%), with a mean age of 55±11 years (range, 26-78 years). Out of 282 AVS procedures, 259 were successful, giving an overall success rate of 92%. The most common reason for failure was inability to localize the right adrenal vein (n=16; 76%). The success rates were 63%, 82%, and 94% during the first, second, and third years, respectively. During the last 8 years the success rate was 95%, and on average 27 procedures were performed annually. Satisfactory AVS success rate was achieved after approximately 36 procedures and satisfactory success rate was maintained by performing approximately 27 procedures annually. AVS should be limited to few operators that perform sufficiently large number of procedures to achieve, and maintain, satisfactory AVS success rate.

  5. Evaluation of factor for one-point venous blood sampling method based on the causality model

    International Nuclear Information System (INIS)

    Matsutomo, Norikazu; Onishi, Hideo; Kobara, Kouichi; Sasaki, Fumie; Watanabe, Haruo; Nagaki, Akio; Mimura, Hiroaki

    2009-01-01

    One-point venous blood sampling method (Mimura, et al.) can evaluate the regional cerebral blood flow (rCBF) value with a high degree of accuracy. However, the method is accompanied by complexity of technique because it requires a venous blood Octanol value, and its accuracy is affected by factors of input function. Therefore, we evaluated the factors that are used for input function to determine the accuracy input function and simplify the technique. The input function which uses the time-dependent brain count of 5 minutes, 15 minutes, and 25 minutes from administration, and the input function in which an objective variable is used as the artery octanol value to exclude the venous blood octanol value are created. Therefore, a correlation between these functions and rCBF value by the microsphere (MS) method is evaluated. Creation of a high-accuracy input function and simplification of technique are possible. The rCBF value obtained by the input function, the factor of which is a time-dependent brain count of 5 minutes from administration, and the objective variable is artery octanol value, had a high correlation with the MS method (y=0.899x+4.653, r=0.842). (author)

  6. Diagnosing unilateral primary aldosteronism - comparison of a clinical prediction score, computed tomography and adrenal venous sampling.

    Science.gov (United States)

    Sze, W C Candy; Soh, Lip Min; Lau, Jeshen H; Reznek, Rodney; Sahdev, Anju; Matson, Matthew; Riddoch, Fiona; Carpenter, Robert; Berney, Dan; Grossman, Ashley B; Chew, Shern L; Akker, Scott A; Druce, Maralyn R; Waterhouse, Mona; Monson, John P; Drake, William M

    2014-07-01

    In patients with primary aldosteronism (PA), adrenalectomy is potentially curative for those correctly identified as having unilateral excessive aldosterone production. It has been suggested that a recently developed and published clinical prediction score (CPS) may correctly identify some patients as having unilateral disease, without recourse to adrenal venous sampling. We have applied the CPS to a large cohort of PA patients with defined and documented outcomes. We also incorporated a minor modification to the CPS and a radiological grading score (RGS) into our analysis to assess whether its performance could be augmented. A total of 75 patients with a robust diagnosis following bilateral adrenal venous cannulation and/or strictly defined surgical outcome were analysed. Applying the CPS to this group of patients produced a sensitivity of 38·8% and a specificity of 88·5% of correctly identifying unilateral aldosterone production. Using a suggested modification to the CPS, in which different levels of hypokalaemia were given different weightings, the sensitivity rose to 40·8%, with an identical specificity. Using the RGS alone improved sensitivity to 91·7%, but specificity was reduced to 62·5%. Applying the recently developed CPS to this cohort of patients, it was not possible to reproduce the 100% specificity reported in the original publication. Using the modified score or incorporating the RGS did not improve its performance. In this cohort, we were unable to show superiority of the CPS over an imaging-based strategy. CPS may have a role in guiding clinical decision-making, especially in those whose adrenal venous sampling (AVS) has been unsuccessful. © 2013 John Wiley & Sons Ltd.

  7. An improved selective sampling method

    International Nuclear Information System (INIS)

    Miyahara, Hiroshi; Iida, Nobuyuki; Watanabe, Tamaki

    1986-01-01

    The coincidence methods which are currently used for the accurate activity standardisation of radio-nuclides, require dead time and resolving time corrections which tend to become increasingly uncertain as countrates exceed about 10 K. To reduce the dependence on such corrections, Muller, in 1981, proposed the selective sampling method using a fast multichannel analyser (50 ns ch -1 ) for measuring the countrates. It is, in many ways, more convenient and possibly potentially more reliable to replace the MCA with scalers and a circuit is described employing five scalers; two of them serving to measure the background correction. Results of comparisons using our new method and the coincidence method for measuring the activity of 60 Co sources yielded agree-ment within statistical uncertainties. (author)

  8. Relative value of computed tomography scanning and venous sampling in establishing the cause of primary hyperaldosteronism

    International Nuclear Information System (INIS)

    Sheaves, R.; Goldin, J.; Reznek, R.H.

    1996-01-01

    The purpose of this study was to evaluate the relative merits of the postural simulation test, adrenal computed tomography (CT) and venous sampling in the differential diagnosis of patients presenting with primary hyperaldosteronism. The records of 20 patients presenting with primary hyperaldosteronism were reviewed retrospectively. There were 15 patients with a unilateral aldosterone-producing adenoma (APA), 4 patients with idiopathic hyperaldosteronism (IHA) and 1 patient with primary adrenal hyperplasia (PAH). Bilateral venous sampling of adrenal veins was attempted in all patients and blood collected for aldosterone and cortisol assay. Plasma aldosterone concentration increased after 4 h of standing in all cases of hyperplasia, but was also demonstrated in 10/15 patients with a surgically-proven APA. CT scanning correctly identified all 15 cases of APA and also classified correctly the remaining 5 cases of hyperplasia. CT scanning may be used alone to confirm the cause of hyperaldosteronism where postural studies suggest an adrenal adenoma, and such patients may be considered for early surgery. 21 refs

  9. 40 CFR 89.507 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing § 89.507 Sample selection. (a) Engines comprising a test sample will be selected at the location...). However, once the manufacturer ships any test engine, it relinquishes the prerogative to conduct retests...

  10. 40 CFR 90.507 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing § 90.507 Sample selection. (a) Engines comprising a test sample will be selected at the location... manufacturer ships any test engine, it relinquishes the prerogative to conduct retests as provided in § 90.508...

  11. Comparison of two analyzers to determine selected venous blood analytes of Quaker parrots (Myiopsitta monachus).

    Science.gov (United States)

    Rettenmund, Christy L; Heatley, J Jill; Russell, Karen E

    2014-06-01

    Point of care devices can assess electrolyte, blood gas, biochemical, and hematologic values in a critical care setting. Although these devices are commonly used in humans and companion mammals, few studies have assessed their use in avian species. This study compares electrolyte, hemoglobin (Hgb), hematocrit (Hct), acid-base, and venous blood gas parameters between the i-STAT and IRMA TruPoint blood gas analysis systems for 35 Quaker parrots. Agreement between the two analyzers and the effect of gender, time lag between sample analysis, and cartridge expiration were evaluated. Male birds had increased Hgb and Hct compared with females, independent of analyzer method. In expired i-STAT cartridges, only glucose significantly increased. Packed cell volume determined by centrifugation was higher than Hct, as calculated by either analyzer. The analyzers had good agreement for total carbon dioxide, bicarbonate, pH, and Hgb, fair agreement for potassium (K), ionized calcium (iCa), venous partial pressure of carbon dioxide, and base excess, and poor agreement for sodium (Na), venous partial pressure of oxygen (PO2), and oxygen saturation (SO2). Values for Na, iCa, PO2, and SO2 were significantly higher on the IRMA than the i-STAT, while K was significantly lower on the IRMA when compared with the i-STAT. The time lag between sample analyses on the i-STAT and IRMA did not be correlate to any analyte changes. Despite these differences, both the i-STAT and the IRMA appear to be acceptable clinical tools in avian critical care, although reference ranges for each analyzer should be created.

  12. Successful Adrenal Venous Sampling by Non-experts with Reference to CT Images

    International Nuclear Information System (INIS)

    Morita, Satoru; Yamazaki, Hiroshi; Sonoyama, Yasuyuki; Nishina, Yu; Ichihara, Atsuhiro; Sakai, Shuji

    2016-01-01

    PurposeTo establish technical success rates and safety of adrenal venous sampling (AVS) performed by non-experts with reference to CT images.Materials and Methods104 AVS procedures with adrenocorticotropic hormone stimulation were performed for patients with suspected primary aldosteronism. One of three radiology residents with 2nd, 5th, and 5th grade experience undertook the procedure under the guidance of an experienced, board-certified interventional radiologist with reference to contrast-enhanced CT images obtained in 102 cases. Successful catheterization of the adrenal veins was assessed using three criteria: an adrenal venous cortisol concentration of more than 200 μg/dL (criterion A); an adrenal vein/inferior vena cava cortisol ratio of more than 5:1 (criterion B); and an adrenal vein/inferior vena cava cortisol ratio of more than 10:1 (criterion C).ResultsThe operators were aware of the anatomy of the left adrenal veins in 102 cases (98 %) and of the right adrenal veins in 99 cases (95 %) prior to the procedure. CT identified the correct position of the right adrenal vein orifice in 82 of 99 cases (83 %). The overall technical success rates for AVS from the right adrenal vein according to criteria A, B, and C, were 96, 96, and 94 %, respectively. Those for the left adrenal vein were 97, 98, and 94 %, respectively. No significant differences in success rates were observed between the operators (p = 0.922–0.984). No major complications, including adrenal vein rupture, were observed.ConclusionsWhen CT images are used to guide AVS, the procedure can be performed successfully and safely even by non-experts.

  13. Successful Adrenal Venous Sampling by Non-experts with Reference to CT Images

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Satoru, E-mail: i@imodey.com; Yamazaki, Hiroshi; Sonoyama, Yasuyuki; Nishina, Yu [Tokyo Women’s Medical University Hospital, Department of Diagnostic Imaging and Nuclear Medicine (Japan); Ichihara, Atsuhiro [Tokyo Women’s Medical University Hospital, Department of Medicine II, Endocrinology and Hypertension (Japan); Sakai, Shuji [Tokyo Women’s Medical University Hospital, Department of Diagnostic Imaging and Nuclear Medicine (Japan)

    2016-07-15

    PurposeTo establish technical success rates and safety of adrenal venous sampling (AVS) performed by non-experts with reference to CT images.Materials and Methods104 AVS procedures with adrenocorticotropic hormone stimulation were performed for patients with suspected primary aldosteronism. One of three radiology residents with 2nd, 5th, and 5th grade experience undertook the procedure under the guidance of an experienced, board-certified interventional radiologist with reference to contrast-enhanced CT images obtained in 102 cases. Successful catheterization of the adrenal veins was assessed using three criteria: an adrenal venous cortisol concentration of more than 200 μg/dL (criterion A); an adrenal vein/inferior vena cava cortisol ratio of more than 5:1 (criterion B); and an adrenal vein/inferior vena cava cortisol ratio of more than 10:1 (criterion C).ResultsThe operators were aware of the anatomy of the left adrenal veins in 102 cases (98 %) and of the right adrenal veins in 99 cases (95 %) prior to the procedure. CT identified the correct position of the right adrenal vein orifice in 82 of 99 cases (83 %). The overall technical success rates for AVS from the right adrenal vein according to criteria A, B, and C, were 96, 96, and 94 %, respectively. Those for the left adrenal vein were 97, 98, and 94 %, respectively. No significant differences in success rates were observed between the operators (p = 0.922–0.984). No major complications, including adrenal vein rupture, were observed.ConclusionsWhen CT images are used to guide AVS, the procedure can be performed successfully and safely even by non-experts.

  14. C-Arm Computed Tomography-Assisted Adrenal Venous Sampling Improved Right Adrenal Vein Cannulation and Sampling Quality in Primary Aldosteronism.

    Science.gov (United States)

    Park, Chung Hyun; Hong, Namki; Han, Kichang; Kang, Sang Wook; Lee, Cho Rok; Park, Sungha; Rhee, Yumie

    2018-05-04

    Adrenal venous sampling (AVS) is a gold standard for subtype classification of primary aldosteronism (PA). However, this procedure has a high failure rate because of the anatomical difficulties in accessing the right adrenal vein. We investigated whether C-arm computed tomography-assisted AVS (C-AVS) could improve the success rate of adrenal sampling. A total of 156 patients, diagnosed with PA who underwent AVS from May 2004 through April 2017, were included. Based on the medical records, we retrospectively compared the overall, left, and right catheterization success rates of adrenal veins during the periods without C-AVS (2004 to 2010, n=32) and with C-AVS (2011 to 2016, n=134). The primary outcome was adequate bilateral sampling defined as a selectivity index (SI) >5. With C-AVS, the rates of adequate bilateral AVS increased from 40.6% to 88.7% (PAVS was an independent predictor of adequate bilateral sampling in the multivariate model (odds ratio, 9.01; PAVS improved the overall success rate of AVS, possibly as a result of better catheterization of right adrenal vein. Copyright © 2018 Korean Endocrine Society.

  15. Adrenal hormones before and after venography during adrenal venous sampling: a self-controlled study.

    Science.gov (United States)

    Koike, Yuya; Matsui, Seishi; Omura, Masao; Makita, Kohzoh; Obara, Alfonso W D; Moriya, Nobukazu; Nishikawa, Tetsuo

    2017-03-01

    A stress reaction involving increased adrenal hormone release occurs when starting adrenal venous sampling (AVS). The purpose of the present study was to investigate the effect of single shot venography on adrenal hormone production during AVS. This was a prospective self-controlled study. We enrolled 54 consecutive patients (21 men, 33 women; mean age 52 ± 11 years) with primary aldosteronism who underwent AVS from May 2014 to February 2015. Under non-stimulated conditions, blood samples were obtained from a common trunk of the left adrenal vein before and after single shot venography. The initial plasma aldosterone and cortisol concentration (PAC and PCC) were compared with those measured after venography for each patient. PAC and PCC were slightly but significantly decreased between before and after venography (after log transformation 2.12 ± 0.73 vs 2.07 ± 0.72, P = 0.00066, 1.89 ± 0.52 vs 1.83 ± 0.53, P = 0.00031, respectively). During non-stimulated left AVS, adrenal hormone secretion was slightly but significantly decreased after venography, similar to the normal time-related stress reaction. Venography did not increase the adrenal hormone secretion.

  16. A Novel Method of Adrenal Venous Sampling via an Antecubital Approach

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiongjing, E-mail: jxj103@hotmail.com; Dong, Hui; Peng, Meng; Che, Wuqiang; Zou, Yubao; Song, Lei; Zhang, Huimin; Wu, Haiying [Chinese Academy of Medical Sciences and Peking Union Medical College, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease (China)

    2017-03-15

    PurposeCurrently, almost all adrenal venous sampling (AVS) procedures are performed by femoral vein access. The purpose of this study was to establish the technique of AVS via an antecubital approach and evaluate its safety and feasibility.Materials and MethodsFrom January 2012 to June 2015, 194 consecutive patients diagnosed as primary aldosteronism underwent AVS via an antecubital approach without ACTH simulation. Catheters used for bilateral adrenal cannulations were recorded. The success rate of bilateral adrenal sampling, operation time, fluoroscopy time, dosage of contrast, and incidence of complications were calculated.ResultsA 5F MPA1 catheter was first used to attempt right adrenal cannulation in all patients. Cannulation of the right adrenal vein was successfully performed in 164 (84.5%) patients. The 5F JR5, Cobra2, and TIG catheters were the ultimate catheters for right adrenal cannulation in 16 (8.2%), 5 (2.6%), and 9 (4.6%) patients, respectively. For left adrenal cannulation, JR5 and Cobra2 catheters were used in 19 (9.8%) and 10 (5.2%) patients, respectively, while only TIG catheters were used in the remaining 165 (85.1%) patients. The rate of successful adrenal sampling on the right, left, and bilateral sides was 91.8%, 93.3%, and 87.6%, respectively. The mean time of operation was (16.3 ± 4.3) minutes, mean fluoroscopy time was (4.7 ± 1.3) minutes, and the mean use of contrast was (14.3 ± 4.7) ml. The incidence of adrenal hematoma was 1.0%.ConclusionsThis study showed that AVS via an antecubital approach was safe and feasible, with a high rate of successful sampling.

  17. Is it useful to repeat an adrenal venous sampling in patients with primary hyperaldosteronism?

    Science.gov (United States)

    Bouhanick, B; Delchier, M-C; Fauvel, J; Rousseau, H; Amar, J; Chamontin, B

    2014-02-01

    Adrenal venous sampling (AVS) is a challenging technical procedure and few patients had AVS procedure twice. To evaluate the reproducibility of the AVS, why AVS were repeated and the conclusions drawn from them. From 1997-2012, 12 patients underwent two AVS. A cortisol level in the adrenal vein greater than or equal to 1.1 to inferior vena cava defined a successful catheterization and a lateralization of secretion corresponded to an aldosterone-to-cortisol vein ratio greater than or equal to 2 between the one side to another. The same side of lateralization of secretion was found in 75% of them. The second AVS were due to technical failure (n=4), unproven lateralization (n=2), a lateralization opposite to the main nodule and ipsilateral to hyperplasia (n=4) on first AVS. For two patients, as the CT was normal, AVS was required again. The second AVS was successful in all patients, including those with an initial technical failure but only patient with technical failure underwent surgery, as BP and kaliemia were controlled. Lateralization on the side of hyperplasia or opposite to the biggest nodule was confirmed in two of four cases. When AVS is unsuccessful for technical reasons, it is worth doing it again but after being sure that surgery is still possibly indicated. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  18. Hypocalcemic stimulation and nonselective venous sampling for localizing parathyroid adenomas: work in progress.

    Science.gov (United States)

    Doppman, J L; Skarulis, M C; Chang, R; Alexander, H R; Bartlett, D; Libutti, S K; Marx, S J; Spiegel, A M

    1998-07-01

    To evaluate whether the release of parathyroid hormone (PTH) from parathyroid tumors during selective parathyroid arteriography can help localize the tumors. In 20 patients (six men, 14 women; age range, 24-72 years) with parathyroid tumors undergoing parathyroid arteriography after failed surgery, serial measurements of PTH were obtained during selective arteriography with nonionic contrast material. PTH levels were measured in the superior vena cava (SVC) before and at varying times from 20 to 120 seconds after arteriography. A 1.4-fold increase in the PTH level of the postarteriographic SVC samples enabled correct prediction of the site of adenoma in 13 of the 20 patients (65%). Of nine patients with positive arteriograms, eight had positive results of postarteriographic sampling. Of 11 patients with negative arteriograms, five had positive results of postarteriographic sampling. Sampling the SVC for PTH gradients after selective parathyroid arteriography correctly indicated the site of the adenoma in 13 of 20 patients (65%).

  19. [Usefulness of arterial calcium stimulation with hepatic venous sampling in the localization diagnosis of endogenous hyperinsulinism].

    Science.gov (United States)

    Moreno Moreno, Paloma; Gutiérrez Alcántara, Carmen; Muñoz-Villanueva, María Del Carmen; Ortega, Rafael Palomares; Corpas Jiménez, María del Sierra; Zurera Tendero, Luis; Benito López, Pedro

    2010-03-01

    The aim of this study was to assess the utility of arterial calcium stimulation with hepatic venous sampling (ASVS) in the localization of tumors in patients with endogenous hyperinsulinism not detected with other methods. We performed a retrospective study of 26 patients admitted to our hospital for hypoglycemia who underwent ASVS because the source of hyperinsulinism was not clearly identified by other imaging techniques. The histopathological result in patients who underwent a surgical procedure was considered the reference for statistical study of the accuracy of this technique. Statistical analysis was performed by comparing proportions with the chi-squared test with Yates' correction for contingency tables, and Cohen's kappa coefficient as a measure of interrater agreement between two observations. Surgery was performed in 17 patients, 13 with positive ASVS and the remaining four with negative results. An insulinoma was removed in 12 patients, and 10 of these were detected in the ASVS. A total of 76.9 % of positive ASVS tests corresponded to a histological diagnosis of insulinoma, and 83% of these insulinomas were positive in ASVS. This association was statistically significant (chi cuadrado=7.340; p=0.012). Two of three patients with nesidioblastosis had a positive response in the ASVS. A good and statistically significant agreement was obtained between histopathologic diagnosis and ASVS results (kappa=0.556, p = 0.007). ASVS is a useful procedure in the localization diagnosis of endogenous hyperinsulinism not detected by other imaging tests. This technique allows tumors in the pancreatic gland to be identified and may be useful in the choice of the surgical technique to be used. Copyright 2009 SEEN. Published by Elsevier Espana. All rights reserved.

  20. Reduction of Radiation Exposure Using Dynamic Trace Digital Angiography and Spot Fluoroscopy During Adrenal Venous Sampling

    International Nuclear Information System (INIS)

    Morita, Satoru; Endo, Kenji; Suzaki, Shingo; Ishizaki, Umiko; Yamazaki, Hiroshi; Nishina, Yu; Sakai, Shuji

    2017-01-01

    PurposeTo compare radiation exposure of adrenal venous sampling (AVS) using dynamic trace digital angiography (DTDA) and spot fluoroscopy with that using conventional methods.Materials and MethodsAVS was performed in 11 patients using DTDA and spot fluoroscopy (Group A) and 11 patients using conventional digital subtraction angiography (DSA) with collimation (Group B). Radiation exposure and image quality of adrenal venography using a five-point scale were compared between the groups.ResultsThe acquisition dose–area product (DAP) using DTDA and fluoro-DAP using spot fluoroscopy in Group A were lower than those using conventional DSA (5.3 ± 3.7 vs. 29.1 ± 20.1 Gy cm"2, p < 0.001) and collimation (33.3 ± 22.9 vs. 59.1 ± 35.7 Gy cm"2, p = 0.088) in Group B. The total DAP in Group A was significantly lower than that in Group B (38.6 ± 25.9 vs. 88.2 ± 53.6 Gy cm"2, p = 0.006). The peak skin dose for patients and operator radiation exposure in Group A were significantly lower than those in Group B (403 ± 340 vs. 771 ± 416 mGy, p = 0.030, and 17.1 ± 14.8 vs. 36.6 ± 21.7 μSv, p = 0.013). The image quality of DTDA (4.4 ± 0.6) was significantly higher than that of digital angiography (3.8 ± 0.9, p = 0.011) and equivalent to that of DSA (4.3 ± 0.8, p = 0.651).ConclusionsRadiation exposure during AVS can be reduced by approximately half for both patients and operators by using DTDA and spot fluoroscopy without sacrificing image quality.

  1. Reduction of Radiation Exposure Using Dynamic Trace Digital Angiography and Spot Fluoroscopy During Adrenal Venous Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Satoru, E-mail: i@imodey.com; Endo, Kenji; Suzaki, Shingo; Ishizaki, Umiko; Yamazaki, Hiroshi; Nishina, Yu; Sakai, Shuji [Tokyo Women’s Medical University Hospital, Department of Diagnostic Imaging and Nuclear Medicine (Radiology) (Japan)

    2017-05-15

    PurposeTo compare radiation exposure of adrenal venous sampling (AVS) using dynamic trace digital angiography (DTDA) and spot fluoroscopy with that using conventional methods.Materials and MethodsAVS was performed in 11 patients using DTDA and spot fluoroscopy (Group A) and 11 patients using conventional digital subtraction angiography (DSA) with collimation (Group B). Radiation exposure and image quality of adrenal venography using a five-point scale were compared between the groups.ResultsThe acquisition dose–area product (DAP) using DTDA and fluoro-DAP using spot fluoroscopy in Group A were lower than those using conventional DSA (5.3 ± 3.7 vs. 29.1 ± 20.1 Gy cm{sup 2}, p < 0.001) and collimation (33.3 ± 22.9 vs. 59.1 ± 35.7 Gy cm{sup 2}, p = 0.088) in Group B. The total DAP in Group A was significantly lower than that in Group B (38.6 ± 25.9 vs. 88.2 ± 53.6 Gy cm{sup 2}, p = 0.006). The peak skin dose for patients and operator radiation exposure in Group A were significantly lower than those in Group B (403 ± 340 vs. 771 ± 416 mGy, p = 0.030, and 17.1 ± 14.8 vs. 36.6 ± 21.7 μSv, p = 0.013). The image quality of DTDA (4.4 ± 0.6) was significantly higher than that of digital angiography (3.8 ± 0.9, p = 0.011) and equivalent to that of DSA (4.3 ± 0.8, p = 0.651).ConclusionsRadiation exposure during AVS can be reduced by approximately half for both patients and operators by using DTDA and spot fluoroscopy without sacrificing image quality.

  2. The quantitative regional cerebral blood flow measurement with autoradiography method using 123I-IMP SPECT. Evaluation of arterialized venous blood sampling as a substitute for arterial blood sampling

    International Nuclear Information System (INIS)

    Ohnishi, Takashi; Yano, Takao; Nakano, Shinichi; Jinnouchi, Seishi; Nagamachi, Shigeki; Flores, L. II; Nakahara, Hiroshi; Watanabe, Katsushi.

    1996-01-01

    The purpose of this study is validation of calibrating a standard input function in autoradiography (ARG) method by one point venous blood sampling as a substitute for that by one point arterial blood sampling. Ten and 20 minutes after intravenous constant infusion of 123 I-IMP, arterialized venous blood sampling from a dorsal vein were performed on 15 patients having ischemic cerebrovascular disease. And arterial blood sampling from radial artery was performed 10 min after 123 I-IMP infusion. The mean difference rates of integrated input function between calibrated standard input function by arterial blood sampling at 10 min and that by venous blood sampling were 4.1±3% and 9.3±5.4% at 10 and 20 min after 123 I-IMP infusion, respectively. The ratio of venous blood radioactivity to arterial blood radioactivity at 10 min after 123 I-IMP infusion was 0.96±0.02. There was an excellent correlation between ARG method CBF values obtained by arterial blood sampling at 10 min and those obtained by arterialized venous blood sampling at 10 min. In conclusion, a substitution by arterialized venous blood sampling from dorsal hand vein for artery can be possible. The optimized time for arterialized venous blood sampling was 10 min after 123 I-IMP infusion. (author)

  3. Sample Selection for Training Cascade Detectors.

    Science.gov (United States)

    Vállez, Noelia; Deniz, Oscar; Bueno, Gloria

    2015-01-01

    Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our attention on a negative sample selection method to properly balance the training data for cascade detectors. The method is based on the selection of the most informative false positive samples generated in one stage to feed the next stage. The results show that the proposed cascade detector with sample selection obtains on average better partial AUC and smaller standard deviation than the other compared cascade detectors.

  4. Sample Selection for Training Cascade Detectors.

    Directory of Open Access Journals (Sweden)

    Noelia Vállez

    Full Text Available Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our attention on a negative sample selection method to properly balance the training data for cascade detectors. The method is based on the selection of the most informative false positive samples generated in one stage to feed the next stage. The results show that the proposed cascade detector with sample selection obtains on average better partial AUC and smaller standard deviation than the other compared cascade detectors.

  5. Comparison of C-arm computed tomography and on-site quick cortisol assay for adrenal venous sampling: A retrospective study of 178 patients.

    Science.gov (United States)

    Chang, Chin-Chen; Lee, Bo-Ching; Chang, Yeun-Chung; Wu, Vin-Cent; Huang, Kuo-How; Liu, Kao-Lang

    2017-12-01

    To compare the performance of on-site quick cortisol assay (QCA) and C-arm computed tomography (CT) assistance on adrenal venous sampling (AVS) without adrenocorticotropic hormone stimulation. The institutional review board at our hospital approved this retrospective study, which included 178 consecutive patients with primary aldosteronism. During AVS, we used C-arm CT to confirm right adrenal cannulation between May 2012 and June 2015 (n = 100) and QCA for bilateral adrenal cannulation between July 2015 and September 2016 (n = 78). Successful AVS required a selectivity index (cortisol adrenal vein /cortisol peripheral ) of ≥ 2.0 bilaterally. The overall success rate of C-arm CT-assisted AVS was 87%, which increased to 97.4% under QCA (P = .013). The procedure time (C-arm CT, 49.5 ± 21.3 min; QCA, 37.5 ± 15.6 min; P AVS. • Adrenal venous sampling (AVS) is a technically challenging procedure. • C-arm CT and quick cortisol assay (QCA) are efficient for assisting AVS. • QCA might outperform C-arm CT in enhancing AVS performance.

  6. Is selective internal radioembolization safe and effective for patients with inoperable hepatocellular carcinoma and venous thrombosis?

    Science.gov (United States)

    Woodall, Charles E; Scoggins, Charles R; Ellis, Susan F; Tatum, Clifton M; Hahl, Michael J; Ravindra, Kadiyala V; McMasters, Kelly M; Martin, Robert C G

    2009-03-01

    The goal of this study was to examine the safety and efficacy of selective internal radioembolization (SIR) for hepatocellular carcinoma (HCC) with portal vein or caval thrombosis (VT), or both. Recent reports have demonstrated that SIR is safe for patients with HCC, but the impact on efficacy of venous thrombosis is unknown. Prospective single-arm study of the use of Therasphere in patients with unresectable HCC enrolled from January 2004 to June 2007. Patients were categorized into three groups based on VT status and therapy. Fifty-two patients were enrolled: 20 patients without VT who received SIR, 15 patients with VT who were treated, and 17 patients (10 with VT) who were not treated because of preprocedure screening failure. Fifty-eight treatments were administered, with a median of two treatments per patient (range of one to three treatments). Child's score was different between groups. Of the VT patients treated, 67% had portal VT, 7% had cava VT, and 26% had both. There were no treatment-related deaths. There was no difference in complications among groups (p = 0.34). Treated patients without thrombosis had a median overall survival of 13.9 months versus 2.7 months for those treated with thrombosis and 5.2 months for the untreated group given best supportive care only (p = 0.01). SIR is safe in patients with HCC. Although SIR can be delivered with minimal morbidity, there might be no benefit for patients with VT. Continued emphasis on multimodality therapy in this population is needed to improve survival.

  7. Measurement of regional cerebral blood flow using one-point venous blood sampling and causality model. Evaluation by comparing with conventional continuous arterial blood sampling method

    International Nuclear Information System (INIS)

    Mimura, Hiroaki; Sone, Teruki; Takahashi, Yoshitake

    2008-01-01

    Optimal setting of the input function is essential for the measurement of regional cerebral blood flow (rCBF) based on the microsphere model using N-isopropyl-4-[ 123 I]iodoamphetamine ( 123 I-IMP), and usually the arterial 123 I-IMP concentration (integral value) in the initial 5 min is used for this purpose. We have developed a new convenient method in which 123 I-IMP concentration in arterial blood sample is estimated from that in venous blood sample. Brain perfusion single photon emission computed tomography (SPECT) with 123 I-IMP was performed in 110 cases of central nervous system disorders. The causality was analyzed between the various parameters of SPECT data and the ratio of octanol-extracted arterial radioactivity concentration during the first 5 min (Caoct) to octanol-extracted venous radioactivity concentration at 27 min after intravenous injection of 123 I-IMP (Cvoct). A high correlation was observed between the measured and estimated values of Caoct/Cvoct (r=0.856) when the following five parameters were included in the regression formula: radioactivity concentration in venous blood sampled at 27 min (Cv), Cvoct, Cvoct/Cv, and total brain radioactivity counts that were measured by a four-head gamma camera 5 min and 28 min after 123 I-IMP injection. Furthermore, the rCBF values obtained using the input parameters estimated by this method were also highly correlated with the rCBF values measured using the continuous arterial blood sampling method (r=0.912). These results suggest that this method would serve as the new, convenient and less invasive method of rCBF measurement in clinical setting. (author)

  8. Effect of prewarming the forearm on the measurement of regional cerebral blood flow with one-point venous sampling by autoradiography method

    International Nuclear Information System (INIS)

    Itoh, Youko H.; Kurabe, Teruhisa; Kazaoka, Yoshiaki; Ishiguchi, Tsuneo; Kawashima, Sadao

    2004-01-01

    Autoradiography (ARG) using 123 I-iodoamphetamine ( 123 I-IMP) is widely performed as an efficient method of measuring local cerebral blood flow. Recently, ARG by a single collection of venous blood has been appreciated as a simple method. In this study, we investigated the effect of warming of the site for collecting venous blood (forearm). The coefficient of correlation of the local cerebral blood flow value obtained from arterial and venous blood samples was 0.766 (p<0.05) in the group without warming (38 patients). The coefficient of correlation similarly obtained in the group with warming (53 patients) was 0.908 (p<0.05). The difference in the correlation efficient was significant (p<0.05) between the two groups. From these results it was concluded that warming the blood-collecting site decreased the difference between the arterial and venous radioactive concentrations and increased the precision of the test. (author)

  9. Robust inference in sample selection models

    KAUST Repository

    Zhelonkin, Mikhail; Genton, Marc G.; Ronchetti, Elvezio

    2015-01-01

    The problem of non-random sample selectivity often occurs in practice in many fields. The classical estimators introduced by Heckman are the backbone of the standard statistical analysis of these models. However, these estimators are very sensitive to small deviations from the distributional assumptions which are often not satisfied in practice. We develop a general framework to study the robustness properties of estimators and tests in sample selection models. We derive the influence function and the change-of-variance function of Heckman's two-stage estimator, and we demonstrate the non-robustness of this estimator and its estimated variance to small deviations from the model assumed. We propose a procedure for robustifying the estimator, prove its asymptotic normality and give its asymptotic variance. Both cases with and without an exclusion restriction are covered. This allows us to construct a simple robust alternative to the sample selection bias test. We illustrate the use of our new methodology in an analysis of ambulatory expenditures and we compare the performance of the classical and robust methods in a Monte Carlo simulation study.

  10. Robust inference in sample selection models

    KAUST Repository

    Zhelonkin, Mikhail

    2015-11-20

    The problem of non-random sample selectivity often occurs in practice in many fields. The classical estimators introduced by Heckman are the backbone of the standard statistical analysis of these models. However, these estimators are very sensitive to small deviations from the distributional assumptions which are often not satisfied in practice. We develop a general framework to study the robustness properties of estimators and tests in sample selection models. We derive the influence function and the change-of-variance function of Heckman\\'s two-stage estimator, and we demonstrate the non-robustness of this estimator and its estimated variance to small deviations from the model assumed. We propose a procedure for robustifying the estimator, prove its asymptotic normality and give its asymptotic variance. Both cases with and without an exclusion restriction are covered. This allows us to construct a simple robust alternative to the sample selection bias test. We illustrate the use of our new methodology in an analysis of ambulatory expenditures and we compare the performance of the classical and robust methods in a Monte Carlo simulation study.

  11. Selective Retrograde Venous Revascularization of the Myocardium when PCI or CABG Is Impossible: Investigation in a Porcine Model

    DEFF Research Database (Denmark)

    Møller, Christian H; Nørgaard, Martin A; Gøtze, Jens P

    2008-01-01

    We investigated the possibility of nourishing the myocardium through selective retrograde coronary venous bypass grafting (CVBG) with an off-pump technique and evaluated various methods of monitoring the physiological effects of this procedure. In a porcine model, the left internal mammary artery...... tension decreased, but with time some recovery was seen. Cardiac troponin T was elevated. Histological analysis showed ischemic changes. In control pigs, microdialysis was performed for 1.5 hours up to LAD artery ligation, after which all pigs died in ventricular fibrillation arrest. No increase...

  12. Privacy problems in the small sample selection

    Directory of Open Access Journals (Sweden)

    Loredana Cerbara

    2013-05-01

    Full Text Available The side of social research that uses small samples for the production of micro data, today finds some operating difficulties due to the privacy law. The privacy code is a really important and necessary law because it guarantees the Italian citizen’s rights, as already happens in other Countries of the world. However it does not seem appropriate to limit once more the possibilities of the data production of the national centres of research. That possibilities are already moreover compromised due to insufficient founds is a common problem becoming more and more frequent in the research field. It would be necessary, therefore, to include in the law the possibility to use telephonic lists to select samples useful for activities directly of interest and importance to the citizen, such as the collection of the data carried out on the basis of opinion polls by the centres of research of the Italian CNR and some universities.

  13. Sample size estimation and sampling techniques for selecting a representative sample

    Directory of Open Access Journals (Sweden)

    Aamir Omair

    2014-01-01

    Full Text Available Introduction: The purpose of this article is to provide a general understanding of the concepts of sampling as applied to health-related research. Sample Size Estimation: It is important to select a representative sample in quantitative research in order to be able to generalize the results to the target population. The sample should be of the required sample size and must be selected using an appropriate probability sampling technique. There are many hidden biases which can adversely affect the outcome of the study. Important factors to consider for estimating the sample size include the size of the study population, confidence level, expected proportion of the outcome variable (for categorical variables/standard deviation of the outcome variable (for numerical variables, and the required precision (margin of accuracy from the study. The more the precision required, the greater is the required sample size. Sampling Techniques: The probability sampling techniques applied for health related research include simple random sampling, systematic random sampling, stratified random sampling, cluster sampling, and multistage sampling. These are more recommended than the nonprobability sampling techniques, because the results of the study can be generalized to the target population.

  14. Mineral Composition of Selected Serbian Propolis Samples

    Directory of Open Access Journals (Sweden)

    Tosic Snezana

    2017-06-01

    Full Text Available The aim of this work was to determine the content of 22 macro- and microelements in ten raw Serbian propolis samples which differ in geographical and botanical origin as well as in polluted agent contents by atomic emission spectrometry with inductively coupled plasma (ICP-OES. The macroelements were more common and present Ca content was the highest while Na content the lowest. Among the studied essential trace elements Fe was the most common element. The levels of toxic elements (Pb, Cd, As and Hg were also analyzed, since they were possible environmental contaminants that could be transferred into propolis products for human consumption. As and Hg were not detected in any of the analyzed samples but a high level of Pb (2.0-9.7 mg/kg was detected and only selected portions of raw propolis could be used to produce natural medicines and dietary supplements for humans. Obtained results were statistically analyzed, and the examined samples showed a wide range of element content.

  15. Use of Capillary Blood Samples Leads to Higher Parasitemia Estimates and Higher Diagnostic Sensitivity of Microscopic and Molecular Diagnostics of Malaria than Venous Blood Samples.

    Science.gov (United States)

    Mischlinger, Johannes; Pitzinger, Paul; Veletzky, Luzia; Groger, Mirjam; Zoleko-Manego, Rella; Adegnika, Ayola A; Agnandji, Selidji T; Lell, Bertrand; Kremsner, Peter G; Tannich, Egbert; Mombo-Ngoma, Ghyslain; Mordmüller, Benjamin; Ramharter, Michael

    2018-05-25

    Diagnosis of malaria is usually based on samples of peripheral blood. However, it is unclear whether capillary (CAP) or venous (VEN) blood samples provide better diagnostic performance. Quantitative differences of parasitemia between CAP and VEN blood and diagnostic performance characteristics were investigated. Patients were recruited between September 2015 and February 2016 in Gabon. Light microscopy and qPCR quantified parasitemia of paired CAP and VEN samples, whose preparation followed the exact same methodology. CAP and VEN performance characteristics using microscopy were evaluated against a qPCR gold-standard. Microscopy revealed a median (IQR) parasites/L of 495 (853,243) in CAP and 429 (524,074) in VEN samples manifesting in a +16.6% (p=0.04) higher CAPparasitemia compared with VENparasitemia. Concordantly, qPCR demonstrated that -0.278 (p=0.006) cycles were required for signal detection in CAP samples. CAPsensitivity of microscopy relative to the gold-standard was 81.5% (77.485.6%) versus VENsensitivity of 73.4% (68.878.1%), while CAPspecificity and VENspecificity were 91%. CAPsensitivity and VENsensitivity dropped to 63.3% and 45.9%, respectively for a sub-population of low-level parasitemias while specificities were 92%. CAP sampling leads to higher parasitemias compared to VEN sampling and improves diagnostic sensitivity. These findings may have important implications for routine diagnostics, research and elimination campaigns of malaria.

  16. Blood venous sample collection: Recommendations overview and a checklist to improve quality.

    Science.gov (United States)

    Giavarina, Davide; Lippi, Giuseppe

    2017-07-01

    The extra-analytical phases of the total testing process have substantial impact on managed care, as well as an inherent high risk of vulnerability to errors which is often greater than that of the analytical phase. The collection of biological samples is a crucial preanalytical activity. Problems or errors occurring shortly before, or soon after, this preanalytical step may impair sample quality and characteristics, or else modify the final results of testing. The standardization of fasting requirements, rest, patient position and psychological state of the patient are therefore crucial for mitigating the impact of preanalytical variability. Moreover, the quality of materials used for collecting specimens, along with their compatibility, can guarantee sample quality and persistence of chemical and physical characteristics of the analytes over time, so safeguarding the reliability of testing. Appropriate techniques and sampling procedures are effective to prevent problems such as hemolysis, undue clotting in the blood tube, draw of insufficient sample volume and modification of analyte concentration. An accurate identification of both patient and blood samples is a key priority as for other healthcare activities. Good laboratory practice and appropriate training of operators, by specifically targeting collection of biological samples, blood in particular, may greatly improve this issue, thus lowering the risk of errors and their adverse clinical consequences. The implementation of a simple and rapid check-list, including verification of blood collection devices, patient preparation and sampling techniques, was found to be effective for enhancing sample quality and reducing some preanalytical errors associated with these procedures. The use of this tool, along with implementation of objective and standardized systems for detecting non-conformities related to unsuitable samples, can be helpful for standardizing preanalytical activities and improving the quality of

  17. Acceptance sampling using judgmental and randomly selected samples

    Energy Technology Data Exchange (ETDEWEB)

    Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

    2010-09-01

    We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

  18. A NEW CLINICAL PREDICTION CRITERION ACCURATELY DETERMINES A SUBSET OF PATIENTS WITH BILATERAL PRIMARY ALDOSTERONISM BEFORE ADRENAL VENOUS SAMPLING.

    Science.gov (United States)

    Kocjan, Tomaz; Janez, Andrej; Stankovic, Milenko; Vidmar, Gaj; Jensterle, Mojca

    2016-05-01

    Adrenal venous sampling (AVS) is the only available method to distinguish bilateral from unilateral primary aldosteronism (PA). AVS has several drawbacks, so it is reasonable to avoid this procedure when the results would not affect clinical management. Our objective was to identify a clinical criterion that can reliably predict nonlateralized AVS as a surrogate for bilateral PA that is not treated surgically. A retrospective diagnostic cross-sectional study conducted at Slovenian national endocrine referral center included 69 consecutive patients (mean age 56 ± 8 years, 21 females) with PA who underwent AVS. PA was confirmed with the saline infusion test (SIT). AVS was performed sequentially during continuous adrenocorticotrophic hormone (ACTH) infusion. The main outcome measures were variables associated with nonlateralized AVS to derive a clinical prediction rule. Sixty-seven (97%) patients had a successful AVS and were included in the statistical analysis. A total of 39 (58%) patients had nonlateralized AVS. The combined criterion of serum potassium ≥3.5 mmol/L, post-SIT aldosterone AVS. The best overall classification accuracy (50/67 = 75%) was achieved using the post-SIT aldosterone level AVS. Our clinical prediction criterion appears to accurately determine a subset of patients with bilateral PA who could avoid unnecessary AVS and immediately commence with medical treatment.

  19. Comparison of C-arm computed tomography and on-site quick cortisol assay for adrenal venous sampling: A retrospective study of 178 patients

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chin-Chen; Lee, Bo-Ching; Chang, Yeun-Chung; Liu, Kao-Lang [National Taiwan University Hospital and National Taiwan University College of Medicine, Department of Medical Imaging, Taipei (China); Wu, Vin-Cent [National Taiwan University Hospital and National Taiwan University College of Medicine, Department of Internal Medicine, Taipei (China); Huang, Kuo-How [National Taiwan University Hospital and National Taiwan University College of Medicine, Department of Urology, Taipei (China); Collaboration: on behalf of the TAIPAI Study Group

    2017-12-15

    To compare the performance of on-site quick cortisol assay (QCA) and C-arm computed tomography (CT) assistance on adrenal venous sampling (AVS) without adrenocorticotropic hormone stimulation. The institutional review board at our hospital approved this retrospective study, which included 178 consecutive patients with primary aldosteronism. During AVS, we used C-arm CT to confirm right adrenal cannulation between May 2012 and June 2015 (n = 100) and QCA for bilateral adrenal cannulation between July 2015 and September 2016 (n = 78). Successful AVS required a selectivity index (cortisol{sub adrenal} {sub vein}/cortisol{sub peripheral}) of ≥ 2.0 bilaterally. The overall success rate of C-arm CT-assisted AVS was 87%, which increased to 97.4% under QCA (P =.013). The procedure time (C-arm CT, 49.5 ± 21.3 min; QCA, 37.5 ± 15.6 min; P <.001) and radiation dose (C-arm CT, 673.9 ± 613.8 mGy; QCA, 346.4 ± 387.8 mGy; P <.001) were also improved. The resampling rate was 16% and 21.8% for C-arm CT and QCA, respectively. The initial success rate of the performing radiologist remained stable during the study period (C-arm CT 75%; QCA, 82.1%, P =.259). QCA might be superior to C-arm CT for improving the performance of AVS. (orig.)

  20. Automated sample plan selection for OPC modeling

    Science.gov (United States)

    Casati, Nathalie; Gabrani, Maria; Viswanathan, Ramya; Bayraktar, Zikri; Jaiswal, Om; DeMaris, David; Abdo, Amr Y.; Oberschmidt, James; Krause, Andreas

    2014-03-01

    It is desired to reduce the time required to produce metrology data for calibration of Optical Proximity Correction (OPC) models and also maintain or improve the quality of the data collected with regard to how well that data represents the types of patterns that occur in real circuit designs. Previous work based on clustering in geometry and/or image parameter space has shown some benefit over strictly manual or intuitive selection, but leads to arbitrary pattern exclusion or selection which may not be the best representation of the product. Forming the pattern selection as an optimization problem, which co-optimizes a number of objective functions reflecting modelers' insight and expertise, has shown to produce models with equivalent quality to the traditional plan of record (POR) set but in a less time.

  1. Heterogeneous Causal Effects and Sample Selection Bias

    DEFF Research Database (Denmark)

    Breen, Richard; Choi, Seongsoo; Holm, Anders

    2015-01-01

    The role of education in the process of socioeconomic attainment is a topic of long standing interest to sociologists and economists. Recently there has been growing interest not only in estimating the average causal effect of education on outcomes such as earnings, but also in estimating how...... causal effects might vary over individuals or groups. In this paper we point out one of the under-appreciated hazards of seeking to estimate heterogeneous causal effects: conventional selection bias (that is, selection on baseline differences) can easily be mistaken for heterogeneity of causal effects....... This might lead us to find heterogeneous effects when the true effect is homogenous, or to wrongly estimate not only the magnitude but also the sign of heterogeneous effects. We apply a test for the robustness of heterogeneous causal effects in the face of varying degrees and patterns of selection bias...

  2. Is there a role for segmental adrenal venous sampling and adrenal sparing surgery in patients with primary aldosteronism?

    Science.gov (United States)

    Satoh, Fumitoshi; Morimoto, Ryo; Seiji, Kazumasa; Satani, Nozomi; Ota, Hideki; Iwakura, Yoshitsugu; Ono, Yoshikiyo; Kudo, Masataka; Nezu, Masahiro; Omata, Kei; Tezuka, Yuta; Kawasaki, Yoshihide; Ishidoya, Shigeto; Arai, Yoichi; Takase, Kei; Nakamura, Yasuhiro; McNamara, Keely; Sasano, Hironobu; Ito, Sadayoshi

    2015-10-01

    Adrenal venous sampling (AVS) is critical to determine the subtype of primary aldosteronism (PA). Central AVS (C-AVS)--that is, the collection of effluents from bilateral adrenal central veins (CV)--sometimes does not allow differentiation between bilateral aldosterone-producing adenomas (APA) and idiopathic hyperaldosteronism. To establish the best treatment course, we have developed segmental AVS (S-AVS); that is, we collect effluents from the tributaries of CV to determine the intra-adrenal sources of aldosterone overproduction. We then evaluated the clinical utility of this novel approach in the diagnosis and treatment of PA. We performed C-AVS and/or S-AVS in 297 PA patients and assessed the accuracy of diagnosis based on the results of C-AVS (n=138, 46.5%) and S-AVS (n=159, 53.5%) by comparison with those of clinicopathological evaluation of resected specimens. S-AVS demonstrated both elevated and attenuated secretion of aldosterone from APA and non-tumorous segments, respectively, in patients with bilateral APA and recurrent APA. These findings were completely confirmed by detailed histopathological examination after surgery. S-AVS, but not C-AVS, also served to identify APA located distal from the CV. Compared to C-AVS, S-AVS served to identify APA in some patients, and its use should expand the pool of patients eligible for adrenal sparing surgery through the identification of unaffected segments, despite the fact that S-AVS requires more expertise and time. Especially, this new technique could enormously benefit patients with bilateral or recurrent APA because of the preservation of non-tumorous glandular tissue. © 2015 European Society of Endocrinology.

  3. Reversing the established order: Should adrenal venous sampling precede cross-sectional imaging in the evaluation of primary aldosteronism?

    Science.gov (United States)

    Asmar, Melissa; Wachtel, Heather; Yan, Yan; Fraker, Douglas L; Cohen, Debbie; Trerotola, Scott O

    2015-08-01

    Adrenal venous sampling (AVS) is the definitive evaluation for primary aldosteronism (PA). Pre-AVS cross-sectional imaging does not reduce the need for AVS. The goal of this study was to examine whether performing AVS prior to imaging could decrease the use of imaging in the evaluation of PA at a high volume, experienced center. We performed a retrospective analysis of all AVS procedures (n = 337) done for PA from 2001-2013. Patients whose cross-sectional imaging reports were unavailable (n = 90) or AVS was non-diagnostic (n = 12) were excluded. AVS was performed using modified Mayo technique. Univariate analysis utilized the χ² test and fisher's exact test. Of the 235 patients analyzed, 63% (n = 148) were male. The mean age was 55 ± 11 years. AVS was non-lateralizing in 43% (n = 101); these patients might have avoided imaging with an AVS-first approach. Imaging and AVS were concordant in 52% (n = 123). In patients ≤40yo (n = 23), 35% (n = 8) had no lateralization on AVS, and might have avoided imaging in an AVS-first approach. Imaging and AVS were concordant in 52% (n = 12) of patients ≤ 40yo, versus 52% (n = 111) of patients > 40 yo (P = 0.987). An AVS-first, imaging-second approach could have avoided CT/MRI in 43% of patients. At a high volume, experienced center, performing AVS first on patients with PA may reduce unnecessary cross-sectional imaging studies. © 2015 Wiley Periodicals, Inc.

  4. Sample Selection for Training Cascade Detectors

    OpenAIRE

    V?llez, Noelia; Deniz, Oscar; Bueno, Gloria

    2015-01-01

    Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our a...

  5. 40 CFR 205.171-3 - Test motorcycle sample selection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Test motorcycle sample selection. 205... ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycle Exhaust Systems § 205.171-3 Test motorcycle sample selection. A test motorcycle to be used for selective enforcement audit testing...

  6. Thermal properties of selected cheeses samples

    Directory of Open Access Journals (Sweden)

    Monika BOŽIKOVÁ

    2016-02-01

    Full Text Available The thermophysical parameters of selected cheeses (processed cheese and half hard cheese are presented in the article. Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms. Cheese goes during processing through the thermal and mechanical manipulation, so thermal properties are one of the most important. Knowledge about thermal parameters of cheeses could be used in the process of quality evaluation. Based on the presented facts thermal properties of selected cheeses which are produced by Slovak producers were measured. Theoretical part of article contains description of cheese and description of plane source method which was used for thermal parameters detection. Thermophysical parameters as thermal conductivity, thermal diffusivity and volume specific heat were measured during the temperature stabilisation. The results are presented as relations of thermophysical parameters to the temperature in temperature range from 13.5°C to 24°C. Every point of graphic relation was obtained as arithmetic average from measured values for the same temperature. Obtained results were statistically processed. Presented graphical relations were chosen according to the results of statistical evaluation and also according to the coefficients of determination for every relation. The results of thermal parameters are in good agreement with values measured by other authors for similar types of cheeses.

  7. The post-occipital spinal venous sinus of the Nile crocodile (Crocodylus niloticus: Its anatomy and use for blood sample collection and intravenous infusions

    Directory of Open Access Journals (Sweden)

    Jan G. Myburgh

    2014-05-01

    Full Text Available The post-occipital sinus of the spinal vein is often used for the collection of blood samples from crocodilians. Although this sampling method has been reported for several crocodilian species, the technique and associated anatomy has not been described in detail in any crocodilian, including the Nile crocodile (Crocodylus niloticus. The anatomy of the cranial neck region was investigated macroscopically, microscopically, radiographically and by means of computed tomography. Latex was injected into the spinal vein and spinal venous sinus of crocodiles to visualise the regional vasculature. The spinal vein ran within the vertebral canal, dorsal to and closely associated with the spinal cord and changed into a venous sinus cranially in the post-occipital region. For blood collection, the spinal venous sinus was accessed through the interarcuate space between the atlas and axis (C1 and C2 by inserting a needle angled just off the perpendicular in the midline through the craniodorsal cervical skin, just cranial to the cranial borders of the first cervical osteoderms. The most convenient method of blood collection was with a syringe and hypodermic needle. In addition, the suitability of the spinal venous sinus for intravenous injections and infusions in live crocodiles was evaluated. The internal diameter of the commercial human epidural catheters used during these investigations was relatively small, resulting in very slow infusion rates. Care should be taken not to puncture the spinal cord or to lacerate the blood vessel wall using this route for blood collection or intravenous infusions.

  8. Forward selection two sample binomial test

    Science.gov (United States)

    Wong, Kam-Fai; Wong, Weng-Kee; Lin, Miao-Shan

    2016-01-01

    Fisher’s exact test (FET) is a conditional method that is frequently used to analyze data in a 2 × 2 table for small samples. This test is conservative and attempts have been made to modify the test to make it less conservative. For example, Crans and Shuster (2008) proposed adding more points in the rejection region to make the test more powerful. We provide another way to modify the test to make it less conservative by using two independent binomial distributions as the reference distribution for the test statistic. We compare our new test with several methods and show that our test has advantages over existing methods in terms of control of the type 1 and type 2 errors. We reanalyze results from an oncology trial using our proposed method and our software which is freely available to the reader. PMID:27335577

  9. Mean hemoglobin levels in venous blood samples and prevalence of anemia in Japanese elementary and junior high school students.

    Science.gov (United States)

    Igarashi, Toru; Itoh, Yasuhiko; Maeda, Miho; Igarashi, Tsutomu; Fukunaga, Yoshitaka

    2012-01-01

    Screening for anemia has been performed in schools in Japan for over 30 years. The long-term effect of the nuclear power plant disaster on the prevalence of anemia in school age children is unknown. This research was performed to evaluate the prevalence of anemia in school age children and to determine grade-level and gender-related reference hemoglobin (Hb) levels prior to the nuclear disaster. Data for this research were obtained from results of screening for anemia obtained by venous blood sampling in schools in 2002. Mean Hb levels were calculated for each grade level (elementary school grades 1-6 and junior high school years 1-3) and according to gender, and the prevalence of anemia was determined. In our research, Tokyo Health Service Association guidelines were used to determine reference Hb levels for anemia. We demonstrated that Hb levels in boys increased with age during childhood and adolescence (from 13.1 ± 0.7 g/dL in 7 year olds to 14.9 ± 1.1 g/dL in 15 year olds); in girls, Hb levels peaked at menarche (13.7 ± 0.8 g/dL in 12 year olds), decreasing slightly thereafter (13.4 ± 1.1 g/dL in 15 year olds). The prevalence of anemia was 0.26% in elementary school boys, 0.27% in elementary school girls, and 1.21% in junior high school boys. The prevalence of anemia in second- and third-year junior high school girls was lower than that in first-year junior high school girls. Among all junior high school girls, 5.73% had mild anemia. Iron-deficiency anemia is the commonest type of anemia in high school girls, secondary to the relative lack of iron due to menstruation, the growth spurt and exercise. Appropriate dietary therapy and treatment of anemia, together with education about the dietary prevention of anemia, are important to reduce the prevalence of anemia in high school students. When complete blood counts are performed in regions thought to be affected by the Fukushima nuclear power plant disaster, our report can serve as a reference during

  10. Mean hemoglobin levels in venous blood samples and prevalence of anemia in Japanese elementary and junior high school students

    International Nuclear Information System (INIS)

    Igarashi, Toru; Itoh, Yasuhiko; Maeda, Miho; Igarashi, Tsutomu; Fukunaga, Yoshitaka

    2012-01-01

    Screening for anemia has been performed in schools in Japan for over 30 years. The long-term effect of the nuclear power plant disaster on the prevalence of anemia in school age children is unknown. This research was performed to evaluate the prevalence of anemia in school age children and to determine grade-level and gender-related reference hemoglobin (Hb) levels prior to the nuclear disaster. Data for this research were obtained from results of screening for anemia obtained by venous blood sampling in schools in 2002. Mean Hb levels were calculated for each grade level (elementary school grades 1-6 and junior high school years 1-3) and according to gender, and the prevalence of anemia was determined. In our research, Tokyo Health Service Association guidelines were used to determine reference Hb levels for anemia. We demonstrated that Hb levels in boys increased with age during childhood and adolescence (from 13.1±0.7 g/dL in 7 year olds to 14.9±1.1 g/dL in 15 year olds); in girls, Hb levels peaked at menarche (13.7±0.8 g/dL in 12 year olds), decreasing slightly thereafter (13.4±1.1 g/dL in 15 year olds). The prevalence of anemia was 0.26% in elementary school boys, 0.27% in elementary school girls, and 1.21% in junior high school boys. The prevalence of anemia in second- and third-year junior high school girls was lower than that in first-year junior high school girls. Among all junior high school girls, 5.73% had mild anemia. Iron-deficiency anemia is the commonest type of anemia in high school girls, secondary to the relative lack of iron due to menstruation, the growth spurt and exercise. Appropriate dietary therapy and treatment of anemia, together with education about the dietary prevention of anemia, are important to reduce the prevalence of anemia in high school students. When complete blood counts are performed in regions thought to be affected by the Fukushima nuclear power plant disaster, our report can serve as a reference during evaluation of Hb

  11. A Multi-institutional Comparison of Adrenal Venous Sampling in Patients with Primary Aldosteronism: Caution Advised if Successful Bilateral Adrenal Vein Sampling is Not Achieved.

    Science.gov (United States)

    Wang, Tracy S; Kline, Greg; Yen, Tina W; Yin, Ziyan; Liu, Ying; Rilling, William; So, Benny; Findling, James W; Evans, Douglas B; Pasieka, Janice L

    2018-02-01

    In patients with primary aldosteronism (PA), adrenal venous sampling (AVS) is recommended to differentiate between unilateral (UNI) or bilateral (BIL) adrenal disease. A recent study suggested that lateralization could be predicted, based on the ratio of aldosterone/cortisol levels (A/C) between the left adrenal vein (LAV) and inferior vena cava (IVC), with a 100% positive predictive value (PPV). This study aimed to validate those findings utilizing a larger, multi-institutional cohort. A retrospective review was performed of patients with PA who underwent AVS from 2 tertiary-care institutions. Laterality was predicted by an A/C ratio of >3:1 between the dominant and non-dominant adrenal. AVS results were compared to LAV/IVC ratios utilizing the published criteria (Lt ≥ 5.5; Rt ≤ 0.5). Of 222 patients, 124 (57%) had UNI and 98 (43%) had BIL disease based on AVS. AVS and LAV/IVC findings were concordant for laterality in 141 (64%) patients (69 UNI, 72 BIL). Using only the LAV/IVC ratio, 54 (24%) patients with UNI disease on AVS who underwent successful surgery would have been assumed to have BAH unless AVS was repeated, and 24 (11%) patients with BIL disease on AVS may have been incorrectly offered surgery (PPV 70%). Based on median LAV/IVC ratios (left 5.26; right 0.31; BIL 2.84), no LAV/IVC ratio accurately predicted laterality. This multi-institutional study of patients with both UNI and BIL PA failed to validate the previously reported PPV of LAV/IVC ratio for lateralization. Caution should be used in interpreting incomplete AVS data to differentiate between UNI versus BIL disease and strong consideration given to repeat AVS prior to adrenalectomy.

  12. UNLABELED SELECTED SAMPLES IN FEATURE EXTRACTION FOR CLASSIFICATION OF HYPERSPECTRAL IMAGES WITH LIMITED TRAINING SAMPLES

    Directory of Open Access Journals (Sweden)

    A. Kianisarkaleh

    2015-12-01

    Full Text Available Feature extraction plays a key role in hyperspectral images classification. Using unlabeled samples, often unlimitedly available, unsupervised and semisupervised feature extraction methods show better performance when limited number of training samples exists. This paper illustrates the importance of selecting appropriate unlabeled samples that used in feature extraction methods. Also proposes a new method for unlabeled samples selection using spectral and spatial information. The proposed method has four parts including: PCA, prior classification, posterior classification and sample selection. As hyperspectral image passes these parts, selected unlabeled samples can be used in arbitrary feature extraction methods. The effectiveness of the proposed unlabeled selected samples in unsupervised and semisupervised feature extraction is demonstrated using two real hyperspectral datasets. Results show that through selecting appropriate unlabeled samples, the proposed method can improve the performance of feature extraction methods and increase classification accuracy.

  13. The role of selective venous sampling in the management of persistent hyperparathyroidism revisited

    NARCIS (Netherlands)

    Witteveen, Janneke E.; Kievit, Job; van Erkel, Arian R.; Morreau, Hans; Romijn, Johannes A.; Hamdy, Neveen A. T.

    2010-01-01

    Localization studies are mandatory prior to revision surgery in patients with persistent hyperparathyroidism in order to improve surgical outcome and reduce the risk of lengthy explorations. However, in this case, noninvasive localization studies are reported to have a poor sensitivity. The aim of

  14. Do the venous blood samples replicate malaria parasite densities found in capillary blood? A field study performed in naturally-infected asymptomatic children in Cameroon.

    Science.gov (United States)

    Sandeu, Maurice M; Bayibéki, Albert N; Tchioffo, Majoline T; Abate, Luc; Gimonneau, Geoffrey; Awono-Ambéné, Parfait H; Nsango, Sandrine E; Diallo, Diadier; Berry, Antoine; Texier, Gaétan; Morlais, Isabelle

    2017-08-17

    The measure of new drug- or vaccine-based approaches for malaria control is based on direct membrane feeding assays (DMFAs) where gametocyte-infected blood samples are offered to mosquitoes through an artificial feeder system. Gametocyte donors are identified by the microscopic detection and quantification of malaria blood stages on blood films prepared using either capillary or venous blood. However, parasites are known to sequester in the microvasculature and this phenomenon may alter accurate detection of parasites in blood films. The blood source may then impact the success of mosquito feeding experiments and investigations are needed for the implementation of DMFAs under natural conditions. Thick blood smears were prepared from blood obtained from asymptomatic children attending primary schools in the vicinity of Mfou (Cameroon) over four transmission seasons. Parasite densities were determined microscopically from capillary and venous blood for 137 naturally-infected gametocyte carriers. The effect of the blood source on gametocyte and asexual stage densities was then assessed by fitting cumulative link mixed models (CLMM). DMFAs were performed to compare the infectiousness of gametocytes from the different blood sources to mosquitoes. Prevalence of Plasmodium falciparum asexual stages among asymptomatic children aged from 4 to 15 years was 51.8% (2116/4087). The overall prevalence of P. falciparum gametocyte carriage was 8.9% and varied from one school to another. No difference in the density of gametocyte and asexual stages was found between capillary and venous blood. Attempts to perform DMFAs with capillary blood failed. Plasmodium falciparum malaria parasite densities do not differ between capillary and venous blood in asymptomatic subjects for both gametocyte and trophozoite stages. This finding suggests that the blood source should not interfere with transmission efficiency in DMFAs.

  15. Comparison of arterial and venous blood gases and the effects of analysis delay and air contamination on arterial samples in patients with chronic obstructive pulmonary disease and healthy controls.

    Science.gov (United States)

    O'Connor, T M; Barry, P J; Jahangir, A; Finn, C; Buckley, B M; El-Gammal, A

    2011-01-01

    Arterial blood gases (ABGs) are often sampled incorrectly, leading to a 'mixed' or venous sample. Delays in analysis and air contamination are common. We measured the effects of these errors in patients with chronic obstructive pulmonary disease (COPD) exacerbations and controls. Arterial and venous samples were analyzed from 30 patients with COPD exacerbation and 30 controls. Venous samples were analysed immediately and arterial samples separated into non-air-contaminated and air-contaminated specimens and analysed at 0, 30, 60, 90 and 180 min. Mean venous pH was 7.371 and arterial pH was 7.407 (p Air contamination was associated with a clinically significant increase in PO₂ in all samples, including those that were immediately analyzed. Arterial and venous pH differ significantly. Venous pH cannot accurately replace arterial pH. Temporal delays in ABG analysis result in a significant decline in measured pH. ABGs should be analysed within 30 min. Air contamination leads to an immediate increase in measured PO₂, indicating that air-contaminated ABGs should be discarded. Copyright © 2010 S. Karger AG, Basel.

  16. Comparison of arterial and venous blood gases and the effects of analysis delay and air contamination on arterial samples in patients with chronic obstructive pulmonary disease and healthy controls.

    LENUS (Irish Health Repository)

    O'Connor, T M

    2012-01-31

    BACKGROUND: Arterial blood gases (ABGs) are often sampled incorrectly, leading to a \\'mixed\\' or venous sample. Delays in analysis and air contamination are common. OBJECTIVES: We measured the effects of these errors in patients with chronic obstructive pulmonary disease (COPD) exacerbations and controls. METHODS: Arterial and venous samples were analyzed from 30 patients with COPD exacerbation and 30 controls. Venous samples were analysed immediately and arterial samples separated into non-air-contaminated and air-contaminated specimens and analysed at 0, 30, 60, 90 and 180 min. RESULTS: Mean venous pH was 7.371 and arterial pH was 7.407 (p < 0.0001). There was a correlation between venous and arterial pH (r = 0.5347, p < 0.0001). The regression equation to predict arterial pH was: arterial pH = 4.2289 + 0.43113 . venous pH. There were no clinically significant differences in arterial PO associated with analysis delay. A statistically significant decline in pH was detected at 30 min in patients with COPD exacerbation (p = 0.0042) and 90 min in controls (p < 0.0001). A clinically significant decline in pH emerged at 73 min in patients with COPD exacerbation and 87 min in controls. Air contamination was associated with a clinically significant increase in PO in all samples, including those that were immediately analyzed. CONCLUSIONS: Arterial and venous pH differ significantly. Venous pH cannot accurately replace arterial pH. Temporal delays in ABG analysis result in a significant decline in measured pH. ABGs should be analysed within 30 min. Air contamination leads to an immediate increase in measured PO, indicating that air-contaminated ABGs should be discarded.

  17. Cholesterol delivery to the adrenal glands estimated by adrenal venous sampling: An in vivo model to determine the contribution of circulating lipoproteins to steroidogenesis in humans.

    Science.gov (United States)

    Buitenwerf, Edward; Dullaart, Robin P F; Muller Kobold, Anneke C; Links, Thera P; Sluiter, Wim J; Connelly, Margery A; Kerstens, Michiel N

    Cholesterol, required for adrenal steroid hormone synthesis, is at least in part derived from circulating lipoproteins. The contribution of high-density lipoproteins (HDL) and low-density lipoproteins (LDL) to adrenal steroidogenesis in humans is unclear. The aim of the study was to determine the extent to which HDL and LDL are taken up by the adrenal glands using samples obtained during adrenal venous sampling (AVS). AVS was successfully performed in 23 patients with primary aldosteronism. Samples were drawn from both adrenal veins and inferior vena cava (IVC). HDL cholesterol (HDL-C) and lipoprotein particle profiles were determined by nuclear magnetic resonance spectroscopy. Apolipoprotein (apo) A-I and apoB were assayed by immunoturbidimetry. Plasma HDL-C and HDL and LDL particle concentrations (HDL-P and LDL-P) were not lower in samples obtained from the adrenal veins compared with the IVC (HDL-C, P = .59; HDL-P, P = .06; LDL-P, P = .93). ApoB was lower in adrenal venous plasma than in IVC (P = .026; P lipoproteins and steroidogenesis. Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  18. Venous Ulcers

    Science.gov (United States)

    Caprini, J.A.; Partsch, H.; Simman, R.

    2013-01-01

    Venous leg ulcers are the most frequent form of wounds seen in patients. This article presents an overview on some practical aspects concerning diagnosis, differential diagnosis and treatment. Duplex ultrasound investigations are essential to ascertain the diagnosis of the underlying venous pathology and to treat venous refluxes. Differential diagnosis includes mainly other vascular lesions (arterial, microcirculatory causes), hematologic and metabolic diseases, trauma, infection, malignancies. Patients with superficial venous incompetence may benefit from endovenous or surgical reflux abolition diagnosed by Duplex ultrasound. The most important basic component of the management is compression therapy, for which we prefer materials with low elasticity applied with high initial pressure (short-stretch bandages and Velcro-strap devices). Local treatment should be simple, absorbing and not sticky dressings keeping adequate moisture balance after debridement of necrotic tissue and biofilms are preferred. After the ulcer is healed compression therapy should be continued in order to prevent recurrence. PMID:26236636

  19. A simple method for measurement of cerebral blood flow using 123I-IMP SPECT with calibrated standard input function by one point blood sampling. Validation of calibration by one point venous blood sampling as a substitute for arterial blood sampling

    International Nuclear Information System (INIS)

    Ito, Hiroshi; Akaizawa, Takashi; Goto, Ryoui

    1994-01-01

    In a simplified method for measurement of cerebral blood flow using one 123 I-IMP SPECT scan and one point arterial blood sampling (Autoradiography method), input function is obtained by calibrating a standard input function by one point arterial blood sampling. A purpose of this study is validation of calibration by one point venous blood sampling as a substitute for one point arterial blood sampling. After intravenous infusion of 123 I-IMP, frequent arterial and venous blood sampling were simultaneously performed on 12 patients of CNS disease without any heart and lung disease and 5 normal volunteers. The radioactivity ratio of venous whole blood which obtained from cutaneous cubital vein to arterial whole blood were 0.76±0.08, 0.80±0.05, 0.81±0.06, 0.83±0.11 at 10, 20, 30, 50 min after 123 I-IMP infusion, respectively. The venous blood radioactivities were always 20% lower than those of arterial blood radioactivity during 50 min. However, the ratio which obtained from cutaneous dorsal hand vein to artery were 0.93±0.02, 0.94±0.05, 0.98±0.04, 0.98±0.03, at 10, 20, 30, 50 min after 123 I-IMP infusion, respectively. The venous blood radioactivity was consistent with artery. These indicate that arterio-venous difference of radioactivity in a peripheral cutaneous vein like a dorsal hand vein is minimal due to arteriovenous shunt in palm. Therefore, a substitution by blood sampling from cutaneous dorsal hand vein for artery will be possible. Optimized time for venous blood sampling evaluated by error analysis was 20 min after 123 I-IMP infusion, which is 10 min later than that of arterial blood sampling. (author)

  20. 40 CFR 205.57-2 - Test vehicle sample selection.

    Science.gov (United States)

    2010-07-01

    ... pursuant to a test request in accordance with this subpart will be selected in the manner specified in the... then using a table of random numbers to select the number of vehicles as specified in paragraph (c) of... with the desig-nated AQL are contained in Appendix I, -Table II. (c) The appropriate batch sample size...

  1. The quasar luminosity function from a variability-selected sample

    Science.gov (United States)

    Hawkins, M. R. S.; Veron, P.

    1993-01-01

    A sample of quasars is selected from a 10-yr sequence of 30 UK Schmidt plates. Luminosity functions are derived in several redshift intervals, which in each case show a featureless power-law rise towards low luminosities. There is no sign of the 'break' found in the recent UVX sample of Boyle et al. It is suggested that reasons for the disagreement are connected with biases in the selection of the UVX sample. The question of the nature of quasar evolution appears to be still unresolved.

  2. The genealogy of samples in models with selection.

    Science.gov (United States)

    Neuhauser, C; Krone, S M

    1997-02-01

    We introduce the genealogy of a random sample of genes taken from a large haploid population that evolves according to random reproduction with selection and mutation. Without selection, the genealogy is described by Kingman's well-known coalescent process. In the selective case, the genealogy of the sample is embedded in a graph with a coalescing and branching structure. We describe this graph, called the ancestral selection graph, and point out differences and similarities with Kingman's coalescent. We present simulations for a two-allele model with symmetric mutation in which one of the alleles has a selective advantage over the other. We find that when the allele frequencies in the population are already in equilibrium, then the genealogy does not differ much from the neutral case. This is supported by rigorous results. Furthermore, we describe the ancestral selection graph for other selective models with finitely many selection classes, such as the K-allele models, infinitely-many-alleles models. DNA sequence models, and infinitely-many-sites models, and briefly discuss the diploid case.

  3. Plasma concentration of selected biochemical markers of endothelial dysfunction in women with various severity of chronic venous insufficiency (CVI-A pilot study.

    Directory of Open Access Journals (Sweden)

    Magdalena Budzyń

    Full Text Available Although the endothelial dysfunction is considered to be implicated in the pathogenesis of chronic venous insufficiency (CVI the endothelial status in patients with venous disorders is still not fully evaluated. Therefore the aim of the study was to measure the concentration of selected markers of endothelial dysfunction: von Willebrand factor (vWf, soluble P-selectin (sP-selectin, soluble thrombomodulin (sTM and soluble VE-cadherin (sVE-cadherin in CVI women who constitute the most numerous group of patients suffering from venous disease.Forty four women with CVI were involved in the study and divided into subgroups based on CEAP classification. Concentration of vWf, sP-selectin, sTM and sVE-cadherin were measured and compared with those obtained in 25 healthy age and sex-matched women.It was found that the concentration of sTM increased and sVEcadherin decreased along with disease severity in CVI women. A significant rise of sTM was observed especially in CVI women, with the highest inflammation status reflected by hsCRP or elastase concentration, and in CVI women with a high oxidative stress manifested by an increased plasma MDA. A significant fall of circulating sVE-cadherin was reported in CVI women with moderate to highest intensity of inflammation and oxidative stress. There was no change in vWF and sP-selectin concentration at any stage of CVI severity.The results of the present study demonstrate the presence of endothelial dysfunction in women suffering from CVI which seems to progress with the disease severity and may be associated with inflammation and enhanced oxidative stress.

  4. Sampling point selection for energy estimation in the quasicontinuum method

    NARCIS (Netherlands)

    Beex, L.A.A.; Peerlings, R.H.J.; Geers, M.G.D.

    2010-01-01

    The quasicontinuum (QC) method reduces computational costs of atomistic calculations by using interpolation between a small number of so-called repatoms to represent the displacements of the complete lattice and by selecting a small number of sampling atoms to estimate the total potential energy of

  5. Robust online tracking via adaptive samples selection with saliency detection

    Science.gov (United States)

    Yan, Jia; Chen, Xi; Zhu, QiuPing

    2013-12-01

    Online tracking has shown to be successful in tracking of previously unknown objects. However, there are two important factors which lead to drift problem of online tracking, the one is how to select the exact labeled samples even when the target locations are inaccurate, and the other is how to handle the confusors which have similar features with the target. In this article, we propose a robust online tracking algorithm with adaptive samples selection based on saliency detection to overcome the drift problem. To deal with the problem of degrading the classifiers using mis-aligned samples, we introduce the saliency detection method to our tracking problem. Saliency maps and the strong classifiers are combined to extract the most correct positive samples. Our approach employs a simple yet saliency detection algorithm based on image spectral residual analysis. Furthermore, instead of using the random patches as the negative samples, we propose a reasonable selection criterion, in which both the saliency confidence and similarity are considered with the benefits that confusors in the surrounding background are incorporated into the classifiers update process before the drift occurs. The tracking task is formulated as a binary classification via online boosting framework. Experiment results in several challenging video sequences demonstrate the accuracy and stability of our tracker.

  6. Risk of venous thromboembolism after total hip and knee replacement in older adults with comorbidity and co-occurring comorbidities in the Nationwide Inpatient Sample (2003-2006

    Directory of Open Access Journals (Sweden)

    Katz Jeffrey N

    2010-09-01

    Full Text Available Abstract Background Venous thromboembolism is a common, fatal, and costly injury which complicates major surgery in older adults. The American College of Chest Physicians recommends high potency prophylaxis regimens for individuals undergoing total hip or knee replacement (THR or TKR, but surgeons are reluctant to prescribe them due to fear of excess bleeding. Identifying a high risk cohort such as older adults with comorbidities and co-occurring comorbidities who might benefit most from high potency prophylaxis would improve how we currently perform preoperative assessment. Methods Using the Nationwide Inpatient Sample, we identified older adults who underwent THR or TKR in the U.S. between 2003 and 2006. Our outcome was VTE, including any pulmonary embolus or deep venous thrombosis. We performed multivariate logistic regression analyses to assess the effects of comorbidities on VTE occurrence. Comorbidities under consideration included coronary artery disease, congestive heart failure (CHF, chronic obstructive pulmonary disease (COPD, diabetes, and cerebrovascular disease. We also examined the impact of co-occurring comorbidities on VTE rates. Results CHF increased odds of VTE in both the THR cohort (OR = 3.08 95% CI 2.05-4.65 and TKR cohort (OR = 2.47 95% CI 1.95-3.14. COPD led to a 50% increase in odds in the TKR cohort (OR = 1.49 95% CI 1.31-1.70. The data did not support synergistic effect of co-occurring comorbidities with respect to VTE occurrence. Conclusions Older adults with CHF undergoing THR or TKR and with COPD undergoing TKR are at increased risk of VTE. If confirmed in other datasets, these older adults may benefit from higher potency prophylaxis.

  7. Patch-based visual tracking with online representative sample selection

    Science.gov (United States)

    Ou, Weihua; Yuan, Di; Li, Donghao; Liu, Bin; Xia, Daoxun; Zeng, Wu

    2017-05-01

    Occlusion is one of the most challenging problems in visual object tracking. Recently, a lot of discriminative methods have been proposed to deal with this problem. For the discriminative methods, it is difficult to select the representative samples for the target template updating. In general, the holistic bounding boxes that contain tracked results are selected as the positive samples. However, when the objects are occluded, this simple strategy easily introduces the noises into the training data set and the target template and then leads the tracker to drift away from the target seriously. To address this problem, we propose a robust patch-based visual tracker with online representative sample selection. Different from previous works, we divide the object and the candidates into several patches uniformly and propose a score function to calculate the score of each patch independently. Then, the average score is adopted to determine the optimal candidate. Finally, we utilize the non-negative least square method to find the representative samples, which are used to update the target template. The experimental results on the object tracking benchmark 2013 and on the 13 challenging sequences show that the proposed method is robust to the occlusion and achieves promising results.

  8. Evaluation of Stress Loaded Steel Samples Using Selected Electromagnetic Methods

    International Nuclear Information System (INIS)

    Chady, T.

    2004-01-01

    In this paper the magnetic leakage flux and eddy current method were used to evaluate changes of materials' properties caused by stress. Seven samples made of ferromagnetic material with different level of applied stress were prepared. First, the leakage magnetic fields were measured by scanning the surface of the specimens with GMR gradiometer. Next, the same samples were evaluated using an eddy current sensor. A comparison between results obtained from both methods was carried out. Finally, selected parameters of the measured signal were calculated and utilized to evaluate level of the applied stress. A strong coincidence between amount of the applied stress and the maximum amplitude of the derivative was confirmed

  9. An Improved Nested Sampling Algorithm for Model Selection and Assessment

    Science.gov (United States)

    Zeng, X.; Ye, M.; Wu, J.; WANG, D.

    2017-12-01

    Multimodel strategy is a general approach for treating model structure uncertainty in recent researches. The unknown groundwater system is represented by several plausible conceptual models. Each alternative conceptual model is attached with a weight which represents the possibility of this model. In Bayesian framework, the posterior model weight is computed as the product of model prior weight and marginal likelihood (or termed as model evidence). As a result, estimating marginal likelihoods is crucial for reliable model selection and assessment in multimodel analysis. Nested sampling estimator (NSE) is a new proposed algorithm for marginal likelihood estimation. The implementation of NSE comprises searching the parameters' space from low likelihood area to high likelihood area gradually, and this evolution is finished iteratively via local sampling procedure. Thus, the efficiency of NSE is dominated by the strength of local sampling procedure. Currently, Metropolis-Hasting (M-H) algorithm and its variants are often used for local sampling in NSE. However, M-H is not an efficient sampling algorithm for high-dimensional or complex likelihood function. For improving the performance of NSE, it could be feasible to integrate more efficient and elaborated sampling algorithm - DREAMzs into the local sampling. In addition, in order to overcome the computation burden problem of large quantity of repeating model executions in marginal likelihood estimation, an adaptive sparse grid stochastic collocation method is used to build the surrogates for original groundwater model.

  10. The difference between fingerstick and venous hemoglobin and hematocrit varies by sex and iron stores.

    Science.gov (United States)

    Cable, Ritchard G; Steele, Whitney R; Melmed, Russell S; Johnson, Bryce; Mast, Alan E; Carey, Patricia M; Kiss, Joseph E; Kleinman, Steven H; Wright, David J

    2012-05-01

    Fingerstick blood samples are used to estimate donor venous hemoglobin (Hb). Fingerstick Hb or hematocrit (Hct) was determined routinely for 2425 selected donors at six blood centers, along with venous Hb. Using sex and measures of iron status including absent iron stores (AIS; ferritin < 12 ng/mL), linear regression models were developed to predict venous Hb from fingerstick. Across all subjects, fingerstick Hb was higher than venous Hb in the higher part of the clinical range, but lower in the lower part of the range. The relationship varied by sex and iron status. Across centers, a female donor had on average a venous Hb result 0.5 to 0.8 g/dL lower than a male donor with the same fingerstick Hb and iron status. Similarly, a donor with AIS had on average a venous Hb result 0.3 to 1.1 g/dL lower than an iron-replete donor with the same fingerstick value and sex. An iron-replete male donor with a fingerstick result at the cutoff (Hb 12.5 g/dL) had an acceptable expected venous Hb (12.8 to 13.8 g/dL). A female donor with AIS with a fingerstick result at the cutoff had an expected venous Hb below 12.5 g/dL (11.7 to 12.4 g/dL). Of females with AIS, 40.2% donated blood when their venous Hb was less than 12.5 g/dL. Fingerstick is considered a useful estimator of venous Hb. However, in some donor groups, particularly female donors with AIS, fingerstick overestimates venous Hb at the donation cutoff. This significant limitation should be considered in setting donor fingerstick Hb or Hct requirements. © 2011 American Association of Blood Banks.

  11. Venous, Arterialized-Venous, or Capillary Glucose Reference Measurements for the Accuracy Assessment of a Continuous Glucose Monitoring System.

    Science.gov (United States)

    Kropff, Jort; van Steen, Sigrid C; deGraaff, Peter; Chan, Man W; van Amstel, Rombout B E; DeVries, J Hans

    2017-11-01

    Different reference methods are used for the accuracy assessment of continuous glucose monitoring (CGM) systems. The effect of using venous, arterialized-venous, or capillary reference measurements on CGM accuracy is unclear. We evaluated 21 individuals with type 1 diabetes using a capillary calibrated CGM system. Venous or arterialized-venous reference glucose samples were taken every 15 min at two separate visits and assessed per YSI 2300 STAT Plus. Arterialization was achieved by heated-hand technique. Capillary samples were collected hourly during the venous reference visit. The investigation sequence (venous or arterialized-venous) was randomized. Effectiveness of arterialization was measured by comparing free venous oxygen pressure (PO2) of both visit days. Primary endpoint was the median absolute relative difference (ARD). Median ARD using arterialized-venous reference samples was not different from venous samples (point estimated difference 0.52%, P = 0.181). When comparing the three reference methods, median ARD was also not different over the full glycemic range (venous 9.0% [n = 681], arterialized-venous 8.3% [n = 684], and capillary 8.1% [n = 205], P = 0.216), nor over the separate glucose ranges. Arterialization was successful (PO2 venous 5.4 kPa vs. arterialized-venous 8.9 kPa, P reference measurements did not significantly impact CGM accuracy. Venous reference seems preferable due to its ease of operation.

  12. Selection of the Sample for Data-Driven $Z \\to \

    CERN Document Server

    Krauss, Martin

    2009-01-01

    The topic of this study was to improve the selection of the sample for data-driven Z → ν ν background estimation, which is a major contribution in supersymmetric searches in ̄ a no-lepton search mode. The data is based on Z → + − samples using data created with ATLAS simulation software. This method works if two leptons are reconstructed, but using cuts that are typical for SUSY searches reconstruction efficiency for electrons and muons is rather low. For this reason it was tried to enhance the data sample. Therefore events were considered, where only one electron was reconstructed. In this case the invariant mass for the electron and each jet was computed to select the jet with the best match for the Z boson mass as not reconstructed electron. This way the sample can be extended but significantly looses purity because of also reconstructed background events. To improve this method other variables have to be considered which were not available for this study. Applying a similar method to muons using ...

  13. Failure Probability Estimation Using Asymptotic Sampling and Its Dependence upon the Selected Sampling Scheme

    Directory of Open Access Journals (Sweden)

    Martinásková Magdalena

    2017-12-01

    Full Text Available The article examines the use of Asymptotic Sampling (AS for the estimation of failure probability. The AS algorithm requires samples of multidimensional Gaussian random vectors, which may be obtained by many alternative means that influence the performance of the AS method. Several reliability problems (test functions have been selected in order to test AS with various sampling schemes: (i Monte Carlo designs; (ii LHS designs optimized using the Periodic Audze-Eglājs (PAE criterion; (iii designs prepared using Sobol’ sequences. All results are compared with the exact failure probability value.

  14. Correlation of Lactic Acid and Base Deficit Values Obtained From Arterial and Peripheral Venous Samples in a Pediatric Population During Intraoperative Care.

    Science.gov (United States)

    Bordes, Brianne M; Walia, Hina; Sebastian, Roby; Martin, David; Tumin, Dmitry; Tobias, Joseph D

    2017-12-01

    Lactic acid and base deficit (BD) values are frequently monitored in the intensive care unit and operating room setting to evaluate oxygenation, ventilation, cardiac output, and peripheral perfusion. Although generally obtained from an arterial cannula, such access may not always be available. The current study prospectively investigates the correlation of arterial and peripheral venous values of BD and lactic acid. The study cohort included 48 patients. Arterial BD values ranged from -8 to 4 mEq/L and peripheral venous BD values ranged from -8 to 4 mEq/L. Arterial lactic acid values ranged from 0.36 to 2.45 μmol/L and peripheral venous lactic acid values ranged from 0.38 to 4 μmol/L. The arterial BD (-0.4 ± 2.2 mEq/L) was not significantly different from the peripheral venous BD (-0.6 ± 2.2 mEq/L). The arterial lactic acid (1.0 ± 0.5 μmol/L) was not significantly different from the peripheral venous lactic acid (1.1 ± 0.6 μmol/L). Pearson correlation coefficients demonstrated a very high correlation between arterial and peripheral venous BD ( r = .88, P lactic acid ( r = .67, P lactic acid corresponded to a 0.9-unit increase in peripheral venous lactic acid (95% CI: 0.6-1.2; P lactic acid and BD values.

  15. Application of the Sampling Selection Technique in Approaching Financial Audit

    Directory of Open Access Journals (Sweden)

    Victor Munteanu

    2018-03-01

    Full Text Available In his professional approach, the financial auditor has a wide range of working techniques, including selection techniques. They are applied depending on the nature of the information available to the financial auditor, the manner in which they are presented - paper or electronic format, and, last but not least, the time available. Several techniques are applied, successively or in parallel, to increase the safety of the expressed opinion and to provide the audit report with a solid basis of information. Sampling is used in the phase of control or clarification of the identified error. The main purpose is to corroborate or measure the degree of risk detected following a pertinent analysis. Since the auditor does not have time or means to thoroughly rebuild the information, the sampling technique can provide an effective response to the need for valorization.

  16. Dynamic multidetector CT and non-contrast-enhanced MR for right adrenal vein imaging: comparison with catheter venography in adrenal venous sampling

    Energy Technology Data Exchange (ETDEWEB)

    Ota, Hideki; Seiji, Kazumasa; Kawabata, Masahiro; Satani, Nozomi; Matsuura, Tomonori; Tominaga, Junya; Takase, Kei [Tohoku University Hospital, Department of Diagnostic Radiology, Sendai (Japan); Omata, Kei; Ono, Yoshikiyo; Iwakura, Yoshitsugu; Morimoto, Ryo; Kudo, Masataka; Satoh, Fumitoshi; Ito, Sadayoshi [Tohoku University Hospital, Division of Nephrology, Endocrinology and Vascular Medicine, Sendai (Japan)

    2016-03-15

    To evaluate visualization of the right adrenal vein (RAV) with multidetector CT and non-contrast-enhanced MR imaging in patients with primary aldosteronism. A total of 125 patients (67 men) scheduled for adrenal venous sampling (AVS) were included. Dynamic 64-detector-row CT and balanced steady-state free precession-based non-contrast-enhanced 3-T MR imaging were performed. RAV visualization based on a four-point score was documented. Both anatomical location and variation on cross-sectional imaging were evaluated, and the findings were compared with catheter venography as the gold standard. The RAV was visualized in 93.2 % by CT and 84.8 % by MR imaging (p = 0.02). Positive predictive values of RAV visualization were 100 % for CT and 95.2 % for MR imaging. Imaging score was significantly higher in CT than MR imaging (p < 0.01). The RAV formed a common trunk with an accessory hepatic vein in 16 % of patients. The RAV orifice level on cross-sectional imaging was concordant with catheter venography within the range of 1/3 vertebral height in >70 % of subjects. Success rate of AVS was 99.2 %. Dynamic CT is a reliable way to map the RAV prior to AVS. Non-contrast-enhanced MR imaging is an alternative when there is a risk of complication from contrast media or radiation exposure. (orig.)

  17. Risk of venous thromboembolism in people admitted to hospital with selected immune-mediated diseases: record-linkage study

    Directory of Open Access Journals (Sweden)

    Handel Adam E

    2011-01-01

    Full Text Available Abstract Background Venous thromboembolism (VTE is a common complication during and after a hospital admission. Although it is mainly considered a complication of surgery, it often occurs in people who have not undergone surgery, with recent evidence suggesting that immune-mediated diseases may play a role in VTE risk. We, therefore, decided to study the risk of deep vein thrombosis (DVT and pulmonary embolism (PE in people admitted to hospital with a range of immune-mediated diseases. Methods We analysed databases of linked statistical records of hospital admissions and death certificates for the Oxford Record Linkage Study area (ORLS1:1968 to 1998 and ORLS2:1999 to 2008 and the whole of England (1999 to 2008. Rate ratios for VTE were determined, comparing immune-mediated disease cohorts with comparison cohorts. Results Significantly elevated risks of VTE were found, in all three populations studied, in people with a hospital record of admission for autoimmune haemolytic anaemia, chronic active hepatitis, dermatomyositis/polymyositis, type 1 diabetes mellitus, multiple sclerosis, myasthenia gravis, myxoedema, pemphigus/pemphigoid, polyarteritis nodosa, psoriasis, rheumatoid arthritis, Sjogren's syndrome, and systemic lupus erythematosus. Rate ratios were considerably higher for some of these diseases than others: for example, for systemic lupus erythematosus the rate ratios were 3.61 (2.36 to 5.31 in the ORLS1 population, 4.60 (3.19 to 6.43 in ORLS2 and 3.71 (3.43 to 4.02 in the England dataset. Conclusions People admitted to hospital with immune-mediated diseases may be at an increased risk of subsequent VTE. Our findings need independent confirmation or refutation; but, if confirmed, there may be a role for thromboprophylaxis in some patients with these diseases.

  18. Effective traffic features selection algorithm for cyber-attacks samples

    Science.gov (United States)

    Li, Yihong; Liu, Fangzheng; Du, Zhenyu

    2018-05-01

    By studying the defense scheme of Network attacks, this paper propose an effective traffic features selection algorithm based on k-means++ clustering to deal with the problem of high dimensionality of traffic features which extracted from cyber-attacks samples. Firstly, this algorithm divide the original feature set into attack traffic feature set and background traffic feature set by the clustering. Then, we calculates the variation of clustering performance after removing a certain feature. Finally, evaluating the degree of distinctiveness of the feature vector according to the result. Among them, the effective feature vector is whose degree of distinctiveness exceeds the set threshold. The purpose of this paper is to select out the effective features from the extracted original feature set. In this way, it can reduce the dimensionality of the features so as to reduce the space-time overhead of subsequent detection. The experimental results show that the proposed algorithm is feasible and it has some advantages over other selection algorithms.

  19. Point-of-care blood gases, electrolytes, chemistries, hemoglobin, and hematocrit measurement in venous samples from pet rabbits.

    Science.gov (United States)

    Selleri, Paolo; Di Girolamo, Nicola

    2014-01-01

    Point-of-care testing is an attractive option in rabbit medicine, because it permits rapid analysis of a panel of electrolytes, chemistries, blood gases, hemoglobin, and hematocrit, requiring only 65 μL of blood. The purpose of this study was to evaluate the performance of a portable clinical analyzer for measurement of pH, partial pressure of CO2, Na, chloride, potassium, blood urea nitrogen, glucose, hematocrit, and hemoglobin in healthy and diseased rabbits. Blood samples obtained from 30 pet rabbits were analyzed immediately after collection by the portable clinical analyzer (PCA) and immediately thereafter (time <20 sec) by a reference analyzer. Bland-Altman plots and Passing-Bablok regression analysis were used to compare the results. Limits of agreement were wide for all the variables studied, with the exception of pH. Most variables presented significant proportional and/or constant bias. The current study provides sufficient evidence that the PCA presents reliability for pH, although its low agreement with a reference analyzer for the other variables does not support their interchangeability. Limits of agreement provided for each variable allow researchers to evaluate if the PCA is reliable enough for their scope. To the authors' knowledge, the present is the first report evaluating a PCA in the rabbit.

  20. Random selection of items. Selection of n1 samples among N items composing a stratum

    International Nuclear Information System (INIS)

    Jaech, J.L.; Lemaire, R.J.

    1987-02-01

    STR-224 provides generalized procedures to determine required sample sizes, for instance in the course of a Physical Inventory Verification at Bulk Handling Facilities. The present report describes procedures to generate random numbers and select groups of items to be verified in a given stratum through each of the measurement methods involved in the verification. (author). 3 refs

  1. Porto-systemic collaterals in cirrhosis of the liver. Selective percutaneous transhepatic catheterization of the portal venous system in portal hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Hoevels, J; Lunderquist, A; Tylen, U; Simert, G [Lund Univ. (Sweden)

    1979-01-01

    In 93 patients with cirrhosis of the liver and portal venous hypertension the main tributaries of the portal vein were examined by percutaneous transhepatic catheterization. The appearance and degree of porto-systemic collaterals were analysed. Esophageal varices were demonstrated in 82 patients. No correlation was found between the portal venous pressure and the extent of porto-systemic communications.

  2. Combined oral contraceptives: venous thrombosis.

    Science.gov (United States)

    de Bastos, Marcos; Stegeman, Bernardine H; Rosendaal, Frits R; Van Hylckama Vlieg, Astrid; Helmerhorst, Frans M; Stijnen, Theo; Dekkers, Olaf M

    2014-03-03

    Combined oral contraceptive (COC) use has been associated with venous thrombosis (VT) (i.e., deep venous thrombosis and pulmonary embolism). The VT risk has been evaluated for many estrogen doses and progestagen types contained in COC but no comprehensive comparison involving commonly used COC is available. To provide a comprehensive overview of the risk of venous thrombosis in women using different combined oral contraceptives. Electronic databases (Pubmed, Embase, Web of Science, Cochrane, CINAHL, Academic Search Premier and ScienceDirect) were searched in 22 April 2013 for eligible studies, without language restrictions. We selected studies including healthy women taking COC with VT as outcome. The primary outcome of interest was a fatal or non-fatal first event of venous thrombosis with the main focus on deep venous thrombosis or pulmonary embolism. Publications with at least 10 events in total were eligible. The network meta-analysis was performed using an extension of frequentist random effects models for mixed multiple treatment comparisons. Unadjusted relative risks with 95% confidence intervals were reported.Two independent reviewers extracted data from selected studies. 3110 publications were retrieved through a search strategy; 25 publications reporting on 26 studies were included. Incidence of venous thrombosis in non-users from two included cohorts was 0.19 and 0.37 per 1 000 person years, in line with previously reported incidences of 0,16 per 1 000 person years. Use of combined oral contraceptives increased the risk of venous thrombosis compared with non-use (relative risk 3.5, 95% confidence interval 2.9 to 4.3). The relative risk of venous thrombosis for combined oral contraceptives with 30-35 μg ethinylestradiol and gestodene, desogestrel, cyproterone acetate, or drospirenone were similar and about 50-80% higher than for combined oral contraceptives with levonorgestrel. A dose related effect of ethinylestradiol was observed for gestodene

  3. Evaluation of pump pulsation in respirable size-selective sampling: part II. Changes in sampling efficiency.

    Science.gov (United States)

    Lee, Eun Gyung; Lee, Taekhee; Kim, Seung Won; Lee, Larry; Flemmer, Michael M; Harper, Martin

    2014-01-01

    This second, and concluding, part of this study evaluated changes in sampling efficiency of respirable size-selective samplers due to air pulsations generated by the selected personal sampling pumps characterized in Part I (Lee E, Lee L, Möhlmann C et al. Evaluation of pump pulsation in respirable size-selective sampling: Part I. Pulsation measurements. Ann Occup Hyg 2013). Nine particle sizes of monodisperse ammonium fluorescein (from 1 to 9 μm mass median aerodynamic diameter) were generated individually by a vibrating orifice aerosol generator from dilute solutions of fluorescein in aqueous ammonia and then injected into an environmental chamber. To collect these particles, 10-mm nylon cyclones, also known as Dorr-Oliver (DO) cyclones, were used with five medium volumetric flow rate pumps. Those were the Apex IS, HFS513, GilAir5, Elite5, and Basic5 pumps, which were found in Part I to generate pulsations of 5% (the lowest), 25%, 30%, 56%, and 70% (the highest), respectively. GK2.69 cyclones were used with the Legacy [pump pulsation (PP) = 15%] and Elite12 (PP = 41%) pumps for collection at high flows. The DO cyclone was also used to evaluate changes in sampling efficiency due to pulse shape. The HFS513 pump, which generates a more complex pulse shape, was compared to a single sine wave fluctuation generated by a piston. The luminescent intensity of the fluorescein extracted from each sample was measured with a luminescence spectrometer. Sampling efficiencies were obtained by dividing the intensity of the fluorescein extracted from the filter placed in a cyclone with the intensity obtained from the filter used with a sharp-edged reference sampler. Then, sampling efficiency curves were generated using a sigmoid function with three parameters and each sampling efficiency curve was compared to that of the reference cyclone by constructing bias maps. In general, no change in sampling efficiency (bias under ±10%) was observed until pulsations exceeded 25% for the

  4. Adult health study reference papers. Selection of the sample. Characteristics of the sample

    Energy Technology Data Exchange (ETDEWEB)

    Beebe, G W; Fujisawa, Hideo; Yamasaki, Mitsuru

    1960-12-14

    The characteristics and selection of the clinical sample have been described in some detail to provide information on the comparability of the exposure groups with respect to factors excluded from the matching criteria and to provide basic descriptive information potentially relevant to individual studies that may be done within the framework of the Adult Health Study. The characteristics under review here are age, sex, many different aspects of residence, marital status, occupation and industry, details of location and shielding ATB, acute radiation signs and symptoms, and prior ABCC medical or pathology examinations. 5 references, 57 tables.

  5. Characterizing the relationship between age and venous thromboembolism in adult trauma patients: findings from the National Trauma Data Bank and the National Inpatient Sample.

    Science.gov (United States)

    Nastasi, Anthony J; Canner, Joseph K; Lau, Brandyn D; Streiff, Michael B; Aboagye, Jonathan K; Kraus, Peggy S; Hobson, Deborah B; Van Arendonk, Kyle J; Haut, Elliott R

    2017-08-01

    Venous thromboembolism (VTE) is a tremendous burden in health care. However, current guidelines lack recommendations regarding the prevention of VTE in older adult trauma patients. Furthermore, the appropriate method of modeling of age in VTE models is currently unclear. Patients included in the National Trauma Data Bank (NTDB) between the years 2008 and 2014 and patients included in the National Inpatient Sample (NIS) between 2009 and 2013 were analyzed. Multiple logistic regression of VTE on age was performed. Of 3,598,881 patients in the NTDB, 34,202 (1.0%) were diagnosed with VTE compared to 5405 (1.1%) of the 505,231 patients in NIS. In both the fully adjusted NTDB and NIS model, age was positively associated with odds of VTE diagnosis under 65 years (NTDB, adjusted odds ratio [aOR]: 1.018, 95% confidence interval [CI]: 1.017-1.019, P < 0.001; NIS, aOR: 1.025, 95% CI 1.022-1.027, P < 0.001). In patients aged ≥65 years, age was negatively associated with odds of VTE diagnosis in the NTDB (aOR: 0.995, 95% CI: 0.992-0.999, P = 0.006) but not in the NIS (aOR: 0.998, 95% CI 0.994-1.002, P = 0.26). Incidence of VTE among adult trauma patients steadily increases with age until 65 years, after which the odds of VTE appear to level off or even slightly decrease. These findings should be applied for improved modeling of VTE in trauma patients. The mechanism behind these findings should be explored before using them to update guidelines for standardized VTE prevention in older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Selection Component Analysis of Natural Polymorphisms using Population Samples Including Mother-Offspring Combinations, II

    DEFF Research Database (Denmark)

    Jarmer, Hanne Østergaard; Christiansen, Freddy Bugge

    1981-01-01

    Population samples including mother-offspring combinations provide information on the selection components: zygotic selection, sexual selection, gametic seletion and fecundity selection, on the mating pattern, and on the deviation from linkage equilibrium among the loci studied. The theory...

  7. Progressive sample processing of band selection for hyperspectral imagery

    Science.gov (United States)

    Liu, Keng-Hao; Chien, Hung-Chang; Chen, Shih-Yu

    2017-10-01

    Band selection (BS) is one of the most important topics in hyperspectral image (HSI) processing. The objective of BS is to find a set of representative bands that can represent the whole image with lower inter-band redundancy. Many types of BS algorithms were proposed in the past. However, most of them can be carried on in an off-line manner. It means that they can only be implemented on the pre-collected data. Those off-line based methods are sometime useless for those applications that are timeliness, particular in disaster prevention and target detection. To tackle this issue, a new concept, called progressive sample processing (PSP), was proposed recently. The PSP is an "on-line" framework where the specific type of algorithm can process the currently collected data during the data transmission under band-interleavedby-sample/pixel (BIS/BIP) protocol. This paper proposes an online BS method that integrates a sparse-based BS into PSP framework, called PSP-BS. In PSP-BS, the BS can be carried out by updating BS result recursively pixel by pixel in the same way that a Kalman filter does for updating data information in a recursive fashion. The sparse regression is solved by orthogonal matching pursuit (OMP) algorithm, and the recursive equations of PSP-BS are derived by using matrix decomposition. The experiments conducted on a real hyperspectral image show that the PSP-BS can progressively output the BS status with very low computing time. The convergence of BS results during the transmission can be quickly achieved by using a rearranged pixel transmission sequence. This significant advantage allows BS to be implemented in a real time manner when the HSI data is transmitted pixel by pixel.

  8. Autonomous site selection and instrument positioning for sample acquisition

    Science.gov (United States)

    Shaw, A.; Barnes, D.; Pugh, S.

    The European Space Agency Aurora Exploration Program aims to establish a European long-term programme for the exploration of Space, culminating in a human mission to space in the 2030 timeframe. Two flagship missions, namely Mars Sample Return and ExoMars, have been proposed as recognised steps along the way. The Exomars Rover is the first of these flagship missions and includes a rover carrying the Pasteur Payload, a mobile exobiology instrumentation package, and the Beagle 2 arm. The primary objective is the search for evidence of past or present life on mars, but the payload will also study the evolution of the planet and the atmosphere, look for evidence of seismological activity and survey the environment in preparation for future missions. The operation of rovers in unknown environments is complicated, and requires large resources not only on the planet but also in ground based operations. Currently, this can be very labour intensive, and costly, if large teams of scientists and engineers are required to assess mission progress, plan mission scenarios, and construct a sequence of events or goals for uplink. Furthermore, the constraints in communication imposed by the time delay involved over such large distances, and line-of-sight required, make autonomy paramount to mission success, affording the ability to operate in the event of communications outages and be opportunistic with respect to scientific discovery. As part of this drive to reduce mission costs and increase autonomy the Space Robotics group at the University of Wales, Aberystwyth is researching methods of autonomous site selection and instrument positioning, directly applicable to the ExoMars mission. The site selection technique used builds on the geometric reasoning algorithms used previously for localisation and navigation [Shaw 03]. It is proposed that a digital elevation model (DEM) of the local surface, generated during traverse and without interaction from ground based operators, can be

  9. 40 CFR 86.607-84 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing of New Light-Duty Vehicles, Light-Duty Trucks, and Heavy-Duty Vehicles § 86.607-84 Sample..., once a manufacturer ships any vehicle from the test sample, it relinquishes the prerogative to conduct...

  10. 40 CFR 91.506 - Engine sample selection.

    Science.gov (United States)

    2010-07-01

    ... paragraph (b)(2) of this section. It defines one-tail, 95 percent confidence intervals. σ=actual test sample... individual engine x=mean of emission test results of the actual sample FEL=Family Emission Limit n=The actual... carry-over engine families: After one engine is tested, the manufacturer will combine the test with the...

  11. 40 CFR 761.353 - Second level of sample selection.

    Science.gov (United States)

    2010-07-01

    .... At the chemical extraction and analysis laboratory, pour the 19-liter subsample onto a plastic sheet..., AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off...

  12. Enhanced Sampling and Analysis, Selection of Technology for Testing

    Energy Technology Data Exchange (ETDEWEB)

    Svoboda, John; Meikrantz, David

    2010-02-01

    The focus of this study includes the investigation of sampling technologies used in industry and their potential application to nuclear fuel processing. The goal is to identify innovative sampling methods using state of the art techniques that could evolve into the next generation sampling and analysis system for metallic elements. This report details the progress made in the first half of FY 2010 and includes a further consideration of the research focus and goals for this year. Our sampling options and focus for the next generation sampling method are presented along with the criteria used for choosing our path forward. We have decided to pursue the option of evaluating the feasibility of microcapillary based chips to remotely collect, transfer, track and supply microliters of sample solutions to analytical equipment in support of aqueous processes for used nuclear fuel cycles. Microchip vendors have been screened and a choice made for the development of a suitable microchip design followed by production of samples for evaluation by ANL, LANL, and INL on an independent basis.

  13. Sample selection and taste correlation in discrete choice transport modelling

    DEFF Research Database (Denmark)

    Mabit, Stefan Lindhard

    2008-01-01

    explain counterintuitive results in value of travel time estimation. However, the results also point at the difficulty of finding suitable instruments for the selection mechanism. Taste heterogeneity is another important aspect of discrete choice modelling. Mixed logit models are designed to capture...... the question for a broader class of models. It is shown that the original result may be somewhat generalised. Another question investigated is whether mode choice operates as a self-selection mechanism in the estimation of the value of travel time. The results show that self-selection can at least partly...... of taste correlation in willingness-to-pay estimation are presented. The first contribution addresses how to incorporate taste correlation in the estimation of the value of travel time for public transport. Given a limited dataset the approach taken is to use theory on the value of travel time as guidance...

  14. Venous thromboembolism in women

    DEFF Research Database (Denmark)

    Group, ESHRE Capri Workshop; Skouby, Sven Olaf

    2013-01-01

    BACKGROUND Venous thromboembolism (VTE) is a specific reproductive health risk for women. METHODS Searches were performed in Medline and other databases. The selection criteria were high-quality studies and studies relevant to clinical reproductive medicine. Summaries were presented and discussed...... is associated with an inherited thrombophilia in men and women. Changes in the coagulation system and in the risk of clinical VTE in women also occur during pregnancy, with the use of reproductive hormones and as a consequence of ovarian stimulation when hyperstimulation syndrome and conception occur together...... therapy (HRT) increases the VTE risk 2- to 4-fold. There is a synergistic effect between thrombophilia and the various reproductive risks. Prevention of VTE during pregnancy should be offered to women with specific risk factors. In women who are at high risk, CHC and HRT should be avoided. CONCLUSIONS...

  15. Experimental breakdown of selected anodized aluminum samples in dilute plasmas

    Science.gov (United States)

    Grier, Norman T.; Domitz, Stanley

    1992-01-01

    Anodized aluminum samples representative of Space Station Freedom structural material were tested for electrical breakdown under space plasma conditions. In space, this potential arises across the insulating anodized coating when the spacecraft structure is driven to a negative bias relative to the external plasma potential due to plasma-surface interaction phenomena. For anodized materials used in the tests, it was found that breakdown voltage varied from 100 to 2000 volts depending on the sample. The current in the arcs depended on the sample, the capacitor, and the voltage. The level of the arc currents varied from 60 to 1000 amperes. The plasma number density varied from 3 x 10 exp 6 to 10 exp 3 ions per cc. The time between arcs increased as the number density was lowered. Corona testing of anodized samples revealed that samples with higher corona inception voltage had higher arcing inception voltages. From this it is concluded that corona testing may provide a method of screening the samples.

  16. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    KAUST Repository

    Elsheikh, Ahmed H.; Wheeler, Mary Fanett; Hoteit, Ibrahim

    2014-01-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using

  17. Sampling dynamics: an alternative to payoff-monotone selection dynamics

    DEFF Research Database (Denmark)

    Berkemer, Rainer

    payoff-monotone nor payoff-positive which has interesting consequences. This can be demonstrated by application to the travelers dilemma, a deliberately constructed social dilemma. The game has just one symmetric Nash equilibrium which is Pareto inefficient. Especially when the travelers have many......'' of the standard game theory result. Both, analytical tools and agent based simulation are used to investigate the dynamic stability of sampling equilibria in a generalized travelers dilemma. Two parameters are of interest: the number of strategy options (m) available to each traveler and an experience parameter...... (k), which indicates the number of samples an agent would evaluate before fixing his decision. The special case (k=1) can be treated analytically. The stationary points of the dynamics must be sampling equilibria and one can calculate that for m>3 there will be an interior solution in addition...

  18. Sampling Efficiency and Performance of Selected Thoracic Aerosol Samplers.

    Science.gov (United States)

    Görner, Peter; Simon, Xavier; Boivin, Alexis; Bau, Sébastien

    2017-08-01

    Measurement of worker exposure to a thoracic health-related aerosol fraction is necessary in a number of occupational situations. This is the case of workplaces with atmospheres polluted by fibrous particles, such as cotton dust or asbestos, and by particles inducing irritation or bronchoconstriction such as acid mists or flour dust. Three personal and two static thoracic aerosol samplers were tested under laboratory conditions. Sampling efficiency with respect to particle aerodynamic diameter was measured in a horizontal low wind tunnel and in a vertical calm air chamber. Sampling performance was evaluated against conventional thoracic penetration. Three of the tested samplers performed well, when sampling the thoracic aerosol at nominal flow rate and two others performed well at optimized flow rate. The limit of flow rate optimization was found when using cyclone samplers. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  19. A redshift survey of IRAS galaxies. I. Sample selection

    International Nuclear Information System (INIS)

    Strauss, M.A.; Davis, M.; Yahil, A.; Huchra, J.P.

    1990-01-01

    A complete all-sky sample of objects, flux-limited at 60 microns, has been extracted from the data base of the IRAS. The sample consists of 5014 objects, of which 2649 are galaxies and 13 are not yet identified. In order to study large-scale structure with this sample, it must be free of systematic biases. Corrections are applied for a major systematic effect in the flux densities listed in the IRAS Point Source Catalog: sources resolved by the IRAS beam have flux densities systematically underestimated. In addition, accurate flux densities are obtained for sources flagged as variable, or of moderate flux quality at 60 microns. The IRAS detectors suffered radiation-induced responsivity enhancement (hysteresis) due to crossings of the satellite scans across the Galactic plane; this effect is measured and is shown to be negligible. 53 refs

  20. Field-based random sampling without a sampling frame: control selection for a case-control study in rural Africa.

    Science.gov (United States)

    Crampin, A C; Mwinuka, V; Malema, S S; Glynn, J R; Fine, P E

    2001-01-01

    Selection bias, particularly of controls, is common in case-control studies and may materially affect the results. Methods of control selection should be tailored both for the risk factors and disease under investigation and for the population being studied. We present here a control selection method devised for a case-control study of tuberculosis in rural Africa (Karonga, northern Malawi) that selects an age/sex frequency-matched random sample of the population, with a geographical distribution in proportion to the population density. We also present an audit of the selection process, and discuss the potential of this method in other settings.

  1. Diagnosis of venous disorders

    International Nuclear Information System (INIS)

    Minar, E.

    1993-01-01

    Limited accuracy in the clinic diagnosis of deep vein thrombosis (VT) makes such diagnostic tests such as duplex sonography or venography necessary. Exact information on the age and extent of the thrombus are necessary for the clinician to optimize the therapeutric management. The correct diagnosis of calf vein thrombosis and of recurrent VT in patients with postphlebitis changes also has implications for treatment. After exclusion of thrombosis, the radiologist should evaluate the leg for other possible causes of symptoms besides VT. Investigation of the venous sytem also has a role in the diagnosis in patients with suspected pulmonary embolism. In patients with chronic venous insuffficiency the deep venous system should assessed for patency and venous valve function. The superficial veins should be differentiated in segments with sufficient or insufficient venous valves, and it is also necessary to look for insufficiency of the perforrating veins. In patients with superficial phlebitis there is risk of propagation into the deep venous system. (orig.) [de

  2. Validity of colour doppler ultrasonography with d-dimers in clinically suspected deep venous thrombosis of the lower limb

    International Nuclear Information System (INIS)

    Babar, T.H.; Nafees, M.N.; Sarwar, S.; Ashraf, N.

    2010-01-01

    Objective: This study was designed to evaluate the validity of colour Doppler ultrasonography with D-dimers in clinically suspected deep venous thrombosis of the lower limb. Study Design: Validation study Place and Duration of study: Radiology Department CMH/MH Rawalpindi Six months from 15 June 2006 to 31 December 2006. Subjects and Methods: Thirty cases of clinically suspected deep venous thrombosis of the lower limb were included in the study selected on non probability convenience sampling technique. Colour Doppler ultrasonography examination of the affected lower limb was carried out and results compared with D-dimers assays results. Results: Among 30 patients who underwent colour Doppler ultrasonography examination of the affected limb for diagnosis of deep venous thrombosis, 27 (90%) were diagnosed to have deep venous thrombosis, 3 (10%) were diagnosed not to have deep venous thrombosis. Amongst them 2 patients had raised D-dimers levels and repeat Doppler ultrasound advised. On revised ultrasound deep venous thrombosis in these patients was confirmed. This showed that colour Doppler ultrasonography examination has sensitivity of 93.1%, specificity 100%, positive predictive value 100%, negative predictive value 33.33% and overall accuracy of 93.33 %. Conclusion: Colour Doppler ultrasonography has a high diagnostic yield in cases of deep venous thrombosis of lower limb when used in conjunction with D-dimers assays. (author)

  3. Systematic sampling of discrete and continuous populations: sample selection and the choice of estimator

    Science.gov (United States)

    Harry T. Valentine; David L. R. Affleck; Timothy G. Gregoire

    2009-01-01

    Systematic sampling is easy, efficient, and widely used, though it is not generally recognized that a systematic sample may be drawn from the population of interest with or without restrictions on randomization. The restrictions or the lack of them determine which estimators are unbiased, when using the sampling design as the basis for inference. We describe the...

  4. Cerebral venous angiomas

    International Nuclear Information System (INIS)

    Agnoli, A.L.; Hildebrandt, G.

    1985-01-01

    Clinical symptoms and radiological signs in 15 patients with cerebral venous malformations are presented and the diagnostic problems discussed. The circulation time in combination with cerebral malformations and angiomas of the scalp are described. CT findings in cases of venous malformations of the brain stem are evaluated. Spot-like enhancement, as well as sharply demarcated round shaped enhancement are characteristic for venous angiomas. Cavernous angiomas usually present as homogenous or inhomogenous round shaped enhanced areas. (Author)

  5. The Gender Wage Gap and Sample Selection via Risk Attitudes

    OpenAIRE

    Jung , Seeun

    2014-01-01

    This paper investigates a new way to estimate the gender wage gap with the introduction of individual risk attitudes using representative Korean data. We es- timate the wage gap with correction for the selection bias, which latter results in the overestimation of this wage gap. Female workers are more risk averse. They hence prefer working in the public sector, where wages are generally lower than in the private sector. It goes on to explain the reduced gender wage gap by develop- ing an appr...

  6. Risk Attitudes, Sample Selection and Attrition in a Longitudinal Field Experiment

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten Igel

    with respect to risk attitudes. Our design builds in explicit randomization on the incentives for participation. We show that there are significant sample selection effects on inferences about the extent of risk aversion, but that the effects of subsequent sample attrition are minimal. Ignoring sample...... selection leads to inferences that subjects in the population are more risk averse than they actually are. Correcting for sample selection and attrition affects utility curvature, but does not affect inferences about probability weighting. Properly accounting for sample selection and attrition effects leads...... to findings of temporal stability in overall risk aversion. However, that stability is around different levels of risk aversion than one might naively infer without the controls for sample selection and attrition we are able to implement. This evidence of “randomization bias” from sample selection...

  7. Analysis of Selected Legacy 85Kr Samples

    Energy Technology Data Exchange (ETDEWEB)

    Jubin, Robert Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-02

    Legacy samples composed of 85Kr encapsulated in solid zeolite 5A material and five small metal tubes containing a mixture of the zeolite combined with a glass matrix resulting from hot isostatic pressing have been preserved. The samples were a result of krypton R&D encapsulation efforts in the late 1970s performed at the Idaho Chemical Processing Plant. These samples were shipped to Oak Ridge National Laboratory (ORNL) in mid-FY 2014. Upon receipt the outer shipping package was opened, and the inner package, removed and placed in a radiological hood. The individual capsules were double bagged as they were removed from the inner shipping pig and placed into individual glass sample bottles for further analysis. The five capsules were then x-ray imaged. Capsules 1 and 4 appear intact and to contain an amorphous mass within the capsules. Capsule 2 clearly shows the saw marks on the capsule and a quantity of loose pellet or bead-like material remaining in the capsule. Capsule 3 shows similar bead-like material within the intact capsule. Capsule 5 had been opened at an undetermined time in the past. The end of this capsule appears to have been cut off, and there are additional saw marks on the side of the capsule. X-ray tomography allowed the capsules to be viewed along the three axes. Of most interest was determining whether there was any residual material in the closed end of Capsule 5. The images confirmed the presence of residual material within this capsule. The material appears to be compacted but still retains some of the bead-like morphology. Based on the nondestructive analysis (NDA) results, a proposed path forward was formulated to advance this effort toward the original goals of understanding the effects of extended storage on the waste form and package. Based on the initial NDA and the fact that there are at least two breached samples, it was proposed that exploratory tests be conducted with the breached specimens before opening the three intact

  8. Learning spectrum's selection in OLAM network for analysis cement samples

    International Nuclear Information System (INIS)

    Huang Ning; Wang Peng; Tang Daiquan; Hu Renlan

    2010-01-01

    It uses OLAM artificial neural network to analyze the samples of cement raw material. Two kinds of spectrums are used for network learning: pure-element spectrum and mix-element spectrum. The output of pure-element method can be used to construct a simulate spectrum, which can be compared with the original spectrum and judge the shift of spectrum; the mix-element method can store more message and correct the matrix effect, but the multicollinearity among spectrums can cause some side effect to the results. (authors)

  9. Mineralogical, chemical, and petrographic analysis of selected rock samples

    International Nuclear Information System (INIS)

    Roy, D.M.

    1976-01-01

    I. The majority of rocks examined from the NTS were found to be siltstones, varying from coarse into the very fine siltstone range, and containing > 60% quartz, usually much higher. Samples of the UEIL series of cores, in contrast, had a large clay mineral fraction, as well as some carbonate present. A few were intermediate silty claystones or argillites. Microphotographs are included to illustrate the variations in texture observed, while most of the data obtained are summarized in tabular form. II. Seven Michigan Salina evaporite specimens were analyzed

  10. Selection of bone samples for 239Pu analyses in man

    International Nuclear Information System (INIS)

    Jee, W.S.S.; Wronski, T.J.; Smith, J.M.; Kimmel, D.B.; Miller, S.C.; Stover, B.J.

    1981-01-01

    Studies on the skeletal macrodistribution, microdistribution, and toxicity of 239 Pu and studies on bone turnover rates show that trabecular bone sites with high turnover rates have the greatest affinity for 239 Pu. In the adult beagle, these high-turnover, trabecular bone sites also show a higher occurrence of osteosarcomas. Correspondingly, high-turnover bone sites in the human would include the ilium (pelvis) and lumbar vertebrae (LVB), sites that are readily obtainable at autopsy. We recommend that the trabecular bone of the ilium and of the LVB be sampled to determine the skeletal radionuclide content of humans

  11. 40 CFR 205.160-2 - Test sample selection and preparation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Test sample selection and preparation... sample selection and preparation. (a) Vehicles comprising the sample which are required to be tested... maintained in any manner unless such preparation, tests, modifications, adjustments or maintenance are part...

  12. Comparison between capillary, venous and arterial levels of protein S100B in patients with severe brain pathology

    DEFF Research Database (Denmark)

    Astrand, Ramona; Romner, Bertil; Reinstrup, Peter

    2012-01-01

    of the study was to investigate the relation between capillary, venous and arterial measurements of protein S100B, primarily by determining whether capillary S100B differ from venous and if capillary S100B can predict venous S100B levels, and secondarily, if arterial S100B samples can substitute venous samples...... in severely brain-injured patients....

  13. Analysis of selected phytotoxins and mycotoxins in environmental samples.

    Science.gov (United States)

    Hoerger, Corinne C; Schenzel, Judith; Strobel, Bjarne W; Bucheli, Thomas D

    2009-11-01

    Natural toxins such as phytotoxins and mycotoxins have been studied in food and feed for decades, but little attention has yet been paid to their occurrence in the environment. Because of increasing awareness of the presence and potential relevance of micropollutants in the environment, phytotoxins and mycotoxins should be considered and investigated as part of the chemical cocktail in natural samples. Here, we compile chemical analytical methods to determine important phytotoxins (i.e. phenolic acids, quinones, benzoxazinones, terpenoids, glycoalkaloids, glucosinolates, isothiocyanates, phytosterols, flavonoids, coumestans, lignans, and chalcones) and mycotoxins (i.e. resorcyclic acid lactones, trichothecenes, fumonisins, and aflatoxins) in environmentally relevant matrices such as surface water, waste water-treatment plant influent and effluent, soil, sediment, manure, and sewage sludge. The main problems encountered in many of the reviewed methods were the frequent unavailability of suitable internal standards (especially isotope-labelled analogues) and often absent or fragmentary method optimization and validation.

  14. Reproductive performance in a select sample of dairy herds.

    Science.gov (United States)

    Ferguson, James D; Skidmore, Andrew

    2013-02-01

    Sixteen herds were selected from a pool of 64 herds nominated by consultants for participation in a national survey to demonstrate excellence in reproductive performance. For inclusion in the survey, herds had to have comprehensive records in a farm computer database or participate in a Dairy Herd Improvement Association record system and have superior reproductive performance as judged by the herd advisor. Herd managers were asked to fill out a questionnaire to describe their reproductive management practices and provide herd records for data analysis. Reproductive analysis was based on individual cow records for active and cull dairy cows that calved during the calendar year 2010. Breeding records by cow were used to calculate indices for insemination rate (IR), conception rate (CR), pregnancy rate (PR), and culling. Herds ranged in size from 262 to 6,126 lactating and dry cows, with a mean of 1,654 [standard deviation (SD) 1,494] cows. Mean days to first insemination (DFS) was 71.2d (SD 4.7d), and IR for first insemination was 86.9%. Mean days between inseminations were 33.4d (SD 3.1d), and 15.4% of insemination intervals were greater than 48 d (range: 7.2 to 21.5%). First-service conception rate was 44.4% (SD 4.8%) across all herds and ranged from 37.5 to 51.8%. Mean PR was 32.0% (SD 3.9%) with a range of 26.5 to 39.4%. Lactation cull rate was 32.2% (SD 12.4%) with a range from 13.6 to 58.1%. Compared with mean data and SD for herds in the Raleigh Dairy Herd Improvement Association system, mean indices for these herds ranked them in the 99 th percentile for IR (using heat detection rate as comparison), 99 th percentile for PR, the bottom 18.6 percentile for DFS, and around the 50th percentile for CR. This suggests that excellent herd reproductive performance was associated with reproductive management that resulted in high insemination rates combined with average CR. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights

  15. Measurement of radioactivity in the environment - Soil - Part 2: Guidance for the selection of the sampling strategy, sampling and pre-treatment of samples

    International Nuclear Information System (INIS)

    2007-01-01

    This part of ISO 18589 specifies the general requirements, based on ISO 11074 and ISO/IEC 17025, for all steps in the planning (desk study and area reconnaissance) of the sampling and the preparation of samples for testing. It includes the selection of the sampling strategy, the outline of the sampling plan, the presentation of general sampling methods and equipment, as well as the methodology of the pre-treatment of samples adapted to the measurements of the activity of radionuclides in soil. This part of ISO 18589 is addressed to the people responsible for determining the radioactivity present in soil for the purpose of radiation protection. It is applicable to soil from gardens, farmland, urban or industrial sites, as well as soil not affected by human activities. This part of ISO 18589 is applicable to all laboratories regardless of the number of personnel or the range of the testing performed. When a laboratory does not undertake one or more of the activities covered by this part of ISO 18589, such as planning, sampling or testing, the corresponding requirements do not apply. Information is provided on scope, normative references, terms and definitions and symbols, principle, sampling strategy, sampling plan, sampling process, pre-treatment of samples and recorded information. Five annexes inform about selection of the sampling strategy according to the objectives and the radiological characterization of the site and sampling areas, diagram of the evolution of the sample characteristics from the sampling site to the laboratory, example of sampling plan for a site divided in three sampling areas, example of a sampling record for a single/composite sample and example for a sample record for a soil profile with soil description. A bibliography is provided

  16. 40 CFR 205.171-2 - Test exhaust system sample selection and preparation.

    Science.gov (United States)

    2010-07-01

    ... Systems § 205.171-2 Test exhaust system sample selection and preparation. (a)(1) Exhaust systems... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Test exhaust system sample selection and preparation. 205.171-2 Section 205.171-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  17. Observed Characteristics and Teacher Quality: Impacts of Sample Selection on a Value Added Model

    Science.gov (United States)

    Winters, Marcus A.; Dixon, Bruce L.; Greene, Jay P.

    2012-01-01

    We measure the impact of observed teacher characteristics on student math and reading proficiency using a rich dataset from Florida. We expand upon prior work by accounting directly for nonrandom attrition of teachers from the classroom in a sample selection framework. We find evidence that sample selection is present in the estimation of the…

  18. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    International Nuclear Information System (INIS)

    Elsheikh, Ahmed H.; Wheeler, Mary F.; Hoteit, Ibrahim

    2014-01-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems

  19. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    Energy Technology Data Exchange (ETDEWEB)

    Elsheikh, Ahmed H., E-mail: aelsheikh@ices.utexas.edu [Institute for Computational Engineering and Sciences (ICES), University of Texas at Austin, TX (United States); Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Wheeler, Mary F. [Institute for Computational Engineering and Sciences (ICES), University of Texas at Austin, TX (United States); Hoteit, Ibrahim [Department of Earth Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal (Saudi Arabia)

    2014-02-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems.

  20. Cerebral sino-venous thrombosis

    International Nuclear Information System (INIS)

    Sayama, Ichiro; Kobayashi, Tsunesaburo; Nakajima, Kenji

    1982-01-01

    Three cases of cerebral sino-venous thrombosis were reported. Repeated CT findings were studied and discussed on account of the treatments for those pathologic conditions. Those of studied cases are; a 22-year-old postpartum woman, a 42-year-old woman with irregular vaginal bleeding, and a 26-year-old man with severe reactive emesis after drinking alcohol. They were treated conservatively. Case 1 died in its acute stage. In the remaining ones, each had an uneventful recovery. CT scan findings of them manifested their exact clinical conditions. These findings were devided into two categories, one was direct signs expressed sino-venous occlusion, the other was indirect signs which appeared as a result of these occlusion. Direct signs cannot always get in every cases with sino-venous occlusion, but as for indirect signs, we can get various changes corresponding to the time taken CT photoes, and they are useful to decide appropriate treatments at that time. Considering suitable treatments for this disease, it is necessary to select most suitable ones according to their pathologic conditions, which may be precisely drawn with CT scans. (J.P.N.)

  1. Current concepts in repair of extremity venous injury.

    Science.gov (United States)

    Williams, Timothy K; Clouse, W Darrin

    2016-04-01

    role in reducing venous hypertensive sequelae as well as a potential role in limb salvage. Appropriate triage selection for extremity vein repair is essential. Copyright © 2016 Society for Vascular Surgery. All rights reserved.

  2. Impact of computerized order entry and pre-mixed dialysis solutions for continuous veno-venous hemodiafiltration on selection of therapy for acute renal failure.

    Science.gov (United States)

    Saadulla, Lawand; Reeves, W Brian; Irey, Brittany; Ghahramani, Nasrollah

    2012-02-01

    To investigate the impacts of availability of pre-mixed solutions and computerized order entry on nephrologists' choice of the initial mode of renal replacement therapy in acute renal failure. We studied 898 patients with acute renal failure in 3 consecutive eras: era 1 (custom-mixed solution; n = 309), era 2 (pre-mixed commercial solution; n = 324), and era 3 (post-computerized order entry; n = 265). The proportion of patients treated with renal replacement therapy and the time from consult to initiation of continuous renal replacement therapy was similar in the 3 eras. Following introduction of the pre-mixed solution, the proportion of patients treated with continuous renal replacement therapy increased (20% vs. 33%; p mixed solution increases the likelihood of initiating continuous renal replacement therapy in acute renal failure, initiating it at a lower creatinine and for older patients, use of continuous veno-venous hemodialysis and higher prescribed continuous renal replacement therapy dose. Computerized order entry implementation is associated with an additional increase in the use of continuous veno-venous hemodialysis, higher total prescribed dialysis dose, and use of CRRT among an increasing number of patients not on mechanical ventilation. The effect of these changes on patient survival is not significant.

  3. Chronic venous disorders

    African Journals Online (AJOL)

    The San Valentino Vascular Screening Project conducted in Italy found a ... developed healthcare systems, the cost of treating advanced venous disease ..... tissue inflammation and necrosis. Sclerosing ... and for its tributaries as an alternative.

  4. Application of strict criteria in adrenal venous sampling increases the proportion of missed patients with unilateral disease who benefit from surgery for primary aldosteronism.

    Science.gov (United States)

    Kline, Gregory; Leung, Alexander; So, Benny; Chin, Alex; Harvey, Adrian; Pasieka, Janice L

    2018-06-01

    Adrenal vein sampling (AVS) is intended to confirm unilateral forms of primary aldosteronism, which are amenable to surgical cure. Excessively strict AVS criteria to define lateralization may result in many patients incorrectly categorized as bilateral primary aldosteronism and opportunity for surgical cure missed. Retrospective review of an AVS-primary aldosteronism database in which surgical cases are verified by standardized outcomes. Having used 'less strict' AVS criteria for lateralization, we examined the distribution of AVS lateralization indices in our confirmed unilateral primary aldosteronism cases both with and without cosyntropin stimulation. The proportion of proven unilateral cases that would have been missed with stricter AVS interpretation criteria was calculated. Particular focus was given to the proportion of missed cases according to use of international guidelines. False-positive lateralization with 'less strict' interpretation was also calculated. Of 80 surgical primary aldosteronism cases, 10-23% would have been missed with AVS lateralization indices of 3 : 1 to 5 : 1, with or without cosyntropin. If strict selectivity indices (for confirmation of catheterization) were combined with strict lateralization indices, up to 70% of unilateral primary aldosteronism cases could have been missed. Use of Endocrine Society AVS guidelines would have missed 21-43% of proven unilateral cases. 'Less strict' AVS interpretation yielded one case (1.2%) of false lateralization. Excessively strict AVS interpretation criteria will result in a high rate of missed unilateral primary aldosteronism with subsequent loss of opportunity for intervention. Use of more lenient lateralization criteria will improve the detection rate of unilateral primary aldosteronism with very low false-positive rate.

  5. 40 CFR 761.247 - Sample site selection for pipe segment removal.

    Science.gov (United States)

    2010-07-01

    ... end of the pipe segment. (3) If the pipe segment is cut with a saw or other mechanical device, take..., take samples from a total of seven segments. (A) Sample the first and last segments removed. (B) Select... total length for purposes of disposal, take samples of each segment that is 1/2 mile distant from the...

  6. 40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...

  7. Prophylaxis of Venous Thrombosis.

    Science.gov (United States)

    Goldhaber, Samuel Z.

    2001-06-01

    Mechanical measures such as graduated compression stockings and intermittent compression boots are available for venous thrombosis prophylaxis, but compliance may be limited. Plantar venous pneumatic compression devices have attained widespread acceptance by both patients and nurses because of their comfort and compact size, but their track record for efficacy is poor. Inferior vena cava filters prevent pulmonary embolism, but do not halt the thrombotic process or prevent venous thrombosis. Pharmacologic prophylaxis traditionally has relied upon minidose unfractionated heparin; however, re-examination is warranted in the face of increasingly ill and complex patients. My opinion is that small, fixed doses of once-daily low molecular weight heparin will eventually replace minidose unfractionated heparin as the standard pharmacologic prophylaxis regimen for most surgical and medical patients. Prolongation of prophylaxis after hospital discharge should receive increased emphasis. Most patients being transferred to a skilled nursing facility should receive venous thromboembolism prophylaxis. Similarly, most patients undergoing total hip or knee replacement should receive prolonged preventive regimens, with at least 1 month of anticoagulation. Despite advances, certain aspects of venous thrombosis prophylaxis remain problematic. First, a surprisingly high number of hospitalized patients develop venous thrombosis because of failed (rather than omitted) prophylaxis. Second, many patients in intensive care have a combination of peripheral vascular disease and active bleeding (usually gastrointestinal) that precludes mechanical or pharmacologic prophylaxis. Third, neurosurgical patients undergoing craniotomy for brain tumors suffer a high rate of venous thrombosis and major pulmonary embolism despite the routine use of combined mechanical and pharmacologic prophylaxis. My opinion is that these three areas, in addition to the hospital culture of prophylaxis, should receive

  8. Inflammation and peripheral venous disease. The San Diego Population Study.

    Science.gov (United States)

    Cushman, M; Callas, P W; Allison, M A; Criqui, M H

    2014-09-02

    The inflammatory response to healing in venous thrombosis might cause vein damage and post-thrombotic syndrome. Inflammation may also be involved in venous insufficiency apart from deep-vein thrombosis. We studied the association of inflammation markers with venous insufficiency in a general population sample. We characterised 2,404 men and women in a general population cohort for peripheral venous disease and its severity using physical exam, symptom assessment, and venous ultrasound. Inflammation markers, C-reactive protein (CRP), fibrinogen, interleukin 1-beta (IL-1-beta), IL-8, IL-10, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, monocyte chemoattractant-1 (MCP-1) and vascular endothelial cell growth factor (VEGF) were compared in 352 case participants with peripheral venous disease and 352 controls with no venous abnormalities frequency matched to cases by age, sex and race. Associations were also evaluated including a subset of 108 cases of severe venous disease, as previously defined. Odds ratios (95% CI), for peripheral venous disease for biomarkers in the top quartile (adjusting for age, race, sex, body mass index and history of venous thrombosis) were 1.8 (1.1-3.0), 1.6 (1.0-2.5) and 1.5 (0.9-2.3) for CRP, fibrinogen and IL-10, respectively. Associations were larger considering cases of severe venous disease, with odds ratios for these three analytes of 2.6 (1.2-5.9), 3.1 (1.3-7.3) and 2.2 (1.1-4.4), and for IL-8: 2.4 (1.1-5.2). There was no association of IL-1-beta, ICAM-1, VCAM-1, E-selectin, MCP-1 or VEGF with overall cases or severe venous disease. In conclusion, a subset of inflammation markers were associated with increased risk of peripheral venous disease, suggesting potential therapeutic targets for treatment.

  9. Data Quality Objectives For Selecting Waste Samples To Test The Fluid Bed Steam Reformer Test

    International Nuclear Information System (INIS)

    Banning, D.L.

    2010-01-01

    This document describes the data quality objectives to select archived samples located at the 222-S Laboratory for Fluid Bed Steam Reformer testing. The type, quantity and quality of the data required to select the samples for Fluid Bed Steam Reformer testing are discussed. In order to maximize the efficiency and minimize the time to treat Hanford tank waste in the Waste Treatment and Immobilization Plant, additional treatment processes may be required. One of the potential treatment processes is the fluid bed steam reformer (FBSR). A determination of the adequacy of the FBSR process to treat Hanford tank waste is required. The initial step in determining the adequacy of the FBSR process is to select archived waste samples from the 222-S Laboratory that will be used to test the FBSR process. Analyses of the selected samples will be required to confirm the samples meet the testing criteria.

  10. On a Robust MaxEnt Process Regression Model with Sample-Selection

    Directory of Open Access Journals (Sweden)

    Hea-Jung Kim

    2018-04-01

    Full Text Available In a regression analysis, a sample-selection bias arises when a dependent variable is partially observed as a result of the sample selection. This study introduces a Maximum Entropy (MaxEnt process regression model that assumes a MaxEnt prior distribution for its nonparametric regression function and finds that the MaxEnt process regression model includes the well-known Gaussian process regression (GPR model as a special case. Then, this special MaxEnt process regression model, i.e., the GPR model, is generalized to obtain a robust sample-selection Gaussian process regression (RSGPR model that deals with non-normal data in the sample selection. Various properties of the RSGPR model are established, including the stochastic representation, distributional hierarchy, and magnitude of the sample-selection bias. These properties are used in the paper to develop a hierarchical Bayesian methodology to estimate the model. This involves a simple and computationally feasible Markov chain Monte Carlo algorithm that avoids analytical or numerical derivatives of the log-likelihood function of the model. The performance of the RSGPR model in terms of the sample-selection bias correction, robustness to non-normality, and prediction, is demonstrated through results in simulations that attest to its good finite-sample performance.

  11. A novel heterogeneous training sample selection method on space-time adaptive processing

    Science.gov (United States)

    Wang, Qiang; Zhang, Yongshun; Guo, Yiduo

    2018-04-01

    The performance of ground target detection about space-time adaptive processing (STAP) decreases when non-homogeneity of clutter power is caused because of training samples contaminated by target-like signals. In order to solve this problem, a novel nonhomogeneous training sample selection method based on sample similarity is proposed, which converts the training sample selection into a convex optimization problem. Firstly, the existing deficiencies on the sample selection using generalized inner product (GIP) are analyzed. Secondly, the similarities of different training samples are obtained by calculating mean-hausdorff distance so as to reject the contaminated training samples. Thirdly, cell under test (CUT) and the residual training samples are projected into the orthogonal subspace of the target in the CUT, and mean-hausdorff distances between the projected CUT and training samples are calculated. Fourthly, the distances are sorted in order of value and the training samples which have the bigger value are selective preference to realize the reduced-dimension. Finally, simulation results with Mountain-Top data verify the effectiveness of the proposed method.

  12. Selecting Sample Preparation Workflows for Mass Spectrometry-Based Proteomic and Phosphoproteomic Analysis of Patient Samples with Acute Myeloid Leukemia.

    Science.gov (United States)

    Hernandez-Valladares, Maria; Aasebø, Elise; Selheim, Frode; Berven, Frode S; Bruserud, Øystein

    2016-08-22

    Global mass spectrometry (MS)-based proteomic and phosphoproteomic studies of acute myeloid leukemia (AML) biomarkers represent a powerful strategy to identify and confirm proteins and their phosphorylated modifications that could be applied in diagnosis and prognosis, as a support for individual treatment regimens and selection of patients for bone marrow transplant. MS-based studies require optimal and reproducible workflows that allow a satisfactory coverage of the proteome and its modifications. Preparation of samples for global MS analysis is a crucial step and it usually requires method testing, tuning and optimization. Different proteomic workflows that have been used to prepare AML patient samples for global MS analysis usually include a standard protein in-solution digestion procedure with a urea-based lysis buffer. The enrichment of phosphopeptides from AML patient samples has previously been carried out either with immobilized metal affinity chromatography (IMAC) or metal oxide affinity chromatography (MOAC). We have recently tested several methods of sample preparation for MS analysis of the AML proteome and phosphoproteome and introduced filter-aided sample preparation (FASP) as a superior methodology for the sensitive and reproducible generation of peptides from patient samples. FASP-prepared peptides can be further fractionated or IMAC-enriched for proteome or phosphoproteome analyses. Herein, we will review both in-solution and FASP-based sample preparation workflows and encourage the use of the latter for the highest protein and phosphorylation coverage and reproducibility.

  13. Selecting Sample Preparation Workflows for Mass Spectrometry-Based Proteomic and Phosphoproteomic Analysis of Patient Samples with Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Maria Hernandez-Valladares

    2016-08-01

    Full Text Available Global mass spectrometry (MS-based proteomic and phosphoproteomic studies of acute myeloid leukemia (AML biomarkers represent a powerful strategy to identify and confirm proteins and their phosphorylated modifications that could be applied in diagnosis and prognosis, as a support for individual treatment regimens and selection of patients for bone marrow transplant. MS-based studies require optimal and reproducible workflows that allow a satisfactory coverage of the proteome and its modifications. Preparation of samples for global MS analysis is a crucial step and it usually requires method testing, tuning and optimization. Different proteomic workflows that have been used to prepare AML patient samples for global MS analysis usually include a standard protein in-solution digestion procedure with a urea-based lysis buffer. The enrichment of phosphopeptides from AML patient samples has previously been carried out either with immobilized metal affinity chromatography (IMAC or metal oxide affinity chromatography (MOAC. We have recently tested several methods of sample preparation for MS analysis of the AML proteome and phosphoproteome and introduced filter-aided sample preparation (FASP as a superior methodology for the sensitive and reproducible generation of peptides from patient samples. FASP-prepared peptides can be further fractionated or IMAC-enriched for proteome or phosphoproteome analyses. Herein, we will review both in-solution and FASP-based sample preparation workflows and encourage the use of the latter for the highest protein and phosphorylation coverage and reproducibility.

  14. 6. Label-free selective plane illumination microscopy of tissue samples

    Directory of Open Access Journals (Sweden)

    Muteb Alharbi

    2017-10-01

    Conclusion: Overall this method meets the demands of the current needs for 3D imaging tissue samples in a label-free manner. Label-free Selective Plane Microscopy directly provides excellent information about the structure of the tissue samples. This work has highlighted the superiority of Label-free Selective Plane Microscopy to current approaches to label-free 3D imaging of tissue.

  15. Accounting for animal movement in estimation of resource selection functions: sampling and data analysis.

    Science.gov (United States)

    Forester, James D; Im, Hae Kyung; Rathouz, Paul J

    2009-12-01

    Patterns of resource selection by animal populations emerge as a result of the behavior of many individuals. Statistical models that describe these population-level patterns of habitat use can miss important interactions between individual animals and characteristics of their local environment; however, identifying these interactions is difficult. One approach to this problem is to incorporate models of individual movement into resource selection models. To do this, we propose a model for step selection functions (SSF) that is composed of a resource-independent movement kernel and a resource selection function (RSF). We show that standard case-control logistic regression may be used to fit the SSF; however, the sampling scheme used to generate control points (i.e., the definition of availability) must be accommodated. We used three sampling schemes to analyze simulated movement data and found that ignoring sampling and the resource-independent movement kernel yielded biased estimates of selection. The level of bias depended on the method used to generate control locations, the strength of selection, and the spatial scale of the resource map. Using empirical or parametric methods to sample control locations produced biased estimates under stronger selection; however, we show that the addition of a distance function to the analysis substantially reduced that bias. Assuming a uniform availability within a fixed buffer yielded strongly biased selection estimates that could be corrected by including the distance function but remained inefficient relative to the empirical and parametric sampling methods. As a case study, we used location data collected from elk in Yellowstone National Park, USA, to show that selection and bias may be temporally variable. Because under constant selection the amount of bias depends on the scale at which a resource is distributed in the landscape, we suggest that distance always be included as a covariate in SSF analyses. This approach to

  16. Using maximum entropy modeling for optimal selection of sampling sites for monitoring networks

    Science.gov (United States)

    Stohlgren, Thomas J.; Kumar, Sunil; Barnett, David T.; Evangelista, Paul H.

    2011-01-01

    Environmental monitoring programs must efficiently describe state shifts. We propose using maximum entropy modeling to select dissimilar sampling sites to capture environmental variability at low cost, and demonstrate a specific application: sample site selection for the Central Plains domain (453,490 km2) of the National Ecological Observatory Network (NEON). We relied on four environmental factors: mean annual temperature and precipitation, elevation, and vegetation type. A “sample site” was defined as a 20 km × 20 km area (equal to NEON’s airborne observation platform [AOP] footprint), within which each 1 km2 cell was evaluated for each environmental factor. After each model run, the most environmentally dissimilar site was selected from all potential sample sites. The iterative selection of eight sites captured approximately 80% of the environmental envelope of the domain, an improvement over stratified random sampling and simple random designs for sample site selection. This approach can be widely used for cost-efficient selection of survey and monitoring sites.

  17. Brain venous pathologies: MRI findings

    International Nuclear Information System (INIS)

    Salvatico, Rosana; Gonzalez, Alejandro; Yanez, Paulina; Romero, Carlos; Trejo, Mariano; Lambre, Hector

    2006-01-01

    Purpose: To describe MRI findings of the different brain venous pathologies. Material and Methods: Between January 2002 and March 2004, 18 patients were studied 10 males and 8 females between 6 and 63 years old; with different brain venous pathologies. In all cases brain MRI were performed including morphological sequences with and without gadolinium injection and angiographic venous sequences. Results: 10 venous occlusions were found, 6 venous angiomas, and 2 presented varices secondary to arteriovenous dural fistula. Conclusion: Brain venous pathologies can appear in many different clinical contexts, with different prognosis and treatment. In all the cases brain MRI was the best imaging study to disclose typical morphologic abnormalities. (author) [es

  18. Optimal Selection of the Sampling Interval for Estimation of Modal Parameters by an ARMA- Model

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning

    1993-01-01

    Optimal selection of the sampling interval for estimation of the modal parameters by an ARMA-model for a white noise loaded structure modelled as a single degree of- freedom linear mechanical system is considered. An analytical solution for an optimal uniform sampling interval, which is optimal...

  19. Correlations fo Sc, rare earths and other elements in selected rock samples from Arrua-i

    Energy Technology Data Exchange (ETDEWEB)

    Facetti, J F; Prats, M [Asuncion Nacional Univ. (Paraguay). Inst. de Ciencias

    1972-01-01

    The Sc and Eu contents in selected rocks samples from the stock of Arrua-i have been determined and correlations established with other elements and with the relative amount of some rare earths. These correlations suggest metasomatic phenomena for the formation of the rock samples.

  20. HOT-DUST-POOR QUASARS IN MID-INFRARED AND OPTICALLY SELECTED SAMPLES

    International Nuclear Information System (INIS)

    Hao Heng; Elvis, Martin; Civano, Francesca; Lawrence, Andy

    2011-01-01

    We show that the hot-dust-poor (HDP) quasars, originally found in the X-ray-selected XMM-COSMOS type 1 active galactic nucleus (AGN) sample, are just as common in two samples selected at optical/infrared wavelengths: the Richards et al. Spitzer/SDSS sample (8.7% ± 2.2%) and the Palomar-Green-quasar-dominated sample of Elvis et al. (9.5% ± 5.0%). The properties of the HDP quasars in these two samples are consistent with the XMM-COSMOS sample, except that, at the 99% (∼ 2.5σ) significance, a larger proportion of the HDP quasars in the Spitzer/SDSS sample have weak host galaxy contributions, probably due to the selection criteria used. Either the host dust is destroyed (dynamically or by radiation) or is offset from the central black hole due to recoiling. Alternatively, the universality of HDP quasars in samples with different selection methods and the continuous distribution of dust covering factor in type 1 AGNs suggest that the range of spectral energy distributions could be related to the range of tilts in warped fueling disks, as in the model of Lawrence and Elvis, with HDP quasars having relatively small warps.

  1. Correlations fo Sc, rare earths and other elements in selected rock samples from Arrua-i

    International Nuclear Information System (INIS)

    Facetti, J.F.; Prats, M.

    1972-01-01

    The Sc and Eu contents in selected rocks samples from the stock of Arrua-i have been determined and correlations established with other elements and with the relative amount of some rare earths. These correlations suggest metasomatic phenomena for the formation of the rock samples

  2. Proposal for selecting an ore sample from mining shaft under Kvanefjeld

    International Nuclear Information System (INIS)

    Lund Clausen, F.

    1979-02-01

    Uranium ore recovered from the tunnel under Kvanefjeld (Greenland) will be processed in a pilot plant. Selection of a fully representative ore sample for both the whole area and single local sites is discussed. A FORTRAN program for ore distribution is presented, in order to enable correct sampling. (EG)

  3. Cerebral venous thrombosis

    International Nuclear Information System (INIS)

    Soralova, T.; Sevcikova, H.; Petersky, D.

    2014-01-01

    We decided to process this theme due to its nonspecific clinical features as they often cause diagnostic problems not only to clinicians but also to diagnostic. It is important to think of this disease mainly in young women who administer hormonal contraception. Imaging methods play the crucial role in diagnostic of cerebral venous sinus thrombosis. The gold standard is a native CT of brain which shows the venous sinus thrombosis as a hyperdense lesion in the locus of the sinus (dense triangle sign), CT venography shows the sinus thrombosis as a defect in a contrast filling of the venous sinus (empty delta sign). Other investigative methods are magnetic resonance imaging or MRA. In short we also mention quite a rare but more serious thrombosis of profound cerebral veins v. cerebri magna-Galeni, vv. cerebri internae). The importance of early diagnostic and non specificity of symptoms is presented in 3 clinical cases that are the part of this work. (author)

  4. Direct venous thrombolysis and venous angioplasty in the upper extremity

    International Nuclear Information System (INIS)

    Hollmann, J.P.; Guenther, R.W.

    1987-01-01

    Venous thromboses of stenoses in the upper extremity are often the result of a compression syndrome of the shoulder girdle, the Paget-von Schroetter syndrome, vascular surgery, space-occupying lesions in the mediastinum or the result of catheterisation. Direct venous thrombolysis and venous angioplasty were performed successfully in six patients. (orig.) [de

  5. Electromembrane extraction as a rapid and selective miniaturized sample preparation technique for biological fluids

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Pedersen-Bjergaard, Stig; Seip, Knut Fredrik

    2015-01-01

    This special report discusses the sample preparation method electromembrane extraction, which was introduced in 2006 as a rapid and selective miniaturized extraction method. The extraction principle is based on isolation of charged analytes extracted from an aqueous sample, across a thin film....... Technical aspects of electromembrane extraction, important extraction parameters as well as a handful of examples of applications from different biological samples and bioanalytical areas are discussed in the paper....

  6. Data Quality Objectives For Selecting Waste Samples For Bench-Scale Reformer Treatability Studies

    International Nuclear Information System (INIS)

    Banning, D.L.

    2011-01-01

    This document describes the data quality objectives to select archived samples located at the 222-S Laboratory for Bench-Scale Reforming testing. The type, quantity, and quality of the data required to select the samples for Fluid Bed Steam Reformer testing are discussed. In order to maximize the efficiency and minimize the time to treat Hanford tank waste in the Waste Treatment and Immobilization Plant, additional treatment processes may be required. One of the potential treatment processes is the fluidized bed steam reformer. A determination of the adequacy of the fluidized bed steam reformer process to treat Hanford tank waste is required. The initial step in determining the adequacy of the fluidized bed steam reformer process is to select archived waste samples from the 222-S Laboratory that will be used in a bench scale tests. Analyses of the selected samples will be required to confirm the samples meet the shipping requirements and for comparison to the bench scale reformer (BSR) test sample selection requirements.

  7. Approaches to sampling and case selection in qualitative research: examples in the geography of health.

    Science.gov (United States)

    Curtis, S; Gesler, W; Smith, G; Washburn, S

    2000-04-01

    This paper focuses on the question of sampling (or selection of cases) in qualitative research. Although the literature includes some very useful discussions of qualitative sampling strategies, the question of sampling often seems to receive less attention in methodological discussion than questions of how data is collected or is analysed. Decisions about sampling are likely to be important in many qualitative studies (although it may not be an issue in some research). There are varying accounts of the principles applicable to sampling or case selection. Those who espouse 'theoretical sampling', based on a 'grounded theory' approach, are in some ways opposed to those who promote forms of 'purposive sampling' suitable for research informed by an existing body of social theory. Diversity also results from the many different methods for drawing purposive samples which are applicable to qualitative research. We explore the value of a framework suggested by Miles and Huberman [Miles, M., Huberman,, A., 1994. Qualitative Data Analysis, Sage, London.], to evaluate the sampling strategies employed in three examples of research by the authors. Our examples comprise three studies which respectively involve selection of: 'healing places'; rural places which incorporated national anti-malarial policies; young male interviewees, identified as either chronically ill or disabled. The examples are used to show how in these three studies the (sometimes conflicting) requirements of the different criteria were resolved, as well as the potential and constraints placed on the research by the selection decisions which were made. We also consider how far the criteria Miles and Huberman suggest seem helpful for planning 'sample' selection in qualitative research.

  8. Chronic venous disease.

    Science.gov (United States)

    Wolinsky, Claire D; Waldorf, Heidi

    2009-11-01

    Identifying characteristic cutaneous findings is important in determining the appropriate management of certain venous diseases. The health care provider should be familiar with the classic description of patterns and distributions of skin manifestations, such as varicose veins, stasis dermatitis, palpable cord, petechiae, and telangiectasias. In addition to the gross appearance of the skin, a skin biopsy may help elucidate a diagnosis. General treatment and prevention of the underlying venous pathology is essential. Furthermore, specific management of skin findings should include therapy to ameliorate progression of disease and symptomatology when warranted.

  9. Central Venous Access

    International Nuclear Information System (INIS)

    Ganeshan, Arul; Warakaulle, Dinuke R.; Uberoi, Raman

    2007-01-01

    Central venous access plays an important role in the management of an ever-increasing population of patients ranging from those that are critically ill to patients with difficult clinical access. Interventional radiologists are key in delivering this service and should be familiar with the wide range of techniques and catheters now available to them. A comprehensive description of these catheters with regard to indications, technical aspects of catheterization, success rates, and associated early and late complications, as well as a review of various published guidelines on central venous catheter insertion are given in this article

  10. Cushing's disease; inferior petrosal sinus venography and samplings

    International Nuclear Information System (INIS)

    Chung, Tae Sub; Suh, Jung Ho; Kim, Dong Ik; Lee, Hyun Chul; Huh, Kap Bum; Kim, Young Soo; Chung, Sang Sup

    1991-01-01

    Hypersecretion of ACTH in patients with Cushing's syndrome originates from either a pituitary tumor (Cushing's disease) or an ectopic ACTH-secreting tumor. These 2 entities may be clinically indistinguishable, and additional difficulty arise because pituitary microadenomas may be radiologically occult. Recently, bilateral selective venous sampling from the inferior petrosal sinuses became the procedure of choice for confirming a false negative study of a combined hormonal test and pituitary ACTH hypersecretion. We performed selective venous catheterization and sampling for ACTH. The central location of the lesion was detected in 1 case (intersinus gradient = 1.1 : 1), and the remaining 5 cases revealed lateralization of the lesions (intersinus gradient = 3.7 - 20.1 : 1), which correlated well with transsphenoidal microadenomectomies in all the cases. We concluded that selective venous ACTH sampling from the inferior petroal sinus is a reliable and useful aid in the diagnosis of Cushing's disease when standard clinical and biochemical studies are inconclusive

  11. Venous ulcers -- self-care

    Science.gov (United States)

    ... surgery to improve blood flow through your veins. Prevention If you are at risk for venous ulcers, take the steps listed above under Wound Care. ... weight if you are overweight. Manage your blood pressure and cholesterol levels. ... Venous leg ulcers - self-care; Venous insufficiency ulcers - self-care; Stasis ...

  12. The Impact of Selection, Gene Conversion, and Biased Sampling on the Assessment of Microbial Demography.

    Science.gov (United States)

    Lapierre, Marguerite; Blin, Camille; Lambert, Amaury; Achaz, Guillaume; Rocha, Eduardo P C

    2016-07-01

    Recent studies have linked demographic changes and epidemiological patterns in bacterial populations using coalescent-based approaches. We identified 26 studies using skyline plots and found that 21 inferred overall population expansion. This surprising result led us to analyze the impact of natural selection, recombination (gene conversion), and sampling biases on demographic inference using skyline plots and site frequency spectra (SFS). Forward simulations based on biologically relevant parameters from Escherichia coli populations showed that theoretical arguments on the detrimental impact of recombination and especially natural selection on the reconstructed genealogies cannot be ignored in practice. In fact, both processes systematically lead to spurious interpretations of population expansion in skyline plots (and in SFS for selection). Weak purifying selection, and especially positive selection, had important effects on skyline plots, showing patterns akin to those of population expansions. State-of-the-art techniques to remove recombination further amplified these biases. We simulated three common sampling biases in microbiological research: uniform, clustered, and mixed sampling. Alone, or together with recombination and selection, they further mislead demographic inferences producing almost any possible skyline shape or SFS. Interestingly, sampling sub-populations also affected skyline plots and SFS, because the coalescent rates of populations and their sub-populations had different distributions. This study suggests that extreme caution is needed to infer demographic changes solely based on reconstructed genealogies. We suggest that the development of novel sampling strategies and the joint analyzes of diverse population genetic methods are strictly necessary to estimate demographic changes in populations where selection, recombination, and biased sampling are present. © The Author 2016. Published by Oxford University Press on behalf of the Society for

  13. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    KAUST Repository

    Elsheikh, Ahmed H.

    2014-02-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems. © 2013 Elsevier Inc.

  14. HICOSMO - cosmology with a complete sample of galaxy clusters - I. Data analysis, sample selection and luminosity-mass scaling relation

    Science.gov (United States)

    Schellenberger, G.; Reiprich, T. H.

    2017-08-01

    The X-ray regime, where the most massive visible component of galaxy clusters, the intracluster medium, is visible, offers directly measured quantities, like the luminosity, and derived quantities, like the total mass, to characterize these objects. The aim of this project is to analyse a complete sample of galaxy clusters in detail and constrain cosmological parameters, like the matter density, Ωm, or the amplitude of initial density fluctuations, σ8. The purely X-ray flux-limited sample (HIFLUGCS) consists of the 64 X-ray brightest galaxy clusters, which are excellent targets to study the systematic effects, that can bias results. We analysed in total 196 Chandra observations of the 64 HIFLUGCS clusters, with a total exposure time of 7.7 Ms. Here, we present our data analysis procedure (including an automated substructure detection and an energy band optimization for surface brightness profile analysis) that gives individually determined, robust total mass estimates. These masses are tested against dynamical and Planck Sunyaev-Zeldovich (SZ) derived masses of the same clusters, where good overall agreement is found with the dynamical masses. The Planck SZ masses seem to show a mass-dependent bias to our hydrostatic masses; possible biases in this mass-mass comparison are discussed including the Planck selection function. Furthermore, we show the results for the (0.1-2.4) keV luminosity versus mass scaling relation. The overall slope of the sample (1.34) is in agreement with expectations and values from literature. Splitting the sample into galaxy groups and clusters reveals, even after a selection bias correction, that galaxy groups exhibit a significantly steeper slope (1.88) compared to clusters (1.06).

  15. A Uniformly Selected Sample of Low-mass Black Holes in Seyfert 1 Galaxies. II. The SDSS DR7 Sample

    Science.gov (United States)

    Liu, He-Yang; Yuan, Weimin; Dong, Xiao-Bo; Zhou, Hongyan; Liu, Wen-Juan

    2018-04-01

    A new sample of 204 low-mass black holes (LMBHs) in active galactic nuclei (AGNs) is presented with black hole masses in the range of (1–20) × 105 M ⊙. The AGNs are selected through a systematic search among galaxies in the Seventh Data Release (DR7) of the Sloan Digital Sky Survey (SDSS), and careful analyses of their optical spectra and precise measurement of spectral parameters. Combining them with our previous sample selected from SDSS DR4 makes it the largest LMBH sample so far, totaling over 500 objects. Some of the statistical properties of the combined LMBH AGN sample are briefly discussed in the context of exploring the low-mass end of the AGN population. Their X-ray luminosities follow the extension of the previously known correlation with the [O III] luminosity. The effective optical-to-X-ray spectral indices α OX, albeit with a large scatter, are broadly consistent with the extension of the relation with the near-UV luminosity L 2500 Å. Interestingly, a correlation of α OX with black hole mass is also found, with α OX being statistically flatter (stronger X-ray relative to optical) for lower black hole masses. Only 26 objects, mostly radio loud, were detected in radio at 20 cm in the FIRST survey, giving a radio-loud fraction of 4%. The host galaxies of LMBHs have stellar masses in the range of 108.8–1012.4 M ⊙ and optical colors typical of Sbc spirals. They are dominated by young stellar populations that seem to have undergone continuous star formation history.

  16. Cerebral venous angioma

    International Nuclear Information System (INIS)

    Inagawa, Tetsuji; Taguchi, Haruyoshi; Kamiya, Kazuko; Yano, Takashi; Nakajima, Reiko

    1984-01-01

    This report presents a 27-year-old male patient who was diagnosed as having cerebral venous angioma in the postero-temporal area by CT scan and cerebral angiography. The patient improved by removing angioma with electrocoagulation of medullary veins. (Namekawa, K.)

  17. Estimating the residential demand function for natural gas in Seoul with correction for sample selection bias

    International Nuclear Information System (INIS)

    Yoo, Seung-Hoon; Lim, Hea-Jin; Kwak, Seung-Jun

    2009-01-01

    Over the last twenty years, the consumption of natural gas in Korea has increased dramatically. This increase has mainly resulted from the rise of consumption in the residential sector. The main objective of the study is to estimate households' demand function for natural gas by applying a sample selection model using data from a survey of households in Seoul. The results show that there exists a selection bias in the sample and that failure to correct for sample selection bias distorts the mean estimate, of the demand for natural gas, downward by 48.1%. In addition, according to the estimation results, the size of the house, the dummy variable for dwelling in an apartment, the dummy variable for having a bed in an inner room, and the household's income all have positive relationships with the demand for natural gas. On the other hand, the size of the family and the price of gas negatively contribute to the demand for natural gas. (author)

  18. Sample selection via angular distance in the space of the arguments of an artificial neural network

    Science.gov (United States)

    Fernández Jaramillo, J. M.; Mayerle, R.

    2018-05-01

    In the construction of an artificial neural network (ANN) a proper data splitting of the available samples plays a major role in the training process. This selection of subsets for training, testing and validation affects the generalization ability of the neural network. Also the number of samples has an impact in the time required for the design of the ANN and the training. This paper introduces an efficient and simple method for reducing the set of samples used for training a neural network. The method reduces the required time to calculate the network coefficients, while keeping the diversity and avoiding overtraining the ANN due the presence of similar samples. The proposed method is based on the calculation of the angle between two vectors, each one representing one input of the neural network. When the angle formed among samples is smaller than a defined threshold only one input is accepted for the training. The accepted inputs are scattered throughout the sample space. Tidal records are used to demonstrate the proposed method. The results of a cross-validation show that with few inputs the quality of the outputs is not accurate and depends on the selection of the first sample, but as the number of inputs increases the accuracy is improved and differences among the scenarios with a different starting sample have and important reduction. A comparison with the K-means clustering algorithm shows that for this application the proposed method with a smaller number of samples is producing a more accurate network.

  19. Models of the venous system

    DEFF Research Database (Denmark)

    Mehlsen, J

    2000-01-01

    Cardiac output is largely controlled by venous return, the driving force of which is the energy remaining at the postcapillary venous site. This force is influenced by forces acting close to the right atrium, and internally or externally upon the veins along their course. Analogue models of the v......Cardiac output is largely controlled by venous return, the driving force of which is the energy remaining at the postcapillary venous site. This force is influenced by forces acting close to the right atrium, and internally or externally upon the veins along their course. Analogue models...... of the venous system require at least three elements: a resistor, a capacitor and an inductor, with the latter being of more importance in the venous than in the arterial system. Non-linearities must be considered in pressure/flow relations in the small venules, during venous collapse, or low flow conditions...

  20. Arterial versus venous lactate: a measure of sepsis in children.

    Science.gov (United States)

    Samaraweera, Sahan Asela; Gibbons, Berwyck; Gour, Anami; Sedgwick, Philip

    2017-08-01

    This study assessed the agreement between arterial and venous blood lactate and pH levels in children with sepsis. This retrospective, three-year study involved 60 PICU patients, with data collected from electronic or paper patient records. The inclusion criteria comprised of children (≤17 years old) with sepsis and those who had a venous blood gas taken first with an arterial blood gas taken after within one hour. The lactate and pH values measured through each method were analysed. There is close agreement between venous and arterial lactate up to 2 mmol/L. As this value increases, this agreement becomes poor. The limits of agreement (LOA) are too large (±1.90 mmol/L) to allow venous and arterial lactate to be used interchangeably. The mean difference and LOA between both methods would be much smaller if derived using lactate values under 2.0 mmol/L. There is close agreement between arterial and venous pH (MD = -0.056, LOA ± 0.121). However, due to extreme variations in pH readings during sepsis, pH alone is an inadequate marker. A venous lactate ≤2 mmol/L can be used as a surrogate for arterial lactate during early management of sepsis in children. However, if the value exceeds 2 mmol/L, an arterial sample must confirm the venous result. What is known: • In children with septic shock, a blood gas is an important test to show the presence of acidosis and high lactic acid. Hyperlactataemia on admission is an early predictor of outcome and is associated with a greater mortality risk. • An arterial sample is the standard for lactate measurement, however getting a sample may be challenging in the emergency department or a general paediatric ward. Venous samples are quicker and easier to obtain. Adult studies generally advise caution in replacing venous lactate values for the arterial standard, whilst paediatric studies are limited in this area. What is new: • This is the first study assessing the agreement between arterial and peripheral venous

  1. Climate Change and Agricultural Productivity in Sub-Saharan Africa: A Spatial Sample Selection Model

    NARCIS (Netherlands)

    Ward, P.S.; Florax, R.J.G.M.; Flores-Lagunes, A.

    2014-01-01

    Using spatially explicit data, we estimate a cereal yield response function using a recently developed estimator for spatial error models when endogenous sample selection is of concern. Our results suggest that yields across Sub-Saharan Africa will decline with projected climatic changes, and that

  2. Decomposing the Gender Wage Gap in the Netherlands with Sample Selection Adjustments

    NARCIS (Netherlands)

    Albrecht, James; Vuuren, van Aico; Vroman, Susan

    2004-01-01

    In this paper, we use quantile regression decomposition methods to analyzethe gender gap between men and women who work full time in the Nether-lands. Because the fraction of women working full time in the Netherlands isquite low, sample selection is a serious issue. In addition to shedding light

  3. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo

    NARCIS (Netherlands)

    Papachroni, D.; Graikou, K.; Kosalec, I.; Damianakos, H.; Ingram, V.J.; Chinou, I.

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their

  4. Gender Wage Gap : A Semi-Parametric Approach With Sample Selection Correction

    NARCIS (Netherlands)

    Picchio, M.; Mussida, C.

    2010-01-01

    Sizeable gender differences in employment rates are observed in many countries. Sample selection into the workforce might therefore be a relevant issue when estimating gender wage gaps. This paper proposes a new semi-parametric estimator of densities in the presence of covariates which incorporates

  5. Testing the normality assumption in the sample selection model with an application to travel demand

    NARCIS (Netherlands)

    van der Klaauw, B.; Koning, R.H.

    2003-01-01

    In this article we introduce a test for the normality assumption in the sample selection model. The test is based on a flexible parametric specification of the density function of the error terms in the model. This specification follows a Hermite series with bivariate normality as a special case.

  6. Testing the normality assumption in the sample selection model with an application to travel demand

    NARCIS (Netherlands)

    van der Klauw, B.; Koning, R.H.

    In this article we introduce a test for the normality assumption in the sample selection model. The test is based on a flexible parametric specification of the density function of the error terms in the model. This specification follows a Hermite series with bivariate normality as a special case.

  7. Principal Stratification in sample selection problems with non normal error terms

    DEFF Research Database (Denmark)

    Rocci, Roberto; Mellace, Giovanni

    The aim of the paper is to relax distributional assumptions on the error terms, often imposed in parametric sample selection models to estimate causal effects, when plausible exclusion restrictions are not available. Within the principal stratification framework, we approximate the true distribut...... an application to the Job Corps training program....

  8. The lack of selection bias in a snowball sampled case-control study on drug abuse.

    Science.gov (United States)

    Lopes, C S; Rodrigues, L C; Sichieri, R

    1996-12-01

    Friend controls in matched case-control studies can be a potential source of bias based on the assumption that friends are more likely to share exposure factors. This study evaluates the role of selection bias in a case-control study that used the snowball sampling method based on friendship for the selection of cases and controls. The cases selected fro the study were drug abusers located in the community. Exposure was defined by the presence of at least one psychiatric diagnosis. Psychiatric and drug abuse/dependence diagnoses were made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria. Cases and controls were matched on sex, age and friendship. The measurement of selection bias was made through the comparison of the proportion of exposed controls selected by exposed cases (p1) with the proportion of exposed controls selected by unexposed cases (p2). If p1 = p2 then, selection bias should not occur. The observed distribution of the 185 matched pairs having at least one psychiatric disorder showed a p1 value of 0.52 and a p2 value of 0.51, indicating no selection bias in this study. Our findings support the idea that the use of friend controls can produce a valid basis for a case-control study.

  9. Sample selection based on kernel-subclustering for the signal reconstruction of multifunctional sensors

    International Nuclear Information System (INIS)

    Wang, Xin; Wei, Guo; Sun, Jinwei

    2013-01-01

    The signal reconstruction methods based on inverse modeling for the signal reconstruction of multifunctional sensors have been widely studied in recent years. To improve the accuracy, the reconstruction methods have become more and more complicated because of the increase in the model parameters and sample points. However, there is another factor that affects the reconstruction accuracy, the position of the sample points, which has not been studied. A reasonable selection of the sample points could improve the signal reconstruction quality in at least two ways: improved accuracy with the same number of sample points or the same accuracy obtained with a smaller number of sample points. Both ways are valuable for improving the accuracy and decreasing the workload, especially for large batches of multifunctional sensors. In this paper, we propose a sample selection method based on kernel-subclustering distill groupings of the sample data and produce the representation of the data set for inverse modeling. The method calculates the distance between two data points based on the kernel-induced distance instead of the conventional distance. The kernel function is a generalization of the distance metric by mapping the data that are non-separable in the original space into homogeneous groups in the high-dimensional space. The method obtained the best results compared with the other three methods in the simulation. (paper)

  10. New sorbent materials for selective extraction of cocaine and benzoylecgonine from human urine samples.

    Science.gov (United States)

    Bujak, Renata; Gadzała-Kopciuch, Renata; Nowaczyk, Alicja; Raczak-Gutknecht, Joanna; Kordalewska, Marta; Struck-Lewicka, Wiktoria; Waszczuk-Jankowska, Małgorzata; Tomczak, Ewa; Kaliszan, Michał; Buszewski, Bogusław; Markuszewski, Michał J

    2016-02-20

    An increase in cocaine consumption has been observed in Europe during the last decade. Benzoylecgonine, as a main urinary metabolite of cocaine in human, is so far the most reliable marker of cocaine consumption. Determination of cocaine and its metabolite in complex biological samples as urine or blood, requires efficient and selective sample pretreatment. In this preliminary study, the newly synthesized sorbent materials were proposed for selective extraction of cocaine and benzoylecgonine from urine samples. Application of these sorbent media allowed to determine cocaine and benzoylecgonine in urine samples at the concentration level of 100ng/ml with good recovery values as 81.7%±6.6 and 73.8%±4.2, respectively. The newly synthesized materials provided efficient, inexpensive and selective extraction of both cocaine and benzoylecgonine from urine samples, which can consequently lead to an increase of the sensitivity of the current available screening diagnostic tests. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Imaging a Large Sample with Selective Plane Illumination Microscopy Based on Multiple Fluorescent Microsphere Tracking

    Science.gov (United States)

    Ryu, Inkeon; Kim, Daekeun

    2018-04-01

    A typical selective plane illumination microscopy (SPIM) image size is basically limited by the field of view, which is a characteristic of the objective lens. If an image larger than the imaging area of the sample is to be obtained, image stitching, which combines step-scanned images into a single panoramic image, is required. However, accurately registering the step-scanned images is very difficult because the SPIM system uses a customized sample mount where uncertainties for the translational and the rotational motions exist. In this paper, an image registration technique based on multiple fluorescent microsphere tracking is proposed in the view of quantifying the constellations and measuring the distances between at least two fluorescent microspheres embedded in the sample. Image stitching results are demonstrated for optically cleared large tissue with various staining methods. Compensation for the effect of the sample rotation that occurs during the translational motion in the sample mount is also discussed.

  12. Transfer function design based on user selected samples for intuitive multivariate volume exploration

    KAUST Repository

    Zhou, Liang; Hansen, Charles

    2013-01-01

    Multivariate volumetric datasets are important to both science and medicine. We propose a transfer function (TF) design approach based on user selected samples in the spatial domain to make multivariate volumetric data visualization more accessible for domain users. Specifically, the user starts the visualization by probing features of interest on slices and the data values are instantly queried by user selection. The queried sample values are then used to automatically and robustly generate high dimensional transfer functions (HDTFs) via kernel density estimation (KDE). Alternatively, 2D Gaussian TFs can be automatically generated in the dimensionality reduced space using these samples. With the extracted features rendered in the volume rendering view, the user can further refine these features using segmentation brushes. Interactivity is achieved in our system and different views are tightly linked. Use cases show that our system has been successfully applied for simulation and complicated seismic data sets. © 2013 IEEE.

  13. Transfer function design based on user selected samples for intuitive multivariate volume exploration

    KAUST Repository

    Zhou, Liang

    2013-02-01

    Multivariate volumetric datasets are important to both science and medicine. We propose a transfer function (TF) design approach based on user selected samples in the spatial domain to make multivariate volumetric data visualization more accessible for domain users. Specifically, the user starts the visualization by probing features of interest on slices and the data values are instantly queried by user selection. The queried sample values are then used to automatically and robustly generate high dimensional transfer functions (HDTFs) via kernel density estimation (KDE). Alternatively, 2D Gaussian TFs can be automatically generated in the dimensionality reduced space using these samples. With the extracted features rendered in the volume rendering view, the user can further refine these features using segmentation brushes. Interactivity is achieved in our system and different views are tightly linked. Use cases show that our system has been successfully applied for simulation and complicated seismic data sets. © 2013 IEEE.

  14. Passive sampling of selected endocrine disrupting compounds using polar organic chemical integrative samplers

    International Nuclear Information System (INIS)

    Arditsoglou, Anastasia; Voutsa, Dimitra

    2008-01-01

    Two types of polar organic chemical integrative samplers (pharmaceutical POCIS and pesticide POCIS) were examined for their sampling efficiency of selected endocrine disrupting compounds (EDCs). Laboratory-based calibration of POCISs was conducted by exposing them at high and low concentrations of 14 EDCs (4-alkyl-phenols, their ethoxylate oligomers, bisphenol A, selected estrogens and synthetic steroids) for different time periods. The kinetic studies showed an integrative uptake up to 28 days. The sampling rates for the individual compounds were obtained. The use of POCISs could result in an integrative approach to the quality status of the aquatic systems especially in the case of high variation of water concentrations of EDCs. The sampling efficiency of POCISs under various field conditions was assessed after their deployment in different aquatic environments. - Calibration and field performance of polar organic integrative samplers for monitoring EDCs in aquatic environments

  15. Semiparametric efficient and robust estimation of an unknown symmetric population under arbitrary sample selection bias

    KAUST Repository

    Ma, Yanyuan

    2013-09-01

    We propose semiparametric methods to estimate the center and shape of a symmetric population when a representative sample of the population is unavailable due to selection bias. We allow an arbitrary sample selection mechanism determined by the data collection procedure, and we do not impose any parametric form on the population distribution. Under this general framework, we construct a family of consistent estimators of the center that is robust to population model misspecification, and we identify the efficient member that reaches the minimum possible estimation variance. The asymptotic properties and finite sample performance of the estimation and inference procedures are illustrated through theoretical analysis and simulations. A data example is also provided to illustrate the usefulness of the methods in practice. © 2013 American Statistical Association.

  16. The Complete Local Volume Groups Sample - I. Sample selection and X-ray properties of the high-richness subsample

    Science.gov (United States)

    O'Sullivan, Ewan; Ponman, Trevor J.; Kolokythas, Konstantinos; Raychaudhury, Somak; Babul, Arif; Vrtilek, Jan M.; David, Laurence P.; Giacintucci, Simona; Gitti, Myriam; Haines, Chris P.

    2017-12-01

    We present the Complete Local-Volume Groups Sample (CLoGS), a statistically complete optically selected sample of 53 groups within 80 Mpc. Our goal is to combine X-ray, radio and optical data to investigate the relationship between member galaxies, their active nuclei and the hot intra-group medium (IGM). We describe sample selection, define a 26-group high-richness subsample of groups containing at least four optically bright (log LB ≥ 10.2 LB⊙) galaxies, and report the results of XMM-Newton and Chandra observations of these systems. We find that 14 of the 26 groups are X-ray bright, possessing a group-scale IGM extending at least 65 kpc and with luminosity >1041 erg s-1, while a further three groups host smaller galaxy-scale gas haloes. The X-ray bright groups have masses in the range M500 ≃ 0.5-5 × 1013 M⊙, based on system temperatures of 0.4-1.4 keV, and X-ray luminosities in the range 2-200 × 1041 erg s-1. We find that ∼53-65 per cent of the X-ray bright groups have cool cores, a somewhat lower fraction than found by previous archival surveys. Approximately 30 per cent of the X-ray bright groups show evidence of recent dynamical interactions (mergers or sloshing), and ∼35 per cent of their dominant early-type galaxies host active galactic nuclei with radio jets. We find no groups with unusually high central entropies, as predicted by some simulations, and confirm that CLoGS is in principle capable of detecting such systems. We identify three previously unrecognized groups, and find that they are either faint (LX, R500 < 1042 erg s-1) with no concentrated cool core, or highly disturbed. This leads us to suggest that ∼20 per cent of X-ray bright groups in the local universe may still be unidentified.

  17. Nested sampling algorithm for subsurface flow model selection, uncertainty quantification, and nonlinear calibration

    KAUST Repository

    Elsheikh, A. H.

    2013-12-01

    Calibration of subsurface flow models is an essential step for managing ground water aquifers, designing of contaminant remediation plans, and maximizing recovery from hydrocarbon reservoirs. We investigate an efficient sampling algorithm known as nested sampling (NS), which can simultaneously sample the posterior distribution for uncertainty quantification, and estimate the Bayesian evidence for model selection. Model selection statistics, such as the Bayesian evidence, are needed to choose or assign different weights to different models of different levels of complexities. In this work, we report the first successful application of nested sampling for calibration of several nonlinear subsurface flow problems. The estimated Bayesian evidence by the NS algorithm is used to weight different parameterizations of the subsurface flow models (prior model selection). The results of the numerical evaluation implicitly enforced Occam\\'s razor where simpler models with fewer number of parameters are favored over complex models. The proper level of model complexity was automatically determined based on the information content of the calibration data and the data mismatch of the calibrated model.

  18. A large sample of Kohonen-selected SDSS quasars with weak emission lines: selection effects and statistical properties

    Science.gov (United States)

    Meusinger, H.; Balafkan, N.

    2014-08-01

    Aims: A tiny fraction of the quasar population shows remarkably weak emission lines. Several hypotheses have been developed, but the weak line quasar (WLQ) phenomenon still remains puzzling. The aim of this study was to create a sizeable sample of WLQs and WLQ-like objects and to evaluate various properties of this sample. Methods: We performed a search for WLQs in the spectroscopic data from the Sloan Digital Sky Survey Data Release 7 based on Kohonen self-organising maps for nearly 105 quasar spectra. The final sample consists of 365 quasars in the redshift range z = 0.6 - 4.2 (z¯ = 1.50 ± 0.45) and includes in particular a subsample of 46 WLQs with equivalent widths WMg iiattention was paid to selection effects. Results: The WLQs have, on average, significantly higher luminosities, Eddington ratios, and accretion rates. About half of the excess comes from a selection bias, but an intrinsic excess remains probably caused primarily by higher accretion rates. The spectral energy distribution shows a bluer continuum at rest-frame wavelengths ≳1500 Å. The variability in the optical and UV is relatively low, even taking the variability-luminosity anti-correlation into account. The percentage of radio detected quasars and of core-dominant radio sources is significantly higher than for the control sample, whereas the mean radio-loudness is lower. Conclusions: The properties of our WLQ sample can be consistently understood assuming that it consists of a mix of quasars at the beginning of a stage of increased accretion activity and of beamed radio-quiet quasars. The higher luminosities and Eddington ratios in combination with a bluer spectral energy distribution can be explained by hotter continua, i.e. higher accretion rates. If quasar activity consists of subphases with different accretion rates, a change towards a higher rate is probably accompanied by an only slow development of the broad line region. The composite WLQ spectrum can be reasonably matched by the

  19. Progressive sampling-based Bayesian optimization for efficient and automatic machine learning model selection.

    Science.gov (United States)

    Zeng, Xueqiang; Luo, Gang

    2017-12-01

    Machine learning is broadly used for clinical data analysis. Before training a model, a machine learning algorithm must be selected. Also, the values of one or more model parameters termed hyper-parameters must be set. Selecting algorithms and hyper-parameter values requires advanced machine learning knowledge and many labor-intensive manual iterations. To lower the bar to machine learning, miscellaneous automatic selection methods for algorithms and/or hyper-parameter values have been proposed. Existing automatic selection methods are inefficient on large data sets. This poses a challenge for using machine learning in the clinical big data era. To address the challenge, this paper presents progressive sampling-based Bayesian optimization, an efficient and automatic selection method for both algorithms and hyper-parameter values. We report an implementation of the method. We show that compared to a state of the art automatic selection method, our method can significantly reduce search time, classification error rate, and standard deviation of error rate due to randomization. This is major progress towards enabling fast turnaround in identifying high-quality solutions required by many machine learning-based clinical data analysis tasks.

  20. A GMM-Based Test for Normal Disturbances of the Heckman Sample Selection Model

    Directory of Open Access Journals (Sweden)

    Michael Pfaffermayr

    2014-10-01

    Full Text Available The Heckman sample selection model relies on the assumption of normal and homoskedastic disturbances. However, before considering more general, alternative semiparametric models that do not need the normality assumption, it seems useful to test this assumption. Following Meijer and Wansbeek (2007, the present contribution derives a GMM-based pseudo-score LM test on whether the third and fourth moments of the disturbances of the outcome equation of the Heckman model conform to those implied by the truncated normal distribution. The test is easy to calculate and in Monte Carlo simulations it shows good performance for sample sizes of 1000 or larger.

  1. Frequency-Selective Signal Sensing with Sub-Nyquist Uniform Sampling Scheme

    DEFF Research Database (Denmark)

    Pierzchlewski, Jacek; Arildsen, Thomas

    2015-01-01

    In this paper the authors discuss a problem of acquisition and reconstruction of a signal polluted by adjacent- channel interference. The authors propose a method to find a sub-Nyquist uniform sampling pattern which allows for correct reconstruction of selected frequencies. The method is inspired...... by the Restricted Isometry Property, which is known from the field of compressed sensing. Then, compressed sensing is used to successfully reconstruct a wanted signal even if some of the uniform samples were randomly lost, e. g. due to ADC saturation. An experiment which tests the proposed method in practice...

  2. 40 CFR 761.308 - Sample selection by random number generation on any two-dimensional square grid.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sample selection by random number... § 761.79(b)(3) § 761.308 Sample selection by random number generation on any two-dimensional square... area created in accordance with paragraph (a) of this section, select two random numbers: one each for...

  3. Medical management of venous ulcers.

    Science.gov (United States)

    Pascarella, Luigi; Shortell, Cynthia K

    2015-03-01

    Venous disease is the most common cause of chronic leg ulceration and represents an advanced clinical manifestation of venous insufficiency. Due to their frequency and chronicity, venous ulcers have a high socioeconomic impact, with treatment costs accounting for 1% of the health care budget in Western countries. The evaluation of patients with venous ulcers should include a thorough medical history for prior deep venous thrombosis, assessment for an hypercoagulable state, and a physical examination. Use of the CEAP (clinical, etiology, anatomy, pathophysiology) Classification System and the revised Venous Clinical Severity Scoring System is strongly recommended to characterize disease severity and assess response to treatment. This venous condition requires lifestyle modification, with affected individuals performing daily intervals of leg elevation to control edema; use of elastic compression garments; and moderate physical activity, such as walking wearing below-knee elastic stockings. Meticulous skin care, treatment of dermatitis, and prompt treatment of cellulitis are important aspects of medical management. The pharmacology of chronic venous insufficiency and venous ulcers include essentially two medications: pentoxifylline and phlebotropic agents. The micronized purified flavonoid fraction is an effective adjunct to compression therapy in patients with large, chronic ulceration. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Malaria parasitemia amongst pregnant women attending selected ...

    African Journals Online (AJOL)

    A cross-sectional study to determine malaria parasitemia amongst 300 randomly selected pregnant women attending government and private healthcare facilities in Rivers State was carried out. Blood samples were obtained through venous procedure and the presence or absence of Plasmodium was determined ...

  5. Population genetics inference for longitudinally-sampled mutants under strong selection.

    Science.gov (United States)

    Lacerda, Miguel; Seoighe, Cathal

    2014-11-01

    Longitudinal allele frequency data are becoming increasingly prevalent. Such samples permit statistical inference of the population genetics parameters that influence the fate of mutant variants. To infer these parameters by maximum likelihood, the mutant frequency is often assumed to evolve according to the Wright-Fisher model. For computational reasons, this discrete model is commonly approximated by a diffusion process that requires the assumption that the forces of natural selection and mutation are weak. This assumption is not always appropriate. For example, mutations that impart drug resistance in pathogens may evolve under strong selective pressure. Here, we present an alternative approximation to the mutant-frequency distribution that does not make any assumptions about the magnitude of selection or mutation and is much more computationally efficient than the standard diffusion approximation. Simulation studies are used to compare the performance of our method to that of the Wright-Fisher and Gaussian diffusion approximations. For large populations, our method is found to provide a much better approximation to the mutant-frequency distribution when selection is strong, while all three methods perform comparably when selection is weak. Importantly, maximum-likelihood estimates of the selection coefficient are severely attenuated when selection is strong under the two diffusion models, but not when our method is used. This is further demonstrated with an application to mutant-frequency data from an experimental study of bacteriophage evolution. We therefore recommend our method for estimating the selection coefficient when the effective population size is too large to utilize the discrete Wright-Fisher model. Copyright © 2014 by the Genetics Society of America.

  6. A field trial of a PCR-based Mansonella ozzardi diagnosis assay detects high-levels of submicroscopic M. ozzardi infections in both venous blood samples and FTA card dried blood spots.

    Science.gov (United States)

    Medeiros, Jansen Fernandes; Almeida, Tatiana Amaral Pires; Silva, Lucyane Bastos Tavares; Rubio, Jose Miguel; Crainey, James Lee; Pessoa, Felipe Arley Costa; Luz, Sergio Luiz Bessa

    2015-05-20

    Mansonella ozzardi is a poorly understood human filarial parasite with a broad distribution throughout Latin America. Most of what is known about its parasitism has come from epidemiological studies that have estimated parasite incidence using light microscopy. Light microscopy can, however, miss lighter, submicroscopic, infections. In this study we have compared M. ozzardi incidence estimates made using light microscopy, with estimates made using PCR. 214 DNA extracts made from Large Volume Venous Blood Samples (LVVBS) were taken from volunteers from two study sites in the Rio Solimões region: Codajás [n = 109] and Tefé [n = 105] and were subsequently assayed for M. ozzardi parasitism using a diagnostic PCR (Mo-dPCR). Peripheral finger-prick blood samples were taken from the same individuals and used for microscopic examination. Finger-prick blood, taken from individuals from Tefé, was also used for the creation of FTAcard dried blood spots (DBS) that were subsequently subjected to Mo-dPCR. Overall M. ozzardi incidence estimates made with LVVBS PCRs were 1.8 times higher than those made using microscopy (44.9% [96/214] compared with 24.3% [52/214]) and 1.5 times higher than the PCR estimates made from FTAcard DBS (48/105 versus 31/105). PCR-based detection of FTAcard DBS proved 1.3 times more sensitive at diagnosing infections from peripheral blood samples than light microscopy did: detecting 24/105 compared with 31/105. PCR of LVVBS reported the fewest number of false negatives, detecting: 44 of 52 (84.6%) individuals diagnosed by microscopy; 27 of 31 (87.1%) of those diagnosed positive from DBSs and 17 out of 18 (94.4%) of those diagnosed as positive by both alternative methodologies. In this study, Mo-dPCR of LVVBS was by far the most sensitive method of detecting M. ozzardi infections and detected submicroscopic infections. Mo-dPCR FTAcard DBS also provided a more sensitive test for M. ozzardi diagnosis than light microscopy based diagnosis did and

  7. Magnetically separable polymer (Mag-MIP) for selective analysis of biotin in food samples.

    Science.gov (United States)

    Uzuriaga-Sánchez, Rosario Josefina; Khan, Sabir; Wong, Ademar; Picasso, Gino; Pividori, Maria Isabel; Sotomayor, Maria Del Pilar Taboada

    2016-01-01

    This work presents an efficient method for the preparation of magnetic nanoparticles modified with molecularly imprinted polymers (Mag-MIP) through core-shell method for the determination of biotin in milk food samples. The functional monomer acrylic acid was selected from molecular modeling, EGDMA was used as cross-linking monomer and AIBN as radical initiator. The Mag-MIP and Mag-NIP were characterized by FTIR, magnetic hysteresis, XRD, SEM and N2-sorption measurements. The capacity of Mag-MIP for biotin adsorption, its kinetics and selectivity were studied in detail. The adsorption data was well described by Freundlich isotherm model with adsorption equilibrium constant (KF) of 1.46 mL g(-1). The selectivity experiments revealed that prepared Mag-MIP had higher selectivity toward biotin compared to other molecules with different chemical structure. The material was successfully applied for the determination of biotin in diverse milk samples using HPLC for quantification of the analyte, obtaining the mean value of 87.4% recovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Forecasting Urban Air Quality via a Back-Propagation Neural Network and a Selection Sample Rule

    Directory of Open Access Journals (Sweden)

    Yonghong Liu

    2015-07-01

    Full Text Available In this paper, based on a sample selection rule and a Back Propagation (BP neural network, a new model of forecasting daily SO2, NO2, and PM10 concentration in seven sites of Guangzhou was developed using data from January 2006 to April 2012. A meteorological similarity principle was applied in the development of the sample selection rule. The key meteorological factors influencing SO2, NO2, and PM10 daily concentrations as well as weight matrices and threshold matrices were determined. A basic model was then developed based on the improved BP neural network. Improving the basic model, identification of the factor variation consistency was added in the rule, and seven sets of sensitivity experiments in one of the seven sites were conducted to obtain the selected model. A comparison of the basic model from May 2011 to April 2012 in one site showed that the selected model for PM10 displayed better forecasting performance, with Mean Absolute Percentage Error (MAPE values decreasing by 4% and R2 values increasing from 0.53 to 0.68. Evaluations conducted at the six other sites revealed a similar performance. On the whole, the analysis showed that the models presented here could provide local authorities with reliable and precise predictions and alarms about air quality if used at an operational scale.

  9. Development of ion imprinted polymers for the selective extraction of lanthanides from environmental samples

    International Nuclear Information System (INIS)

    Moussa, Manel

    2016-01-01

    The analysis of the lanthanide ions present at trace level in complex environmental matrices requires often a purification and preconcentration step. The solid phase extraction (SPE) is the most used sample preparation technique. To improve the selectivity of this step, Ion Imprinted Polymers (IIPs) can be used as SPE solid supports. The aim of this work was the development of IIPs for the selective extraction of lanthanide ions from environmental samples. In a first part, IIPs were prepared according to the trapping approach using 5,7-dichloroquinoline-8-ol as non-vinylated ligand. For the first time, the loss of the trapped ligand during template ion removal and sedimentation steps was demonstrated by HPLC-UV. Moreover, this loss was not repeatable, which led to a lack of repeatability of the SPE profiles. It was then demonstrated that the trapping approach is not appropriate for the IIPs synthesis. In a second part, IIPs were synthesized by chemical immobilization of methacrylic acid as vinylated monomer. The repeatability of the synthesis and the SPE protocol were confirmed. A good selectivity of the IIPs for all the lanthanide ions was obtained. IIPs were successfully used to selectively extract lanthanide ions from tap and river water. Finally, IIPs were synthesized by chemical immobilization of methacrylic acid and 4-vinylpyridine as functional monomers and either a light (Nd 3+ ) or a heavy (Er 3+ ) lanthanide ion as template. Both kinds of IIPs led to a similar selectivity for all lanthanide ions. Nevertheless, this selectivity can be modified by changing the nature and the pH of the washing solution used in the SPE protocol. (author)

  10. Management of venous thromboembolism.

    Science.gov (United States)

    Parakh, R; Kakkar, V V; Kakkar, A K

    2007-01-01

    Venous Thromboembolism is an important healthcare problem the world over, resulting in significant morbidity, mortality and resource expenditure. The rationale for use of thromboprophylaxis is based on solid principles and scientific evidence. Indian perspective on this topic is lacking due to the non-availability of published Indian data. This document reviews the available International and Indian data and discusses the relevance of recommendations for prevention and management of Venous Thromboembolism (VTE) in the Indian context. Meetings of various specialists from different Indian hospitals in the field of Gastrointestinal Surgery, General and Vascular Surgery, Hematology, Intensive Care, Obstetrics and Gynecology, Oncology and Orthopedics were held in the months of August 2005 to January 2006. The guidelines published by American College of Chest Physicians (ACCP), the International Union of Angiology (IUA), and the Royal College of Obstetricians and Gynecologists (RCOG), were discussed during these meetings. The relevance of these guidelines and the practical implications of following these in a developing country like India were also discussed. Any published data from India was collected from data base searches and the results, along with personal experiences of the participating specialists were discussed. The experiences and impressions of the experts during these meetings have been included in this document. Data from recent sources (International Union of Angiology and the National Comprehensive Cancer Network (NCCN) Practice guidelines in Oncology on Venous thromboembolic disease) was subsequently also included in this document. The suggestions formulated in this document are practical, and would intend to serve as a useful practical reference. A number of unanswered questions remain in the field of thromboprophylaxis, and carefully designed research protocols may help answer some of these. Implementation of the suggestions outlined in the document

  11. Venous leg ulcers

    Science.gov (United States)

    2008-01-01

    Introduction Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0/1000 people have active leg ulcers. Prevalence increases with age to about 20/1000 in people aged over 80 years. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of standard treatments, adjuvant treatments, and organisational interventions for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 80 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression bandages and stockings, cultured allogenic (single or bilayer) skin replacement, debriding agents, dressings (cellulose, collagen, film, foam, hyaluronic acid-derived, semi-occlusive alginate), hydrocolloid (occlusive) dressings in the presence of compression, intermittent pneumatic compression, intravenous prostaglandin E1, larval therapy, laser treatment (low-level), leg ulcer clinics, multilayer elastic system, multilayer elastomeric (or non-elastomeric) high-compression regimens or bandages, oral treatments (aspirin, flavonoids, pentoxifylline, rutosides, stanozolol, sulodexide, thromboxane alpha2 antagonists, zinc), peri

  12. Does self-selection affect samples' representativeness in online surveys? An investigation in online video game research.

    Science.gov (United States)

    Khazaal, Yasser; van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

    2014-07-07

    The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Our objective was to explore the representativeness of a self-selected sample of online gamers using online players' virtual characters (avatars). All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars' characteristics were defined using various games' scores, reported on the WoW's official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted.

  13. Novel joint selection methods can reduce sample size for rheumatoid arthritis clinical trials with ultrasound endpoints.

    Science.gov (United States)

    Allen, John C; Thumboo, Julian; Lye, Weng Kit; Conaghan, Philip G; Chew, Li-Ching; Tan, York Kiat

    2018-03-01

    To determine whether novel methods of selecting joints through (i) ultrasonography (individualized-ultrasound [IUS] method), or (ii) ultrasonography and clinical examination (individualized-composite-ultrasound [ICUS] method) translate into smaller rheumatoid arthritis (RA) clinical trial sample sizes when compared to existing methods utilizing predetermined joint sites for ultrasonography. Cohen's effect size (ES) was estimated (ES^) and a 95% CI (ES^L, ES^U) calculated on a mean change in 3-month total inflammatory score for each method. Corresponding 95% CIs [nL(ES^U), nU(ES^L)] were obtained on a post hoc sample size reflecting the uncertainty in ES^. Sample size calculations were based on a one-sample t-test as the patient numbers needed to provide 80% power at α = 0.05 to reject a null hypothesis H 0 : ES = 0 versus alternative hypotheses H 1 : ES = ES^, ES = ES^L and ES = ES^U. We aimed to provide point and interval estimates on projected sample sizes for future studies reflecting the uncertainty in our study ES^S. Twenty-four treated RA patients were followed up for 3 months. Utilizing the 12-joint approach and existing methods, the post hoc sample size (95% CI) was 22 (10-245). Corresponding sample sizes using ICUS and IUS were 11 (7-40) and 11 (6-38), respectively. Utilizing a seven-joint approach, the corresponding sample sizes using ICUS and IUS methods were nine (6-24) and 11 (6-35), respectively. Our pilot study suggests that sample size for RA clinical trials with ultrasound endpoints may be reduced using the novel methods, providing justification for larger studies to confirm these observations. © 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

  14. Stability of selected volatile breath constituents in Tedlar, Kynar and Flexfilm sampling bags

    Science.gov (United States)

    Mochalski, Paweł; King, Julian; Unterkofler, Karl; Amann, Anton

    2016-01-01

    The stability of 41 selected breath constituents in three types of polymer sampling bags, Tedlar, Kynar, and Flexfilm, was investigated using solid phase microextraction and gas chromatography mass spectrometry. The tested molecular species belong to different chemical classes (hydrocarbons, ketones, aldehydes, aromatics, sulphurs, esters, terpenes, etc.) and exhibit close-to-breath low ppb levels (3–12 ppb) with the exception of isoprene, acetone and acetonitrile (106 ppb, 760 ppb, 42 ppb respectively). Stability tests comprised the background emission of contaminants, recovery from dry samples, recovery from humid samples (RH 80% at 37 °C), influence of the bag’s filling degree, and reusability. Findings yield evidence of the superiority of Tedlar bags over remaining polymers in terms of background emission, species stability (up to 7 days for dry samples), and reusability. Recoveries of species under study suffered from the presence of high amounts of water (losses up to 10%). However, only heavier volatiles, with molecular masses higher than 90, exhibited more pronounced losses (20–40%). The sample size (the degree of bag filling) was found to be one of the most important factors affecting the sample integrity. To sum up, it is recommended to store breath samples in pre-conditioned Tedlar bags up to 6 hours at the maximum possible filling volume. Among the remaining films, Kynar can be considered as an alternative to Tedlar; however, higher losses of compounds should be expected even within the first hours of storage. Due to the high background emission Flexfilm is not suitable for sampling and storage of samples for analyses aiming at volatiles at a low ppb level. PMID:23323261

  15. Size selective isocyanate aerosols personal air sampling using porous plastic foams

    International Nuclear Information System (INIS)

    Cong Khanh Huynh; Trinh Vu Duc

    2009-01-01

    As part of a European project (SMT4-CT96-2137), various European institutions specialized in occupational hygiene (BGIA, HSL, IOM, INRS, IST, Ambiente e Lavoro) have established a program of scientific collaboration to develop one or more prototypes of European personal samplers for the collection of simultaneous three dust fractions: inhalable, thoracic and respirable. These samplers based on existing sampling heads (IOM, GSP and cassettes) use Polyurethane Plastic Foam (PUF) according to their porosity to support sampling and separator size of the particles. In this study, the authors present an original application of size selective personal air sampling using chemical impregnated PUF to perform isocyanate aerosols capturing and derivatizing in industrial spray-painting shops.

  16. ENDOVASCULAR TREATMENT FOR DISORDERS OF THE VENOUS SYSTEM

    Directory of Open Access Journals (Sweden)

    A. G. Osiev

    2015-01-01

    Full Text Available The annual rate of deep vein thrombosis in general population is from 5 to 9 cases per 10 000, whereas for venous thromboembolism (deep vein thrombosis and pulmonary embolism taken together amounts to 14 cases per 10 000. To improve longterm results of therapy for thrombosis of deep veins of the lower extremities, it is important to restore venous function and outflow. Anticoagulant therapy with low weight or non-fractionated heparin preparations remains the most widely used method of management. However, total or partial thrombosis resolution under anticoagulant treatment is achieved only in 4 and 14% of cases, respectively. Thrombolysis allows for early resorption of the thrombus by means of a minimally invasive procedure with lower risk of complication. After the venous flow is restored, the aim of treatment is to prevent damage to the venous valves, venous hypertension and repeated thrombosis with development of the post-thrombotic syndrome. Compared to anticoagulation, systemic thrombolysis has the benefit of more rapid clot resorption and less damage to the venous valve. One of its serious limitations is a high bleeding risk related to higher doses of the drug administered through a peripheral vein catheter. Therefore, selective intra-clot administration of thombolytics (direct catheter thrombolysis has been suggested as an alternative. For more effective therapy with the use of lower doses of thrombolytics, the so called pharmaco-mechanical thrombectomy has been developed. Venous stenosis hindering the venous outflow is frequently seen after direct catheter or pharmaco-mechanical thrombolysis. Angioplasty with stent placement is recommended in the cases with residual venous abnormality after successful thrombolysis and thrombectomy. 

  17. THE zCOSMOS-SINFONI PROJECT. I. SAMPLE SELECTION AND NATURAL-SEEING OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, C.; Renzini, A. [INAF-OAPD, Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova (Italy); Foerster Schreiber, N. M.; Hicks, E. K. S.; Genzel, R.; Tacconi, L.; Davies, R. [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Cresci, G. [Osservatorio Astrofisico di Arcetri (OAF), INAF-Firenze, Largo E. Fermi 5, I-50125 Firenze (Italy); Peng, Y.; Lilly, S.; Carollo, M.; Oesch, P. [Institute of Astronomy, Department of Physics, Eidgenossische Technische Hochschule, ETH Zurich CH-8093 (Switzerland); Vergani, D.; Pozzetti, L.; Zamorani, G. [INAF-Bologna, Via Ranzani, I-40127 Bologna (Italy); Daddi, E. [CEA-Saclay, DSM/DAPNIA/Service d' Astrophysique, F-91191 Gif-Sur Yvette Cedex (France); Maraston, C. [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, PO1 3HE Portsmouth (United Kingdom); McCracken, H. J. [IAP, 98bis bd Arago, F-75014 Paris (France); Bouche, N. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Shapiro, K. [Aerospace Research Laboratories, Northrop Grumman Aerospace Systems, Redondo Beach, CA 90278 (United States); and others

    2011-12-10

    The zCOSMOS-SINFONI project is aimed at studying the physical and kinematical properties of a sample of massive z {approx} 1.4-2.5 star-forming galaxies, through SINFONI near-infrared integral field spectroscopy (IFS), combined with the multiwavelength information from the zCOSMOS (COSMOS) survey. The project is based on one hour of natural-seeing observations per target, and adaptive optics (AO) follow-up for a major part of the sample, which includes 30 galaxies selected from the zCOSMOS/VIMOS spectroscopic survey. This first paper presents the sample selection, and the global physical characterization of the target galaxies from multicolor photometry, i.e., star formation rate (SFR), stellar mass, age, etc. The H{alpha} integrated properties, such as, flux, velocity dispersion, and size, are derived from the natural-seeing observations, while the follow-up AO observations will be presented in the next paper of this series. Our sample appears to be well representative of star-forming galaxies at z {approx} 2, covering a wide range in mass and SFR. The H{alpha} integrated properties of the 25 H{alpha} detected galaxies are similar to those of other IFS samples at the same redshifts. Good agreement is found among the SFRs derived from H{alpha} luminosity and other diagnostic methods, provided the extinction affecting the H{alpha} luminosity is about twice that affecting the continuum. A preliminary kinematic analysis, based on the maximum observed velocity difference across the source and on the integrated velocity dispersion, indicates that the sample splits nearly 50-50 into rotation-dominated and velocity-dispersion-dominated galaxies, in good agreement with previous surveys.

  18. Antibiotic content of selective culture media for isolation of Capnocytophaga species from oral polymicrobial samples.

    Science.gov (United States)

    Ehrmann, E; Jolivet-Gougeon, A; Bonnaure-Mallet, M; Fosse, T

    2013-10-01

    In oral microbiome, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of fastidious Capnocytophaga species. The performances of six culture media (blood agar, chocolate blood agar, VCAT medium, CAPE medium, bacitracin chocolate blood agar and VK medium) were compared with literature data concerning five other media (FAA, LB, TSBV, CapR and TBBP media). To understand variable growth on selective media, the MICs of each antimicrobial agent contained in this different media (colistin, kanamycin, trimethoprim, trimethoprim-sulfamethoxazole, vancomycin, aztreonam and bacitracin) were determined for all Capnocytophaga species. Overall, VCAT medium (Columbia, 10% cooked horse blood, polyvitaminic supplement, 3·75 mg l(-1) of colistin, 1·5 mg l(-1) of trimethoprim, 1 mg l(-1) of vancomycin and 0·5 mg l(-1) of amphotericin B, Oxoid, France) was the more efficient selective medium, with regard to the detection of Capnocytophaga species from oral samples (P culture, a simple blood agar allowed the growth of all Capnocytophaga species. Nonetheless, in oral samples, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of Capnocytophaga species. The demonstrated superiority of VCAT medium made its use essential for the optimal detection of this bacterial genus. This work showed that extreme caution should be exercised when reporting the isolation of Capnocytophaga species from oral polymicrobial samples, because the culture medium is a determining factor. © 2013 The Society for Applied Microbiology.

  19. Mineralocorticoid hypertension: clinical and laboratory studies with special reference to selective percutaneous venography combined with aldosterone assay in the adrenal venous blood

    International Nuclear Information System (INIS)

    Wajchenberg, B.L.; Liberman, B.; Novaes, M.

    1977-01-01

    With the purpose of demonstrating the presence of hypertension, hypokalemia and alkalosis were studied. The presence of daily aldosteronism was verified in five patients; the sixth one presented no daily aldosteronism but an increase of 18-OH-DOCA production, an ACTH dependente mineralocorticoid. The presence of tumor (less than 0.9cm) could not be shown in two patients by bilateral selective adrenal venography. The aldosterone assay during catherization of adrenal vein of those patients permitted to determine the tumoral side. Attention must be given to the fact that the blood collection of adrenal vein must always be made during adrenal venography to demonstrate the presence of short unilateral tumor or bilateral disease [pt

  20. Chronic Venous Disease under pressure

    NARCIS (Netherlands)

    S.W.I. Reeder (Suzan)

    2013-01-01

    textabstractIn chapter 1 we provide a general introduction of this thesis. Chronic venous disease (CVD) is a common medical condition that affects 2-64% of the worldwide population and leads to leg ulcers in 1% of the Western population. Venous leg ulceration (VLU) has an unfavorable prognosis with

  1. A novel variable selection approach that iteratively optimizes variable space using weighted binary matrix sampling.

    Science.gov (United States)

    Deng, Bai-chuan; Yun, Yong-huan; Liang, Yi-zeng; Yi, Lun-zhao

    2014-10-07

    In this study, a new optimization algorithm called the Variable Iterative Space Shrinkage Approach (VISSA) that is based on the idea of model population analysis (MPA) is proposed for variable selection. Unlike most of the existing optimization methods for variable selection, VISSA statistically evaluates the performance of variable space in each step of optimization. Weighted binary matrix sampling (WBMS) is proposed to generate sub-models that span the variable subspace. Two rules are highlighted during the optimization procedure. First, the variable space shrinks in each step. Second, the new variable space outperforms the previous one. The second rule, which is rarely satisfied in most of the existing methods, is the core of the VISSA strategy. Compared with some promising variable selection methods such as competitive adaptive reweighted sampling (CARS), Monte Carlo uninformative variable elimination (MCUVE) and iteratively retaining informative variables (IRIV), VISSA showed better prediction ability for the calibration of NIR data. In addition, VISSA is user-friendly; only a few insensitive parameters are needed, and the program terminates automatically without any additional conditions. The Matlab codes for implementing VISSA are freely available on the website: https://sourceforge.net/projects/multivariateanalysis/files/VISSA/.

  2. Selection of Sampling Pumps Used for Groundwater Monitoring at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Schalla, Ronald; Webber, William D.; Smith, Ronald M.

    2001-11-05

    The variable frequency drive centrifugal submersible pump, Redi-Flo2a made by Grundfosa, was selected for universal application for Hanford Site groundwater monitoring. Specifications for the selected pump and five other pumps were evaluated against current and future Hanford groundwater monitoring performance requirements, and the Redi-Flo2 was selected as the most versatile and applicable for the range of monitoring conditions. The Redi-Flo2 pump distinguished itself from the other pumps considered because of its wide range in output flow rate and its comparatively moderate maintenance and low capital costs. The Redi-Flo2 pump is able to purge a well at a high flow rate and then supply water for sampling at a low flow rate. Groundwater sampling using a low-volume-purging technique (e.g., low flow, minimal purge, no purge, or micropurgea) is planned in the future, eliminating the need for the pump to supply a high-output flow rate. Under those conditions, the Well Wizard bladder pump, manufactured by QED Environmental Systems, Inc., may be the preferred pump because of the lower capital cost.

  3. Concurrent and Longitudinal Associations Among Temperament, Parental Feeding Styles, and Selective Eating in a Preschool Sample.

    Science.gov (United States)

    Kidwell, Katherine M; Kozikowski, Chelsea; Roth, Taylor; Lundahl, Alyssa; Nelson, Timothy D

    2018-06-01

    To examine the associations among negative/reactive temperament, feeding styles, and selective eating in a sample of preschoolers because preschool eating behaviors likely have lasting implications for children's health. A community sample of preschoolers aged 3-5 years (M = 4.49 years, 49.5% female, 75.7% European American) in the Midwest of the United States was recruited to participate in the study (N = 297). Parents completed measures of temperament and feeding styles at two time points 6 months apart. A series of regressions indicated that children who had temperaments high in negative affectivity were significantly more likely to experience instrumental and emotional feeding styles. They were also significantly more likely to be selective eaters. These associations were present when examined both concurrently and after 6 months. This study provides a novel investigation of child temperament and eating behaviors, allowing for a better understanding of how negative affectivity is associated with instrumental feeding, emotional feeding, and selective eating. These results inform interventions to improve child health.

  4. Epidural venous stasis in spinal stenosis

    International Nuclear Information System (INIS)

    Kaiser, M.C.; Capesius, P.; Poos, D.; Gratia, G.; Roilgen, A.; Sandt, G.

    1984-01-01

    Computed tomography permits reliable demonstration of the spinal canal and its contents. Measurements of the sagittal diameter of the bony canal do not take into consideration size, shape and state of intraspinal soft tissue structures, i.e. the thecal sac and its own contents, epidural fat and blood circulation pattern. Three particularly illustrative cases were selected in which obvious epidural venous engorgement was visualized in association with spinal stenosis. The authors think that epidural venous stasis occuring in segmental spinal stenosis is a CT sign of clinically significant narrowing of the neural canal. Accurate recognition of the type of lumbar stenosis together with epidural blood flow alterations permits a better understanding of the existing lesions. Thus, a more precise and specific surgical approach is possible. (orig.)

  5. Correlations Between Life-Detection Techniques and Implications for Sampling Site Selection in Planetary Analog Missions

    Science.gov (United States)

    Gentry, Diana M.; Amador, Elena S.; Cable, Morgan L.; Chaudry, Nosheen; Cullen, Thomas; Jacobsen, Malene B.; Murukesan, Gayathri; Schwieterman, Edward W.; Stevens, Adam H.; Stockton, Amanda; Tan, George; Yin, Chang; Cullen, David C.; Geppert, Wolf

    2017-10-01

    We conducted an analog sampling expedition under simulated mission constraints to areas dominated by basaltic tephra of the Eldfell and Fimmvörðuháls lava fields (Iceland). Sites were selected to be "homogeneous" at a coarse remote sensing resolution (10-100 m) in apparent color, morphology, moisture, and grain size, with best-effort realism in numbers of locations and replicates. Three different biomarker assays (counting of nucleic-acid-stained cells via fluorescent microscopy, a luciferin/luciferase assay for adenosine triphosphate, and quantitative polymerase chain reaction (qPCR) to detect DNA associated with bacteria, archaea, and fungi) were characterized at four nested spatial scales (1 m, 10 m, 100 m, and >1 km) by using five common metrics for sample site representativeness (sample mean variance, group F tests, pairwise t tests, and the distribution-free rank sum H and u tests). Correlations between all assays were characterized with Spearman's rank test. The bioluminescence assay showed the most variance across the sites, followed by qPCR for bacterial and archaeal DNA; these results could not be considered representative at the finest resolution tested (1 m). Cell concentration and fungal DNA also had significant local variation, but they were homogeneous over scales of >1 km. These results show that the selection of life detection assays and the number, distribution, and location of sampling sites in a low biomass environment with limited a priori characterization can yield both contrasting and complementary results, and that their interdependence must be given due consideration to maximize science return in future biomarker sampling expeditions.

  6. Effects of soil water saturation on sampling equilibrium and kinetics of selected polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Kim, Pil-Gon; Roh, Ji-Yeon; Hong, Yongseok; Kwon, Jung-Hwan

    2017-10-01

    Passive sampling can be applied for measuring the freely dissolved concentration of hydrophobic organic chemicals (HOCs) in soil pore water. When using passive samplers under field conditions, however, there are factors that might affect passive sampling equilibrium and kinetics, such as soil water saturation. To determine the effects of soil water saturation on passive sampling, the equilibrium and kinetics of passive sampling were evaluated by observing changes in the distribution coefficient between sampler and soil (K sampler/soil ) and the uptake rate constant (k u ) at various soil water saturations. Polydimethylsiloxane (PDMS) passive samplers were deployed into artificial soils spiked with seven selected polycyclic aromatic hydrocarbons (PAHs). In dry soil (0% water saturation), both K sampler/soil and k u values were much lower than those in wet soils likely due to the contribution of adsorption of PAHs onto soil mineral surfaces and the conformational changes in soil organic matter. For high molecular weight PAHs (chrysene, benzo[a]pyrene, and dibenzo[a,h]anthracene), both K sampler/soil and k u values increased with increasing soil water saturation, whereas they decreased with increasing soil water saturation for low molecular weight PAHs (phenanthrene, anthracene, fluoranthene, and pyrene). Changes in the sorption capacity of soil organic matter with soil water content would be the main cause of the changes in passive sampling equilibrium. Henry's law constant could explain the different behaviors in uptake kinetics of the selected PAHs. The results of this study would be helpful when passive samplers are deployed under various soil water saturations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Composition of Trace Metals in Dust Samples Collected from Selected High Schools in Pretoria, South Africa

    Directory of Open Access Journals (Sweden)

    J. O. Olowoyo

    2016-01-01

    Full Text Available Potential health risks associated with trace metal pollution have necessitated the importance of monitoring their levels in the environment. The present study investigated the concentrations and compositions of trace metals in dust samples collected from classrooms and playing ground from the selected high schools In Pretoria. Schools were selected from Pretoria based on factors such as proximity to high traffic ways, industrial areas, and residential areas. Thirty-two dust samples were collected from inside and outside the classrooms, where learners often stay during recess period. The dust samples were analysed for trace metal concentrations using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS. The composition of the elements showed that the concentrations of Zn were more than all other elements except from one of the schools. There were significant differences in the concentrations of trace metals from the schools (p<0.05. Regular cleaning, proximity to busy road, and well maintained gardens seem to have positive effects on the concentrations of trace metals recorded from the classrooms dust. The result further revealed a positive correlation for elements such as Pb, Cu, Zn, Mn, and Sb, indicating that the dust might have a common source.

  8. Detection of Salmonella spp. in veterinary samples by combining selective enrichment and real-time PCR.

    Science.gov (United States)

    Goodman, Laura B; McDonough, Patrick L; Anderson, Renee R; Franklin-Guild, Rebecca J; Ryan, James R; Perkins, Gillian A; Thachil, Anil J; Glaser, Amy L; Thompson, Belinda S

    2017-11-01

    Rapid screening for enteric bacterial pathogens in clinical environments is essential for biosecurity. Salmonella found in veterinary hospitals, particularly Salmonella enterica serovar Dublin, can pose unique challenges for culture and testing because of its poor growth. Multiple Salmonella serovars including Dublin are emerging threats to public health given increasing prevalence and antimicrobial resistance. We adapted an automated food testing method to veterinary samples and evaluated the performance of the method in a variety of matrices including environmental samples ( n = 81), tissues ( n = 52), feces ( n = 148), and feed ( n = 29). A commercial kit was chosen as the basis for this approach in view of extensive performance characterizations published by multiple independent organizations. A workflow was established for efficiently and accurately testing veterinary matrices and environmental samples by use of real-time PCR after selective enrichment in Rappaport-Vassiliadis soya (RVS) medium. Using this method, the detection limit for S. Dublin improved by 100-fold over subculture on selective agars (eosin-methylene blue, brilliant green, and xylose-lysine-deoxycholate). Overall, the procedure was effective in detecting Salmonella spp. and provided next-day results.

  9. Selective removal of phosphate for analysis of organic acids in complex samples.

    Science.gov (United States)

    Deshmukh, Sandeep; Frolov, Andrej; Marcillo, Andrea; Birkemeyer, Claudia

    2015-04-03

    Accurate quantitation of compounds in samples of biological origin is often hampered by matrix interferences one of which occurs in GC-MS analysis from the presence of highly abundant phosphate. Consequently, high concentrations of phosphate need to be removed before sample analysis. Within this context, we screened 17 anion exchange solid-phase extraction (SPE) materials for selective phosphate removal using different protocols to meet the challenge of simultaneous recovery of six common organic acids in aqueous samples prior to derivatization for GC-MS analysis. Up to 75% recovery was achieved for the most organic acids, only the low pKa tartaric and citric acids were badly recovered. Compared to the traditional approach of phosphate removal by precipitation, SPE had a broader compatibility with common detection methods and performed more selectively among the organic acids under investigation. Based on the results of this study, it is recommended that phosphate removal strategies during the analysis of biologically relevant small molecular weight organic acids consider the respective pKa of the anticipated analytes and the detection method of choice. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Acrylamide exposure among Turkish toddlers from selected cereal-based baby food samples.

    Science.gov (United States)

    Cengiz, Mehmet Fatih; Gündüz, Cennet Pelin Boyacı

    2013-10-01

    In this study, acrylamide exposure from selected cereal-based baby food samples was investigated among toddlers aged 1-3 years in Turkey. The study contained three steps. The first step was collecting food consumption data and toddlers' physical properties, such as gender, age and body weight, using a questionnaire given to parents by a trained interviewer between January and March 2012. The second step was determining the acrylamide levels in food samples that were reported on by the parents in the questionnaire, using a gas chromatography-mass spectrometry (GC-MS) method. The last step was combining the determined acrylamide levels in selected food samples with individual food consumption and body weight data using a deterministic approach to estimate the acrylamide exposure levels. The mean acrylamide levels of baby biscuits, breads, baby bread-rusks, crackers, biscuits, breakfast cereals and powdered cereal-based baby foods were 153, 225, 121, 604, 495, 290 and 36 μg/kg, respectively. The minimum, mean and maximum acrylamide exposures were estimated to be 0.06, 1.43 and 6.41 μg/kg BW per day, respectively. The foods that contributed to acrylamide exposure were aligned from high to low as bread, crackers, biscuits, baby biscuits, powdered cereal-based baby foods, baby bread-rusks and breakfast cereals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Polymer platforms for selective detection of cocaine in street samples adulterated with levamisole.

    Science.gov (United States)

    Florea, Anca; Cowen, Todd; Piletsky, Sergey; De Wael, Karolien

    2018-08-15

    Accurate drug detection is of utmost importance for fighting against drug abuse. With a high number of cutting agents and adulterants being added to cut or mask drugs in street powders the number of false results is increasing. We demonstrate for the first time the usefulness of employing polymers readily synthesized by electrodeposition to selectively detect cocaine in the presence of the commonly used adulterant levamisole. The polymers were selected by computational modelling to exhibit high binding affinity towards cocaine and deposited directly on the surface of graphene-modified electrodes via electropolymerization. The resulting platforms allowed a distinct electrochemical signal for cocaine, which is otherwise suppressed by levamisole. Square wave voltammetry was used to quantify cocaine alone and in the presence of levamisole. The usefulness of the platforms was demonstrated in the screening of real street samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Rapid determination of trace level copper in tea infusion samples by solid contact ion selective electrode

    Directory of Open Access Journals (Sweden)

    Aysenur Birinci

    2016-07-01

    Full Text Available A new solid contact copper selective electrode with a poly (vinyl chloride (PVC membrane consisting of o-xylylenebis(N,N-diisobutyldithiocarbamate as ionophore has been prepared. The main novelties of constructed ion selective electrode concept are the enhanced robustness, cheapness, and fastness due to the use of solid contacts. The electrode exhibits a rapid (< 10 seconds and near-Nernstian response to Cu2+ activity from 10−1 to 10−6 mol/L at the pH range of 4.0–6.0. No serious interference from common ions was found. The electrode characterizes by high potential stability, reproducibility, and full repeatability. The electrode was used as an indicator electrode in potentiometric titration of Cu(II ions with EDTA and for the direct assay of tea infusion samples by means of the calibration graph technique. The results compared favorably with those obtained by the atomic absorption spectroscopy (AAS.

  13. Antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. isolated from chicken samples.

    Science.gov (United States)

    Er, Buket; Demirhan, Burak; Onurdag, Fatma Kaynak; Ozgacar, Selda Özgen; Oktem, Aysel Bayhan

    2014-03-01

    Salmonella spp. are widespread foodborne pathogens that contaminate egg and poultry meats. Attachment, colonization, as well as biofilm formation capacity of Salmonella spp. on food and contact surfaces of food may cause continuous contamination. Biofilm may play a crucial role in the survival of salmonellae under unfavorable environmental conditions, such as in animal slaughterhouses and processing plants. This could serve as a reservoir compromising food safety and human health. Addition of antimicrobial preservatives extends shelf lives of food products, but even when products are supplemented with adequate amounts of preservatives, it is not always possible to inhibit the microorganisms in a biofilm community. In this study, our aims were i) to determine the minimum inhibitory concentrations (MIC) and minimum biofilm inhibitory concentrations (MBIC) of selected preservatives against planktonic and biofilm forms of Salmonella spp. isolated from chicken samples and Salmonella Typhimurium SL1344 standard strain, ii) to show the differences in the susceptibility patterns of same strains versus the planktonic and biofilm forms to the same preservative agent, and iii) to determine and compare antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. For this purpose, Salmonella Typhimurium SL1344 standard strain and 4 Salmonella spp. strains isolated from chicken samples were used. Investigation of antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. was done according to Clinical and Laboratory Standards Institute M100-S18 guidelines and BioTimer assay, respectively. As preservative agents, pure ciprofloxacin, sodium nitrite, potassium sorbate, sodium benzoate, methyl paraben, and propyl paraben were selected. As a result, it was determined that MBIC values are greater than the MIC values of the preservatives. This result verified the resistance seen in a biofilm community to food

  14. Pesticides, selected elements, and other chemicals in adult total diet samples October 1979-September 1980

    International Nuclear Information System (INIS)

    Gartrell, M.J.; Craun, J.C.; Podrebarac, D.S.; Gunderson, E.L.

    1985-01-01

    The US Food and Drug Administration (FDA) conducts Total Diet Studies to determine the dietary intake of selected pesticides, industrial chemicals, and elements (including radionuclides). These studies involve the retail purchase and analysis of foods representative of the diets of infants, toddlers, and adults. The individual food items are separated into a number of food groups, each of which is analyzed as a composite. This report summarizes the results for adult Total Diet samples collected in 20 cities between October 1979 and September 1980. The average concentration, range of concentrations, and calculated average daily intake of each chemical found are presented by food group. The average daily intakes of the chemicals are similar to those found in the several preceding years and are within acceptable limits. The results for samples collected during the same period that represent the diets of infants and toddlers are reported separately

  15. A genetic algorithm-based framework for wavelength selection on sample categorization.

    Science.gov (United States)

    Anzanello, Michel J; Yamashita, Gabrielli; Marcelo, Marcelo; Fogliatto, Flávio S; Ortiz, Rafael S; Mariotti, Kristiane; Ferrão, Marco F

    2017-08-01

    In forensic and pharmaceutical scenarios, the application of chemometrics and optimization techniques has unveiled common and peculiar features of seized medicine and drug samples, helping investigative forces to track illegal operations. This paper proposes a novel framework aimed at identifying relevant subsets of attenuated total reflectance Fourier transform infrared (ATR-FTIR) wavelengths for classifying samples into two classes, for example authentic or forged categories in case of medicines, or salt or base form in cocaine analysis. In the first step of the framework, the ATR-FTIR spectra were partitioned into equidistant intervals and the k-nearest neighbour (KNN) classification technique was applied to each interval to insert samples into proper classes. In the next step, selected intervals were refined through the genetic algorithm (GA) by identifying a limited number of wavelengths from the intervals previously selected aimed at maximizing classification accuracy. When applied to Cialis®, Viagra®, and cocaine ATR-FTIR datasets, the proposed method substantially decreased the number of wavelengths needed to categorize, and increased the classification accuracy. From a practical perspective, the proposed method provides investigative forces with valuable information towards monitoring illegal production of drugs and medicines. In addition, focusing on a reduced subset of wavelengths allows the development of portable devices capable of testing the authenticity of samples during police checking events, avoiding the need for later laboratorial analyses and reducing equipment expenses. Theoretically, the proposed GA-based approach yields more refined solutions than the current methods relying on interval approaches, which tend to insert irrelevant wavelengths in the retained intervals. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Cold Spray Deposition of Freestanding Inconel Samples and Comparative Analysis with Selective Laser Melting

    Science.gov (United States)

    Bagherifard, Sara; Roscioli, Gianluca; Zuccoli, Maria Vittoria; Hadi, Mehdi; D'Elia, Gaetano; Demir, Ali Gökhan; Previtali, Barbara; Kondás, Ján; Guagliano, Mario

    2017-10-01

    Cold spray offers the possibility of obtaining almost zero-porosity buildups with no theoretical limit to the thickness. Moreover, cold spray can eliminate particle melting, evaporation, crystallization, grain growth, unwanted oxidation, undesirable phases and thermally induced tensile residual stresses. Such characteristics can boost its potential to be used as an additive manufacturing technique. Indeed, deposition via cold spray is recently finding its path toward fabrication of freeform components since it can address the common challenges of powder-bed additive manufacturing techniques including major size constraints, deposition rate limitations and high process temperature. Herein, we prepared nickel-based superalloy Inconel 718 samples with cold spray technique and compared them with similar samples fabricated by selective laser melting method. The samples fabricated using both methods were characterized in terms of mechanical strength, microstructural and porosity characteristics, Vickers microhardness and residual stresses distribution. Different heat treatment cycles were applied to the cold-sprayed samples in order to enhance their mechanical characteristics. The obtained data confirm that cold spray technique can be used as a complementary additive manufacturing method for fabrication of high-quality freestanding components where higher deposition rate, larger final size and lower fabrication temperatures are desired.

  17. 40 CFR Appendix A to Subpart F of... - Sampling Plans for Selective Enforcement Auditing of Nonroad Engines

    Science.gov (United States)

    2010-07-01

    ... Enforcement Auditing of Nonroad Engines A Appendix A to Subpart F of Part 89 Protection of Environment... NONROAD COMPRESSION-IGNITION ENGINES Selective Enforcement Auditing Pt. 89, Subpt. F, App. A Appendix A to Subpart F of Part 89—Sampling Plans for Selective Enforcement Auditing of Nonroad Engines Table 1—Sampling...

  18. 40 CFR Appendix A to Subpart G of... - Sampling Plans for Selective Enforcement Auditing of Marine Engines

    Science.gov (United States)

    2010-07-01

    ... Enforcement Auditing of Marine Engines A Appendix A to Subpart G of Part 91 Protection of Environment...-IGNITION ENGINES Selective Enforcement Auditing Regulations Pt. 91, Subpt. G, App. A Appendix A to Subpart G of Part 91—Sampling Plans for Selective Enforcement Auditing of Marine Engines Table 1—Sampling...

  19. Parameter selection for peak alignment in chromatographic sample profiling: Objective quality indicators and use of control samples

    NARCIS (Netherlands)

    Peters, S.; van Velzen, E.; Janssen, H.-G.

    2009-01-01

    In chromatographic profiling applications, peak alignment is often essential as most chromatographic systems exhibit small peak shifts over time. When using currently available alignment algorithms, there are several parameters that determine the outcome of the alignment process. Selecting the

  20. Selective extraction of dimethoate from cucumber samples by use of molecularly imprinted microspheres

    Directory of Open Access Journals (Sweden)

    Jiao-Jiao Du

    2015-06-01

    Full Text Available Molecularly imprinted polymers for dimethoate recognition were synthesized by the precipitation polymerization technique using methyl methacrylate (MMA as the functional monomer and ethylene glycol dimethacrylate (EGDMA as the cross-linker. The morphology, adsorption and recognition properties were investigated by scanning electron microscopy (SEM, static adsorption test, and competitive adsorption test. To obtain the best selectivity and binding performance, the synthesis and adsorption conditions of MIPs were optimized through single factor experiments. Under the optimized conditions, the resultant polymers exhibited uniform size, satisfactory binding capacity and significant selectivity. Furthermore, the imprinted polymers were successfully applied as a specific solid-phase extractants combined with high performance liquid chromatography (HPLC for determination of dimethoate residues in the cucumber samples. The average recoveries of three spiked samples ranged from 78.5% to 87.9% with the relative standard deviations (RSDs less than 4.4% and the limit of detection (LOD obtained for dimethoate as low as 2.3 μg/mL. Keywords: Molecularly imprinted polymer, Precipitation polymerization, Dimethoate, Cucumber, HPLC

  1. ACTIVE LEARNING TO OVERCOME SAMPLE SELECTION BIAS: APPLICATION TO PHOTOMETRIC VARIABLE STAR CLASSIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    Richards, Joseph W.; Starr, Dan L.; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; Berian James, J. [Astronomy Department, University of California, Berkeley, CA 94720-7450 (United States); Brink, Henrik [Dark Cosmology Centre, Juliane Maries Vej 30, 2100 Copenhagen O (Denmark); Long, James P.; Rice, John, E-mail: jwrichar@stat.berkeley.edu [Statistics Department, University of California, Berkeley, CA 94720-7450 (United States)

    2012-01-10

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL-where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up-is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  2. ACTIVE LEARNING TO OVERCOME SAMPLE SELECTION BIAS: APPLICATION TO PHOTOMETRIC VARIABLE STAR CLASSIFICATION

    International Nuclear Information System (INIS)

    Richards, Joseph W.; Starr, Dan L.; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; Berian James, J.; Brink, Henrik; Long, James P.; Rice, John

    2012-01-01

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL—where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up—is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  3. Active Learning to Overcome Sample Selection Bias: Application to Photometric Variable Star Classification

    Science.gov (United States)

    Richards, Joseph W.; Starr, Dan L.; Brink, Henrik; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; James, J. Berian; Long, James P.; Rice, John

    2012-01-01

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL—where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up—is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  4. A quick method based on SIMPLISMA-KPLS for simultaneously selecting outlier samples and informative samples for model standardization in near infrared spectroscopy

    Science.gov (United States)

    Li, Li-Na; Ma, Chang-Ming; Chang, Ming; Zhang, Ren-Cheng

    2017-12-01

    A novel method based on SIMPLe-to-use Interactive Self-modeling Mixture Analysis (SIMPLISMA) and Kernel Partial Least Square (KPLS), named as SIMPLISMA-KPLS, is proposed in this paper for selection of outlier samples and informative samples simultaneously. It is a quick algorithm used to model standardization (or named as model transfer) in near infrared (NIR) spectroscopy. The NIR experiment data of the corn for analysis of the protein content is introduced to evaluate the proposed method. Piecewise direct standardization (PDS) is employed in model transfer. And the comparison of SIMPLISMA-PDS-KPLS and KS-PDS-KPLS is given in this research by discussion of the prediction accuracy of protein content and calculation speed of each algorithm. The conclusions include that SIMPLISMA-KPLS can be utilized as an alternative sample selection method for model transfer. Although it has similar accuracy to Kennard-Stone (KS), it is different from KS as it employs concentration information in selection program. This means that it ensures analyte information is involved in analysis, and the spectra (X) of the selected samples is interrelated with concentration (y). And it can be used for outlier sample elimination simultaneously by validation of calibration. According to the statistical data results of running time, it is clear that the sample selection process is more rapid when using KPLS. The quick algorithm of SIMPLISMA-KPLS is beneficial to improve the speed of online measurement using NIR spectroscopy.

  5. Venous hemodynamic changes in lower limb venous disease

    DEFF Research Database (Denmark)

    Lee, Byung Boong; Nicolaides, Andrew N; Myers, Kenneth

    2016-01-01

    ). Their aim was to confirm or dispel long-held hemodynamic principles and to provide a comprehensive review of venous hemodynamic concepts underlying the pathophysiology of lower limb venous disorders, their usefulness for investigating patients and the relevant hemodynamic changes associated with various...... forms of treatment. Chapter 1 is devoted to basic hemodynamic concepts and normal venous physiology. Chapter 2 presents the mechanism and magnitude of hemodynamic changes in acute deep vein thrombosis indicating their pathophysiological and clinical significance. Chapter 3 describes the hemodynamic...... changes that occur in different classes of chronic venous disease and their relation to the anatomic extent of disease in the macrocirculation and microcirculation. The next four chapters (Chapters 4-7) describe the hemodynamic changes resulting from treatment by compression using different materials...

  6. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  7. The Swift Gamma-Ray Burst Host Galaxy Legacy Survey. I. Sample Selection and Redshift Distribution

    Science.gov (United States)

    Perley, D. A.; Kruhler, T.; Schulze, S.; Postigo, A. De Ugarte; Hjorth, J.; Berger, E.; Cenko, S. B.; Chary, R.; Cucchiara, A.; Ellis, R.; hide

    2016-01-01

    We introduce the Swift Gamma-Ray Burst Host Galaxy Legacy Survey (SHOALS), a multi-observatory high redshift galaxy survey targeting the largest unbiased sample of long-duration gamma-ray burst (GRB) hosts yet assembled (119 in total). We describe the motivations of the survey and the development of our selection criteria, including an assessment of the impact of various observability metrics on the success rate of afterglow-based redshift measurement. We briefly outline our host galaxy observational program, consisting of deep Spitzer/IRAC imaging of every field supplemented by similarly deep, multicolor optical/near-IR photometry, plus spectroscopy of events without preexisting redshifts. Our optimized selection cuts combined with host galaxy follow-up have so far enabled redshift measurements for 110 targets (92%) and placed upper limits on all but one of the remainder. About 20% of GRBs in the sample are heavily dust obscured, and at most 2% originate from z > 5.5. Using this sample, we estimate the redshift-dependent GRB rate density, showing it to peak at z approx. 2.5 and fall by at least an order of magnitude toward low (z = 0) redshift, while declining more gradually toward high (z approx. 7) redshift. This behavior is consistent with a progenitor whose formation efficiency varies modestly over cosmic history. Our survey will permit the most detailed examination to date of the connection between the GRB host population and general star-forming galaxies, directly measure evolution in the host population over cosmic time and discern its causes, and provide new constraints on the fraction of cosmic star formation occurring in undetectable galaxies at all redshifts.

  8. Selective whole genome amplification for resequencing target microbial species from complex natural samples.

    Science.gov (United States)

    Leichty, Aaron R; Brisson, Dustin

    2014-10-01

    Population genomic analyses have demonstrated power to address major questions in evolutionary and molecular microbiology. Collecting populations of genomes is hindered in many microbial species by the absence of a cost effective and practical method to collect ample quantities of sufficiently pure genomic DNA for next-generation sequencing. Here we present a simple method to amplify genomes of a target microbial species present in a complex, natural sample. The selective whole genome amplification (SWGA) technique amplifies target genomes using nucleotide sequence motifs that are common in the target microbe genome, but rare in the background genomes, to prime the highly processive phi29 polymerase. SWGA thus selectively amplifies the target genome from samples in which it originally represented a minor fraction of the total DNA. The post-SWGA samples are enriched in target genomic DNA, which are ideal for population resequencing. We demonstrate the efficacy of SWGA using both laboratory-prepared mixtures of cultured microbes as well as a natural host-microbe association. Targeted amplification of Borrelia burgdorferi mixed with Escherichia coli at genome ratios of 1:2000 resulted in >10(5)-fold amplification of the target genomes with genomic extracts from Wolbachia pipientis-infected Drosophila melanogaster resulted in up to 70% of high-throughput resequencing reads mapping to the W. pipientis genome. By contrast, 2-9% of sequencing reads were derived from W. pipientis without prior amplification. The SWGA technique results in high sequencing coverage at a fraction of the sequencing effort, thus allowing population genomic studies at affordable costs. Copyright © 2014 by the Genetics Society of America.

  9. The Quasar Fraction in Low-Frequency Selected Complete Samples and Implications for Unified Schemes

    Science.gov (United States)

    Willott, Chris J.; Rawlings, Steve; Blundell, Katherine M.; Lacy, Mark

    2000-01-01

    Low-frequency radio surveys are ideal for selecting orientation-independent samples of extragalactic sources because the sample members are selected by virtue of their isotropic steep-spectrum extended emission. We use the new 7C Redshift Survey along with the brighter 3CRR and 6C samples to investigate the fraction of objects with observed broad emission lines - the 'quasar fraction' - as a function of redshift and of radio and narrow emission line luminosity. We find that the quasar fraction is more strongly dependent upon luminosity (both narrow line and radio) than it is on redshift. Above a narrow [OII] emission line luminosity of log(base 10) (L(sub [OII])/W) approximately > 35 [or radio luminosity log(base 10) (L(sub 151)/ W/Hz.sr) approximately > 26.5], the quasar fraction is virtually independent of redshift and luminosity; this is consistent with a simple unified scheme with an obscuring torus with a half-opening angle theta(sub trans) approximately equal 53 deg. For objects with less luminous narrow lines, the quasar fraction is lower. We show that this is not due to the difficulty of detecting lower-luminosity broad emission lines in a less luminous, but otherwise similar, quasar population. We discuss evidence which supports at least two probable physical causes for the drop in quasar fraction at low luminosity: (i) a gradual decrease in theta(sub trans) and/or a gradual increase in the fraction of lightly-reddened (0 approximately quasar luminosity; and (ii) the emergence of a distinct second population of low luminosity radio sources which, like M8T, lack a well-fed quasar nucleus and may well lack a thick obscuring torus.

  10. Determination of specific activity of americium and plutonium in selected environmental samples

    International Nuclear Information System (INIS)

    Trebunova, T.

    1999-01-01

    The aim of this work was development of method for determination of americium and plutonium in environmental samples. Developed method was evaluated on soil samples and after they was applied on selected samples of fishes (smoked mackerel, herring and fillet from Alaska hake). The method for separation of americium is based on liquid separation with Aliquate-336, precipitation with oxalic acid and using of chromatographic material TRU-Spec TM .The intervals of radiochemical yields were from 13.0% to 80.9% for plutonium-236 and from 10.5% to 100% for americium-241. Determined specific activities of plutonium-239,240 were from (2.3 ± 1.4) mBq/kg to (82 ± 29) mBq/kg, the specific activities of plutonium-238 were from (14.2 ± 3.7) mBq/kg to (708 ± 86) mBq/kg. The specific activities of americium-241 were from (1.4 ± 0.9) mBq/kg to (3360 ± 210) mBq/kg. The fishes from Baltic Sea as well as from North Sea show highest specific activities then fresh-water fishes from Slovakia. Therefore the monitoring of alpha radionuclides in foods imported from territories with nuclear testing is recommended

  11. Spectral Characterization of H2020/PTAL Mineral Samples: Implications for In Situ Martian Exploration and Mars Sample Selection

    Science.gov (United States)

    Lantz, C.; Pilorget, C.; Poulet, F.; Riu, L.; Dypvik, H.; Hellevang, H.; Rull Perez, F.; Veneranda, M.; Cousin, A.; Viennet, J.-C.; Werner, S. C.

    2018-04-01

    We present combined analysis performed in the framework of the Planetary Terrestrial Analogues Library (H2020 project). XRD, NIR, Raman, and LIBS spectroscopies are used to characterise samples to prepare ExoMars/ESA and Mars2020/NASA observations.

  12. Obscured AGN at z similar to 1 from the zCOSMOS-Bright Survey : I. Selection and optical properties of a [Ne v]-selected sample

    NARCIS (Netherlands)

    Mignoli, M.; Vignali, C.; Gilli, R.; Comastri, A.; Zamorani, G.; Bolzonella, M.; Bongiorno, A.; Lamareille, F.; Nair, P.; Pozzetti, L.; Lilly, S. J.; Carollo, C. M.; Contini, T.; Kneib, J. -P.; Le Fevre, O.; Mainieri, V.; Renzini, A.; Scodeggio, M.; Bardelli, S.; Caputi, K.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Iovino, A.; Kampczyk, P.; Knobel, C.; Kovac, K.; Le Borgne, J. -F.; Le Brun, V.; Maier, C.; Pello, R.; Peng, Y.; Montero, E. Perez; Presotto, V.; Silverman, J. D.; Tanaka, M.; Tasca, L.; Tresse, L.; Vergani, D.; Zucca, E.; Bordoloi, R.; Cappi, A.; Cimatti, A.; Koekemoer, A. M.; McCracken, H. J.; Moresco, M.; Welikala, N.

    Aims. The application of multi-wavelength selection techniques is essential for obtaining a complete and unbiased census of active galactic nuclei (AGN). We present here a method for selecting z similar to 1 obscured AGN from optical spectroscopic surveys. Methods. A sample of 94 narrow-line AGN

  13. Venous access: options, approaches and issues

    International Nuclear Information System (INIS)

    Asch, M.R.

    2001-01-01

    Venous access is an essential part of medical practice. It is needed to obtain blood samples to make the diagnosis and to administer fluids or medicines as part of treatment. Although relatively new in the history of medicine, the placement and maintenance of the various venous access devices now occupies a significant portion of many vascular and interventional radiology practices. Thus, it is important to have a thorough understanding of these devices and their uses. The first long-term venous access devices were used in 1973. These were placed via a surgical cut-down on the subclavian vein. In 1982, the first subcutaneous implantable ports were described. These procedures were initially performed by surgeons, but over the last 5-10 years, both the insertion and management of these devices has shifted to interventional radiologists. Peripherally inserted central catheter (PICC) lines have almost completely supplanted the use of standard central lines (Fig. 1). A number of factors have facilitated this - namely, ready and less expensive room access, outpatient procedure and radiologists' accessibility and familiarity with image-guidance procedures and catheters and guide wires. (author)

  14. Hydrocephalus in cerebral venous thrombosis

    NARCIS (Netherlands)

    Zuurbier, Susanna M.; van den Berg, René; Troost, Dirk; Majoie, Charles B.; Stam, Jan; Coutinho, Jonathan M.

    2015-01-01

    Increased intracranial pressure is common in cerebral venous thrombosis (CVT), but hydrocephalus is rarely reported in these patients. We examined the frequency, pathophysiology and associated clinical manifestations of hydrocephalus in patients with CVT admitted to our hospital between 2000 and

  15. Venous thromboembolism and arterial complications.

    Science.gov (United States)

    Prandoni, Paolo; Piovella, Chiara; Pesavento, Raffaele

    2012-04-01

    An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, smoking, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. Total anomalous pulmonary venous return

    Science.gov (United States)

    ... pulmonary venous return, x-ray References Fraser CD, Kane LC. Congenital heart disease. In: Townsend CM Jr, ... 62. Review Date 10/17/2017 Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, ...

  17. Concentration of ions in selected bottled water samples sold in Malaysia

    Science.gov (United States)

    Aris, Ahmad Zaharin; Kam, Ryan Chuan Yang; Lim, Ai Phing; Praveena, Sarva Mangala

    2013-03-01

    Many consumers around the world, including Malaysians, have turned to bottled water as their main source of drinking water. The aim of this study is to determine the physical and chemical properties of bottled water samples sold in Selangor, Malaysia. A total of 20 bottled water brands consisting of `natural mineral (NM)' and `packaged drinking (PD)' types were randomly collected and analyzed for their physical-chemical characteristics: hydrogen ion concentration (pH), electrical conductivity (EC) and total dissolved solids (TDS), selected major ions: calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na), and minor trace constituents: copper (Cu) and zinc (Zn) to ascertain their suitability for human consumption. The results obtained were compared with guideline values recommended by World Health Organization (WHO) and Malaysian Ministry of Health (MMOH), respectively. It was found that all bottled water samples were in accordance with the guidelines set by WHO and MMOH except for one sample (D3) which was below the pH limit of 6.5. Both NM and PD bottled water were dominated by Na + K > Ca > Mg. Low values for EC and TDS in the bottled water samples showed that water was deficient in essential elements, likely an indication that these were removed by water treatment. Minerals like major ions were present in very low concentrations which could pose a risk to individuals who consume this water on a regular basis. Generally, the overall quality of the supplied bottled water was in accordance to standards and guidelines set by WHO and MMOH and safe for consumption.

  18. Calibration model maintenance in melamine resin production: Integrating drift detection, smart sample selection and model adaptation.

    Science.gov (United States)

    Nikzad-Langerodi, Ramin; Lughofer, Edwin; Cernuda, Carlos; Reischer, Thomas; Kantner, Wolfgang; Pawliczek, Marcin; Brandstetter, Markus

    2018-07-12

    selection of samples by active learning (AL) used for subsequent model adaptation is advantageous compared to passive (random) selection in case that a drift leads to persistent prediction bias allowing more rapid adaptation at lower reference measurement rates. Fully unsupervised adaptation using FLEXFIS-PLS could improve predictive accuracy significantly for light drifts but was not able to fully compensate for prediction bias in case of significant lack of fit w.r.t. the latent variable space. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Improving venous leg ulcer management

    OpenAIRE

    Weller, Carolina Dragica

    2017-01-01

    This thesis reports several different methods to develop and evaluate complex interventions designed to improve venous leg ulcer management. Chronic venous leg ulcers (VLU) are the most common chronic wound problem in the community. Its health and economic burden is predicted to increase due to ageing of the community and increase in prevalence of diabetes and obesity. Although many patients seek health care for VLU, most do not receive the most effective management. Patients with this condi...

  20. Dietary trace element intakes of a selected sample of Canadian elderly women

    International Nuclear Information System (INIS)

    Gibson, R.S.; MacDonald, A.C.; Martinez, O.B.

    1984-01-01

    Energy, and selected trace intakes of a sample of 90 noninstitutionalized Canadian women (mean age 66.2 +/- 6.2 years) living in a University community and consuming self-selected diets were assessed by chemical analysis of one-day duplicate diets and via 1-day dietary records collected by the subjects. Mean gross energy intake (determined via bomb calorimetry was 6.0 +/- 2.4 MJ (1435 +/- 580 kcal) and mean intakes of Cu and Mn (determined via atomic absorption spectrophotometry) were 1.2 +/- 0.6 mg and 3.8 +/- 2.1 mg/day, respectively. Instrumental neutron activation analysis was used for Cr - median = 77.4 μg/day; Se - median = 69.6 μg/day; Zn - mean + SD = 7.7 +/- 3.6 mg/day; Ag - median = 26.9 μg/day; Cs - median = 4.8 μg/day; Rb - median = 1.6 mg/day; Sb - median = 1.8 μg/day; Sc - median = 0.3 μg/day. Dietary intakes of Cr, Mn and Se for the majority of the subjects fell within the US safe and adequate range. In contrast, a high proportion of subjects had apparently low intakes of dietary Cu and Zn in relation to current US dietary recommendations

  1. Determination of Nd3+ Ions in Solution Samples by a Coated Wire Ion-Selective Sensor

    Directory of Open Access Journals (Sweden)

    Hassan Ali Zamani

    2012-01-01

    Full Text Available A new coated wire electrode (CWE using 5-(methylsulfanyl-3-phenyl-1H-1,2,4-triazole (MPT as an ionophore has been developed as a neodymium ion-selective sensor. The sensor exhibits Nernstian response for the Nd3+ ions in the concentration range of 1.0×10−6-1.0×10−2 M with detection limit of 3.7×10−7 M. It displays a Nernstian slope of 20.2±0.2 mV/decade in the pH range of 2.7–8.1. The proposed sensor also exhibits a fast response time of ∼5 s. The sensor revealed high selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions, including members of the lanthanide family other than Nd3+. The electrode was used as an indicator electrode in the potentiometric titration of Nd(III ions with EDTA. The electrode was also employed for the determination of the Nd3+ ions concentration in water solution samples.

  2. Semi-selective medium for Fusarium graminearum detection in seed samples

    Directory of Open Access Journals (Sweden)

    Marivane Segalin

    2010-12-01

    Full Text Available Fungi of the genus Fusarium cause a variety of difficult to control diseases in different crops, including winter cereals and maize. Among the species of this genus Fusarium graminearum deserves attention. The aim of this work was to develop a semi-selective medium to study this fungus. In several experiments, substrates for fungal growth were tested, including fungicides and antibiotics such as iprodiona, nystatin and triadimenol, and the antibacterial agents streptomycin and neomycin sulfate. Five seed samples of wheat, barley, oat, black beans and soybeans for F. graminearum detection by using the media Nash and Snyder agar (NSA, Segalin & Reis agar (SRA and one-quarter dextrose agar (1/4PDA; potato 50g; dextrose 5g and agar 20g, either unsupplemented or supplemented with various concentrations of the antimicrobial agents cited above. The selected components and concentrations (g.L-1 of the proposed medium, Segalin & Reis agar (SRA-FG, were: iprodiona 0.05; nystatin 0,025; triadimenol 0.015; neomycin sulfate 0.05; and streptomycin sulfate, 0.3 added of ¼ potato sucrose agar. In the isolation from seeds of cited plant species, the sensitivity of this medium was similar to that of NSA but with de advantage of maintaining the colony morphological aspects similar to those observed in potato-dextrose-agar medium.

  3. Surgical model pig ex vivo for venous dissection teaching in medical schools.

    Science.gov (United States)

    Tube, Milton Ignacio Carvalho; Spencer-Netto, Fernando Antonio Campelo; Oliveira, Anderson Igor Pereira de; Holanda, Arthur Cesário de; Barros, Bruno Leão Dos Santos; Rezende, Caio Cezar Gomes; Cavalcanti, João Pedro Guerra; Batista, Marília Apolinário; Campos, Josemberg Marins

    2017-02-01

    To investigate a method for development of surgical skills in medical students simulating venous dissection in surgical ex vivo pig model. Prospective, analytical, experimental, controlled study with four stages: selection, theoretical teaching, training and assessment. Sample of 312 students was divided into two groups: Group A - 2nd semester students; Group B - students of 8th semester. The groups were divided into five groups of 12 students, trained two hours per week in the semester. They set up four models to three students in each skill station assisted by a monitor. Teaching protocol emergency procedures training were applied to venous dissection, test goal-discursive and OSATS scale. The pre-test confirmed that the methodology has not been previously applied to the students. The averages obtained in the theoretical evaluation reached satisfactory parameters in both groups. The results of applying OSATS scale showed the best performance in group A compared to group B, however, both groups had satisfactory medium. The method was enough to raise a satisfactory level of skill both groups in venous dissection running on surgical swine ex vivo models.

  4. Correcting Classifiers for Sample Selection Bias in Two-Phase Case-Control Studies

    Science.gov (United States)

    Theis, Fabian J.

    2017-01-01

    Epidemiological studies often utilize stratified data in which rare outcomes or exposures are artificially enriched. This design can increase precision in association tests but distorts predictions when applying classifiers on nonstratified data. Several methods correct for this so-called sample selection bias, but their performance remains unclear especially for machine learning classifiers. With an emphasis on two-phase case-control studies, we aim to assess which corrections to perform in which setting and to obtain methods suitable for machine learning techniques, especially the random forest. We propose two new resampling-based methods to resemble the original data and covariance structure: stochastic inverse-probability oversampling and parametric inverse-probability bagging. We compare all techniques for the random forest and other classifiers, both theoretically and on simulated and real data. Empirical results show that the random forest profits from only the parametric inverse-probability bagging proposed by us. For other classifiers, correction is mostly advantageous, and methods perform uniformly. We discuss consequences of inappropriate distribution assumptions and reason for different behaviors between the random forest and other classifiers. In conclusion, we provide guidance for choosing correction methods when training classifiers on biased samples. For random forests, our method outperforms state-of-the-art procedures if distribution assumptions are roughly fulfilled. We provide our implementation in the R package sambia. PMID:29312464

  5. Source apportionment and location by selective wind sampling and Positive Matrix Factorization.

    Science.gov (United States)

    Venturini, Elisa; Vassura, Ivano; Raffo, Simona; Ferroni, Laura; Bernardi, Elena; Passarini, Fabrizio

    2014-10-01

    In order to determine the pollution sources in a suburban area and identify the main direction of their origin, PM2.5 was collected with samplers coupled with a wind select sensor and then subjected to Positive Matrix Factorization (PMF) analysis. In each sample, soluble ions, organic carbon, elemental carbon, levoglucosan, metals, and Polycyclic Aromatic Hydrocarbons (PAHs) were determined. PMF results identified six main sources affecting the area: natural gas home appliances, motor vehicles, regional transport, biomass combustion, manufacturing activities, and secondary aerosol. The connection of factor temporal trends with other parameters (i.e., temperature, PM2.5 concentration, and photochemical processes) confirms factor attributions. PMF analysis indicated that the main source of PM2.5 in the area is secondary aerosol. This should be mainly due to regional contributions, owing to both the secondary nature of the source itself and the higher concentration registered in inland air masses. The motor vehicle emission source contribution is also important. This source likely has a prevalent local origin. The most toxic determined components, i.e., PAHs, Cd, Pb, and Ni, are mainly due to vehicular traffic. Even if this is not the main source in the study area, it is the one of greatest concern. The application of PMF analysis to PM2.5 collected with this new sampling technique made it possible to obtain more detailed results on the sources affecting the area compared to a classical PMF analysis.

  6. Characteristic of selected frequency luminescence for samples collected in deserts north to Beijing

    International Nuclear Information System (INIS)

    Li Dongxu; Wei Mingjian; Wang Junping; Pan Baolin; Zhao Shiyuan; Liu Zhaowen

    2009-01-01

    Surface sand samples were collected in eight sites of the Horqin and Otindag deserts located in north to Beijing. BG2003 luminescence spectrograph was used to analyze the emitted photons and characteristic spectra of the selected frequency luminescence were obtained. It was found that high intensities of emitted photons stimulated by heat from 85 degree C-135 degree C and 350 degree C-400 degree C. It belong to the traps of 4.13 eV (300 nm), 4.00 eV (310 nm), 3.88 eV (320 nm) and 2.70 eV (460 nm), and the emitted photons belong to traps of 4.00 eV (310 nm), 3.88 eV (320 nm) and 2.70 eV (460 nm) were stimulated by green laser. And sand samples of the eight sites can respond to the increase of definite radiological dose at each wavelength, which is the characteristic spectrum to provide radiation dosimetry basis for dating. There are definite district characteristic in their characteristic spectra. (authors)

  7. Clinical impact of strict criteria for selectivity and lateralization in adrenal vein sampling.

    Science.gov (United States)

    Gasparetto, Alessandro; Angle, John F; Darvishi, Pasha; Freeman, Colbey W; Norby, Ray G; Carey, Robert M

    2015-04-01

    Selectivity index (SI) and lateralization index (LI) thresholds determine the adequacy of adrenal vein sampling (AVS) and the degree of lateralization. The purpose of this study was investigate the clinical outcome of patients whose adrenal vein sampling was interpreted using "strict criteria" (SC) (SIpre-stimuli≥3, SIpost-stimuli≥5 and LIpre-stimuli≥4, LIpost-stimuli≥4). A retrospective review of 73 consecutive AVS procedures was performed and 67 were technically successful. Forty-three patients showed lateralization and underwent surgery, while 24 did not lateralize and were managed conservatively. Systolic blood pressure (SBP), diastolic blood pressure (DBP), kalemia (K(+)), and the change in number of blood pressure (BP) medications were recorded for each patient before and after AVS and potential surgery were performed. In the surgery group, BP and K(+) changed respectively from 160±5.3/100±2.0 mmHg to 127±3.3/80±1.9 (p blood pressure medications were six (14.0%) in the lateralized group and 22 (91.7%) in the non-lateralized group (p <0.001). AVS interpretation with SC leads to significant clinical improvement in both patients who underwent surgery and those managed conservatively.

  8. Multiwavelength diagnostics of accretion in an X-ray selected sample of CTTSs

    Science.gov (United States)

    Curran, R. L.; Argiroffi, C.; Sacco, G. G.; Orlando, S.; Peres, G.; Reale, F.; Maggio, A.

    2011-02-01

    Context. High resolution X-ray spectroscopy has revealed soft X-rays from high density plasma in classical T Tauri stars (CTTSs), probably arising from the accretion shock region. However, the mass accretion rates derived from the X-ray observations are consistently lower than those derived from UV/optical/NIR studies. Aims: We aim to test the hypothesis that the high density soft X-ray emission originates from accretion by analysing, in a homogeneous manner, optical accretion indicators for an X-ray selected sample of CTTSs. Methods: We analyse optical spectra of the X-ray selected sample of CTTSs and calculate the accretion rates based on measuring the Hα, Hβ, Hγ, He ii 4686 Å, He i 5016 Å, He i 5876 Å, O i 6300 Å, and He i 6678 Å equivalent widths. In addition, we also calculate the accretion rates based on the full width at 10% maximum of the Hα line. The different optical tracers of accretion are compared and discussed. The derived accretion rates are then compared to the accretion rates derived from the X-ray spectroscopy. Results: We find that, for each CTTS in our sample, the different optical tracers predict mass-accretion rates that agree within the errors, albeit with a spread of ≈ 1 order of magnitude. Typically, mass-accretion rates derived from Hα and He i 5876 Å are larger than those derived from Hβ, Hγ, and O i. In addition, the Hα full width at 10%, whilst a good indicator of accretion, may not accurately measure the mass-accretion rate. When the optical mass-accretion rates are compared to the X-ray derived mass-accretion rates, we find that: a) the latter are always lower (but by varying amounts); b) the latter range within a factor of ≈ 2 around 2 × 10-10 M⊙ yr-1, despite the former spanning a range of ≈ 3 orders of magnitude. We suggest that the systematic underestimate of the X-ray derived mass-accretion rates could depend on the density distribution inside the accretion streams, where the densest part of the stream is

  9. Soil sampling intercomparison exercise by selected laboratories of the ALMERA Network

    International Nuclear Information System (INIS)

    2009-01-01

    The IAEA's Seibersdorf Laboratories in Austria have the programmatic responsibility to provide assistance to Member State laboratories in maintaining and improving the reliability of analytical measurement results, both in radionuclide and trace element determinations. This is accomplished through the provision of reference materials of terrestrial origin, validated analytical procedures, training in the implementation of internal quality control, and through the evaluation of measurement performance by the organization of worldwide and regional interlaboratory comparison exercises. The IAEA is mandated to support global radionuclide measurement systems related to accidental or intentional releases of radioactivity in the environment. To fulfil this obligation and ensure a reliable, worldwide, rapid and consistent response, the IAEA coordinates an international network of analytical laboratories for the measurement of environmental radioactivity (ALMERA). The network was established by the IAEA in 1995 and makes available to Member States a world-wide network of analytical laboratories capable of providing reliable and timely analysis of environmental samples in the event of an accidental or intentional release of radioactivity. A primary requirement for the ALMERA members is participation in the IAEA interlaboratory comparison exercises, which are specifically organized for ALMERA on a regular basis. These exercises are designed to monitor and demonstrate the performance and analytical capabilities of the network members, and to identify gaps and problem areas where further development is needed. In this framework, the IAEA organized a soil sampling intercomparison exercise (IAEA/SIE/01) for selected laboratories of the ALMERA network. The main objective of this exercise was to compare soil sampling procedures used by different participating laboratories. The performance evaluation results of the interlaboratory comparison exercises performed in the framework of

  10. Venous chest anatomy: clinical implications

    International Nuclear Information System (INIS)

    Chasen, M.H.; Charnsangavej, C.

    1998-01-01

    This article provides a practical approach to the clinical implications and importance of understanding the collateral venous anatomy of the thorax. Routine radiography, conventional venography, computed tomography (CT), and magnetic resonance (MR) imaging studies provide correlative anatomic models for the demonstration of how interconnecting collateral vascular networks within the thorax maintain venous stability at all times. Five major systems comprise the collateral venous network of the thorax ( Fig. 1 ). These include the paravertebral, azygos-hemiazygos, internal mammary, lateral thoracic, and anterior jugular venous systems (AJVS). The five systems are presented in the following sequence: (a) a brief introduction to the importance of catheter position and malposition in understanding access to the thoracic venous system, (b) the anatomy of the azygos-hemiazygos systems and their relationship with the paravertebral plexus, (c) the importance of the AJVS, (d) 'loop' concepts interconnecting the internal mammary and azygos-hemiazygos systems by means of the lateral thoracic and intercostal veins, and (e) the interconnecting venous networks on the thoracic side of the thoracoabdominal junction. Certain aspects of the venous anatomy of the thorax will not be discussed in this chapter and include (a) the intra-abdominal anastomoses between the superior and inferior vena cavae (IVC) via the internal mammary, lateral thoracic, and azygos-hemiazygos systems (beyond the scope of this article), (b) potential collateral vessels involving vertebral, parascapular, thyroidal, thymic, and other smaller veins that might anastomose with the major systems, and (c) anatomic variants and pitfalls that may mimic pathologic conditions (space limitations). (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Arterialized and venous blood lactate concentration difference during different exercise intensities

    Directory of Open Access Journals (Sweden)

    Leandro C. Felippe

    2017-06-01

    Conclusion: These results suggest a delayed lactate appearance in the venous blood, which is accentuated at higher exercise intensities. The lactate measured in arterialized and venous blood is interchangeable only when blood samples are collected at least 10 minutes after the exercise starts.

  12. Central venous catheter-related thrombosis in senile male patients: New risk factors and predictors.

    Science.gov (United States)

    Liu, Gao; Fu, Zhi-Qing; Zhu, Ping; Li, Shi-Jun

    2015-06-01

    Central venous catheterization (CVC)-related venous thrombosis is a common but serious clinical complication, thus prevention and treatment on this problem should be extensively investigated. In this research, we aimed to investigate the incidence rate of CVC-related venous thrombosis in senile patients and give a further discussion on the related risk factors and predictors. A total of 324 hospitalized senile male patients subjected to CVC were selected. Retrospective investigation and analysis were conducted on age, underlying diseases, clinical medications, catheterization position and side, catheter retention time, and incidence of CVC-related venous thrombosis complications. Basic laboratory test results during catheterization and thrombogenesis were also collected and analyzed. Among the 324 patients, 20 cases (6.17%) of CVC-related venous thrombosis were diagnoseds. The incidence rate of CVC-related venous thrombosis in subclavian vein catheterization was significantly lower than that in femoral vein catheterization (Pcatheterization (Pcatheterization and internal jugular vein catheterization (Pvenous thrombosis history (Pvenous thrombosis in senile male patients. Subclavian vein catheterization was the most appropriate choice among senile patients to decrease the incidence of CVC-related venous thrombosis. Previous venous thrombosis history, high lactate dehydrogenase level, low HDL level, and low albumin level were important risk factors in predicting CVC-related venous thrombosis.

  13. 40 CFR Appendix A to Subpart F of... - Sampling Plans for Selective Enforcement Auditing of Small Nonroad Engines

    Science.gov (United States)

    2010-07-01

    ... Enforcement Auditing of Small Nonroad Engines A Appendix A to Subpart F of Part 90 Protection of Environment...-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Selective Enforcement Auditing Pt. 90, Subpt. F, App. A Appendix A to Subpart F of Part 90—Sampling Plans for Selective Enforcement Auditing of Small Nonroad Engines...

  14. Gamma radiation measurement in select sand samples from Camburi beach - Vitoria, Espirito Santo, Brazil: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Livia F.; Pecequilo, Brigitte R.S.; Aquino, Reginaldo R., E-mail: lfbarros@ipen.b, E-mail: brigitte@ipen.b, E-mail: raquino@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The variation of natural radioactivity along the surface of the beach sands of Camburi, located in Vitoria, capital of Espirito Santo, southeastern Brazil, was determined from the contents of {sup 226}Ra, {sup 232}Th and {sup 40}K. Eleven collecting points was selected along all the 6 km extension of the Camburi beach. Sand samples collected from all established points on January 2011 were dried and sealed in standard 100 mL polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks ingrowth period, in order to allow the secular equilibrium in the {sup 238}U and {sup 232}Th series. The {sup 226}Ra concentration was determined from the weighted average concentrations of {sup 214}Pb and {sup 214}Bi. The {sup 232}Th concentration was determined from the weighted average concentrations of {sup 228}Ac, {sup 212}Pb and {sup 212}Bi and the {sup 40}K from its single gamma transition. Preliminary results show activity concentrations varying from 5 Bq.kg{sup -1} to {sup 222} Bq.kg{sup -1} for {sup 226}Ra and from 14 Bq.kg{sup -1} to 1074 Bq.kg{sup -'}1 for {sup 232}Th, both with the highest values for Camburi South and Central. For {sup 40}K, the activity concentrations ranged from 14 Bq.kg{sup -1} to 179 Bq.kg{sup -1} and the highest values were obtained for Camburi South. (author)

  15. Crude protein, fibre and phytic acid in vitro digestibility of selected legume and buckwheat samples

    Directory of Open Access Journals (Sweden)

    Petra Vojtíšková

    2013-01-01

    Full Text Available The aim of this study was to determine crude protein, fibre and phytic acid in vitro digestibility of selected legumes and buckwheat products. All analyses except the phytic acid contents were performed in the line with the Commission Regulation (EC No. 152/2009. A modified version of Holt’s Method was used for phytic acid (phytate determination. None of all samples contained more than 11% of moisture. Soybeans are rich in crude protein; they contain nearly 40% of this compound. The content of crude protein in buckwheat flours was about 14%. The highest amount of phytate was found in common beans and soybeans-about 2 g/100 g of dry matter. On the other hand, the lowest phytate content was observed in buckwheat pasta (F. esculentum groats was 1.9 g per 100 g of dry matter. In vitro digestibility was determined using an incubator Daisy and pepsin enzymes and the combination of pepsin and pancreatin. The highest coefficient of crude protein digestibility was discovered to be in peels and wholemeal flour. The greatest fibre digestibility coefficients were obtained for peels, which contain about 65% of fibre in their dry matter. When pepsin was used, a higher phytic acid digestibility coefficient for G. max, Ph. vulgaris, peels, flour, groats and broken groats was observed; while when the combination of pepsin and pancreatin was used, higher phytic acid digestibility coefficients for peas, lentil and wholemeal flour were observed.

  16. Gamma radiation measurement in select sand samples from Camburi beach - Vitoria, Espirito Santo, Brazil: preliminary results

    International Nuclear Information System (INIS)

    Barros, Livia F.; Pecequilo, Brigitte R.S.; Aquino, Reginaldo R.

    2011-01-01

    The variation of natural radioactivity along the surface of the beach sands of Camburi, located in Vitoria, capital of Espirito Santo, southeastern Brazil, was determined from the contents of 226 Ra, 232 Th and 40 K. Eleven collecting points was selected along all the 6 km extension of the Camburi beach. Sand samples collected from all established points on January 2011 were dried and sealed in standard 100 mL polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks ingrowth period, in order to allow the secular equilibrium in the 238 U and 232 Th series. The 226 Ra concentration was determined from the weighted average concentrations of 214 Pb and 214 Bi. The 232 Th concentration was determined from the weighted average concentrations of 228 Ac, 212 Pb and 212 Bi and the 40 K from its single gamma transition. Preliminary results show activity concentrations varying from 5 Bq.kg -1 to 222 Bq.kg -1 for 226 Ra and from 14 Bq.kg -1 to 1074 Bq.kg -' 1 for 232 Th, both with the highest values for Camburi South and Central. For 40 K, the activity concentrations ranged from 14 Bq.kg -1 to 179 Bq.kg -1 and the highest values were obtained for Camburi South. (author)

  17. Analysis of a selected sample of RR Lyrae stars in the LMC from OGLE-III

    International Nuclear Information System (INIS)

    Chen Bing-Qiu; Jiang Bi-Wei; Yang Ming

    2013-01-01

    A systematic study of RR Lyrae stars is performed using a selected sample of 655 objects in the Large Magellanic Cloud (LMC) with long-term observations and numerous measurements from the Optical Gravitational Lensing Experiment III project. The phase dispersion method and linear superposition of the harmonic oscillations are used to derive the pulsation frequency and properties of light variation. It is found that a dichotomy exists in Oosterhoff Type I and Oosterhoff Type II for RR Lyrae stars in the LMC. Due to our strict criteria for identifying a frequency, a lower limit for the incidence rate of Blazhko modulation in the LMC is estimated in various subclasses of RR Lyrae stars. For fundamental-mode RR Lyrae stars, the rate of 7.5% is smaller than the previous result. In the case of the first-overtone RR Lyrae variables, the rate of 9.1% is relatively high. In addition to the Blazhko variables, 15 objects are identified to pulsate in the fundamental/first-overtone double mode. Furthermore, four objects show a period ratio around 0.6, which makes them very likely to be rare pulsators in the fundamental/second-overtone double mode. (research papers)

  18. 40 CFR Appendix Xi to Part 86 - Sampling Plans for Selective Enforcement Auditing of Light-Duty Vehicles

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Sampling Plans for Selective Enforcement Auditing of Light-Duty Vehicles XI Appendix XI to Part 86 Protection of Environment ENVIRONMENTAL... Enforcement Auditing of Light-Duty Vehicles 40% AQL Table 1—Sampling Plan Code Letter Annual sales of...

  19. Molecularly imprinted membrane extraction combined with high-performance liquid chromatography for selective analysis of cloxacillin from shrimp samples.

    Science.gov (United States)

    Du, Wei; Sun, Min; Guo, Pengqi; Chang, Chun; Fu, Qiang

    2018-09-01

    Nowadays, the abuse of antibiotics in aquaculture has generated considerable problems for food safety. Therefore, it is imperative to develop a simple and selective method for monitoring illegal use of antibiotics in aquatic products. In this study, a method combined molecularly imprinted membranes (MIMs) extraction and liquid chromatography was developed for the selective analysis of cloxacillin from shrimp samples. The MIMs was synthesized by UV photopolymerization, and characterized by scanning electron microscope, Fourier transform infrared spectra, thermo-gravimetric analysis and swelling test. The results showed that the MIMs exhibited excellent permselectivity, high adsorption capacity and fast adsorption rate for cloxacillin. Finally, the method was utilized to determine cloxacillin from shrimp samples, with good accuracies and acceptable relative standard deviation values for precision. The proposed method was a promising alternative for selective analysis of cloxacillin in shrimp samples, due to the easy-operation and excellent selectivity. Copyright © 2018. Published by Elsevier Ltd.

  20. Surgical management of venous malformations.

    Science.gov (United States)

    Loose, D A

    2007-01-01

    Among vascular malformations, the predominantly venous malformations represent the majority of cases. They form a clinical entity and therefore need clear concepts concerning diagnosis and treatment. This paper presents an overview of contemporary classification as well as tactics and techniques of treatment. According to the Hamburg Classification, predominantly venous malformations are categorized into truncular and extratruncular forms, with truncular forms distinguished as obstructions and dilations, and extratruncular forms as limited or infiltrating. The tactics of treatment represent surgical and non-surgical methods or combined techniques. Surgical approaches utilize different tactics and techniques that are adopted based on the pathologic form and type of the malformation: (I) operation to reduce the haemodynamic activity of the malformation; (II) operation to eliminate the malformation; and (III) reconstructive operation. As for (I), a type of a tactic is the operation to derive the venous flow. In (II), the total or partial removal of the venous malformation is demonstrated subdivided into three different techniques. In this way, the infiltrating as well as the limited forms can be treated. An additional technique is dedicated to the treatment of a marginal vein. Approach (III) involves the treatment of venous aneurysms, where a variety of techniques have been successful. Long-term follow-up demonstrates positive results in 91% of the cases. Congenital predominantly venous malformations should be treated according to the principles developed during the past decades in vascular surgery, interventional treatment and multidisciplinary treatment. The days of predominantly conservative treatment should be relegated to the past. Special skills and experiences are necessary to carry out appropriate surgical strategy, and the required operative techniques should be dictated by the location and type of malformation and associated findings.

  1. Chemical and X-ray diffraction analysis on selected samples from the TMI-2 reactor core

    International Nuclear Information System (INIS)

    Kleykamp, H.; Pejsa, R.

    1991-05-01

    Selected samples from different positions of the damaged TMI-2 reactor core were investigated by X-ray microanalysis and X-ray diffraction. The measurements yield the following resolidified phases after cooling: Cd and In depleted Ag absorber material, intermetallic Zr-steel compounds, fully oxidized Zircaloy, UO 2 -ZrO 2 solid solutions and their decomposed phases, and Fe-Al-Cr-Zr spinels. The composition of the phases and their lattice parameters as well as the eutectic and monotectic character can serve as indicators of local temperatures of the core. The reaction sequences are estimated from the heterogeneous equilibria of these phases. The main conclusions are: (1) Liquefaction onset is locally possible by Inconel-Zircaloy and steel-Zircaloy reactions of spacers and absorber guide tubes at 930deg C. However, increased rates of dissolution occur above 1200deg C. (2) UO 2 dissolution in the Inconel-steel-Zircaloy melt starts at 1300deg C with increased rates above 1900deg C. (3) Fuel temperatures in the core centre are increased above 2550deg C, liquid (U,Zr)O 2 is generated. (4) Square UO 2 particles are reprecipitated from the Incoloy-steel-Zircaloy-UO 2 melt during cooling, the remaining metallic melt is oxygen poor; two types of intermetallic phases are formed. (5) Oxidized Fe and Zr and Al 2 O 3 from burnable absorber react to spinels which form a low melting eutectic with the fuel at 1500deg C. The spinel acts as lubricant for fuel transport to the lower reactor plenum above 1500deg C. (6) Ruthenium (Ru-106) is dissolved in the steel phase, antimony (Sb-125) in the α-Ag absorber during liquefaction. (7) Oxidation of the Zircaloy-steel phases takes place mainly in the reflood stage 3 of the accident scenario. (orig.) [de

  2. Investigation of selected trace elements in hair samples of eczema patients

    International Nuclear Information System (INIS)

    Osman, N. O.

    2010-12-01

    The aim of this case-control study was to investigate the relationship between selected trace elements and skin diseases, namely eczema. Fifty five patients affected by the most frequent eczema types were recruited at the onset of disease at the hospital of dermatology in Khartoum together with thirty healthy controls. Fe, Zn, Cu, and Ni were measured in hair samples obtained from both patients and control group using Atomic Absorption Spectrometry (AAS). Data analysis was performed using the T-test. Partial correlation was used to study the relationship between the elemental concentration. Certified reference material (IAEA-85) Hair Powder) produced by the International Atomic Energy Agency (IAEA) was used as a quality control to check the accuracy and precision of the analytical technique, good agreement was achieved for all elements under investigation. Significant variations (p<0.05) in the concentrations of Fe, Zn, Cu, and Ni in the hair of the patients compared to the control group, and this difference was a decrease of iron, zinc and copper, therefore, should be given to the patient doses of these elements, while there was an increase in the nickel. So it is not included in the treatment. These interesting associations between the levels the of trace elements could be used as an indication for the disease as well as to monitor the treatment. Comparisons of the results obtained in the present study with those conducted for other population in the literature showed very close agreement. The levels of the elements under investigation are comparable with the data obtained from the literature for other populations with exception of Fe which was found to be very high in Sudanese population. (Author)

  3. Electron microprobe analyses of selected samples from deep rock disposal experiment No. 1

    International Nuclear Information System (INIS)

    Hlava, P.F.; Chambers, W.F.

    1976-04-01

    Deep Rock Disposal Experiment No. 1 was designed to provide information about the interaction between a molten, glass-based, nuclear waste simulant and rock material. Selected samples from this experiment were examined by optical microscopy and electron probe microanalysis. Analysis of the homogenized material in the convection cell that was created in the central portion of the melt region shows that an amount of rock equal to about one-half of the original amount of waste simulant was incorporated in the melt during the experiment. Stagnant melt at the sides of the cell formed a glass with large compositional gradients. A white band separated the convected and stagnant materials. The color of the band is attributed to light scattering by small crystallites formed during cooling. Four types of crystallites grew from the melt: two oxides, a Mg--Fe borate, and a silicate. Spinel (MgO, Cr 2 O 3 , FeO (Fe 2 O 3 ), and NiO) was the most common crystallite in the glass. The spinel crystallites found within the convection cell displayed skeletal morphology and oscillatory zoning which indicates growth at varying temperatures as they were carried along by convection. A single cluster of nonskeletal (Fe,Cr) 2 O 3 crystallites was found at the bottom of the melt zone where convection did not occur. Mg--Fe borate crystallites grew in clusters in the central portion of the convection cell after convection ceased. A silicate similar to Fe-rich diopside (CaMgSi 2 O 6 ) with unusual amounts of Ce 2 O 3 and other heavy metal oxides formed as larger crystallites in the stagnant melt at the side of the convection cell and as many very small crystallites in the white band

  4. Investigation of selected trace elements in hair samples of eczema patients

    Energy Technology Data Exchange (ETDEWEB)

    Osman, N O [Atomic Energy Council, Sudan Academy of Sciences (SAS), Khartoum (Sudan)

    2010-12-15

    The aim of this case-control study was to investigate the relationship between selected trace elements and skin diseases, namely eczema. Fifty five patients affected by the most frequent eczema types were recruited at the onset of disease at the hospital of dermatology in Khartoum together with thirty healthy controls. Fe, Zn, Cu, and Ni were measured in hair samples obtained from both patients and control group using Atomic Absorption Spectrometry (AAS). Data analysis was performed using the T-test. Partial correlation was used to study the relationship between the elemental concentration. Certified reference material (IAEA-85) Hair Powder) produced by the International Atomic Energy Agency (IAEA) was used as a quality control to check the accuracy and precision of the analytical technique, good agreement was achieved for all elements under investigation. Significant variations (p<0.05) in the concentrations of Fe, Zn, Cu, and Ni in the hair of the patients compared to the control group, and this difference was a decrease of iron, zinc and copper, therefore, should be given to the patient doses of these elements, while there was an increase in the nickel. So it is not included in the treatment. These interesting associations between the levels the of trace elements could be used as an indication for the disease as well as to monitor the treatment. Comparisons of the results obtained in the present study with those conducted for other population in the literature showed very close agreement. The levels of the elements under investigation are comparable with the data obtained from the literature for other populations with exception of Fe which was found to be very high in Sudanese population. (Author)

  5. Venous abnormalities demonstrated by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T; Tsukune, Y; Ashida, H; Tokuda, M; Oyama, Y [St. Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

    1980-05-01

    CT is capable of demonstrating various venous changes. However, little have been described on this subject in the literature. Examples of various venous abnormalities such as obstructed jugular vein, superior and inferior vena cava (IVC), tumor invasion of IVC and renal vein and venous changes in portal hypertension were presented. It was stressed that noninvasive CT is a good tool in diagnosis of some of venous changes and may be able to eliminate angiography in such cases.

  6. Colorectal cancer with venous tumor thrombosis

    OpenAIRE

    Kensuke Otani; Soichiro Ishihara; Keisuke Hata; Koji Murono; Kazuhito Sasaki; Koji Yasuda; Takeshi Nishikawa; Toshiaki Tanaka; Tomomichi Kiyomatsu; Kazushige Kawai; Hiroaki Nozawa; Hironori Yamaguchi; Toshiaki Watanabe

    2018-01-01

    Summary: Colorectal cancer is seldom accompanied by venous tumor thrombosis, and little is known about the features of venous tumor thrombosis in colorectal cancer. However, some reports show that colorectal cancer patients can develop venous tumor thrombosis and warn clinicians not to overlook this complication. In this report, we perform a review of 43 previously reported cases and investigate the characteristics of colorectal cancer accompanied by venous tumor thrombosis. The histological ...

  7. Reference values for venous and capillary S100B in children

    DEFF Research Database (Denmark)

    Astrand, Ramona; Romner, Bertil; Lanke, Jan

    2011-01-01

    The current management guidelines for pediatric mild head injury (MHI) liberally recommend computed tomography (CT) and frequent admission. Serum protein S100B, currently used in management of adult head injury, has recently shown potential for reducing unnecessary CT scans after pediatric mild h...... head injury. Capillary sampling in children is commonly used when venous sampling fails or is inappropriate. We present reference values for both venous and capillary samples of protein S100B in children....

  8. Re-Emergence of Under-Selected Stimuli, after the Extinction of Over-Selected Stimuli in an Automated Match to Samples Procedure

    Science.gov (United States)

    Broomfield, Laura; McHugh, Louise; Reed, Phil

    2008-01-01

    Stimulus over-selectivity occurs when one of potentially many aspects of the environment comes to control behaviour. In two experiments, adults with no developmental disabilities, were trained and tested in an automated match to samples (MTS) paradigm. In Experiment 1, participants completed two conditions, in one of which the over-selected…

  9. Mineralogy, petrology and whole-rock chemistry data compilation for selected samples of Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Connolly, J.R.

    1991-12-01

    Petrologic, bulk chemical, and mineralogic data are presented for 49 samples of tuffaceous rocks from core holes USW G-1 and UE-25a number-sign 1 at Yucca Mountain, Nevada. Included, in descending stratigraphic order, are 11 samples from the Topopah Spring Member of the Paintbrush Tuff, 12 samples from the Tuffaceous Beds of Calico Hills, 3 samples from the Prow Pass Member of the Crater Flat Tuff, 20 samples from the Bullfrog Member of the Crater Flat Tuff and 3 samples from the Tram Member of the Crater Flat Tuff. The suite of samples contains a wide variety of petrologic types, including zeolitized, glassy, and devitrified tuffs. Data vary considerably between groups of samples, and include thin section descriptions (some with modal analyses for which uncertainties are estimated), electron microprobe analyses of mineral phases and matrix, mineral identifications by X-ray diffraction, and major element analyses with uncertainty estimates

  10. A quantitative method to detect explosives and selected semivolatiles in soil samples by Fourier transform infrared spectroscopy

    International Nuclear Information System (INIS)

    Clapper-Gowdy, M.; Dermirgian, J.; Robitaille, G.

    1995-01-01

    This paper describes a novel Fourier transform infrared (FTIR) spectroscopic method that can be used to rapidly screen soil samples from potentially hazardous waste sites. Samples are heated in a thermal desorption unit and the resultant vapors are collected and analyzed in a long-path gas cell mounted in a FTIR. Laboratory analysis of a soil sample by FTIR takes approximately 10 minutes. This method has been developed to identify and quantify microgram concentrations of explosives in soil samples and is directly applicable to the detection of selected volatile organics, semivolatile organics, and pesticides

  11. Determination of selected metals in coal samples from Lafia-Obi and ...

    African Journals Online (AJOL)

    coal samples were determined using atomic absorption spectroscopy (AAS). All the samples have comparable chromium and copper contents, while iron, aluminum, magnesium and potassium content vary to some extent. Metals concentrations in both Lafia-Obi and Chikila coal samples are within the limits allowed by the ...

  12. Familial Clustering of Venous Thromboembolism

    DEFF Research Database (Denmark)

    Sindet-Pedersen, Caroline; Oestergaard, Louise Bruun; Gundlund, Anna

    2016-01-01

    BACKGROUND: Identification of risk factors for venous thromboembolism (VTE) is of utmost importance to improve current prophylactic regimes and treatment guidelines. The extent to which a family history contributes to the risk of VTE needs further exploration. OBJECTIVES: To examine the relative ...

  13. Venous thrombosis : a patient's view

    NARCIS (Netherlands)

    Korlaar, Inez van

    2006-01-01

    The studies described in this thesis had two main aims: 1) To study the quality of life of patients with venous thrombosis and to examine the role of illness perceptions in explaining the quality of life of these patients. 2) To assess the psychological consequences of genetic testing for

  14. History of venous leg ulcers.

    Science.gov (United States)

    Gianfaldoni, S; Wollina, U; Lotti, J; Gianfaldoni, R; Lotti, T; Fioranelli, M; Roccia, M G

    To retrieve the history of venous ulcers and of skin lesions in general, we must go back to the appearance of human beings on earth. It is interesting to note that cutaneous injuries evolved parallel to human society. An essential first step in the pathogenesis of ulcers was represented by the transition of the quadruped man to Homo Erectus. This condition was characterized by a greater gravitational pressure on the lower limbs, with consequences on the peripheral venous system. Furthermore, human evolution was characterized by an increased risk of traumatic injuries, secondary to his natural need to create fire and hunt (e.g. stones, iron, fire, animal fighting). Humans then began to fight one another until they came to real wars, with increased frequency of wounds and infectious complications. The situation degraded with the introduction of horse riding, introduced by the Scites, who first tamed animals in the 7th century BC. This condition exhibited iliac veins at compression phenomena, favouring the venous stasis. With time, man continued to evolve until the modern age, which is characterized by increased risk factors for venous wounds such as poor physical activity and dietary errors (1, 2).

  15. Splanchnic venous thrombosis and pancreatitis.

    Science.gov (United States)

    Nadkarni, Nikhil A; Khanna, Sahil; Vege, Santhi Swaroop

    2013-08-01

    Pancreatitis is an inflammatory process with local and systemic manifestations. One such local manifestation is thrombosis in splanchnic venous circulation, predominantly of the splenic vein. The literature on this important complication is very sparse. This review offers an overview of mechanism of thrombosis, its pathophysiology, diagnosis, and management in the setting of acute as well as chronic pancreatitis.

  16. DNA barcoding of selected UAE medicinal plant species: a comparative assessment of herbarium and fresh samples.

    Science.gov (United States)

    Enan, Mohamed Rizk; Palakkott, Abdul Rasheed; Ksiksi, Taoufik Saleh

    2017-01-01

    It is commonly difficult to extract and amplify DNA from herbarium samples as they are old and preserved using different compounds. In addition, such samples are subjected to the accumulation of intrinsically produced plant substances over long periods (up to hundreds of years). DNA extraction from desert flora may pause added difficulties as many contain high levels of secondary metabolites. Herbarium samples from the Biology Department (UAE University) plant collection and fresh plant samples, collected from around Al-Ain (UAE), were used in this study. The three barcode loci for the coding genes matK, rbcL and rpoC1-were amplified. Our results showed that T. terresteris , H. robustum , T. pentandrus and Z. qatarense were amplified using all three primers for both fresh and herbaium samples. Both fresh and herbarium samples of C. comosum , however, were not amplified at all, using the three primers. Herbarium samples from A. javanica , C. imbricatum , T. aucherana and Z. simplex were not amplified with any of the three primers. For fresh samples 90, 90 and 80% of the samples were amplified using matK, rbcL and rpoC1, respectively. In short, fresh samples were significantly better amplified than those from herbarium sources, using the three primers. Both fresh and herbarium samples from one species ( C. comosum ), however, were not successfully amplified. It is also concluded that the rbcL regions showed real potentials to distinguish the UAE species under investigation into the appropriate family and genus.

  17. Selection bias in population-based cancer case-control studies due to incomplete sampling frame coverage.

    Science.gov (United States)

    Walsh, Matthew C; Trentham-Dietz, Amy; Gangnon, Ronald E; Nieto, F Javier; Newcomb, Polly A; Palta, Mari

    2012-06-01

    Increasing numbers of individuals are choosing to opt out of population-based sampling frames due to privacy concerns. This is especially a problem in the selection of controls for case-control studies, as the cases often arise from relatively complete population-based registries, whereas control selection requires a sampling frame. If opt out is also related to risk factors, bias can arise. We linked breast cancer cases who reported having a valid driver's license from the 2004-2008 Wisconsin women's health study (N = 2,988) with a master list of licensed drivers from the Wisconsin Department of Transportation (WDOT). This master list excludes Wisconsin drivers that requested their information not be sold by the state. Multivariate-adjusted selection probability ratios (SPR) were calculated to estimate potential bias when using this driver's license sampling frame to select controls. A total of 962 cases (32%) had opted out of the WDOT sampling frame. Cases age <40 (SPR = 0.90), income either unreported (SPR = 0.89) or greater than $50,000 (SPR = 0.94), lower parity (SPR = 0.96 per one-child decrease), and hormone use (SPR = 0.93) were significantly less likely to be covered by the WDOT sampling frame (α = 0.05 level). Our results indicate the potential for selection bias due to differential opt out between various demographic and behavioral subgroups of controls. As selection bias may differ by exposure and study base, the assessment of potential bias needs to be ongoing. SPRs can be used to predict the direction of bias when cases and controls stem from different sampling frames in population-based case-control studies.

  18. Microbiological sampling plan based on risk classification to verify supplier selection and production of served meals in food service operation.

    Science.gov (United States)

    Lahou, Evy; Jacxsens, Liesbeth; Van Landeghem, Filip; Uyttendaele, Mieke

    2014-08-01

    Food service operations are confronted with a diverse range of raw materials and served meals. The implementation of a microbial sampling plan in the framework of verification of suppliers and their own production process (functionality of their prerequisite and HACCP program), demands selection of food products and sampling frequencies. However, these are often selected without a well described scientifically underpinned sampling plan. Therefore, an approach on how to set-up a focused sampling plan, enabled by a microbial risk categorization of food products, for both incoming raw materials and meals served to the consumers is presented. The sampling plan was implemented as a case study during a one-year period in an institutional food service operation to test the feasibility of the chosen approach. This resulted in 123 samples of raw materials and 87 samples of meal servings (focused on high risk categorized food products) which were analyzed for spoilage bacteria, hygiene indicators and food borne pathogens. Although sampling plans are intrinsically limited in assessing the quality and safety of sampled foods, it was shown to be useful to reveal major non-compliances and opportunities to improve the food safety management system in place. Points of attention deduced in the case study were control of Listeria monocytogenes in raw meat spread and raw fish as well as overall microbial quality of served sandwiches and salads. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Geochemistry of Selected Coal Samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

    Science.gov (United States)

    Belkin, Harvey E.; Tewalt, Susan J.

    2007-01-01

    and ash (generally Indonesia although, at present, there are concerns about the strong need for a major revision in mining laws and foreign investment policies (Wahju, 2004; United States Embassy Jakarta, 2004). The World Coal Quality Inventory (WoCQI) program of the U.S. Geological Survey (Tewalt and others, 2005) is a cooperative project with about 50 countries (out of 70 coal-producing countries world-wide). The WoCQI initiative has collected and published extensive coal quality data from the world's largest coal producers and consumers. The important aspects of the WoCQI program are; (1) samples from active mines are collected, (2) the data have a high degree of internal consistency with a broad array of coal quality parameters, and (3) the data are linked to GIS and available through the world-wide-web. The coal quality parameters include proximate and ultimate analysis, sulfur forms, major-, minor-, and trace-element concentrations and various technological tests. This report contains geochemical data from a selected group of Indonesian coal samples from a range of coal types, localities, and ages collected for the WoCQI program.

  20. Selection of representative calibration sample sets for near-infrared reflectance spectroscopy to predict nitrogen concentration in grasses

    DEFF Research Database (Denmark)

    Shetty, Nisha; Rinnan, Åsmund; Gislum, René

    2012-01-01

    ) algorithm were used and compared. Both Puchwein and CADEX methods provide a calibration set equally distributed in space, and both methods require a minimum prior of knowledge. The samples were also selected randomly using complete random, cultivar random (year fixed), year random (cultivar fixed......) and interaction (cultivar × year fixed) random procedures to see the influence of different factors on sample selection. Puchwein's method performed best with lowest RMSEP followed by CADEX, interaction random, year random, cultivar random and complete random. Out of 118 samples of the complete calibration set...... effectively enhance the cost-effectiveness of NIR spectral analysis by reducing the number of analyzed samples in the calibration set by more than 80%, which substantially reduces the effort of laboratory analyses with no significant loss in prediction accuracy....

  1. Tomographic imaging of 12 fracture samples selected from Olkiluoto deep drillholes

    International Nuclear Information System (INIS)

    Kuva, J.; Voutilainen, M.; Timonen, J.; Aaltonen, I.

    2010-06-01

    Rock samples from Olkiluoto were imaged with X-ray tomography to analyze distributions of mineral components and alteration of rock around different fracture types. Twelve samples were analyzed, which contained three types of fractures, and each sample was scanned with two different resolutions. Three dimensional reconstructions of the samples with four or five distinct mineral components displayed changes in the mineral distribution around previously water conducting fractures, which extended to a depth of several millimeters away from fracture surfaces. In addition, structure of fracture filling minerals is depicted. (orig.)

  2. Obscured AGN at z ~ 1 from the zCOSMOS-Bright Survey. I. Selection and optical properties of a [Ne v]-selected sample

    Science.gov (United States)

    Mignoli, M.; Vignali, C.; Gilli, R.; Comastri, A.; Zamorani, G.; Bolzonella, M.; Bongiorno, A.; Lamareille, F.; Nair, P.; Pozzetti, L.; Lilly, S. J.; Carollo, C. M.; Contini, T.; Kneib, J.-P.; Le Fèvre, O.; Mainieri, V.; Renzini, A.; Scodeggio, M.; Bardelli, S.; Caputi, K.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Iovino, A.; Kampczyk, P.; Knobel, C.; Kovač, K.; Le Borgne, J.-F.; Le Brun, V.; Maier, C.; Pellò, R.; Peng, Y.; Perez Montero, E.; Presotto, V.; Silverman, J. D.; Tanaka, M.; Tasca, L.; Tresse, L.; Vergani, D.; Zucca, E.; Bordoloi, R.; Cappi, A.; Cimatti, A.; Koekemoer, A. M.; McCracken, H. J.; Moresco, M.; Welikala, N.

    2013-08-01

    Aims: The application of multi-wavelength selection techniques is essential for obtaining a complete and unbiased census of active galactic nuclei (AGN). We present here a method for selecting z ~ 1 obscured AGN from optical spectroscopic surveys. Methods: A sample of 94 narrow-line AGN with 0.65 advantage of the large amount of data available in the COSMOS field, the properties of the [Ne v]-selected type 2 AGN were investigated, focusing on their host galaxies, X-ray emission, and optical line-flux ratios. Finally, a previously developed diagnostic, based on the X-ray-to-[Ne v] luminosity ratio, was exploited to search for the more heavily obscured AGN. Results: We found that [Ne v]-selected narrow-line AGN have Seyfert 2-like optical spectra, although their emission line ratios are diluted by a star-forming component. The ACS morphologies and stellar component in the optical spectra indicate a preference for our type 2 AGN to be hosted in early-type spirals with stellar masses greater than 109.5 - 10 M⊙, on average higher than those of the galaxy parent sample. The fraction of galaxies hosting [Ne v]-selected obscured AGN increases with the stellar mass, reaching a maximum of about 3% at ≈2 × 1011 M⊙. A comparison with other selection techniques at z ~ 1, namely the line-ratio diagnostics and X-ray detections, shows that the detection of the [Ne v] λ3426 line is an effective method for selecting AGN in the optical band, in particular the most heavily obscured ones, but cannot provide a complete census of type 2 AGN by itself. Finally, the high fraction of [Ne v]-selected type 2 AGN not detected in medium-deep (≈100-200 ks) Chandra observations (67%) is suggestive of the inclusion of Compton-thick (i.e., with NH > 1024 cm-2) sources in our sample. The presence of a population of heavily obscured AGN is corroborated by the X-ray-to-[Ne v] ratio; we estimated, by means of an X-ray stacking technique and simulations, that the Compton-thick fraction in our

  3. Polymer platforms for selective detection of cocaine in street samples adulterated with levamisole

    OpenAIRE

    Florea, Anca; Cowen, Todd; Piletsky, Sergey; Wael, De, Karolien

    2018-01-01

    Abstract: Accurate drug detection is of utmost importance for fighting against drug abuse. With a high number of cutting agents and adulterants being added to cut or mask drugs in street powders the number of false results is increasing. We demonstrate for the first time the usefulness of employing polymers readily synthesized by electrodeposition to selectively detect cocaine in the presence of the commonly used adulterant levamisole. The polymers were selected by computational modelling to ...

  4. Selective solid-phase extraction of Ni(II) by an ion-imprinted polymer from water samples

    International Nuclear Information System (INIS)

    Saraji, Mohammad; Yousefi, Hamideh

    2009-01-01

    A new ion-imprinted polymer (IIP) material was synthesized by copolymerization of 4-vinylpyridine as monomer, ethyleneglycoldimethacrylate as crosslinking agent and 2,2'-azobis-sobutyronitrile as initiator in the presence of Ni-dithizone complex. The IIP was used as sorbent in a solid-phase extraction column. The effects of sampling volume, elution conditions, sample pH and sample flow rate on the extraction of Ni ions form water samples were studied. The maximum adsorption capacity and the relative selectivity coefficients of imprinted polymer for Ni(II)/Co(II), Ni(II)/Cu(II) and Ni(II)/Cd(II) were calculated. Compared with non-imprinted polymer particles, the IIP had higher selectivity for Ni(II). The relative selectivity factor (α r ) values of Ni(II)/Co(II), Ni(II)/Cu(II) and Ni(II)/Cd(II) were 21.6, 54.3, and 22.7, respectively, which are greater than 1. The relative standard deviation of the five replicate determinations of Ni(II) was 3.4%. The detection limit for 150 mL of sample was 1.6 μg L -1 using flame atomic absorption spectrometry. The developed method was successfully applied to the determination of trace nickel in water samples with satisfactory results.

  5. Mass Spectrometry-Based Adrenal and Peripheral Venous Steroid Profiling for Subtyping Primary Aldosteronism

    NARCIS (Netherlands)

    Eisenhofer, G.; Dekkers, T.; Peitzsch, M.; Dietz, A.S.; Bidlingmaier, M.; Treitl, M.; Williams, T.A.; Bornstein, S.R.; Haase, M.; Rump, L.C.; Willenberg, H.S.; Beuschlein, F.; Deinum, J.; Lenders, J.W.; Reincke, M.

    2016-01-01

    BACKGROUND: Differentiating patients with primary aldosteronism caused by aldosterone-producing adenomas (APAs) from those with bilateral adrenal hyperplasia (BAH), which is essential for choice of therapeutic intervention, relies on adrenal venous sampling (AVS)-based measurements of aldosterone

  6. Selecting a sampling method to aid in vegetation management decisions in loblolly pine plantations

    Science.gov (United States)

    David R. Weise; Glenn R. Glover

    1993-01-01

    Objective methods to evaluate hardwood competition in young loblolly pine (Pinustaeda L.) plantations are not widely used in the southeastern United States. Ability of common sampling rules to accurately estimate hardwood rootstock attributes at low sampling intensities and across varying rootstock spatial distributions is unknown. Fixed area plot...

  7. In the absence of a central venous catheter, risk of venous thromboembolism is low in critically injured children, adolescents, and young adults: evidence from the National Trauma Data Bank.

    Science.gov (United States)

    O'Brien, Sarah H; Candrilli, Sean D

    2011-05-01

    To describe the incidence and risk factors of venous thromboembolism in a large sample of critical care pediatric, adolescent, and young adult trauma patients. The National Trauma Data Bank-the largest and most complete aggregation of trauma registry data in the United States. Seven hundred eighty-four level I to level IV trauma centers. Patients ≤ 21 yrs of age who spent at least 1 day in a critical care unit during a trauma admission between 2001 and 2005. To characterize differences between patients with and without venous thromboembolism, we extracted variables regarding patient demographics, injury pattern and severity, procedures, total length of stay, and intensive care unit and ventilator days. Odds ratios for predictors of venous thromboembolism were estimated with a logistic regression model. Among the 135,032 critical care patients analyzed, venous thromboembolism was uncommon (6 per 1,000 discharges). Placement of a central venous catheter was a significant predictor of venous thromboembolism (odds ratio = 2.24; p central venous catheter were of even greater magnitude, particularly in adolescents and young adults. The risk of venous thromboembolism in critical care patients without a central venous catheter was central venous access.

  8. Duplex imaging of residual venous obstruction to guide duration of therapy for lower extremity deep venous thrombosis.

    Science.gov (United States)

    Stephenson, Elliot J P; Liem, Timothy K

    2015-07-01

    Clinical trials have shown that the presence of ultrasound-identified residual venous obstruction (RVO) on follow-up scanning may be associated with an elevated risk for recurrence, thus providing a potential tool to help determine the optimal duration of anticoagulant therapy. We performed a systematic review to evaluate the clinical utility of post-treatment duplex imaging in predicting venous thromboembolism (VTE) recurrence and in adjusting duration of anticoagulation. The Ovid MEDLINE Database, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews of Effects were queried for the terms residual thrombus or obstruction, duration of therapy, deep vein thrombosis, deep venous thrombosis, DVT, venous thromboembolism, VTE, antithrombotic therapy, and anticoagulation, and 228 studies were selected for review. Six studies determined the rate of VTE recurrence on the basis of the presence or absence of RVO. Findings on venous ultrasound scans frequently remained abnormal in 38% to 80% of patients, despite at least 3 months of therapeutic anticoagulation. In evaluating for VTE recurrence, the definition of RVO varied widely in the literature. Some studies have shown an association between RVO and VTE recurrence, whereas other studies have not. Overall, the presence of RVO is a mild risk factor for recurrence (odds ratio, 1.3-2.0), but only when surveillance imaging is performed soon after the index deep venous thrombosis (3 months). RVO is a mild risk factor for VTE recurrence. The presence or absence of ultrasound-identified RVO has a limited role in guiding the duration of therapeutic anticoagulation. Further research is needed to evaluate its utility relative to other known risk factors for VTE recurrence. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  9. Venous sinus stenting for pseudotumour cerebri with venous sinus stenosis

    International Nuclear Information System (INIS)

    Chen Huairui; Bai Rulin; Wu Xiaojun; Qi Xiangqian; Mei Qiyong; Lu Yicheng

    2011-01-01

    Objective: To explore the relation between venous sinus stenosis and pseduotumour cerebri and to discuss the efficacy and strategy of venous sinus stenting for its treatment. Methods: Venous sinus stenting was performed in a total of 9 patients with pseudotumour cerebri accompanied by dural sinus stenosis. The clinical data, including the clinical presentations, intracranial pressure, angiographic findings, pressure of dural sinus,methods of treatment and the therapeutic results, were retrospectively analyzed. Results: Bilateral disc edema was seen in all patients. The pressure gradient in the lateral sinuses was obviously high before stenting (22.67±7.25)mmHg in all patients and a reduction in intra-sinus pressure and pressure gradient was also found (5.78±3.77)mmHg. The symptoms associated with intracranial hypertension were gradually improved or disappeared in two weeks after the placement of the stent in all cases, and the intracranial pressure dropped evidently (12.78±5.97)cm H 2 O. Vision was improved in 7 cases at three months, whereas it remained poor in 2 cases despite normalized intracranial pressure. There was no other permanent procedure-related morbidity. The patients were followed up for 3 months to 5 years, and no recurrence developed. Conclusion: Lateral sinus stenting is an effective method for the treatment of pseudotumour cerebri with dural sinus stenosis. (authors)

  10. Radiologically-placed venous ports in children under venous anesthesia

    International Nuclear Information System (INIS)

    Jang, Joo Yeon; Jeon, Ung Bae; Choo, Ki Seok; Hwang, Jae Yeon; Kim, Yong Woo; Lee, Yun Jin; Nam, Sang Ool; Lim, Young Tak

    2015-01-01

    To evaluate the efficacy and safety of radiologic venous port placement in children under venous anesthesia. Between April 2009 and July 2011, 44 ports were implanted in 41 children (24 boys, 17 girls). The age of patients ranged from 9 months to 19 years (mean, 6.5 years) and their body weights ranged from 6.8 kg to 56.3 kg (mean, 23.2 kg). Right internal jugular vein access was used in 42 ports, right subclavian vein in 1, and left subclavian in 1. Durability and complications of port implantation were reviewed. The technical success rate was 100%. The catheter life was 10-661 days (mean 246 days). Two patients died during the follow-up period, 21 and 6 ports were removed at the end of treatment or as a result of complications, respectively. One port was removed and replaced by a Hickmann catheter. Three ports were explanted due to port-related sepsis, one due to a catheter kink, and two for unexplained fever or insertion site pain. The overall port-related infection was 3 cases (6.8%, 0.28/1000 catheter days). Venous port placement by interventional radiologists in children under intravenous sedation is relatively safe, with a high rate of technical success and low rate of complications.

  11. Radiologically-placed venous ports in children under venous anesthesia

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Joo Yeon; Jeon, Ung Bae; Choo, Ki Seok; Hwang, Jae Yeon; Kim, Yong Woo; Lee, Yun Jin; Nam, Sang Ool; Lim, Young Tak [Pusan National University School of Medicine, Yangsan (Korea, Republic of)

    2015-02-15

    To evaluate the efficacy and safety of radiologic venous port placement in children under venous anesthesia. Between April 2009 and July 2011, 44 ports were implanted in 41 children (24 boys, 17 girls). The age of patients ranged from 9 months to 19 years (mean, 6.5 years) and their body weights ranged from 6.8 kg to 56.3 kg (mean, 23.2 kg). Right internal jugular vein access was used in 42 ports, right subclavian vein in 1, and left subclavian in 1. Durability and complications of port implantation were reviewed. The technical success rate was 100%. The catheter life was 10-661 days (mean 246 days). Two patients died during the follow-up period, 21 and 6 ports were removed at the end of treatment or as a result of complications, respectively. One port was removed and replaced by a Hickmann catheter. Three ports were explanted due to port-related sepsis, one due to a catheter kink, and two for unexplained fever or insertion site pain. The overall port-related infection was 3 cases (6.8%, 0.28/1000 catheter days). Venous port placement by interventional radiologists in children under intravenous sedation is relatively safe, with a high rate of technical success and low rate of complications.

  12. A Simple Analytical Method Using HPLC with Fluorescence Detection to Determine Selected Polycyclic Aromatic Compounds in Filter Samples

    International Nuclear Information System (INIS)

    Garcia, S.; Perez, R. M.

    2014-01-01

    A study on the comparison and evaluation of a miniaturized extraction method for the determination of selected PACs in sample filters is presented. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the intermediate precision. (Author)

  13. The size selectivity of the main body of a sampling pelagic pair trawl in freshwater reservoirs during the night

    Czech Academy of Sciences Publication Activity Database

    Říha, Milan; Jůza, Tomáš; Prchalová, Marie; Mrkvička, Tomáš; Čech, Martin; Draštík, Vladislav; Muška, Milan; Kratochvíl, Michal; Peterka, Jiří; Tušer, Michal; Vašek, Mojmír; Kubečka, Jan

    2012-01-01

    Roč. 127, September (2012), s. 56-60 ISSN 0165-7836 R&D Projects: GA MZe(CZ) QH81046 Institutional support: RVO:60077344 Keywords : quantitative sampling * gear selectivity * trawl * reservoirs Subject RIV: GL - Fishing Impact factor: 1.695, year: 2012

  14. Geochemical and mineralogical study of selected weathered samples from Olkiluoto site

    International Nuclear Information System (INIS)

    Lindberg, A.

    2009-02-01

    Optical microscopy, chemical analyses and X-ray diffraction method were used to study the influence of weathering from 11 drill core samples from shallow depths (< 25 m). The samples, 4 to 22 cm in length were drilled from Olkiluoto study site, Eurajoki, and they represent the common rock types of local bedrock: mica gneiss, tonalitic and granodioritic gneiss. Two of the samples were macroscopically unweathered and 9 of them were remarkably altered. The alteration was shown as porosity, the abundance of chlorite instead of biotite and pink, unclear feldspars. Many samples also contained red-brown hematite and fractures, some of them coated with secondary minerals, even clay. Microscopically the most visible feature of weathering was the total alteration of plagioclase and cordierite to sericite. In many samples also biotite was richly altered to chlorite and opaque minerals. Microfractures were common and they were filled by hematite, kaolinite and fine-grained muscovite (sericite). Hematite was, in some cases, also largely replacing the weathered minerals, feldspars and cordierite. Chemical alteration was not clear, because the alteration of main minerals have produced secondary minerals with almost the same chemical composition without any reasonable depleting or enrichment of certain elements. X-ray diffraction determination of samples proved, that often plagioclase was replaced by mica and biotite by chlorite. In some cases the samples contained products of chemical weathering, kaolinite and smectite. (orig.)

  15. Passive sampling of selected pesticides in aquatic environment using polar organic chemical integrative samplers.

    Science.gov (United States)

    Thomatou, Alphanna-Akrivi; Zacharias, Ierotheos; Hela, Dimitra; Konstantinou, Ioannis

    2011-08-01

    Polar chemical integrative samplers (POCIS) were examined for their sampling efficiency of 12 pesticides and one metabolite commonly detected in surface waters. Laboratory-based calibration experiments of POCISs were conducted. The determined passive sampling rates were applied for the monitoring of pesticides levels in Lake Amvrakia, Western Greece. Spot sampling was also performed for comparison purposes. Calibration experiments were performed on the basis of static renewal exposure of POCIS under stirred conditions for different time periods of up to 28 days. The analytical procedures were based on the coupling of POCIS and solid phase extraction by Oasis HLB cartridges with gas chromatography-mass spectrometry. The recovery of the target pesticides from the POCIS was generally >79% with relative standard deviation (RSD) monitoring campaign using both passive and spot sampling whereas higher concentrations were measured by spot sampling in most cases. Passive sampling by POCIS provides a useful tool for the monitoring of pesticides in aquatic systems since integrative sampling at rates sufficient for analytical quantitation of ambient levels was observed. Calibration data are in demand for a greater number of compounds in order to extend the use in environmental monitoring.

  16. Automatic Samples Selection Using Histogram of Oriented Gradients (HOG Feature Distance

    Directory of Open Access Journals (Sweden)

    Inzar Salfikar

    2018-01-01

    Full Text Available Finding victims at a disaster site is the primary goal of Search-and-Rescue (SAR operations. Many technologies created from research for searching disaster victims through aerial imaging. but, most of them are difficult to detect victims at tsunami disaster sites with victims and backgrounds which are look similar. This research collects post-tsunami aerial imaging data from the internet to builds dataset and model for detecting tsunami disaster victims. Datasets are built based on distance differences from features every sample using Histogram-of-Oriented-Gradient (HOG method. We use the longest distance to collect samples from photo to generate victim and non-victim samples. We claim steps to collect samples by measuring HOG feature distance from all samples. the longest distance between samples will take as a candidate to build the dataset, then classify victim (positives and non-victim (negatives samples manually. The dataset of tsunami disaster victims was re-analyzed using cross-validation Leave-One-Out (LOO with Support-Vector-Machine (SVM method. The experimental results show the performance of two test photos with 61.70% precision, 77.60% accuracy, 74.36% recall and f-measure 67.44% to distinguish victim (positives and non-victim (negatives.

  17. Nested sampling algorithm for subsurface flow model selection, uncertainty quantification, and nonlinear calibration

    KAUST Repository

    Elsheikh, A. H.; Wheeler, M. F.; Hoteit, Ibrahim

    2013-01-01

    Calibration of subsurface flow models is an essential step for managing ground water aquifers, designing of contaminant remediation plans, and maximizing recovery from hydrocarbon reservoirs. We investigate an efficient sampling algorithm known

  18. Woody species diversity in forest plantations in a mountainous region of Beijing, China: effects of sampling scale and species selection.

    Directory of Open Access Journals (Sweden)

    Yuxin Zhang

    Full Text Available The role of forest plantations in biodiversity conservation has gained more attention in recent years. However, most work on evaluating the diversity of forest plantations focuses only on one spatial scale; thus, we examined the effects of sampling scale on diversity in forest plantations. We designed a hierarchical sampling strategy to collect data on woody species diversity in planted pine (Pinus tabuliformis Carr., planted larch (Larix principis-rupprechtii Mayr., and natural secondary deciduous broadleaf forests in a mountainous region of Beijing, China. Additive diversity partition analysis showed that, compared to natural forests, the planted pine forests had a different woody species diversity partitioning pattern at multi-scales (except the Simpson diversity in the regeneration layer, while the larch plantations did not show multi-scale diversity partitioning patterns that were obviously different from those in the natural secondary broadleaf forest. Compare to the natural secondary broadleaf forests, the effects of planted pine forests on woody species diversity are dependent on the sampling scale and layers selected for analysis. Diversity in the planted larch forest, however, was not significantly different from that in the natural forest for all diversity components at all sampling levels. Our work demonstrated that the species selected for afforestation and the sampling scales selected for data analysis alter the conclusions on the levels of diversity supported by plantations. We suggest that a wide range of scales should be considered in the evaluation of the role of forest plantations on biodiversity conservation.

  19. Mixed Capillary Venous Retroperitoneal Hemangioma

    Directory of Open Access Journals (Sweden)

    Mohit Godar

    2013-01-01

    Full Text Available We report a case of mixed capillary venous hemangioma of the retroperitoneum in a 61-year-old man. Abdominal ultrasonography showed a mass to be hypoechoic with increased flow in color Doppler imaging. Dynamic contrast-enhanced computed tomography revealed a centripetal filling-in of the mass, located anterior to the left psoas muscle at the level of sacroiliac joint. On the basis of imaging features, preoperative diagnosis of hemangioma was considered and the mass was excised by laparoscopic method. Immunohistochemical studies were strongly positive for CD31 and CD34, and negative for calretinin, EMA, WT1, HMB45, Ki67, synaptophysin, and lymphatic endothelial cell marker D2–40. Histologically, the neoplasm was diagnosed as mixed capillary venous hemangioma.

  20. Determination of chloride in MOX samples using chloride ion selective electrode

    Energy Technology Data Exchange (ETDEWEB)

    Govindan, R; Das, D K; Mallik, G K; Sumathi, A; Patil, Sangeeta; Raul, Seema; Bhargava, V K; Kamath, H S [Bhabha Atomic Research Centre, Tarapur (India). Advanced Fuel Fabrication Facility

    1997-09-01

    The chloride present in the MOX fuel is separated from the matrix by pyrohydrolysis at a temperature of 950 {+-} 50 degC and is then analyzed by chloride ion selective electrode (Cl-ISE). The range covered is 0.4-4 ppm with a precision of better than {+-}5% R.S.D. (author). 4 refs., 1 tab.

  1. Endovascular Interventions for Acute and Chronic Lower Extremity Deep Venous Disease: State of the Art.

    Science.gov (United States)

    Sista, Akhilesh K; Vedantham, Suresh; Kaufman, John A; Madoff, David C

    2015-07-01

    The societal and individual burden caused by acute and chronic lower extremity venous disease is considerable. In the past several decades, minimally invasive endovascular interventions have been developed to reduce thrombus burden in the setting of acute deep venous thrombosis to prevent both short- and long-term morbidity and to recanalize chronically occluded or stenosed postthrombotic or nonthrombotic veins in symptomatic patients. This state-of-the-art review provides an overview of the techniques and challenges, rationale, patient selection criteria, complications, postinterventional care, and outcomes data for endovascular intervention in the setting of acute and chronic lower extremity deep venous disease. Online supplemental material is available for this article.

  2. Selectivity and limitations of carbon sorption tubes for capturing siloxanes in biogas during field sampling.

    Science.gov (United States)

    Tansel, Berrin; Surita, Sharon C

    2016-06-01

    Siloxane levels in biogas can jeopardize the warranties of the engines used at the biogas to energy facilities. The chemical structure of siloxanes consists of silicon and oxygen atoms, alternating in position, with hydrocarbon groups attached to the silicon side chain. Siloxanes can be either in cyclic (D) or linear (L) configuration and referred with a letter corresponding to their structure followed by a number corresponding to the number of silicon atoms present. When siloxanes are burned, the hydrocarbon fraction is lost and silicon is converted to silicates. The purpose of this study was to evaluate the adequacy of activated carbon gas samplers for quantitative analysis of siloxanes in biogas samples. Biogas samples were collected from a landfill and an anaerobic digester using multiple carbon sorbent tubes assembled in series. One set of samples was collected for 30min (sampling 6-L gas), and the second set was collected for 60min (sampling 12-L gas). Carbon particles were thermally desorbed and analyzed by Gas Chromatography Mass Spectrometry (GC/MS). The results showed that biogas sampling using a single tube would not adequately capture octamethyltrisiloxane (L3), hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). Even with 4 tubes were used in series, D5 was not captured effectively. The single sorbent tube sampling method was adequate only for capturing trimethylsilanol (TMS) and hexamethyldisiloxane (L2). Affinity of siloxanes for activated carbon decreased with increasing molecular weight. Using multiple carbon sorbent tubes in series can be an appropriate method for developing a standard procedure for determining siloxane levels for low molecular weight siloxanes (up to D3). Appropriate quality assurance and quality control procedures should be developed for adequately quantifying the levels of the higher molecular weight siloxanes in biogas with sorbent tubes

  3. MRI in venous thromboembolic disease

    International Nuclear Information System (INIS)

    Sostman, H.D.; Debatin, J.F.; Spritzer, C.E.; Coleman, R.E.; Grist, T.M.; MacFall, J.R.

    1993-01-01

    We evaluated the ability of magnetic resonance (MR) imaging to detect deep venous thrombosis (DVT) and pulmonary embolism (PE). MR venography was performed on 217 patients suspected of having DVT. Cine-MR imaging of the pulmonary arteries was performed in 14 other patients who were thought to have PE based on other imaging studies. In a third group of 5 patients, MR pulmonary angiograms were performed in the sagittal and coronal planes with a multislice fast gradient recalled echo technique. All but one of the 217 MR venograms were technically adequate. In 72 patients with correlative imaging studies (venography and ultrasound) MR venography was 99% sensitive and 95% specific. On the basis of follow-up (mean 8.3 months), no false-negative MR venograms were detected in an additional 64 patients. In 11 other patients MR revealed a diagnosis other than DVT. Cine-MR showed PE in all 14 patients evaluated. MR pulmonary arteriography demonstrated filling defects consistent with acute PE in 2 of 3 patients with acute PE; in the third patient only a questionable filling defect was seen. Coarctations or webs were found in the pulmonary arteries of both patients with chronic PE. These preliminary data suggest that MR imaging may be able to evaluate both the peripheral venous and the pulmonary arterial component of venous thromboembolic disease. Further technical refinement and more extensive clinical experience will be required to establish the role of this method in diagnosing pulmonary embolism, but MR venography is now used routinely in our hospital for the diagnosis of deep venous thrombosis. (orig.)

  4. Significance of venous anastomosis in fingertip replantation.

    Science.gov (United States)

    Hattori, Yasunori; Doi, Kazuteru; Ikeda, Keisuke; Abe, Yukio; Dhawan, Vikas

    2003-03-01

    Adequate venous outflow is the most important factor for successful fingertip replantation. The authors have attempted venous anastomosis in all cases of fingertip replantation to overcome postoperative congestion. In this article, the significance of venous repair for fingertip replantation is described from the authors' results of 64 complete fingertip amputations in 55 consecutive patients, which were replanted from January of 1996 to June of 2001. The overall survival rate was 86 percent. Of the 44 replantations in zone I, 37 survived, and the success rate was 84 percent. Of the 20 replantations in zone II, 18 survived, and the success rate was 90 percent. Venous anastomosis was attempted in all cases, but it was possible in 39 zone I and in all zone II replantations. For arterial repair, vein grafts were necessary in 17 of the 44 zone I and in one of the 20 zone II replantations; for venous repair, they were necessary in six zone I replantations and one zone II replantation. Postoperative vascular complications occurred in 15 replantations. There were five cases of arterial thrombosis and 10 cases of venous congestion. Venous congestion occurred in nine zone I and one zone II replantations. In five of these 10 replantations, venous anastomosis was not possible. In another five replantations, venous outflow was established at the time of surgery, but occlusion occurred subsequently. Except for the five failures resulting from arterial thrombosis, successful venous repair was possible in 49 of 59 replantations (83 percent). Despite the demand for skillful microsurgical technique and longer operation time, the authors' results using venous anastomosis in successful fingertip replantations are encouraging. By performing venous anastomosis, external bleeding can be avoided and a higher survival rate can be achieved. Venous anastomosis for fingertip replantation is a reliable and worthwhile procedure.

  5. Determination of different contaminants in selective drinking water samples collected from Peshawar valley area

    International Nuclear Information System (INIS)

    Ihsanullah; Khan, M.; Khattak, T.N.; Sattar, A.

    1999-01-01

    Among the pollutants carried through sewage, industrial effluents, fertilizers, pesticides; heavy metals and various pathogenic bacteria are directly related to human/animal diseases. Samples of drinking water were collected from different locations, in the Peshawar area. Cadmium, lead and copper levels in these samples were determined by potentiometric stripping analysis (PSA). The data indicated wide variation in the concentration of these heavy metals. Variation in results is discussed on the basis of some possible sources of contamination. The concentration of cadmium and lead in all the samples was higher compared to the values given in the guideline of World Health Organization (WHO) for drinking water. Copper was below the detection limit in majority of the samples. The values of Cd, Pb and Cu were in the range of 0.023-2.75, 0.025-1.88 and 0-0.67 mg/1 respectively. Various physical quality indices (ph, electrical conductivity and total solids) and pathogenic bacteria (E. coli and total coliforms) were also determined in water samples. Most of the drinking waters was found contaminated with higher levels of Cd and Pb and pathogenic bacteria and hence, considered unfit for drinking purposes. (author)

  6. The impact of sample size and marker selection on the study of haplotype structures

    Directory of Open Access Journals (Sweden)

    Sun Xiao

    2004-03-01

    Full Text Available Abstract Several studies of haplotype structures in the human genome in various populations have found that the human chromosomes are structured such that each chromosome can be divided into many blocks, within which there is limited haplotype diversity. In addition, only a few genetic markers in a putative block are needed to capture most of the diversity within a block. There has been no systematic empirical study of the effects of sample size and marker set on the identified block structures and representative marker sets, however. The purpose of this study was to conduct a detailed empirical study to examine such impacts. Towards this goal, we have analysed three representative autosomal regions from a large genome-wide study of haplotypes with samples consisting of African-Americans and samples consisting of Japanese and Chinese individuals. For both populations, we have found that the sample size and marker set have significant impact on the number of blocks and the total number of representative markers identified. The marker set in particular has very strong impacts, and our results indicate that the marker density in the original datasets may not be adequate to allow a meaningful characterisation of haplotype structures. In general, we conclude that we need a relatively large sample size and a very dense marker panel in the study of haplotype structures in human populations.

  7. Biobanking of fresh frozen tissue from clinical surgical specimens: transport logistics, sample selection, and histologic characterization.

    Science.gov (United States)

    Botling, Johan; Micke, Patrick

    2011-01-01

    Access to high-quality fresh frozen tissue is critical for translational cancer research and molecular -diagnostics. Here we describe a workflow for the collection of frozen solid tissue samples derived from fresh human patient specimens after surgery. The routines have been in operation at Uppsala University Hospital since 2001. We have integrated cryosection and histopathologic examination of each biobank sample into the biobank manual. In this way, even small, macroscopically ill-defined lesions can be -procured without a diagnostic hazard due to the removal of uncharacterized tissue from a clinical -specimen. Also, knowledge of the histomorphology of the frozen tissue sample - tumor cell content, stromal components, and presence of necrosis - is pivotal before entering a biobank case into costly molecular profiling studies.

  8. Studying hardness, workability and minimum bending radius in selectively laser-sintered Ti–6Al–4V alloy samples

    Science.gov (United States)

    Galkina, N. V.; Nosova, Y. A.; Balyakin, A. V.

    2018-03-01

    This research is relevant as it tries to improve the mechanical and service performance of the Ti–6Al–4V titanium alloy obtained by selective laser sintering. For that purpose, sintered samples were annealed at 750 and 850°C for an hour. Sintered and annealed samples were tested for hardness, workability and microstructure. It was found that incomplete annealing of selectively laser-sintered Ti–6Al–4V samples results in an insignificant reduction in hardness and ductility. Sintered and incompletely annealed samples had a hardness of 32..33 HRC, which is lower than the value of annealed parts specified in standards. Complete annealing at temperature 850°C reduces the hardness to 25 HRC and ductility by 15...20%. Incomplete annealing lowers the ductility factor from 0.08 to 0.06. Complete annealing lowers that value to 0.025. Complete annealing probably results in the embrittlement of sintered samples, perhaps due to their oxidation and hydrogenation in the air. Optical metallography showed lateral fractures in both sintered and annealed samples, which might be the reason why they had lower hardness and ductility.

  9. Use of space-filling curves to select sample locations in natural resource monitoring studies

    Science.gov (United States)

    Andrew Lister; Charles T. Scott

    2009-01-01

    The establishment of several large area monitoring networks over the past few decades has led to increased research into ways to spatially balance sample locations across the landscape. Many of these methods are well documented and have been used in the past with great success. In this paper, we present a method using geographic information systems (GIS) and fractals...

  10. Chemical and physical characteristics of tar samples from selected Manufactured Gas Plant (MGP) sites

    International Nuclear Information System (INIS)

    Ripp, J.; Taylor, B.; Mauro, D.; Young, M.

    1993-05-01

    A multiyear, multidisciplinary project concerning the toxicity of former Manufactured Gas Plant (MGP) tarry residues was initiated by EPRI under the Environmental Behavior of Organic Substances (EBOS) Program. This report concerns one portion of that work -- the collection and chemical characterization of tar samples from several former MGP sites. META Environmental, Inc. and Atlantic Environmental Services, Inc. were contracted by EPRI to collect several samples of tarry residues from former MGP sites with varied historical gas production processes and from several parts of the country. The eight tars collected during this program were physically very different. Some tars were fluid and easily pumped from existing wells, while other tars were thicker, semi-solid, or solid. Although care was taken to collect only tar, the nature of the residues at several sites made it impossible not to collect other material, such as soil, gravel, and plant matter. After the samples were collected, they were analyzed for 37 organic compounds, 8 metals, and cyanide. In addition, elemental analysis was performed on the tar samples for carbon, hydrogen, oxygen, sulfur and nitrogen content and several physical/chemical properties were determined for each tar. The tars were mixed together in different batches and distributed to researchers for use in animal toxicity studies. The results of this work show that, although the tars were produced from different processes and stored in different manners, they had some chemical similarities. All of the tars, with the exception of one unusual solid tar, contained similar relative abundances of polycyclic aromatic hydrocarbons (PAHs)

  11. Risk Factors for Drug Abuse among Nepalese Samples Selected from a Town of Eastern Nepal

    Science.gov (United States)

    Niraula, Surya Raj; Chhetry, Devendra Bahadur; Singh, Girish Kumar; Nagesh, S.; Shyangwa, Pramod Mohan

    2009-01-01

    The study focuses on the serious issue related to the adolescents' and adults' behavior and health. It aims to identify the risk factors for drug abuse from samples taken from a town of Eastern Nepal. This is a matched case-control study. The conditional logistic regression method was adopted for data analysis. The diagnosis cut off was determined…

  12. Multi-Factor Policy Evaluation and Selection in the One-Sample Situation

    NARCIS (Netherlands)

    C.M. Chen (Chien-Ming)

    2008-01-01

    textabstractFirms nowadays need to make decisions with fast information obsolesce. In this paper I deal with one class of decision problems in this situation, called the “one-sample” problems: we have finite options and one sample of the multiple criteria with which we use to evaluate those options.

  13. Structure and Mechanical Properties of the AlSi10Mg Alloy Samples Manufactured by Selective Laser Melting

    Science.gov (United States)

    Li, Xiaodan; Ni, Jiaqiang; Zhu, Qingfeng; Su, Hang; Cui, Jianzhong; Zhang, Yifei; Li, Jianzhong

    2017-11-01

    The AlSi10Mg alloy samples with the size of 14×14×91mm were produced by the selective laser melting (SLM) method in different building direction. The structures and the properties at -70°C of the sample in different direction were investigated. The results show that the structure in different building direction shows different morphology. The fish scale structures distribute on the side along the building direction, and the oval structures distribute on the side vertical to the building direction. Some pores in with the maximum size of 100 μm exist of the structure. And there is no major influence for the build orientation on the tensile properties. The tensile strength and the elongation of the sample in the building direction are 340 Mpa and 11.2 % respectively. And the tensile strength and the elongation of the sample vertical to building direction are 350 Mpa and 13.4 % respectively

  14. Study on the effects of sample selection on spectral reflectance reconstruction based on the algorithm of compressive sensing

    International Nuclear Information System (INIS)

    Zhang, Leihong; Liang, Dong

    2016-01-01

    In order to solve the problem that reconstruction efficiency and precision is not high, in this paper different samples are selected to reconstruct spectral reflectance, and a new kind of spectral reflectance reconstruction method based on the algorithm of compressive sensing is provided. Four different color numbers of matte color cards such as the ColorChecker Color Rendition Chart and Color Checker SG, the copperplate paper spot color card of Panton, and the Munsell colors card are chosen as training samples, the spectral image is reconstructed respectively by the algorithm of compressive sensing and pseudo-inverse and Wiener, and the results are compared. These methods of spectral reconstruction are evaluated by root mean square error and color difference accuracy. The experiments show that the cumulative contribution rate and color difference of the Munsell colors card are better than those of the other three numbers of color cards in the same conditions of reconstruction, and the accuracy of the spectral reconstruction will be affected by the training sample of different numbers of color cards. The key technology of reconstruction means that the uniformity and representation of the training sample selection has important significance upon reconstruction. In this paper, the influence of the sample selection on the spectral image reconstruction is studied. The precision of the spectral reconstruction based on the algorithm of compressive sensing is higher than that of the traditional algorithm of spectral reconstruction. By the MATLAB simulation results, it can be seen that the spectral reconstruction precision and efficiency are affected by the different color numbers of the training sample. (paper)

  15. Assessment of selected contaminants in streambed- and suspended-sediment samples collected in Bexar County, Texas, 2007-09

    Science.gov (United States)

    Wilson, Jennifer T.

    2011-01-01

    Elevated concentrations of sediment-associated contaminants are typically associated with urban areas such as San Antonio, Texas, in Bexar County, the seventh most populous city in the United States. This report describes an assessment of selected sediment-associated contaminants in samples collected in Bexar County from sites on the following streams: Medio Creek, Medina River, Elm Creek, Martinez Creek, Chupaderas Creek, Leon Creek, Salado Creek, and San Antonio River. During 2007-09, the U.S. Geological Survey periodically collected surficial streambed-sediment samples during base flow and suspended-sediment (large-volume suspended-sediment) samples from selected streams during stormwater runoff. All sediment samples were analyzed for major and trace elements and for organic compounds including halogenated organic compounds and polycyclic aromatic hydrocarbons (PAHs). Selected contaminants in streambed and suspended sediments in watersheds of the eight major streams in Bexar County were assessed by using a variety of methods—observations of occurrence and distribution, comparison to sediment-quality guidelines and data from previous studies, statistical analyses, and source indicators. Trace elements concentrations were low compared to the consensus-based sediment-quality guidelines threshold effect concentration (TEC) and probable effect concentration (PEC). Trace element concentrations were greater than the TEC in 28 percent of the samples and greater than the PEC in 1.5 percent of the samples. Chromium concentrations exceeded sediment-quality guidelines more frequently than concentrations of any other constituents analyzed in this study (greater than the TEC in 69 percent of samples and greater than the PEC in 8 percent of samples). Mean trace element concentrations generally are lower in Bexar County samples compared to concentrations in samples collected during previous studies in the Austin and Fort Worth, Texas, areas, but considering the relatively

  16. Analysis of the vertebral venous system in relation to cerebral venous drainage on MR angiography

    International Nuclear Information System (INIS)

    Baik, Seung Kug; Sohn, Chul Ho; Kim, Gab Chul; Kim, Yong Sun

    2004-01-01

    In the supine position, cerebral venous drainage occurs primarily through the internal jugular veins, as seen on venous phase cerebral angiography. However, in the erect position, the vertebral venous system represents the major alternative pathway of cerebral venous drainage, while outflow through the internal jugular veins is absent or negligible. The purpose of this study is to evaluate the vertebral venous system and its relationship between the surrounding venous structures using magnetic resonance angiography (MRA) in the case of subjects in the supine position. We retrospectively reviewed the results of 65 patients (M:F = 31: 34, mean age 61.6 years) who underwent multi-phase contrast-enhanced carotid MRA. The imaging studies were performed using a 3.0 T MR unit (TR: 5.2, TE: 1.1, FA: 20, 3.8 thickness, EC: 1). We analyzed the appearance and extent of the vertebral venous system (vertebral venous plexus and vertebral artery venous plexus) and the internal jugular vein on the venous phase images. We also evaluated the main drainage pattern of the cerebral venous drainage and the drainage pattern of the vertebral venous system. The visualized vertebral venous system was defined as either poor, vertebral venous plexus dominant, vertebral artery venous plexus dominant or mixed. In the vertebral venous system, the vertebral artery venous plexus was visualized in 54 cases (83%). The appearance of the visualized vertebral artery venous plexus was symmetrical in 39 cases (72%) and asymmetrical in 15 cases (28%). The extent of the visualized vertebral artery venous plexus was partial in 26 cases (48%) and complete in 28 cases (52%). The vertebral venous plexus was visualized in 62 cases (95%). The appearance of the visualized vertebral artery venous plexus was symmetrical in 43 cases (69%) and asymmetrical in 19 cases (31%). The extent of the visualized vertebral artery venous plexus was partial in 35 cases (56%) and complete in 27 cases (44%). The appearance of the

  17. Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation

    NARCIS (Netherlands)

    van Beest, Paul A.; van der Schors, Alice; Liefers, Henriëtte; Coenen, Ludo G. J.; Braam, Richard L.; Habib, Najib; Braber, Annemarije; Scheeren, Thomas W. L.; Kuiper, Michaël A.; Spronk, Peter E.

    2012-01-01

    Objective: The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients. Design: Prospective observational controlled study. Setting: Nonacademic university-affiliated

  18. The relationship between the FFM and personality disorders in a personnel selection sample.

    Science.gov (United States)

    Nederström, Mikael; Furnham, Adrian

    2012-10-01

    The relationships between the Five Factor Model (FFM) personality and personality disorders were investigated. A sample of real-life job applicants completed two personality questionnaires with different theoretical backgrounds in a psychological assessment center. The job applicants provided self-descriptions both on the FFM inventory and on a personality disorder trait inventory. A subsample of these candidates was interviewed by expert psychologists upon entrance to the assessment center. The psychologists assessed the same disorder traits of each target in job interviews. Both self-descriptions were used to predict the expert assessments. The results demonstrated considerable overlap between the FFM measures of normal and measures of abnormal personality in both samples and regardless of assessment method. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

  19. Volatile compounds in samples of cork and also produced by selected fungi.

    Science.gov (United States)

    Barreto, M C; Vilas Boas, L; Carneiro, L C; San Romão, M V

    2011-06-22

    The production of volatile compounds by microbial communities of cork samples taken during the cork manufacturing process was investigated. The majority of volatiles were found in samples collected at two stages: resting after the first boiling and nontreated cork disks. Volatile profiles produced by microbiota in both stages are similar. The releasable volatile compounds and 2,4,6-trichloroanisole (TCA) produced in cork-based culture medium by five isolated fungal species in pure and mixed cultures were also analyzed by gas chromatography coupled with mass spectrometry (GC-MS).The results showed that 1-octen-3-ol and esters of fatty acids (medium chain length C8-C20) were the main volatile compounds produced by either pure fungal species or their mixture. Apparently, Penicillium glabrum is the main contributor to the overall volatile composition observed in the mixed culture. The production of releasable TCA on cork cannot be attributed to any of the assayed fungal isolates.

  20. Suitability of selected free-gas and dissolved-gas sampling containers for carbon isotopic analysis.

    Science.gov (United States)

    Eby, P; Gibson, J J; Yi, Y

    2015-07-15

    Storage trials were conducted for 2 to 3 months using a hydrocarbon and carbon dioxide gas mixture with known carbon isotopic composition to simulate typical hold times for gas samples prior to isotopic analysis. A range of containers (both pierced and unpierced) was periodically sampled to test for δ(13)C isotopic fractionation. Seventeen containers were tested for free-gas storage (20°C, 1 atm pressure) and 7 containers were tested for dissolved-gas storage, the latter prepared by bubbling free gas through tap water until saturated (20°C, 1 atm) and then preserved to avoid biological activity by acidifying to pH 2 with phosphoric acid and stored in the dark at 5°C. Samples were extracted using valves or by piercing septa, and then introduced into an isotope ratio mass spectrometer for compound-specific δ(13)C measurements. For free gas, stainless steel canisters and crimp-top glass serum bottles with butyl septa were most effective at preventing isotopic fractionation (pierced and unpierced), whereas silicone and PTFE-butyl septa allowed significant isotopic fractionation. FlexFoil and Tedlar bags were found to be effective only for storage of up to 1 month. For dissolved gas, crimp-top glass serum bottles with butyl septa were again effective, whereas silicone and PTFE-butyl were not. FlexFoil bags were reliable for up to 2 months. Our results suggest a range of preferred containers as well as several that did not perform very well for isotopic analysis. Overall, the results help establish better QA/QC procedures to avoid isotopic fractionation when storing environmental gas samples. Recommended containers for air transportation include steel canisters and glass serum bottles with butyl septa (pierced and unpierced). Copyright © 2015 John Wiley & Sons, Ltd.

  1. New procedure of selected biogenic amines determination in wine samples by HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Piasta, Anna M.; Jastrzębska, Aneta, E-mail: aj@chem.uni.torun.pl; Krzemiński, Marek P.; Muzioł, Tadeusz M.; Szłyk, Edward

    2014-06-27

    Highlights: • We proposed new procedure for derivatization of biogenic amines. • The NMR and XRD analysis confirmed the purity and uniqueness of derivatives. • Concentration of biogenic amines in wine samples were analyzed by RP-HPLC. • Sample contamination and derivatization reactions interferences were minimized. - Abstract: A new procedure for determination of biogenic amines (BA): histamine, phenethylamine, tyramine and tryptamine, based on the derivatization reaction with 2-chloro-1,3-dinitro-5-(trifluoromethyl)-benzene (CNBF), is proposed. The amines derivatives with CNBF were isolated and characterized by X-ray crystallography and {sup 1}H, {sup 13}C, {sup 19}F NMR spectroscopy in solution. The novelty of the procedure is based on the pure and well-characterized products of the amines derivatization reaction. The method was applied for the simultaneous analysis of the above mentioned biogenic amines in wine samples by the reversed phase-high performance liquid chromatography. The procedure revealed correlation coefficients (R{sup 2}) between 0.9997 and 0.9999, and linear range: 0.10–9.00 mg L{sup −1} (histamine); 0.10–9.36 mg L{sup -1} (tyramine); 0.09–8.64 mg L{sup −1} (tryptamine) and 0.10–8.64 mg L{sup −1} (phenethylamine), whereas accuracy was 97%–102% (recovery test). Detection limit of biogenic amines in wine samples was 0.02–0.03 mg L{sup −1}, whereas quantification limit ranged 0.05–0.10 mg L{sup −1}. The variation coefficients for the analyzed amines ranged between 0.49% and 3.92%. Obtained BA derivatives enhanced separation the analytes on chromatograms due to the inhibition of hydrolysis reaction and the reduction of by-products formation.

  2. Radiation hazards evaluation for selected sand samples from Camburi beach, Vitoria, Espirito Santo, Brazil

    International Nuclear Information System (INIS)

    Barros, Livia F.; Pecequilo, Brigitte R.S.

    2013-01-01

    In this work, a single location at Camburi beach, known to be a naturally high background region, was studied. Radiation hazards indexes and annual effective dose were evaluated from the 226 Ra, 232 Th and 40 K sands activities concentrations. Sand samples were monthly collected during 2011, dried, sealed in standard 100 mL HPDE polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks in-growth period. The 226 Ra concentration was determined from the weighted average concentrations of 214 Pb and 214 Bi. The 232 Th concentration was determined from the weighted average concentrations of 228 Ac, 212 Pb and 212 Bi and the 4 0K from its single gamma transition. The results, considering samples gamma-rays self-attenuation, show activities concentrations in the range from 6 Bq kg -1 to 39 Bq kg -1 for 226 Ra, 13 Bq kg -1 to 161 Bq kg -1 for 232 Th, and 7 Bq kg -1 to 65 Bq kg -1 for 40 K. The radium equivalent activity for the studied samples ranged from 26 Bq kg -1 to 274 Bq kg - '1. The external and internal hazard indexes varied, respectively, from 0.07 to 0.74 and from 0.09 to 0.85. The annual effective dose values laid from 0.07 mSv.y -1 to 0.72 mSv.y - '1. All values obtained in this work are below the radiological protection recommended limits. (author)

  3. Typeability of PowerPlex Y (Promega) profiles in selected tissue samples incubated in various environments.

    Science.gov (United States)

    Niemcunowicz-Janica, Anna; Pepiński, Witold; Janica, Jacek Robert; Janica, Jerzy; Skawrońska, Małgorzata; Koc-Zórawska, Ewa

    2007-01-01

    In cases of decomposed bodies, Y chromosomal STR markers may be useful in identification of a male relative. The authors assessed typeability of PowerPlex Y (Promega) loci in post mortem tissue material stored in various environments. Kidney, spleen and pancreas specimens were collected during autopsies of five persons aged 20-30 years, whose time of death was determined within the limit of 14 hours. Tissue material was incubated at 21 degrees C and 4 degrees C in various environmental conditions. DNA was extracted by the organic method from tissue samples collected in 7-day intervals and subsequently typed using the PowerPlexY-STR kit and ABI 310. A fast decrease in the typeability rate was seen in specimens incubated in peat soil and in sand. Kidney tissue samples were typeable in all PowerPlexY-STR loci within 63 days of incubation at 4 degrees C. Faster DNA degradation was recorded in spleen and pancreas specimens. In samples with negative genotyping results, no DNA was found by fluorometric quantitation. Decomposed soft tissues are a potential material for DNA typing.

  4. Clinicoroentgenological diagnosis of chronic venous ovarian insufficiency

    International Nuclear Information System (INIS)

    Grakova, L.S.; Galkin, E.V.; Naumova, E.B.

    1989-01-01

    The paper is devoted to clinicoroentgenological correlations of venous renogonadal hemodynamics in 168 women of reproductive age (151 women with infertility, habitual abortion, disordered menstrual function and 17 patients without disorders of the reproductive tract). Clinicolaboratory investigation was followed by visceral and parietal flebography for the detection of a pathological venous reflux into the ovarian pampiniform plexus. Clinicoroentgenological semiotics of chronic venous ovarian insufficiency was analyzed. Infertility was shown to be the main clinical manifestation of ovarian varicocele

  5. Recurrent pain is associated with decreased selective attention in a population-based sample.

    Science.gov (United States)

    Gijsen, C P; Dijkstra, J B; van Boxtel, M P J

    2011-01-01

    Studies which have examined the impact of pain on cognitive functioning in the general population are scarce. In the present study we assessed the predictive value of recurrent pain on cognitive functioning in a population-based study (N=1400). Furthermore, we investigated the effect of pain on cognitive functioning in individuals with specific pain complaints (i.e. back pain, gastric pain, muscle pain and headache). Cognitive functioning was assessed using the Stroop Color-Word Interference test (Stroop interference), the Letter-Digit-Substitution test (LDST) and the Visual Verbal learning Task (VVLT). Pain was measured with the COOP/WONCA pain scale (Dartmouth Primary Care Cooperative Information Project/World Organization of National Colleges, Academies, and Academic Associations of General Practice /Family Physicians). We controlled for the effects of age, sex, level of education and depressive symptoms. It was demonstrated that pain had a negative impact on the performance on the Stroop interference but not on the VVLT and the LDST. This indicates that subjects who reported extreme pain had more problems with selective attention and were more easily distracted. Effects were in general larger in the specific pain groups when compared to the associations found in the total group. Implications of these findings are discussed. The experience of recurrent pain has a negative influence on selective attention in a healthy population. Copyright © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  6. Central and peripheral venous lines-associated blood stream infections in the critically ill surgical patients.

    Science.gov (United States)

    Ugas, Mohamed Ali; Cho, Hyongyu; Trilling, Gregory M; Tahir, Zainab; Raja, Humaera Farrukh; Ramadan, Sami; Jerjes, Waseem; Giannoudis, Peter V

    2012-09-04

    Critically ill surgical patients are always at increased risk of actual or potentially life-threatening health complications. Central/peripheral venous lines form a key part of their care. We review the current evidence on incidence of central and peripheral venous catheter-related bloodstream infections in critically ill surgical patients, and outline pathways for prevention and intervention. An extensive systematic electronic search was carried out on the relevant databases. Articles were considered suitable for inclusion if they investigated catheter colonisation and catheter-related bloodstream infection. Two independent reviewers engaged in selecting the appropriate articles in line with our protocol retrieved 8 articles published from 1999 to 2011. Outcomes on CVC colonisation and infections were investigated in six studies; four of which were prospective cohort studies, one prospective longitudinal study and one retrospective cohort study. Outcomes relating only to PICCs were reported in one prospective randomised trial. We identified only one study that compared CVC- and PICC-related complications in surgical intensive care units. Although our search protocol may not have yielded an exhaustive list we have identified a key deficiency in the literature, namely a paucity of studies investigating the incidence of CVC- and PICC-related bloodstream infection in exclusively critically ill surgical populations. In summary, the diverse definitions for the diagnosis of central and peripheral venous catheter-related bloodstream infections along with the vastly different sample size and extremely small PICC population size has, predictably, yielded inconsistent findings. Our current understanding is still limited; the studies we have identified do point us towards some tentative understanding that the CVC/PICC performance remains inconclusive.

  7. Product-selective blot: a technique for measuring enzyme activities in large numbers of samples and in native electrophoresis gels

    International Nuclear Information System (INIS)

    Thompson, G.A.; Davies, H.M.; McDonald, N.

    1985-01-01

    A method termed product-selective blotting has been developed for screening large numbers of samples for enzyme activity. The technique is particularly well suited to detection of enzymes in native electrophoresis gels. The principle of the method was demonstrated by blotting samples from glutaminase or glutamate synthase reactions into an agarose gel embedded with ion-exchange resin under conditions favoring binding of product (glutamate) over substrates and other substances in the reaction mixture. After washes to remove these unbound substances, the product was measured using either fluorometric staining or radiometric techniques. Glutaminase activity in native electrophoresis gels was visualized by a related procedure in which substrates and products from reactions run in the electrophoresis gel were blotted directly into a resin-containing image gel. Considering the selective-binding materials available for use in the image gel, along with the possible detection systems, this method has potentially broad application

  8. Selective trace enrichment of chlorotriazine pesticides from natural waters and sediment samples using terbuthylazine molecularly imprinted polymers

    Science.gov (United States)

    Ferrer, I.; Lanza, F.; Tolokan, A.; Horvath, V.; Sellergren, B.; Horvai, G.; Barcelo, D.

    2000-01-01

    Two molecularly imprinted polymers were synthesized using either dichloromethane or toluene as the porogen and terbuthylazine as the template and were used as solid-phase extraction cartridges for the enrichment of six chlorotriazines (deisopropylatrazine, deethylatrazine, simazine, atrazine, propazine, and terbuthylazine) in natural water and sediment samples. The extracted samples were analyzed by liquid chromatography/diode array detection (LC/DAD). Several washing solvents, as well as different volumes, were tested for their ability to remove the matrix components nonspecifically adsorbed on the sorbents. This cleanup step was shown to be of prime importance to the successful extraction of the pesticides from the aqueous samples. The optimal analytical conditions were obtained when the MIP imprinted using dichloromethane was the sorbent, 2 mL of dichloromethane was used in the washing step, and the preconcentrated analytes were eluted with 8 mL of methanol. The recoveries were higher than 80% for all the chlorotriazines except for propazine (53%) when 50- or 100-mL groundwater samples, spiked at 1 ??g/L level, were analyzed. The limits of detection varied from 0.05 to 0.2 ??g/L when preconcentrating a 100-mL groundwater sample. Natural sediment samples from the Ebre Delta area (Tarragona, Spain) containing atrazine and deethylatrazine were Soxhlet extracted and analyzed by the methodology developed in this work. No significant interferences from the sample matrix were noticed, thus indicating good selectivity of the MIP sorbents used.

  9. Sonographic detection of portal venous gas

    International Nuclear Information System (INIS)

    Lee, Wang Yul; Lee, S. K.; Cho, O. K.

    1989-01-01

    Portal venous gas suggests underlying bowel disease such as strangulating intestinal obstruction and its demonstration carries with it an important implications with respect to patient management. Radiography has been the gold standard for the detection of portal venous gas. We have experienced two cases of portal venous gas diagnosed by ultrasound. Sonographic findings were floating echoes in the main portal vein and highly echogenic linear or patchy echoes within the hepatic parenchyma. Simple abdominal films of those cases failed to demonstrate gas in the portal venous system

  10. [Evaluation of the Charing Cross Venous Ulcer Questionnaire in patients with chronic venous ulcers in Uruguay].

    Science.gov (United States)

    Tafernaberry, Gabriela; Otero, Gabriela; Agorio, Caroline; Dapueto, Juan J

    2016-01-01

    Chronic venous ulcers (CVU) represent a frequent condition, with difficult therapeutic approaches, that impact on patients’ quality of life, and generate an economic burden to patients and health systems. To perform the cultural adaptation and initial evaluation of the Charing Cross Venous Ulcer Questionnaire (CCVUQ) for Uruguay, and to study the health-related quality of life (HRQL) of patients with CVU. The translated and culturally adapted version of the CCVUQ was applied to a convenience sample of 50 patients. In addition, the PROMIS Global Health Survey was included in the assessment. Both questionnaires showed good internal consistency (Cronbach alfa > 0.70). A statistically significant association was observed between the CCVUQ total scores, its subscales and both dimensions of the PROMIS: Global Physical (GPH) and Global Mental Health (GMH) (rho ≥ 0.40). The CCVUQ mean score was 54.9 ± 42 points while GPH and GMH mean scores were 37.9 ± 29 points, and 43.1 ± 35.1 points respectively. Simple linear regression showed that patients with higher income reported better emotional well-being, while in younger patients, ulcers had a higher impact on Emotional Status and Cosmetics. The translated and adapted version of the CCVUQ was easy to comprehend and apply, showing good psychometric properties. When used in association with the PROMIS Global Health Measure it provides complementary information. HRQL was severely affected in the study sample.

  11. Effect of selective logging on genetic diversity and gene flow in Cariniana legalis sampled from a cacao agroforestry system.

    Science.gov (United States)

    Leal, J B; Santos, R P; Gaiotto, F A

    2014-01-28

    The fragments of the Atlantic Forest of southern Bahia have a long history of intense logging and selective cutting. Some tree species, such as jequitibá rosa (Cariniana legalis), have experienced a reduction in their populations with respect to both area and density. To evaluate the possible effects of selective logging on genetic diversity, gene flow, and spatial genetic structure, 51 C. legalis individuals were sampled, representing the total remaining population from the cacao agroforestry system. A total of 120 alleles were observed from the 11 microsatellite loci analyzed. The average observed heterozygosity (0.486) was less than the expected heterozygosity (0.721), indicating a loss of genetic diversity in this population. A high fixation index (FIS = 0.325) was found, which is possibly due to a reduction in population size, resulting in increased mating among relatives. The maximum (1055 m) and minimum (0.095 m) distances traveled by pollen or seeds were inferred based on paternity tests. We found 36.84% of unique parents among all sampled seedlings. The progenitors of the remaining seedlings (63.16%) were most likely out of the sampled area. Positive and significant spatial genetic structure was identified in this population among classes 10 to 30 m away with an average coancestry coefficient between pairs of individuals of 0.12. These results suggest that the agroforestry system of cacao cultivation is contributing to maintaining levels of diversity and gene flow in the studied population, thus minimizing the effects of selective logging.

  12. Colorimetric biomimetic sensor systems based on molecularly imprinted polymer membranes for highly-selective detection of phenol in environmental samples

    Directory of Open Access Journals (Sweden)

    Sergeyeva T. A.

    2014-05-01

    Full Text Available Aim. Development of an easy-to-use colorimetric sensor system for fast and accurate detection of phenol in envi- ronmental samples. Methods. Technique of molecular imprinting, method of in situ polymerization of molecularly imprinted polymer membranes. Results. The proposed sensor is based on free-standing molecularly imprinted polymer (MIP membranes, synthesized by in situ polymerization, and having in their structure artificial binding sites capable of selective phenol recognition. The quantitative detection of phenol, selectively adsorbed by the MIP membranes, is based on its reaction with 4-aminoantipyrine, which gives a pink-colored product. The intensity of staining of the MIP membrane is proportional to phenol concentration in the analyzed sample. Phenol can be detected within the range 50 nM–10 mM with limit of detection 50 nM, which corresponds to the concentrations that have to be detected in natural and waste waters in accordance with environmental protection standards. Stability of the MIP-membrane-based sensors was assessed during 12 months storage at room temperature. Conclusions. The sensor system provides highly-selective and sensitive detection of phenol in both mo- del and real (drinking, natural, and waste water samples. As compared to traditional methods of phenol detection, the proposed system is characterized by simplicity of operation and can be used in non-laboratory conditions.

  13. Determination of Selected Polycyclic Aromatic Compounds in Particulate Matter Samples with Low Mass Loading: An Approach to Test Method Accuracy

    Directory of Open Access Journals (Sweden)

    Susana García-Alonso

    2017-01-01

    Full Text Available A miniaturized analytical procedure to determine selected polycyclic aromatic compounds (PACs in low mass loadings (<10 mg of particulate matter (PM is evaluated. The proposed method is based on a simple sonication/agitation method using small amounts of solvent for extraction. The use of a reduced sample size of particulate matter is often limiting for allowing the quantification of analytes. This also leads to the need for changing analytical procedures and evaluating its performance. The trueness and precision of the proposed method were tested using ambient air samples. Analytical results from the proposed method were compared with those of pressurized liquid and microwave extractions. Selected PACs (polycyclic aromatic hydrocarbons (PAHs and nitro polycyclic aromatic hydrocarbons (NPAHs were determined by liquid chromatography with fluorescence detection (HPLC/FD. Taking results from pressurized liquid extractions as reference values, recovery rates of sonication/agitation method were over 80% for the most abundant PAHs. Recovery rates of selected NPAHs were lower. Enhanced rates were obtained when methanol was used as a modifier. Intermediate precision was estimated by data comparison from two mathematical approaches: normalized difference data and pooled relative deviations. Intermediate precision was in the range of 10–20%. The effectiveness of the proposed method was evaluated in PM aerosol samples collected with very low mass loadings (<0.2 mg during characterization studies from turbofan engine exhausts.

  14. Recursive SVM feature selection and sample classification for mass-spectrometry and microarray data

    Directory of Open Access Journals (Sweden)

    Harris Lyndsay N

    2006-04-01

    Full Text Available Abstract Background Like microarray-based investigations, high-throughput proteomics techniques require machine learning algorithms to identify biomarkers that are informative for biological classification problems. Feature selection and classification algorithms need to be robust to noise and outliers in the data. Results We developed a recursive support vector machine (R-SVM algorithm to select important genes/biomarkers for the classification of noisy data. We compared its performance to a similar, state-of-the-art method (SVM recursive feature elimination or SVM-RFE, paying special attention to the ability of recovering the true informative genes/biomarkers and the robustness to outliers in the data. Simulation experiments show that a 5 %-~20 % improvement over SVM-RFE can be achieved regard to these properties. The SVM-based methods are also compared with a conventional univariate method and their respective strengths and weaknesses are discussed. R-SVM was applied to two sets of SELDI-TOF-MS proteomics data, one from a human breast cancer study and the other from a study on rat liver cirrhosis. Important biomarkers found by the algorithm were validated by follow-up biological experiments. Conclusion The proposed R-SVM method is suitable for analyzing noisy high-throughput proteomics and microarray data and it outperforms SVM-RFE in the robustness to noise and in the ability to recover informative features. The multivariate SVM-based method outperforms the univariate method in the classification performance, but univariate methods can reveal more of the differentially expressed features especially when there are correlations between the features.

  15. Geochemistry and petrology of selected coal samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Belkin, Harvey E.; Tewalt, Susan J. [U.S. Geological Survey, 956 National Center, Reston, VA 20192 (United States); Hower, James C. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); Stucker, J.D. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States)]|[University of Kentucky Department of Earth and Environmental Sciences, Lexington, KY 40506 (United States); O' Keefe, J.M.K. [Morehead State University, Department of Physical Science, Morehead, KY 40351 (United States)

    2009-01-31

    Indonesia has become the world's largest exporter of thermal coal and is a major supplier to the Asian coal market, particularly as the People's Republic of China is now (2007) and perhaps may remain a net importer of coal. Indonesia has had a long history of coal production, mainly in Sumatra and Kalimantan, but only in the last two decades have government and commercial forces resulted in a remarkable coal boom. A recent assessment of Indonesian coal-bed methane (CBM) potential has motivated active CBM exploration. Most of the coal is Paleogene and Neogene, low to moderate rank and has low ash yield and sulfur (generally < 10 and < 1 wt.%, respectively). Active tectonic and igneous activity has resulted in significant rank increase in some coal basins. Eight coal samples are described that represent the major export and/or resource potential of Sumatra, Kalimantan, Sulawesi, and Papua. Detailed geochemistry, including proximate and ultimate analysis, sulfur forms, and major, minor, and trace element determinations are presented. Organic petrology and vitrinite reflectance data reflect various precursor flora assemblages and rank variations, including sample composites from active igneous and tectonic areas. A comparison of Hazardous Air Pollutants (HAPs) elements abundance with world and US averages show that the Indonesian coals have low combustion pollution potential. (author)

  16. Assessment of DDT levels in selected environmental media and biological samples from Mexico and Central America.

    Science.gov (United States)

    Pérez-Maldonado, Iván N; Trejo, Antonio; Ruepert, Clemens; Jovel, Reyna del Carmen; Méndez, Mónica Patricia; Ferrari, Mirtha; Saballos-Sobalvarro, Emilio; Alexander, Carlos; Yáñez-Estrada, Leticia; Lopez, Dania; Henao, Samuel; Pinto, Emilio R; Díaz-Barriga, Fernando

    2010-03-01

    Taking into account the environmental persistence and the toxicity of DDT, the Pan American Health Organization (PAHO) organized a surveillance program in Mesoamerica which included the detection of residual DDT in environmental (soil) and biological samples (fish tissue and children's blood). This program was carried out in communities from Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. This paper presents the first report of that program. As expected, the results show that the levels for [summation operator] DDT in soil (outdoor or indoor) and fish samples in the majority of the locations studied are below guidelines. However, in some locations, we found children with high concentrations of DDT as in Mexico (mean level 50.2 ng/mL). Furthermore, in some communities and for some matrices, the DDT/DDE quotient is higher than one and this may reflect a recent DDT exposure. Therefore, more efforts are needed to avoid exposure and to prevent the reintroduction of DDT into the region. In this regard it is important to know that under the surveillance of PAHO and with the support of UNEP, a regional program in Mesoamerica for the collection and disposal of DDT and other POPs stockpiles is in progress. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  17. Geochemistry and petrology of selected coal samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

    International Nuclear Information System (INIS)

    Belkin, Harvey E.; Tewalt, Susan J.; Hower, James C.; Stucker, J.D.; O'Keefe, J.M.K.

    2009-01-01

    Indonesia has become the world's largest exporter of thermal coal and is a major supplier to the Asian coal market, particularly as the People's Republic of China is now (2007) and perhaps may remain a net importer of coal. Indonesia has had a long history of coal production, mainly in Sumatra and Kalimantan, but only in the last two decades have government and commercial forces resulted in a remarkable coal boom. A recent assessment of Indonesian coal-bed methane (CBM) potential has motivated active CBM exploration. Most of the coal is Paleogene and Neogene, low to moderate rank and has low ash yield and sulfur (generally < 10 and < 1 wt.%, respectively). Active tectonic and igneous activity has resulted in significant rank increase in some coal basins. Eight coal samples are described that represent the major export and/or resource potential of Sumatra, Kalimantan, Sulawesi, and Papua. Detailed geochemistry, including proximate and ultimate analysis, sulfur forms, and major, minor, and trace element determinations are presented. Organic petrology and vitrinite reflectance data reflect various precursor flora assemblages and rank variations, including sample composites from active igneous and tectonic areas. A comparison of Hazardous Air Pollutants (HAPs) elements abundance with world and US averages show that the Indonesian coals have low combustion pollution potential. (author)

  18. Sample selection, preparation methods, and the apparent tensile properties of silkworm (B. mori) cocoon silk.

    Science.gov (United States)

    Reed, Emily J; Bianchini, Lindsay L; Viney, Christopher

    2012-06-01

    Reported literature values of the tensile properties of natural silk cover a wide range. While much of this inconsistency is the result of variability that is intrinsic to silk, some is also a consequence of differences in the way that silk is prepared for tensile tests. Here we explore how measured mechanical properties of Bombyx mori cocoon silk are affected by two intrinsic factors (the location from which the silk is collected within the cocoon, and the color of the silk), and two extrinsic factors (the storage conditions prior to testing, and different styles of reeling the fiber). We find that extrinsic and therefore controllable factors can affect the properties more than the intrinsic ones studied. Our results suggest that enhanced inter-laboratory collaborations, that lead to standardized sample collection, handling, and storage protocols prior to mechanical testing, would help to decrease unnecessary (and complicating) variation in reported tensile properties. Copyright © 2011 Wiley Periodicals, Inc.

  19. Selected social-psychological characteristics of a sample of Israeli cancer patients: facts and implications.

    Science.gov (United States)

    Baider, L; Sarell, M; Edelstein, E L

    1982-02-01

    This paper presents some sociodemographic, medical and psychological data gathered in an ongoing study aimed at early identification of the psychosocial coping potential of adult, Jewish cancer patients in Israel. We show the distribution of a sample of 86 patients on variables such as age, sex, marital status, place of birth, religiosity, medical diagnosis, treatment modality, and duration of illness. We describe the patients' reported behavioral changes, their perceptions of the nature and causes of their illness, and their views on the supportive resources available to them. We also analyze patients' expectations regarding their future functioning in the areas of work, household, family and social relations, and leisure-time activities. On the basis of these initial analyses, we present some recommendations for the improvement of social-psychological intervention with cancer patients.

  20. The AlSi10Mg samples produced by selective laser melting: single track, densification, microstructure and mechanical behavior

    International Nuclear Information System (INIS)

    Wei, Pei; Wei, Zhengying; Chen, Zhen; Du, Jun; He, Yuyang; Li, Junfeng; Zhou, Yatong

    2017-01-01

    Highlights: • The thermal behavior of AlSi10Mg molten pool was analyzed. • The SLM-processed sample with a relatively low surface roughness was obtained. • Effects of parameters on surface topography of scan track were investigated. • Effects of parameters on microstructure of parts were investigated. • Optimum processing parameters for AlSi10Mg SLM was obtained. - Abstract: This densification behavior and attendant microstructural characteristics of the selective laser melting (SLM) processed AlSi10Mg alloy affected by the processing parameters were systematically investigated. The samples with a single track were produced by SLM to study the influences of laser power and scanning speed on the surface morphologies of scan tracks. Additionally, the bulk samples were produced to investigate the influence of the laser power, scanning speed, and hatch spacing on the densification level and the resultant microstructure. The experimental results showed that the level of porosity of the SLM-processed samples was significantly governed by energy density of laser beam and the hatch spacing. The tensile properties of SLM-processed samples and the attendant fracture surface can be enhanced by decreasing the level of porosity. The microstructure of SLM-processed samples consists of supersaturated Al-rich cellular structure along with eutectic Al/Si situated at the cellular boundaries. The Si content in the cellular boundaries increases with increasing the laser power and decreasing the scanning speed. The hardness of SLM-processed samples was significantly improved by this fine microstructure compared with the cast samples. Moreover, the hardness of SLM-processed samples at overlaps was lower than the hardness observed at track cores.

  1. The AlSi10Mg samples produced by selective laser melting: single track, densification, microstructure and mechanical behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Pei; Wei, Zhengying, E-mail: zywei@mail.xjtu.edu.cn; Chen, Zhen; Du, Jun; He, Yuyang; Li, Junfeng; Zhou, Yatong

    2017-06-30

    Highlights: • The thermal behavior of AlSi10Mg molten pool was analyzed. • The SLM-processed sample with a relatively low surface roughness was obtained. • Effects of parameters on surface topography of scan track were investigated. • Effects of parameters on microstructure of parts were investigated. • Optimum processing parameters for AlSi10Mg SLM was obtained. - Abstract: This densification behavior and attendant microstructural characteristics of the selective laser melting (SLM) processed AlSi10Mg alloy affected by the processing parameters were systematically investigated. The samples with a single track were produced by SLM to study the influences of laser power and scanning speed on the surface morphologies of scan tracks. Additionally, the bulk samples were produced to investigate the influence of the laser power, scanning speed, and hatch spacing on the densification level and the resultant microstructure. The experimental results showed that the level of porosity of the SLM-processed samples was significantly governed by energy density of laser beam and the hatch spacing. The tensile properties of SLM-processed samples and the attendant fracture surface can be enhanced by decreasing the level of porosity. The microstructure of SLM-processed samples consists of supersaturated Al-rich cellular structure along with eutectic Al/Si situated at the cellular boundaries. The Si content in the cellular boundaries increases with increasing the laser power and decreasing the scanning speed. The hardness of SLM-processed samples was significantly improved by this fine microstructure compared with the cast samples. Moreover, the hardness of SLM-processed samples at overlaps was lower than the hardness observed at track cores.

  2. Hyperthyroidism and cerebral venous thrombosis.

    Science.gov (United States)

    Mouton, S; Nighoghossian, N; Berruyer, M; Derex, L; Philippeau, F; Cakmak, S; Honnorat, J; Hermier, M; Trouillas, P

    2005-01-01

    The demonstration of an underlying prothrombotic condition in cerebral venous thrombosis (CVT) may have important practical consequences in terms of prevention. Thyrotoxicosis through a hypercoagulable state may be a predisposing factor for CVT. The authors present the cases of 4 patients who developed CVT and hyperthyroidism. At the acute stage, hyperthyroidism was associated with an increase in factor VIII (FVIII). At follow-up, FVIII level remained increased in 2 patients. Hyperthyroidism may have an impact on FVIII level. Accordingly in patients with hyperthyroidism and neurological symptoms, the diagnosis of CVT should be considered and an exhaustive coagulation screening may be appropriate. (c) 2005 S. Karger AG, Basel.

  3. Selecting between-sample RNA-Seq normalization methods from the perspective of their assumptions.

    Science.gov (United States)

    Evans, Ciaran; Hardin, Johanna; Stoebel, Daniel M

    2017-02-27

    RNA-Seq is a widely used method for studying the behavior of genes under different biological conditions. An essential step in an RNA-Seq study is normalization, in which raw data are adjusted to account for factors that prevent direct comparison of expression measures. Errors in normalization can have a significant impact on downstream analysis, such as inflated false positives in differential expression analysis. An underemphasized feature of normalization is the assumptions on which the methods rely and how the validity of these assumptions can have a substantial impact on the performance of the methods. In this article, we explain how assumptions provide the link between raw RNA-Seq read counts and meaningful measures of gene expression. We examine normalization methods from the perspective of their assumptions, as an understanding of methodological assumptions is necessary for choosing methods appropriate for the data at hand. Furthermore, we discuss why normalization methods perform poorly when their assumptions are violated and how this causes problems in subsequent analysis. To analyze a biological experiment, researchers must select a normalization method with assumptions that are met and that produces a meaningful measure of expression for the given experiment. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Rational approach to solvent system selection for liquid-liquid extraction-assisted sample pretreatment in counter-current chromatography.

    Science.gov (United States)

    Wang, Jiajia; Gu, Dongyu; Wang, Miao; Guo, Xinfeng; Li, Haoquan; Dong, Yue; Guo, Hong; Wang, Yi; Fan, Mengqi; Yang, Yi

    2017-05-15

    A rational liquid-liquid extraction approach was established to pre-treat samples for high-speed counter-current chromatography (HSCCC). n-Hexane-ethyl acetate-methanol-water (4:5:4:5, v/v) and (1:5:1:5, v/v) were selected as solvent systems for liquid-liquid extraction by systematically screening K of target compounds to remove low- and high-polarity impurities in the sample, respectively. After liquid-liquid extraction was performed, 1.4g of crude sample II was obtained from 18.5g of crude sample I which was extracted from the flowers of Robinia pseudoacacia L., and then separated with HSCCC by using a solvent system composed of n-hexane-ethyl acetate-methanol-water (1:2:1:2, v/v). As a result, 31mg of robinin and 37mg of kaempferol 7-O-α-l-rhamnopyranoside were isolated from 200mg of crude sample II in a single run of HSCCC. A scale-up separation was also performed, and 160mg of robinin with 95% purity and 188mg of kaempferol 7-O-α-l-rhamnopyranoside with 97% purity were produced from 1.2g of crude sample II. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Arterial and venous plasma levels of bupivacaine following epidural and intercostal nerve blocks.

    Science.gov (United States)

    Moore, D C; Mather, L E; Bridenbaugh, P O; Bridenbaugh, L D; Balfour, R I; Lysons, D F; Horton, W G

    1976-07-01

    Arterial and peripheral venous plasma levels of bupivacaine were determined in 30 patients following epidural anesthesia using 150 and 225 mg, as well as following intercostal nerve block with 400 mg. Arterial levels were consistently higher than levels in simultaneously sampled venous blood, and the highest levels occurred with bilateral intercostal nerve block. No evidence of systemic toxicity was observed. The results suggest that bupivacaine may have a wider margin of safety in man than is now stated.

  6. Pilot studies for the North American Soil Geochemical Landscapes Project - Site selection, sampling protocols, analytical methods, and quality control protocols

    Science.gov (United States)

    Smith, D.B.; Woodruff, L.G.; O'Leary, R. M.; Cannon, W.F.; Garrett, R.G.; Kilburn, J.E.; Goldhaber, M.B.

    2009-01-01

    In 2004, the US Geological Survey (USGS) and the Geological Survey of Canada sampled and chemically analyzed soils along two transects across Canada and the USA in preparation for a planned soil geochemical survey of North America. This effort was a pilot study to test and refine sampling protocols, analytical methods, quality control protocols, and field logistics for the continental survey. A total of 220 sample sites were selected at approximately 40-km intervals along the two transects. The ideal sampling protocol at each site called for a sample from a depth of 0-5 cm and a composite of each of the O, A, and C horizons. The Ca, Fe, K, Mg, Na, S, Ti, Ag, As, Ba, Be, Bi, Cd, Ce, Co, Cr, Cs, Cu, Ga, In, La, Li, Mn, Mo, Nb, Ni, P, Pb, Rb, Sb, Sc, Sn, Sr, Te, Th, Tl, U, V, W, Y, and Zn by inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry following a near-total digestion in a mixture of HCl, HNO3, HClO4, and HF. Separate methods were used for Hg, Se, total C, and carbonate-C on this same size fraction. Only Ag, In, and Te had a large percentage of concentrations below the detection limit. Quality control (QC) of the analyses was monitored at three levels: the laboratory performing the analysis, the USGS QC officer, and the principal investigator for the study. This level of review resulted in an average of one QC sample for every 20 field samples, which proved to be minimally adequate for such a large-scale survey. Additional QC samples should be added to monitor within-batch quality to the extent that no more than 10 samples are analyzed between a QC sample. Only Cr (77%), Y (82%), and Sb (80%) fell outside the acceptable limits of accuracy (% recovery between 85 and 115%) because of likely residence in mineral phases resistant to the acid digestion. A separate sample of 0-5-cm material was collected at each site for determination of organic compounds. A subset of 73 of these samples was analyzed for a suite of

  7. A Principle Component Analysis of Galaxy Properties from a Large, Gas-Selected Sample

    Directory of Open Access Journals (Sweden)

    Yu-Yen Chang

    2012-01-01

    concluded that this is in conflict with the CDM model. Considering the importance of the issue, we reinvestigate the problem using the principal component analysis on a fivefold larger sample and additional near-infrared data. We use databases from the Arecibo Legacy Fast Arecibo L-band Feed Array Survey for the gas properties, the Sloan Digital Sky Survey for the optical properties, and the Two Micron All Sky Survey for the near-infrared properties. We confirm that the parameters are indeed correlated where a single physical parameter can explain 83% of the variations. When color (g-i is included, the first component still dominates but it develops a second principal component. In addition, the near-infrared color (i-J shows an obvious second principal component that might provide evidence of the complex old star formation. Based on our data, we suggest that it is premature to pronounce the failure of the CDM model and it motivates more theoretical work.

  8. Green Synthesis of Fluorescent Carbon Dots for Selective Detection of Tartrazine in Food Samples.

    Science.gov (United States)

    Xu, Hua; Yang, Xiupei; Li, Gu; Zhao, Chuan; Liao, Xiangjun

    2015-08-05

    A simple, economical, and green method for the preparation of water-soluble, high-fluorescent carbon quantum dots (C-dots) has been developed via hydrothermal process using aloe as a carbon source. The synthesized C-dots were characterized by atomic force microscope (AFM), transmission electron microscopy (TEM), fluorescence spectrophotometer, UV-vis absorption spectra as well as Fourier transform infrared spectroscopy (FTIR). The results reveal that the as-prepared C-dots were spherical shape with an average diameter of 5 nm and emit bright yellow photoluminescence (PL) with a quantum yield of approximately 10.37%. The surface of the C-dots was rich in hydroxyl groups and presented various merits including high fluorescent quantum yield, excellent photostability, low toxicity and satisfactory solubility. Additionally, we found that one of the widely used synthetic food colorants, tartrazine, could result in a strong fluorescence quenching of the C-dots through a static quenching process. The decrease of fluorescence intensity made it possible to determine tartrazine in the linear range extending from 0.25 to 32.50 μM, This observation was further successfully applied for the determination of tartrazine in food samples collected from local markets, suggesting its great potential toward food routine analysis. Results from our study may shed light on the production of fluorescent and biocompatible nanocarbons due to our simple and environmental benign strategy to synthesize C-dots in which aloe was used as a carbon source.

  9. Soft X-Ray Observations of a Complete Sample of X-Ray--selected BL Lacertae Objects

    Science.gov (United States)

    Perlman, Eric S.; Stocke, John T.; Wang, Q. Daniel; Morris, Simon L.

    1996-01-01

    We present the results of ROSAT PSPC observations of the X-ray selected BL Lacertae objects (XBLs) in the complete Einstein Extended Medium Sensitivity Survey (EM MS) sample. None of the objects is resolved in their respective PSPC images, but all are easily detected. All BL Lac objects in this sample are well-fitted by single power laws. Their X-ray spectra exhibit a variety of spectral slopes, with best-fit energy power-law spectral indices between α = 0.5-2.3. The PSPC spectra of this sample are slightly steeper than those typical of flat ratio-spectrum quasars. Because almost all of the individual PSPC spectral indices are equal to or slightly steeper than the overall optical to X-ray spectral indices for these same objects, we infer that BL Lac soft X-ray continua are dominated by steep-spectrum synchrotron radiation from a broad X-ray jet, rather than flat-spectrum inverse Compton radiation linked to the narrower radio/millimeter jet. The softness of the X-ray spectra of these XBLs revives the possibility proposed by Guilbert, Fabian, & McCray (1983) that BL Lac objects are lineless because the circumnuclear gas cannot be heated sufficiently to permit two stable gas phases, the cooler of which would comprise the broad emission-line clouds. Because unified schemes predict that hard self-Compton radiation is beamed only into a small solid angle in BL Lac objects, the steep-spectrum synchrotron tail controls the temperature of the circumnuclear gas at r ≤ 1018 cm and prevents broad-line cloud formation. We use these new ROSAT data to recalculate the X-ray luminosity function and cosmological evolution of the complete EMSS sample by determining accurate K-corrections for the sample and estimating the effects of variability and the possibility of incompleteness in the sample. Our analysis confirms that XBLs are evolving "negatively," opposite in sense to quasars, with Ve/Va = 0.331±0.060. The statistically significant difference between the values for X

  10. Polymeric membrane sensors based on Cd(II) Schiff base complexes for selective iodide determination in environmental and medicinal samples.

    Science.gov (United States)

    Singh, Ashok Kumar; Mehtab, Sameena

    2008-01-15

    The two cadmium chelates of schiff bases, N,N'-bis(salicylidene)-1,4-diaminobutane, (Cd-S(1)) and N,N'-bis(salicylidene)-3,4-diaminotoluene (Cd-S(2)), have been synthesized and explored as ionophores for preparing PVC-based membrane sensors selective to iodide(I) ion. Potentiometric investigations indicate high affinity of these receptors for iodide ion. Polyvinyl chloride (PVC)-based membranes of Cd-S(1) and Cd-S(2) using as hexadecyltrimethylammonium bromide (HTAB) cation discriminator and o-nitrophenyloctyl ether (o-NPOE), dibutylphthalate (DBP), acetophenone (AP) and tributylphosphate (TBP) as plasticizing solvent mediators were prepared and investigated as iodide-selective sensors. The best performance was shown by the membrane of composition (w/w) of (Cd-S(1)) (7%):PVC (31%):DBP (60%):HTAB (2%). The sensor works well over a wide concentration range 5.3x10(-7) to 1.0x10(-2)M with Nernstian compliance (59.2mVdecade(-1) of activity) within pH range 2.5-9.0 with a response time of 11s and showed good selectivity for iodide ion over a number of anions. The sensor exhibits adequate life (3 months) with good reproducibility (S.D.+/-0.24mV) and could be used successfully for the determination of iodide content in environmental water samples and mouth wash samples.

  11. A simple highly sensitive and selective aptamer-based colorimetric sensor for environmental toxins microcystin-LR in water samples.

    Science.gov (United States)

    Li, Xiuyan; Cheng, Ruojie; Shi, Huijie; Tang, Bo; Xiao, Hanshuang; Zhao, Guohua

    2016-03-05

    A simple and highly sensitive aptamer-based colorimetric sensor was developed for selective detection of Microcystin-LR (MC-LR). The aptamer (ABA) was employed as recognition element which could bind MC-LR with high-affinity, while gold nanoparticles (AuNPs) worked as sensing materials whose plasma resonance absorption peaks red shifted upon binding of the targets at a high concentration of sodium chloride. With the addition of MC-LR, the random coil aptamer adsorbed on Au NPs altered into regulated structure to form MC-LR-aptamer complexes and broke away from the surface of Au NPs, leading to the aggregation of AuNPs, and the color converted from red to blue due to the interparticle plasmon coupling. Results showed that our aptamer-based colorimetric sensor exhibited rapid and sensitive detection performance for MC-LR with linear range from 0.5 nM to 7.5 μM and the detection limit reached 0.37 nM. Meanwhile, the pollutants usually coexisting with MC-LR in pollutant water samples had not demonstrated disturbance for detecting of MC-LR. The mechanism was also proposed suggesting that high affinity interaction between aptamer and MC-LR significantly enhanced the sensitivity and selectivity for MC-LR detection. Besides, the established method was utilized in analyzing real water samples and splendid sensitivity and selectivity were obtained as well. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Pulmonary venous abnormalities encountered on pre ...

    African Journals Online (AJOL)

    Multidetector computed tomography (MDCT) elegantly renders pulmonary venous anatomy. With increasing numbers of radiofrequency ablation procedures being performed, there is now a greater emphasis on pre-procedure imaging to delineate this anatomy. Pulmonary venous mapping studies can be performed with or ...

  13. REVIEW ARTICLE Venous thromboembolism associated with ...

    Indian Academy of Sciences (India)

    Navya

    2017-03-24

    Mar 24, 2017 ... Venous thromboembolism associated with protein S deficiency due to ... 2 Institute of Cardiology, Jagiellonian University Medical College, Kraków, Poland ... It has been long recognized that reduced PS activity is a risk factor for venous ... 1988). Sequencing of PROS1 gene intensified studies of genotype-.

  14. Sex-specific aspects of venous thrombosis

    NARCIS (Netherlands)

    Roach, Rachel Elizabeth Jo

    2014-01-01

    Venous thrombosis is a disease that occurs in 1-2 per 1000 people per year. At the time of their first venous thrombosis, approximately 50% of women are exposed to reproductive risk factors (oral contraception, postmenopausal hormone therapy, pregnancy and the puerperium). In this thesis, we showed

  15. Venous Thromboembolism in Patients With Thrombocytopenia

    DEFF Research Database (Denmark)

    Bælum, Jens Kristian; Ellingsen Moe, Espen; Nybo, Mads

    2017-01-01

    BACKGROUND: Venous thromboembolism (VTE) is a frequent and potentially lethal condition. Venous thrombi are mainly constituted of fibrin and red blood cells, but platelets also play an important role in VTE formation. Information about VTE in patients with thrombocytopenia is, however, missing. O...... having thrombocytopenia with VTE seem to be safely treated with anticoagulants without increased occurrence of bleeding....

  16. Risk factors for venous thromboembolism during pregnancy

    DEFF Research Database (Denmark)

    Jensen, Thomas Bo; Gerds, Thomas Alexander; Grøn, Randi

    2013-01-01

    Pregnant women are at an increased risk of venous thromboembolism (VTE). Risk factors for VTE among pregnant women are not sufficiently investigated.......Pregnant women are at an increased risk of venous thromboembolism (VTE). Risk factors for VTE among pregnant women are not sufficiently investigated....

  17. Clinical quality indicators of venous leg ulcers

    DEFF Research Database (Denmark)

    Kjaer, Monica L; Mainz, Jan; Soernsen, Lars T

    2005-01-01

    In the clinical setting, diagnosis and treatment of venous leg ulcers can vary considerably from patient to patient. The first step to reducing this variation is to document venous leg ulcer care through use of quantitative scientific documentation principles. This requires the development of val...

  18. A BMPy Road for Venous Development.

    Science.gov (United States)

    Goddard, Lauren M; Kahn, Mark L

    2017-09-11

    Detailed molecular pathways for the specific growth of arteries and lymphatic vessels have been identified, but the mechanisms controlling venous vessel growth have been obscure. Tischfield and colleagues (2017) shed new light on this problem by identifying a role for BMP signaling in development of the cerebral venous system. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. PeptideManager: A Peptide Selection Tool for Targeted Proteomic Studies Involving Mixed Samples from Different Species

    Directory of Open Access Journals (Sweden)

    Kevin eDemeure

    2014-09-01

    Full Text Available The search for clinically useful protein biomarkers using advanced mass spectrometry approaches represents a major focus in cancer research. However, the direct analysis of human samples may be challenging due to limited availability, the absence of appropriate control samples, or the large background variability observed in patient material. As an alternative approach, human tumors orthotopically implanted into a different species (xenografts are clinically relevant models that have proven their utility in pre-clinical research. Patient derived xenografts for glioblastoma have been extensively characterized in our laboratory and have been shown to retain the characteristics of the parental tumor at the phenotypic and genetic level. Such models were also found to adequately mimic the behavior and treatment response of human tumors. The reproducibility of such xenograft models, the possibility to identify their host background and perform tumor-host interaction studies, are major advantages over the direct analysis of human samples.At the proteome level, the analysis of xenograft samples is challenged by the presence of proteins from two different species which, depending on tumor size, type or location, often appear at variable ratios. Any proteomics approach aimed at quantifying proteins within such samples must consider the identification of species specific peptides in order to avoid biases introduced by the host proteome. Here, we present an in-house methodology and tool developed to select peptides used as surrogates for protein candidates from a defined proteome (e.g., human in a host proteome background (e.g., mouse, rat suited for a mass spectrometry analysis. The tools presented here are applicable to any species specific proteome, provided a protein database is available. By linking the information from both proteomes, PeptideManager significantly facilitates and expedites the selection of peptides used as surrogates to analyze

  20. Selection of reference genes for tissue/organ samples on day 3 fifth-instar larvae in silkworm, Bombyx mori.

    Science.gov (United States)

    Wang, Genhong; Chen, Yanfei; Zhang, Xiaoying; Bai, Bingchuan; Yan, Hao; Qin, Daoyuan; Xia, Qingyou

    2018-06-01

    The silkworm, Bombyx mori, is one of the world's most economically important insect. Surveying variations in gene expression among multiple tissue/organ samples will provide clues for gene function assignments and will be helpful for identifying genes related to economic traits or specific cellular processes. To ensure their accuracy, commonly used gene expression quantification methods require a set of stable reference genes for data normalization. In this study, 24 candidate reference genes were assessed in 10 tissue/organ samples of day 3 fifth-instar B. mori larvae using geNorm and NormFinder. The results revealed that, using the combination of the expression of BGIBMGA003186 and BGIBMGA008209 was the optimum choice for normalizing the expression data of the B. mori tissue/organ samples. The most stable gene, BGIBMGA003186, is recommended if just one reference gene is used. Moreover, the commonly used reference gene encoding cytoplasmic actin was the least appropriate reference gene of the samples investigated. The reliability of the selected reference genes was further confirmed by evaluating the expression profiles of two cathepsin genes. Our results may be useful for future studies involving the quantification of relative gene expression levels of different tissue/organ samples in B. mori. © 2018 Wiley Periodicals, Inc.

  1. A novel method of selective removal of human DNA improves PCR sensitivity for detection of Salmonella Typhi in blood samples.

    Science.gov (United States)

    Zhou, Liqing; Pollard, Andrew J

    2012-07-27

    Enteric fever is a major public health problem, causing an estimated 21million new cases and 216,000 or more deaths every year. Current diagnosis of the disease is inadequate. Blood culture only identifies 45 to 70% of the cases and is time-consuming. Serological tests have very low sensitivity and specificity. Clinical samples obtained for diagnosis of enteric fever in the field generally have blood, so that even PCR-based methods, widely used for detection of other infectious diseases, are not a straightforward option in typhoid diagnosis. We developed a novel method to enrich target bacterial DNA by selective removal of human DNA from blood samples, enhancing the sensitivity of PCR tests. This method offers the possibility of improving PCR assays directly using clinical specimens for diagnosis of this globally important infectious disease. Blood samples were mixed with ox bile for selective lysis of human blood cells and the released human DNA was then digested with addition of bile resistant micrococcal nuclease. The intact Salmonella Typhi bacteria were collected from the specimen by centrifugation and the DNA extracted with QIAamp DNA mini kit. The presence of Salmonella Typhi bacteria in blood samples was detected by PCR with the fliC-d gene of Salmonella Typhi as the target. Micrococcal nuclease retained activity against human blood DNA in the presence of up to 9% ox bile. Background human DNA was dramatically removed from blood samples through the use of ox bile lysis and micrococcal nuclease for removal of mammalian DNA. Consequently target Salmonella Typhi DNA was enriched in DNA preparations and the PCR sensitivity for detection of Salmonella Typhi in spiked blood samples was enhanced by 1,000 fold. Use of a combination of selective ox-bile blood cell lysis and removal of human DNA with micrococcal nuclease significantly improves PCR sensitivity and offers a better option for improved typhoid PCR assays directly using clinical specimens in diagnosis of

  2. Factors in selecting serum samples for use in determining the positive/negative threshold (cut-off) in ELISA

    International Nuclear Information System (INIS)

    Jacobson, R.H.

    1998-01-01

    The threshold (cut-off) that defines whether a test result is seropositive or seronegative is calculated by testing serum samples from a subpopulation of animals that is assumed to represent the target population in all aspects. For this proposition to be true, it is essential to consider the variables in the target population that must be represented in the subpopulation. Without representation of the variables in the subpopulation, it is likely that the cut-off selected for the test will be errant and will misclassify animals as to their infection status. The purpose of this paper is to identify a few of the principal variables that need to be taken into account when selecting a subpopulation of animals for test validation. (author)

  3. A highly selective and sensitive Tb3+-acetylacetone photo probe for the assessment of acetazolamide in pharmaceutical and serum samples

    Science.gov (United States)

    Youssef, A. O.

    2018-04-01

    A novel, simple, sensitive and selective spectrofluorimetric method was developed for the determination of Acetazolamide in pharmaceutical tablets and serum samples using photo probe Tb3+-ACAC. The Acetazolamide can remarkably quench the luminescence intensity of Tb3+-ACAC complex in DMSO at pH 6.8 and λex = 350 nm. The quenching of luminescence intensity of Tb3+-ACAC complex especially the electrical band at λem = 545 nm is used for the assessment of Acetazolamide in the pharmaceutical tablet and serum samples. The dynamic range found for the determination of Acetazolamide concentration is 4.49 × 10-9-1.28 × 10-7 mol L-1, and the limit of detection (LOD) and limit of quantification (LOQ) are (4.0 × 10-9 and 1.21 × 10-8) mol L-1, respectively.

  4. Clinicopathologic analysis of Passeriform venous blood reflects transitions in elevation and habitat

    Directory of Open Access Journals (Sweden)

    Heatley JJ

    2013-06-01

    Full Text Available J Jill Heatley,1 Jennifer Cary,2 Karen E Russell,3 Gary Voelker2 1Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, 2Department of Wildlife and Fisheries Sciences and Texas A&M Biodiversity Research and Teaching Collections, Texas A&M University, 3Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, College Station, TX, USA Abstract: Jugular blood samples from 110 Passeriformes collected at several Texas locations were analyzed for multiple clinicopathologic parameters between April 2010 and August 2011. Electrolyte, blood gas, and select erythrocyte parameters were analyzed on site with a point of care analyzer, and gender, age, body condition score, location, and species were recorded. Many analytes exhibited a Gaussian distribution across species and are reported as a single range. Taxon affected electrolyte and red blood cell parameters, but not most blood gas or acid base variables. Migratory status affected select electrolytes but few blood gas variables. Red blood cell parameters were affected the most by variables of age, taxonomic group, and gender, but not migratory life history. We found significant changes in glucose and numerous acid base analytes in birds sampled from habitats with evolutionarily recent ecologic degradation. We advocate the use of these analytes, particularly venous blood gas values, as determined by a point of care analyzer, as reasonable biomarkers for determination of Passeriform population health, but also recommend that red blood cell parameters and electrolyte concentrations be controlled for age, species, and gender in future studies. Further, based on our investigation, venous blood gas values and acid base balance in Passeriformes can assess the health of an ecosystem. Keywords: avian, biochemistry, blood gas, electrolyte, hematology, Passerine

  5. A large sample of Kohonen selected E+A (post-starburst) galaxies from the Sloan Digital Sky Survey

    Science.gov (United States)

    Meusinger, H.; Brünecke, J.; Schalldach, P.; in der Au, A.

    2017-01-01

    Context. The galaxy population in the contemporary Universe is characterised by a clear bimodality, blue galaxies with significant ongoing star formation and red galaxies with only a little. The migration between the blue and the red cloud of galaxies is an issue of active research. Post starburst (PSB) galaxies are thought to be observed in the short-lived transition phase. Aims: We aim to create a large sample of local PSB galaxies from the Sloan Digital Sky Survey (SDSS) to study their characteristic properties, particularly morphological features indicative of gravitational distortions and indications for active galactic nuclei (AGNs). Another aim is to present a tool set for an efficient search in a large database of SDSS spectra based on Kohonen self-organising maps (SOMs). Methods: We computed a huge Kohonen SOM for ∼106 spectra from SDSS data release 7. The SOM is made fully available, in combination with an interactive user interface, for the astronomical community. We selected a large sample of PSB galaxies taking advantage of the clustering behaviour of the SOM. The morphologies of both PSB galaxies and randomly selected galaxies from a comparison sample in SDSS Stripe 82 (S82) were inspected on deep co-added SDSS images to search for indications of gravitational distortions. We used the Portsmouth galaxy property computations to study the evolutionary stage of the PSB galaxies and archival multi-wavelength data to search for hidden AGNs. Results: We compiled a catalogue of 2665 PSB galaxies with redshifts z 3 Å and z cloud, in agreement with the idea that PSB galaxies represent the transitioning phase between actively and passively evolving galaxies. The relative frequency of distorted PSB galaxies is at least 57% for EW(Hδ) > 5 Å, significantly higher than in the comparison sample. The search for AGNs based on conventional selection criteria in the radio and MIR results in a low AGN fraction of ∼2-3%. We confirm an MIR excess in the mean SED of

  6. The NuSTAR  Extragalactic Surveys: X-Ray Spectroscopic Analysis of the Bright Hard-band Selected Sample

    Science.gov (United States)

    Zappacosta, L.; Comastri, A.; Civano, F.; Puccetti, S.; Fiore, F.; Aird, J.; Del Moro, A.; Lansbury, G. B.; Lanzuisi, G.; Goulding, A.; Mullaney, J. R.; Stern, D.; Ajello, M.; Alexander, D. M.; Ballantyne, D. R.; Bauer, F. E.; Brandt, W. N.; Chen, C.-T. J.; Farrah, D.; Harrison, F. A.; Gandhi, P.; Lanz, L.; Masini, A.; Marchesi, S.; Ricci, C.; Treister, E.

    2018-02-01

    We discuss the spectral analysis of a sample of 63 active galactic nuclei (AGN) detected above a limiting flux of S(8{--}24 {keV})=7× {10}-14 {erg} {{{s}}}-1 {{cm}}-2 in the multi-tiered NuSTAR extragalactic survey program. The sources span a redshift range z=0{--}2.1 (median =0.58). The spectral analysis is performed over the broad 0.5–24 keV energy range, combining NuSTAR with Chandra and/or XMM-Newton data and employing empirical and physically motivated models. This constitutes the largest sample of AGN selected at > 10 {keV} to be homogeneously spectrally analyzed at these flux levels. We study the distribution of spectral parameters such as photon index, column density ({N}{{H}}), reflection parameter ({\\boldsymbol{R}}), and 10–40 keV luminosity ({L}{{X}}). Heavily obscured ({log}[{N}{{H}}/{{cm}}-2]≥slant 23) and Compton-thick (CT; {log}[{N}{{H}}/{{cm}}-2]≥slant 24) AGN constitute ∼25% (15–17 sources) and ∼2–3% (1–2 sources) of the sample, respectively. The observed {N}{{H}} distribution agrees fairly well with predictions of cosmic X-ray background population-synthesis models (CXBPSM). We estimate the intrinsic fraction of AGN as a function of {N}{{H}}, accounting for the bias against obscured AGN in a flux-selected sample. The fraction of CT AGN relative to {log}[{N}{{H}}/{{cm}}-2]=20{--}24 AGN is poorly constrained, formally in the range 2–56% (90% upper limit of 66%). We derived a fraction (f abs) of obscured AGN ({log}[{N}{{H}}/{{cm}}-2]=22{--}24) as a function of {L}{{X}} in agreement with CXBPSM and previous zvalues.

  7. 40 CFR Appendix X to Part 86 - Sampling Plans for Selective Enforcement Auditing of Heavy-Duty Engines and Light-Duty Trucks

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Sampling Plans for Selective Enforcement Auditing of Heavy-Duty Engines and Light-Duty Trucks X Appendix X to Part 86 Protection of... Plans for Selective Enforcement Auditing of Heavy-Duty Engines and Light-Duty Trucks Table 1—Sampling...

  8. [Venous catheter-related infections].

    Science.gov (United States)

    Ferrer, Carmen; Almirante, Benito

    2014-02-01

    Venous catheter-related infections are a problem of particular importance, due to their frequency, morbidity and mortality, and because they are potentially preventable clinical processes. At present, the majority of hospitalized patients and a considerable number of outpatients are carriers of these devices. There has been a remarkable growth of knowledge of the epidemiology of these infections, the most appropriate methodology for diagnosis, the therapeutic and, in particular, the preventive strategies. Multimodal strategies, including educational programs directed at staff and a bundle of simple measures for implementation, applied to high-risk patients have demonstrated great effectiveness for their prevention. In this review the epidemiology, the diagnosis, and the therapeutic and preventive aspects of these infections are updated. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  9. Bias due to sample selection in propensity score matching for a supportive housing program evaluation in New York City.

    Directory of Open Access Journals (Sweden)

    Sungwoo Lim

    Full Text Available OBJECTIVES: Little is known about influences of sample selection on estimation in propensity score matching. The purpose of the study was to assess potential selection bias using one-to-one greedy matching versus optimal full matching as part of an evaluation of supportive housing in New York City (NYC. STUDY DESIGN AND SETTINGS: Data came from administrative data for 2 groups of applicants who were eligible for an NYC supportive housing program in 2007-09, including chronically homeless adults with a substance use disorder and young adults aging out of foster care. We evaluated the 2 matching methods in their ability to balance covariates and represent the original population, and in how those methods affected outcomes related to Medicaid expenditures. RESULTS: In the population with a substance use disorder, only optimal full matching performed well in balancing covariates, whereas both methods created representative populations. In the young adult population, both methods balanced covariates effectively, but only optimal full matching created representative populations. In the young adult population, the impact of the program on Medicaid expenditures was attenuated when one-to-one greedy matching was used, compared with optimal full matching. CONCLUSION: Given covariate balancing with both methods, attenuated program impacts in the young adult population indicated that one-to-one greedy matching introduced selection bias.

  10. Selective detection of Co2+ by fluorescent nano probe: Diagnostic approach for analysis of environmental samples and biological activities

    Science.gov (United States)

    Mahajan, Prasad G.; Dige, Nilam C.; Desai, Netaji K.; Patil, Shivajirao R.; Kondalkar, Vijay V.; Hong, Seong-Karp; Lee, Ki Hwan

    2018-06-01

    Nowadays scientist over the world are engaging to put forth improved methods to detect metal ion in an aqueous medium based on fluorescence studies. A simple, selective and sensitive method was proposed for detection of Co2+ ion using fluorescent organic nanoparticles. We synthesized a fluorescent small molecule viz. 4,4‧-{benzene-1,4-diylbis-[(Z)methylylidenenitrilo]}dibenzoic acid (BMBA) to explore its suitability as sensor for Co2+ ion and biocompatibility in form of nanoparticles. Fluorescence nanoparticles (BMBANPs) prepared by simple reprecipitation method. Aggregation induced enhanced emission of BMBANPs exhibits the narrower particle size of 68 nm and sphere shape morphology. The selective fluorescence quenching was observed by addition of Co2+ and does not affected by presence of other coexisting ion solutions. The photo-physical properties, viz. UV-absorption, fluorescence emission, and lifetime measurements are in support of ligand-metal interaction followed by static fluorescence quenching phenomenon in emission of BMBANPs. Finally, we develop a simple analytical method for selective and sensitive determination of Co2+ ion in environmental samples. The cell culture E. coli, Bacillus sps., and M. tuberculosis H37RV strain in the vicinity of BMBANPs indicates virtuous anti-bacterial and anti-tuberculosis activity which is of additional novel application shown by prepared nanoparticles.

  11. Cerebral venous outflow and cerebrospinal fluid dynamics

    Directory of Open Access Journals (Sweden)

    Clive B. Beggs

    2014-12-01

    Full Text Available In this review, the impact of restricted cerebral venous outflow on the biomechanics of the intracranial fluid system is investigated. The cerebral venous drainage system is often viewed simply as a series of collecting vessels channeling blood back to the heart. However there is growing evidence that it plays an important role in regulating the intracranial fluid system. In particular, there appears to be a link between increased cerebrospinal fluid (CSF pulsatility in the Aqueduct of Sylvius and constricted venous outflow. Constricted venous outflow also appears to inhibit absorption of CSF into the superior sagittal sinus. The compliance of the cortical bridging veins appears to be critical to the behaviour of the intracranial fluid system, with abnormalities at this location implicated in normal pressure hydrocephalus. The compliance associated with these vessels appears to be functional in nature and dependent on the free egress of blood out of the cranium via the extracranial venous drainage pathways. Because constricted venous outflow appears to be linked with increased aqueductal CSF pulsatility, it suggests that inhibited venous blood outflow may be altering the compliance of the cortical bridging veins.

  12. Assessing the joint effect of population stratification and sample selection in studies of gene-gene (environment interactions

    Directory of Open Access Journals (Sweden)

    Cheng KF

    2012-01-01

    Full Text Available Abstract Background It is well known that the presence of population stratification (PS may cause the usual test in case-control studies to produce spurious gene-disease associations. However, the impact of the PS and sample selection (SS is less known. In this paper, we provide a systematic study of the joint effect of PS and SS under a more general risk model containing genetic and environmental factors. We provide simulation results to show the magnitude of the bias and its impact on type I error rate of the usual chi-square test under a wide range of PS level and selection bias. Results The biases to the estimation of main and interaction effect are quantified and then their bounds derived. The estimated bounds can be used to compute conservative p-values for the association test. If the conservative p-value is smaller than the significance level, we can safely claim that the association test is significant regardless of the presence of PS or not, or if there is any selection bias. We also identify conditions for the null bias. The bias depends on the allele frequencies, exposure rates, gene-environment odds ratios and disease risks across subpopulations and the sampling of the cases and controls. Conclusion Our results show that the bias cannot be ignored even the case and control data were matched in ethnicity. A real example is given to illustrate application of the conservative p-value. These results are useful to the genetic association studies of main and interaction effects.

  13. New Trends in Management of Epilepsy in Patients with Cerebral Venous Malformations: Our Experience

    Directory of Open Access Journals (Sweden)

    Ivan P. Artyukhov

    2016-09-01

    Full Text Available Background: Venous vascular malformations, also known as venous angiomas or, more exactly, developmental venous anomalies (DVAs, represent congenital, anatomically variant pathways in the normal venous drainage of the brain area. In general neurological practice, DVAs are not considered epileptogenic, therefore, in conducting neuroimaging as a rule, not taken into account. A positive correlation, however, between the location of the DVAs and the electroencephalographic seizure focus is debated. Materials and Methods: The present study provides a complete analysis of clinical and MRI characteristics of symptomatic epilepsies associated with cerebral venous malformations in children and adults. Patients were selected after a retrospective search through the database of the Neurological Center of Epileptology, Neurogenetics and Brain Research of the University Clinic into which, since 2016, patients were prospectively entered. To date (February 2016, there is a total of 5,856 patients with epilepsy of which there are 105 patients with congenital malformations of the brain, and 32 of them were found to have principal diagnosis of DVA. Results: Cavernous angiomas prevailed among venous anomalies (53.1%; DVAs were registered in 46.9% of cases. The associated analysis of DVA localization and the epileptic seizure types showed a direct relationship in 60.0% cases. Conclusion: DVAs as a cause of seizures are important to consider when examining patients with epileptic seizures.

  14. Central venous catheters: the role of radiology

    International Nuclear Information System (INIS)

    Tan, P.L.; Gibson, M.

    2006-01-01

    The insertion and management of long-term venous catheters have long been the province of anaesthetists, intensive care physicians and surgeons. Radiologists are taking an increasing role in the insertion of central venous catheters (CVCs) because of their familiarity with the imaging equipment and their ability to manipulate catheters and guide-wires. The radiological management of the complications of CVCs has also expanded as a result. This article reviews the role of radiology in central venous access, covering the detection and management of their complications

  15. Peripheral Venous Access Ports: Outcomes Analysis in 109 Patients

    International Nuclear Information System (INIS)

    Bodner, Leonard J.; Nosher, John L.; Patel, Kaushik M.; Siegel, Randall L.; Biswal, Rajiv; Gribbin, Christopher E.; Tokarz, Robert

    2000-01-01

    Purpose: To perform a retrospective outcomes analysis of central venous catheters with peripheral venous access ports, with comparison to published data.Methods: One hundred and twelve central venous catheters with peripherally placed access ports were placed under sonographic guidance in 109 patients over a 4-year period. Ports were placed for the administration of chemotherapy, hyperalimentation, long-term antibiotic therapy, gamma-globulin therapy, and frequent blood sampling. A vein in the upper arm was accessed in each case and the catheter was passed to the superior vena cava or right atrium. Povidone iodine skin preparation was used in the first 65 port insertions. A combination of Iodophor solution and povidone iodine solution was used in the last 47 port insertions. Forty patients received low-dose (1 mg) warfarin sodium beginning the day after port insertion. Three patients received higher doses of warfarin sodium for preexistent venous thrombosis. Catheter performance and complications were assessed and compared with published data.Results: Access into the basilic or brachial veins was obtained in all cases. Ports remained functional for a total of 28,936 patient days. The port functioned in 50% of patients until completion of therapy, or the patient's expiration. Ports were removed prior to completion of therapy in 18% of patients. Eleven patients (9.9% of ports placed) suffered an infectious complication (0.38 per thousand catheter-days)-in nine, at the port implantation site, in two along the catheter. In all 11 instances the port was removed. Port pocket infection in the early postoperative period occurred in three patients (4.7%) receiving a Betadine prep vs two patients (4.2%) receiving a standard O.R. prep. This difference was not statistically significant (p = 0.9). Venous thrombosis occurred in three patients (6.8%) receiving warfarin sodium and in two patients (3%) not receiving warfarin sodium. This difference was not statistically significant

  16. A Virtual Observatory Census to Address Dwarfs Origins (AVOCADO). I. Science goals, sample selection, and analysis tools

    Science.gov (United States)

    Sánchez-Janssen, R.; Amorín, R.; García-Vargas, M.; Gomes, J. M.; Huertas-Company, M.; Jiménez-Esteban, F.; Mollá, M.; Papaderos, P.; Pérez-Montero, E.; Rodrigo, C.; Sánchez Almeida, J.; Solano, E.

    2013-06-01

    Context. Even though they are by far the most abundant of all galaxy types, the detailed properties of dwarf galaxies are still only poorly characterised - especially because of the observational challenge that their intrinsic faintness and weak clustering properties represent. Aims: AVOCADO aims at establishing firm conclusions on the formation and evolution of dwarf galaxies by constructing and analysing a homogeneous, multiwavelength dataset for a statistically significant sample of approximately 6500 nearby dwarfs (Mi - 5 log h100 > - 18 mag). The sample is selected to lie within the 20 < D < 60 h100-1 Mpc volume covered by the SDSS-DR7 footprint, and is thus volume-limited for Mi - 5 log h100 < -16 mag dwarfs - but includes ≈1500 fainter systems. We will investigate the roles of mass and environment in determining the current properties of the different dwarf morphological types - including their structure, their star formation activity, their chemical enrichment history, and a breakdown of their stellar, dust, and gas content. Methods: We present the sample selection criteria and describe the suite of analysis tools, some of them developed in the framework of the Virtual Observatory. We use optical spectra and UV-to-NIR imaging of the dwarf sample to derive star formation rates, stellar masses, ages, and metallicities - which are supplemented with structural parameters that are used to classify them morphologically. This unique dataset, coupled with a detailed characterisation of each dwarf's environment, allows for a fully comprehensive investigation of their origins and enables us to track the (potential) evolutionary paths between the different dwarf types. Results: We characterise the local environment of all dwarfs in our sample, paying special attention to trends with current star formation activity. We find that virtually all quiescent dwarfs are located in the vicinity (projected distances ≲ 1.5 h100-1 Mpc) of ≳ L∗ companions, consistent with

  17. Venous thromboembolism and coffee: critical review and meta-analysis.

    Science.gov (United States)

    Lippi, Giuseppe; Mattiuzzi, Camilla; Franchini, Massimo

    2015-07-01

    Among the various risk factors of venous thromboembolism (VTE), nutrients seem to play a significant role in the pathogenesis of this condition. This study aimed to clarify the relationship between coffee intake and venous thrombosis, and we performed a critical review of clinical studies that have been published so far. An electronic search was carried out in Medline, Scopus and ISI Web of Science with the keywords "coffee" AND "venous thromboembolism" OR "deep vein thrombosis" OR "pulmonary embolism" in "Title/Abstract/Keywords", with no language and date restriction. According to our criteria, three studies (two prospective and one case-control) were finally selected (inter-study heterogeneity: 78%; P<0.001). Cumulative data suggests that a modest intake of coffee (i.e., 1-4 cups/day) may be associated with an 11% increased risk of VTE compared to abstainers, whereas a larger intake (i.e., ≥5 coffee/day) may be associated with a 25% decreased risk. Our analysis of published data seemingly confirm the existence of a U-shape relationship between coffee intake and VTE, thus exhibiting a trend that overlaps with that previously reported for cardiovascular disease (CVD).

  18. Quantitative analysis of semivolatile organic compounds in selected fractions of air sample extracts by GC/MI-IR spectrometry

    International Nuclear Information System (INIS)

    Childers, J.W.; Wilson, N.K.; Barbour, R.K.

    1990-01-01

    The authors are currently investigating the capabilities of gas chromatography/matrix isolation infrared (GC/MI-IR) spectrometry for the determination of semivolatile organic compounds (SVOCs) in environmental air sample extracts. Their efforts are focused on the determination of SVOCs such as alkylbenzene positional isomers, which are difficult to separate chromatographically and to distinguish by conventional electron-impact ionization GC/mass spectrometry. They have performed a series of systematic experiments to identify sources of error in quantitative GC/MI-IR analyses. These experiments were designed to distinguish between errors due to instrument design or performance and errors that arise from some characteristic inherent to the GC/MI-IR technique, such as matrix effects. They have investigated repeatability as a function of several aspects of GC/MI IR spectrometry, including sample injection, spectral acquisition, cryogenic disk movement, and matrix deposition. The precision, linearity, dynamic range, and detection limits of a commercial GC/MI-IR system for target SVOCs were determined and compared to those obtained with the system's flame ionization detector. The use of deuterated internal standards in the quantitative GC/MI-IR analysis of selected fractions of ambient air sample extracts will be demonstrated. They will also discuss the current limitations of the technique in quantitative analyses and suggest improvements for future consideration

  19. Factors influencing safety in a sample of marked pedestrian crossings selected for safety inspections in the city of Oslo.

    Science.gov (United States)

    Elvik, Rune; Sørensen, Michael W J; Nævestad, Tor-Olav

    2013-10-01

    This paper reports an analysis of factors influencing safety in a sample of marked pedestrian crossings in the city of Oslo, Norway. The sample consists of 159 marked pedestrian crossings where a total of 316 accidents were recorded during a period of five years. The crossings were selected for inspection because of they were, for various reasons, regarded as sub-standard. The sample of crossings is therefore not representative of all pedestrian crossings in Oslo. Factors influencing the number of accidents were studied by means of negative binomial regression. Factors that were studied included the volume of pedestrians and vehicles, the number of traffic lanes at the crossing, the location of the crossing (midblock or junction), the type of traffic control, the share of pedestrians using the crossing and the speed of approaching vehicles. The analysis confirmed the presence of a "safety-in-numbers" effect, meaning that an increase in the number of pedestrians is associated with a lower risk of accident for each pedestrian. Crossings located in four-leg junctions or roundabouts had more accidents than crossings located in three-leg junctions or on sections between junctions. A high share of pedestrians crossing the road outside the marked crossing was associated with a high number of accidents. Increased speed was associated with an increased number of accidents. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Optimal Subset Selection of Time-Series MODIS Images and Sample Data Transfer with Random Forests for Supervised Classification Modelling.

    Science.gov (United States)

    Zhou, Fuqun; Zhang, Aining

    2016-10-25

    Nowadays, various time-series Earth Observation data with multiple bands are freely available, such as Moderate Resolution Imaging Spectroradiometer (MODIS) datasets including 8-day composites from NASA, and 10-day composites from the Canada Centre for Remote Sensing (CCRS). It is challenging to efficiently use these time-series MODIS datasets for long-term environmental monitoring due to their vast volume and information redundancy. This challenge will be greater when Sentinel 2-3 data become available. Another challenge that researchers face is the lack of in-situ data for supervised modelling, especially for time-series data analysis. In this study, we attempt to tackle the two important issues with a case study of land cover mapping using CCRS 10-day MODIS composites with the help of Random Forests' features: variable importance, outlier identification. The variable importance feature is used to analyze and select optimal subsets of time-series MODIS imagery for efficient land cover mapping, and the outlier identification feature is utilized for transferring sample data available from one year to an adjacent year for supervised classification modelling. The results of the case study of agricultural land cover classification at a regional scale show that using only about a half of the variables we can achieve land cover classification accuracy close to that generated using the full dataset. The proposed simple but effective solution of sample transferring could make supervised modelling possible for applications lacking sample data.

  1. Bulgeless galaxies at intermediate redshift: Sample selection, color properties, and the existence of powerful active galactic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bizzocchi, Luca; Leonardo, Elvira; Grossi, Marco; Afonso, José; Fernandes, Cristina; Retrê, João [Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisbon (Portugal); Filho, Mercedes E.; Lobo, Catarina [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Griffith, Roger L. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Anton, Sonia [Centro de Investigação em Ciências Geo-Espaciais, Faculdade de Ciências da Universidade do Porto, Porto (Portugal); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Brinchmann, Jarle [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Henriques, Bruno [Max-Planck-Institut für Astrophysik, Karl Schwarzschild Straße 1, D-85748 Garching bei München (Germany); Messias, Hugo [Departamento de astronomía, Av. Esteban Iturra 6to piso, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción (Chile)

    2014-02-10

    We present a catalog of bulgeless galaxies, which includes 19,225 objects selected in four of the deepest, largest multi-wavelength data sets available—COSMOS, AEGIS, GEMS, and GOODS—at intermediate redshift (0.4 ≤ z ≤ 1.0). The morphological classification was provided by the Advanced Camera for Surveys General Catalog (ACS-GC), which used publicly available data obtained with the ACS instrument on the Hubble Space Telescope. Rest-frame photometric quantities were derived using kcorrect. We analyze the properties of the sample and the evolution of pure-disk systems with redshift. Very massive [log (M {sub *}/M {sub ☉}) > 10.5] bulgeless galaxies contribute to ∼30% of the total galaxy population number density at z ≥ 0.7, but their number density drops substantially with decreasing redshift. We show that only a negligible fraction of pure disks appear to be quiescent systems, and red sequence bulgeless galaxies show indications of dust-obscured star formation. X-ray catalogs were used to search for X-ray emission within our sample. After visual inspection and detailed parametric morphological fitting we identify 30 active galactic nuclei (AGNs) that reside in galaxies without a classical bulge. The finding of such peculiar objects at intermediate redshift shows that while AGN growth in merger-free systems is a rare event (0.2% AGN hosts in this sample of bulgeless galaxies), it can indeed happen relatively early in the history of the universe.

  2. Accretion Properties of a Sample of Hard X-Ray (<60 keV) Selected Seyfert 1 Galaxies

    Science.gov (United States)

    Wang, J.; Mao, Y. F.; Wei, J. Y.

    2009-02-01

    We examine the accretion properties in a sample of 42 hard (3-60 keV) X-ray selected nearby broad-line active galactic nuclei (AGNs). The energy range in the sample is harder than that usually used in similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey, and complemented by the released INTEGRAL AGN catalog. The black hole masses, bolometric luminosities of AGN, and Eddington ratios are derived from their optical spectra in terms of the broad Hβ emission line. The tight correlation between the hard X-ray (3-20 keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the Hβ emission line. In addition, all of these hard X-ray AGNs are biased toward luminous objects with a high Eddington ratio (mostly between 0.01 and 0.1) and a low column density (Simbol-X, and NeXT. Finally, the correlation between RFe (= optical Fe II/Hβ) and disk temperature as assessed by T vprop (L/L Edd)M -1 BH leads us to suggest that the strength of the Fe II emission is mainly determined by the shape of the ionizing spectrum.

  3. SDSS-IV MaNGA: faint quenched galaxies - I. Sample selection and evidence for environmental quenching

    Science.gov (United States)

    Penny, Samantha J.; Masters, Karen L.; Weijmans, Anne-Marie; Westfall, Kyle B.; Bershady, Matthew A.; Bundy, Kevin; Drory, Niv; Falcón-Barroso, Jesús; Law, David; Nichol, Robert C.; Thomas, Daniel; Bizyaev, Dmitry; Brownstein, Joel R.; Freischlad, Gordon; Gaulme, Patrick; Grabowski, Katie; Kinemuchi, Karen; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Roman-Lopes, Alexandre; Pan, Kaike; Simmons, Audrey; Wake, David A.

    2016-11-01

    Using kinematic maps from the Sloan Digital Sky Survey (SDSS) Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, we reveal that the majority of low-mass quenched galaxies exhibit coherent rotation in their stellar kinematics. Our sample includes all 39 quenched low-mass galaxies observed in the first year of MaNGA. The galaxies are selected with Mr > -19.1, stellar masses 109 M⊙ 1.9. They lie on the size-magnitude and σ-luminosity relations for previously studied dwarf galaxies. Just six (15 ± 5.7 per cent) are found to have rotation speeds ve, rot 5 × 1010 M⊙), supporting the hypothesis that galaxy-galaxy or galaxy-group interactions quench star formation in low-mass galaxies. The local bright galaxy density for our sample is ρproj = 8.2 ± 2.0 Mpc-2, compared to ρproj = 2.1 ± 0.4 Mpc-2 for a star-forming comparison sample, confirming that the quenched low-mass galaxies are preferentially found in higher density environments.

  4. Are there clinical signs and symptoms of infection to indicate the presence of multidrug-resistant bacteria in venous ulcers?

    Science.gov (United States)

    Dos Santos, Silvana de Lima Vieira; Martins, Marlene Andrade; do Prado, Marinésia Aparecida; Soriano, José Verdú; Bachion, Maria Márcia

    2017-12-01

    The selection of topical and systemic therapies for the treatment of venous ulcers with signs of infection is challenging and should be accompanied by specific precautionary measures to protect against cross-contamination in the presence of multidrug-resistant microorganisms. However, there are still no clinical indicators for this situation, and confirmation of resistant strains occurs through culture and sensitivity, which can take up to 14 days. During this period, protective measures may no longer be taken, contributing to the spread of these pathogens. This study aimed to analyze the relationship between clinical signs and symptoms of infection in venous ulcers and the presence of antimicrobial-resistant Staphylococcus aureus and/or Pseudomonas spp. A cross-sectional study was developed including 69 patients with 98 venous ulcers. Clinical observation protocol was applied to detect infection indicators established by the European Wound Management Association and microbiological analysis of samples of the lesions. Fisher's exact test and χ 2 were used for analyses (P 70%): discoloration of the opaque type and/or dark brick red and increased exudate volume; 31 (31.6%) ulcer samples showed positive culture for the bacteria studied. There was no relationship between signs and symptoms of infection and the presence of multidrug-resistant microorganisms. Taking into account the percentage of lesions with resistant strains, for safe care, contact precautionary measures should be implemented in the treatment rooms, in addition to standard precautions. Copyright © 2017 Society for Vascular Nursing, Inc. Published by Elsevier Inc. All rights reserved.

  5. Iliac Vein Interrogation Augments Venous Ulcer Healing in Patients Who Have Failed Standard Compression Therapy along with Pathological Venous Closure.

    Science.gov (United States)

    Mousa, Albeir Y; Broce, Mike; Yacoub, Michael; AbuRahma, Ali F

    2016-07-01

    .3 weeks, P = 0.055). The final VCCS score was not significantly different (IVI = 7.9 ± 9.5 vs. NIVI = 10.0 ± 6.5, P = 0.578). However, compared with the NIVI group, the healing time for patients who actually received IVAS was marginally lower (5.8 ± 3.6 weeks, P = 0.075) and final VCCS was significantly lower (2.4 ± 2.9, P = 0.031). Veins that received IVI and IVAS remained patent and the associated ulcers were healed (100%). The small sample size and retrospective design limit the strength of the conclusions but the findings suggest that further studies are needed to define the exact role of IVI including angioplasty/stenting for patients with chronic venous ulcers. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. A novel approach for assessing the progression of deep venous thrombosis by area of venous thrombus in ultrasonic elastography.

    Science.gov (United States)

    Wang, Chao; Wang, Lei; Zhang, Yuhui; Chen, Ming

    2014-04-01

    Exact age determination of deep venous thrombosis (DVT) is important for an appropriate treatment. The purpose of this present study is to assess the age of acute DVT with the area of venous thrombi in elasticity imaging during the thrombosis procession. The thrombus area is obtained from a specially designed program. It was applied to clot specimens induced in human great saphenous (n = 15) at selected time points following the initiation of thrombosis. The relative mean proportion of blood clots was 50.01% ± 12.44% at day 1; 69.94% ± 8.19% at day 3; 81.93% ± 6.15% at day 6; and 92.37% ± 4.06% at day 9. The results indicated that the thrombus area increased significantly over time, while the normalized strain values inside the thrombus changed only a little. The pathological analyses also showed the same results. Therefore, we conclude that the area of venous thrombi in elasticity imaging may be a novel function for acute DVT staging.

  7. Femoral venous catheters: a safe alternative for delivering parenteral alimentation.

    Science.gov (United States)

    Friedman, B; Kanter, G; Titus, D

    1994-04-01

    Femoral vein catheterization is an alternative method of obtaining central venous access. Placement of femoral venous catheters (FVCs) is possible in the majority of patients, suitable for most indications, and associated with a low complication rate during insertion. We wished to determine the incidence of infections or other complications resulting when parenteral nutrition was delivered through FVCs. Fifty-two patients were followed from a hospital-wide population including patients in the critical care units. Triple-lumen catheters were placed by using the sterile Seldinger technique, and sites were examined daily for inflammation. Bacteriologic surveillance was accomplished by submitting the catheter tip for semiquantitative cultures. If catheter line sepsis was suspected, blood samples for cultures were drawn through the catheter and peripherally. The rate of occurrence of colonized catheters was 9.6% (five of 52), and catheter sepsis was found in one case (1.9%). Other than inflammation at six (11.5%) of 52 catheter sites, noninfectious complications of FVCs were not found. On the basis of these findings, we consider FVC-delivered parenteral alimentation a safe and effective alternative to other forms of central venous access.

  8. Intracranial developmental venous anomaly: is it asymptomatic?

    Science.gov (United States)

    Puente, A Bolívar; de Asís Bravo Rodríguez, F; Bravo Rey, I; Romero, E Roldán

    2018-03-16

    Intracranial developmental venous anomalies are the most common vascular malformation. In the immense majority of cases, these anomalies are asymptomatic and discovered incidentally, and they are considered benign. Very exceptionally, however, they can cause neurological symptoms. In this article, we present three cases of patients with developmental venous anomalies that presented with different symptoms owing to complications derived from altered venous drainage. These anomalies were located in the left insula, right temporal lobe, and cerebellum. The exceptionality of the cases presented as well as of the images associated, which show the mechanism through which the symptoms developed, lies in the low incidence of symptomatic developmental venous anomalies reported in the literature. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. [Emphysematous gastritis with concomitant portal venous air].

    Science.gov (United States)

    Jeong, Min Yeong; Kim, Jin Il; Kim, Jae Young; Kim, Hyun Ho; Jo, Ik Hyun; Seo, Jae Hyun; Kim, Il Kyu; Cheung, Dae Young

    2015-02-01

    Emphysematous gastritis is a rare form of gastritis caused by infection of the stomach wall by gas forming bacteria. It is a very rare condition that carries a high mortality rate. Portal venous gas shadow represents elevation of intestinal luminal pressure which manifests as emphysematous gastritis or gastric emphysema. Literature reviews show that the mortality rate is especially high when portal venous gas shadow is present on CT scan. Until recently, the treatment of emphysematous gastritis has been immediate surgical intervention. However, there is a recent trend of avoiding surgery because of the frequent occurrence of post-operative complications such as anastomosis leakage. In addition, aggressive surgical treatment has failed to show significant improvement in prognosis. Recently, the authors experienced a case of emphysematous gastritis accompanied by portal venous gas which was treated successfully by conservative treatment without immediate surgical intervention. Herein, we present a case of emphysematous gastritis with concomitant portal venous air along with literature review.

  10. VENOUS THROMBOEMBOLISM PROPHYLAXIS – THE OTHER ...

    African Journals Online (AJOL)

    ABSTRACT. Background: There are no local guidelines for prophylaxis against Venous Thrombo-Embolism (VTE). .... of leg ulceration in the age matched general population. (9.6% to ... number of deaths and its cause amongst these patients.

  11. Imaging of head and neck venous malformations

    International Nuclear Information System (INIS)

    Flis, Christine M.; Connor, Stephen E.

    2005-01-01

    Venous malformations (VMs) are non proliferative lesions that consist of dysplastic venous channels. The aim of imaging is to characterise the lesion and define its anatomic extent. We will describe the plain film, ultrasound (US) (including colour and duplex Doppler), computed tomography (CT), magnetic resonance imaging (MRI), conventional angiographic and direct phlebographic appearances of venous malformations. They will be illustrated at a number of head and neck locations, including orbit, oral cavity, superficial and deep facial space, supraglottic and intramuscular. An understanding of the classification of such vascular anomalies is required to define the correct therapeutic procedure to employ. Image-guided sclerotherapy alone or in combination with surgery is now the first line treatment option in many cases of head and neck venous malformations, so the radiologist is now an integral part of the multidisciplinary management team. (orig.)

  12. [Venous thromboembolic disease: presentation of a case].

    Science.gov (United States)

    Mirpuri-Mirpuri, P G; Álvarez-Cordovés, M M; Pérez-Monje, A

    2013-01-01

    Venous thromboembolic disease in its clinical spectrum includes both deep vein thrombosis and pulmonary thromboembolism, which is usually a complication of deep vein thrombosis. It is a relatively common disease with significant morbidity and requires an accurate diagnosis. They are numerous risk factors for venous thromboembolism, and there is evidence that the risk of thromboembolic disease increases proportionally to the number of predisposing risk factors present. The primary care physician should know the risk factors and suspect the presence of venous thromboembolic disease when there is a compatible clnical picture. The treatment for this pathology is anticoagulation. We report a patient with cardiovascular risk factors who was seen with pain in the right leg and shortness of breath and referred to the hospital with suspected venous thromboembolism, atrial fibrillation and pleural effusion. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  13. Out-of-pocket costs, primary care frequent attendance and sample selection: Estimates from a longitudinal cohort design.

    Science.gov (United States)

    Pymont, Carly; McNamee, Paul; Butterworth, Peter

    2018-03-20

    This paper examines the effect of out-of-pocket costs on subsequent frequent attendance in primary care using data from the Personality and Total Health (PATH) Through Life Project, a representative community cohort study from Canberra, Australia. The analysis sample comprised 1197 respondents with two or more GP consultations, and uses survey data linked to administrative health service use (Medicare) data which provides data on the number of consultations and out-of-pocket costs. Respondents identified in the highest decile of GP use in a year were defined as Frequent Attenders (FAs). Logistic regression models that did not account for potential selection effects showed that out-of-pocket costs incurred during respondents' prior two consultations were significantly associated with subsequent FA status. Respondents who incurred higher costs ($15-$35; or >$35) were less likely to become FAs than those who incurred no or low (attenders. Copyright © 2018. Published by Elsevier B.V.

  14. LOCAL BENCHMARKS FOR THE EVOLUTION OF MAJOR-MERGER GALAXIES-SPITZER OBSERVATIONS OF A K-BAND SELECTED SAMPLE

    International Nuclear Information System (INIS)

    Xu, C. Kevin; Cheng Yiwen; Lu Nanyao; Mazzarella, Joseph M.; Cutri, Roc; Domingue, Donovan; Huang Jiasheng; Gao Yu; Sun, W.-H.; Surace, Jason

    2010-01-01

    We present Spitzer observations for a sample of close major-merger galaxy pairs (KPAIR sample) selected from cross-matches between the Two Micron All Sky Survey and Sloan Digital Sky Survey Data Release 3. The goals are to study the star formation activity in these galaxies and to set a local bench mark for the cosmic evolution of close major mergers. The Spitzer KPAIR sample (27 pairs, 54 galaxies) includes all spectroscopically confirmed spiral-spiral (S+S) and spiral-elliptical (S+E) pairs in a parent sample that is complete for primaries brighter than K = 12.5 mag, projected separations of 5 h -1 kpc ≤ s ≤ 20 h -1 kpc, and mass ratios ≤2.5. The Spitzer data, consisting of images in seven bands (3.6, 4.5, 5.8, 8, 24, 70, 160 μm), show very diversified IR emission properties. Compared to single spiral galaxies in a control sample, only spiral galaxies in S+S pairs show significantly enhanced specific star formation rate (sSFR = SFR/M), whereas spiral galaxies in S+E pairs do not. Furthermore, the SFR enhancement of spiral galaxies in S+S pairs is highly mass-dependent. Only those with M ∼> 10 10.5 M sun show significant enhancement. Relatively low-mass (M ∼ 10 10 M sun ) spirals in S+S pairs have about the same SFR/M compared to their counterparts in the control sample, while those with 10 11 M sun have on average a ∼3 times higher SFR/M than single spirals. There is evidence for a correlation between the global star formation activities (but not the nuclear activities) of the component galaxies in massive S+S major-merger pairs (the H olmberg effect ) . There is no significant difference in the SFR/M between the primaries and the secondaries, nor between spirals of SEP KPAIR =2.54 x 10 -4 (M sun yr -1 Mpc -3 ).

  15. Venous trauma in the Lebanon War--2006.

    Science.gov (United States)

    Nitecki, Samy S; Karram, Tony; Hoffman, Aaron; Bass, Arie

    2007-10-01

    Reports on venous trauma are relatively sparse. Severe venous trauma is manifested by hemorrhage, not ischemia. Bleeding may be internal or external and rarely may lead to hypovolemic shock. Repair of major extremity veins has been a subject of controversy and the current teaching is to avoid venous repair in an unstable or multi-trauma patient. The aim of the current paper is to present our recent experience in major venous trauma during the Lebanon conflict, means of diagnosis and treatment in a level I trauma center. All cases of major venous trauma, either isolated or combined with arterial injury, admitted to the emergency room during the 33-day conflict were reviewed. Out of 511 wounded soldiers and civilians who were admitted to our service over this period, 12 (2.3%) sustained a penetrating venous injury either isolated (5) or combined with arterial injury (7). All injuries were secondary to high velocity penetrating missiles or from multiple pellets stored in long-range missiles. All injuries were accompanied by additional insult to soft tissue, bone and viscera. The mean injury severity score was 15. Severe external bleeding was the presenting symptom in three cases of isolated venous injury (jugular, popliteal and femoral). The diagnosis of a major venous injury was made by a CTA scan in five cases, angiography in one and during surgical exploration in six cases. All injured veins were repaired: three by venous interposition grafts, four by end to end anastomosis, three by lateral suture and two by endovascular techniques. None of the injuries was treated by ligation of a major named vein. Immediate postoperative course was uneventful in all patients and the 30-day follow-up (by clinical assessment and duplex scan) has demonstrated a patent repair with no evidence of thrombosis. Without contradicting the wisdom of ligating major veins in the setup of multi-trauma or an unstable patient, our experience indicates that a routine repair of venous trauma can

  16. Selective extraction of emerging contaminants from water samples by dispersive liquid-liquid microextraction using functionalized ionic liquids.

    Science.gov (United States)

    Yao, Cong; Li, Tianhao; Twu, Pamela; Pitner, William R; Anderson, Jared L

    2011-03-25

    Functionalized ionic liquids containing the tris(pentafluoroethyl)trifluorophosphate (FAP) anion were used as extraction solvents in dispersive liquid-liquid microextraction (DLLME) for the extraction of 14 emerging contaminants from water samples. The extraction efficiencies and selectivities were compared to those of an in situ IL DLLME method which uses an in situ metathesis reaction to exchange 1-butyl-3-methylimidazolium chloride (BMIM-Cl) to 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (BMIM-NTf(2)). Compounds containing tertiary amine functionality were extracted with high selectivity and sensitivity by the 1-(6-amino-hexyl)-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate (HNH(2)MPL-FAP) IL compared to other FAP-based ILs and the BMIM-NTf(2) IL. On the other hand, polar or acidic compounds without amine groups exhibited higher enrichment factors using the BMIM-NTf(2) IL. The detection limits for the studied analytes varied from 0.1 to 55.1 μg/L using the traditional IL DLLME method with the HNH(2)MPL-FAP IL as extraction solvent, and from 0.1 to 55.8 μg/L using in situ IL DLLME method with BMIM-Cl+LiNTf(2) as extraction solvent. A 93-fold decrease in the detection limit of caffeine was observed when using the HNH(2)MPL-FAP IL compared to that obtained using in situ IL DLLME method. Real water samples including tap water and creek water were analyzed with both IL DLLME methods and yielded recoveries ranging from 91% to 110%. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Fingertip replantation without venous anastomosis.

    Science.gov (United States)

    Chen, Yi-Chieh; Chan, Fuan Chiang; Hsu, Chung-Chen; Lin, Yu-Te; Chen, Chien-Tzung; Lin, Chih-Hung

    2013-03-01

    Replantation of amputated fingertips is a technical challenge, as many salvage procedures fail because no suitable vein in the fingertip is available for anastomosis. In this study, we examined our experience in fingertip replantation in cases without venous anastomosis with our established fingertip replantation treatment protocol. Between August 2002 and August 2010, a retrospective study examined all patients who had undergone fingertip replantation at Chang-Gung Memorial Hospital. All the patients (n = 24) suffered from complete digital amputations at or distal to the interphalangeal joint of the thumb, or distal to distal interphalangeal joint of the fingers. A total of 30 fingertips that were salvaged by microsurgical anastomosis of the digital arteries but not of digital veins were included in this study. On satisfactory arterial anastomosis, a 2-mm incision was made over the fingertip with a number 11 Scalpel blade, and 0.1 to 0.2 mL heparin (5000 IU/mL) was injected subcutaneously around the incision immediately and once per day thereafter to ensure continuous blood drainage from the replanted fingertip. None of the replanted nail plate was removed, and no medical leeches were used. The perfusion of the replanted digits and patient's hemoglobin level were closely monitored. The wound bleeding was maintained until physiologic venous outflow was restored. Of 30 fingertips, 27 (90%) replanted fingertips survived. The average length needed for maintaining external bleeding by chemical leech was 6.8 days (range, 5-10 days). Twelve patients (including a 2-year-old child) received blood transfusions. The average amount of blood transfusion in the 23 adults was 4.0 units (range, 0-16 units) for each patient or 3.29 units (range, 0-14 units) for each digit. A 2-year-old child received 100 mL blood transfusion or 50 mL for each digit. This study showed that a protocol that promotes controlled bleeding from the fingertip is essential to achieve consistent high

  18. Evaluation of pump pulsation in respirable size-selective sampling: Part III. Investigation of European standard methods.

    Science.gov (United States)

    Soo, Jhy-Charm; Lee, Eun Gyung; Lee, Larry A; Kashon, Michael L; Harper, Martin

    2014-10-01

    Lee et al. (Evaluation of pump pulsation in respirable size-selective sampling: part I. Pulsation measurements. Ann Occup Hyg 2014a;58:60-73) introduced an approach to measure pump pulsation (PP) using a real-world sampling train, while the European Standards (EN) (EN 1232-1997 and EN 12919-1999) suggest measuring PP using a resistor in place of the sampler. The goal of this study is to characterize PP according to both EN methods and to determine the relationship of PP between the published method (Lee et al., 2014a) and the EN methods. Additional test parameters were investigated to determine whether the test conditions suggested by the EN methods were appropriate for measuring pulsations. Experiments were conducted using a factorial combination of personal sampling pumps (six medium- and two high-volumetric flow rate pumps), back pressures (six medium- and seven high-flow rate pumps), resistors (two types), tubing lengths between a pump and resistor (60 and 90 cm), and different flow rates (2 and 2.5 l min(-1) for the medium- and 4.4, 10, and 11.2 l min(-1) for the high-flow rate pumps). The selection of sampling pumps and the ranges of back pressure were based on measurements obtained in the previous study (Lee et al., 2014a). Among six medium-flow rate pumps, only the Gilian5000 and the Apex IS conformed to the 10% criterion specified in EN 1232-1997. Although the AirChek XR5000 exceeded the 10% limit, the average PP (10.9%) was close to the criterion. One high-flow rate pump, the Legacy (PP=8.1%), conformed to the 10% criterion in EN 12919-1999, while the Elite12 did not (PP=18.3%). Conducting supplemental tests with additional test parameters beyond those used in the two subject EN standards did not strengthen the characterization of PPs. For the selected test conditions, a linear regression model [PPEN=0.014+0.375×PPNIOSH (adjusted R2=0.871)] was developed to determine the PP relationship between the published method (Lee et al., 2014a) and the EN methods

  19. Pathophysiology of spontaneous venous gas embolism

    Science.gov (United States)

    Lambertsen, C. J.; Albertine, K. H.; Pisarello, J. B.; Flores, N. D.

    1991-01-01

    The use of controllable degrees and durations of continuous isobaric counterdiffusion venous gas embolism to investigate effects of venous gas embolism upon blood, cardiovascular, and respiratory gas exchange function, as well as pathological effects upon the lung and its microcirculation is discussed. Use of N2O/He counterdiffusion permitted performance of the pathophysiologic and pulmonary microstructural effects at one ATA without hyperbaric or hypobaric exposures.

  20. "Every Gene Is Everywhere but the Environment Selects": Global Geolocalization of Gene Sharing in Environmental Samples through Network Analysis.

    Science.gov (United States)

    Fondi, Marco; Karkman, Antti; Tamminen, Manu V; Bosi, Emanuele; Virta, Marko; Fani, Renato; Alm, Eric; McInerney, James O

    2016-05-13

    The spatial distribution of microbes on our planet is famously formulated in the Baas Becking hypothesis as "everything is everywhere but the environment selects." While this hypothesis does not strictly rule out patterns caused by geographical effects on ecology and historical founder effects, it does propose that the remarkable dispersal potential of microbes leads to distributions generally shaped by environmental factors rather than geographical distance. By constructing sequence similarity networks from uncultured environmental samples, we show that microbial gene pool distributions are not influenced nearly as much by geography as ecology, thus extending the Bass Becking hypothesis from whole organisms to microbial genes. We find that gene pools are shaped by their broad ecological niche (such as sea water, fresh water, host, and airborne). We find that freshwater habitats act as a gene exchange bridge between otherwise disconnected habitats. Finally, certain antibiotic resistance genes deviate from the general trend of habitat specificity by exhibiting a high degree of cross-habitat mobility. The strong cross-habitat mobility of antibiotic resistance genes is a cause for concern and provides a paradigmatic example of the rate by which genes colonize new habitats when new selective forces emerge. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. Risk factors for hospital-associated venous thromboembolism in critically ill children following cardiothoracic surgery or therapeutic cardiac catheterisation.

    Science.gov (United States)

    Atchison, Christie M; Amankwah, Ernest; Wilhelm, Jean; Arlikar, Shilpa; Branchford, Brian R; Stock, Arabela; Streiff, Michael; Takemoto, Clifford; Ayala, Irmel; Everett, Allen; Stapleton, Gary; Jacobs, Marshall L; Jacobs, Jeffrey P; Goldenberg, Neil A

    2018-02-01

    Paediatric hospital-associated venous thromboembolism is a leading quality and safety concern at children's hospitals. The aim of this study was to determine risk factors for hospital-associated venous thromboembolism in critically ill children following cardiothoracic surgery or therapeutic cardiac catheterisation. We conducted a retrospective, case-control study of children admitted to the cardiovascular intensive care unit at Johns Hopkins All Children's Hospital (St. Petersburg, Florida, United States of America) from 2006 to 2013. Hospital-associated venous thromboembolism cases were identified based on ICD-9 discharge codes and validated using radiological record review. We randomly selected two contemporaneous cardiovascular intensive care unit controls without hospital-associated venous thromboembolism for each hospital-associated venous thromboembolism case, and limited the study population to patients who had undergone cardiothoracic surgery or therapeutic cardiac catheterisation. Odds ratios and 95% confidence intervals for associations between putative risk factors and hospital-associated venous thromboembolism were determined using univariate and multivariate logistic regression. Among 2718 admissions to the cardiovascular intensive care unit during the study period, 65 met the criteria for hospital-associated venous thromboembolism (occurrence rate, 2%). Restriction to cases and controls having undergone the procedures of interest yielded a final study population of 57 hospital-associated venous thromboembolism cases and 76 controls. In a multiple logistic regression model, major infection (odds ratio=5.77, 95% confidence interval=1.06-31.4), age ⩽1 year (odds ratio=6.75, 95% confidence interval=1.13-160), and central venous catheterisation (odds ratio=7.36, 95% confidence interval=1.13-47.8) were found to be statistically significant independent risk factors for hospital-associated venous thromboembolism in these children. Patients with all three

  2. MR findings of cerebral venous sinus thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Myung Kwan; Chang, Kee Hyun; Han, Moon Hee; Choi, Choong Gom [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1994-10-15

    To describe MR findings of cerebral venous sinus thrombosis. We reviewed 11 MR images of six patients with cerebral venous sinus thrombosis. The MR images were retrospectively analyzed in terms of location and signal intensity of the thrombi, parenchymal lesions such as hemorrhage and edema, and changes in follow up study obtained in 4 patients. The thrombus in venous sinus was visualized on MRI in all six patients. The most frequently involved sites were superior sagittal sinus(n=4) and left transverse sinus(n=4). Signal intensity of the thrombus was isointense or hyperintense on both T1- and T2-weighted images with loss of normal signal void of the sinus on all sequences in all patients. Parenchymal lesion was patients in five of six cases, manifested as local hemorrhage in three and edema in three cases(one case overlapped). Local edema seen in three patients was completely resolved on follow up study of seven to 29 days intervals. It is concluded that iso- or high signal intensity with loss of signal void in venous sinus is virtually diagnostic of venous sinus thrombosis. If there are local parenchymal lesions such as hemorrhage and/or edema of unknown causes, cerebral venous sinus thrombosis should be included in differential diagnosis.

  3. Extraction and Analysis of Strontium in Water Sample Using a Sr2+ Selective Polymer as the Absorbent Phase

    Directory of Open Access Journals (Sweden)

    Rongjian Ying

    2015-01-01

    Full Text Available A kind of Sr2+ selective resin was applied as an absorption phase to extract Sr2+ ion from an aqueous solution, and the amount of Sr2+ was determined using inductively coupled plasma optical emission spectrometer. Factors, including absorption time, temperature, stirring rate, salt-out effect, desorption, and the pH of the aqueous solution, were investigated to optimize the absorption efficiency of Sr2+. Foreign ions were examined to observe their effects on the absorption behavior of Sr2+. The optimum condition was absorption time at 20 min, pH of aqueous solution 7, temperature of 35°C, and 600 rpm stirring rate. A 10 mL solution of 0.1 mol/L HCl is used as the desorption agent. The linear range of Sr2+ concentrations from 50 to 1200 μg/L was investigated with the slope of 183 μg/L. The limit of detection was 21 μg/L with 4.23% relative standard deviation. The correlation coefficient was found to be 0.9947. Under the optimized conditions, the concentrations of Sr2+ in four water samples were detected by the developed method. We propose that this method effectively extracts strontium ion from environmental water samples.

  4. Highly selective ionic liquid-based microextraction method for sensitive trace cobalt determination in environmental and biological samples

    International Nuclear Information System (INIS)

    Berton, Paula; Wuilloud, Rodolfo G.

    2010-01-01

    A simple and rapid dispersive liquid-liquid microextraction procedure based on an ionic liquid (IL-DLLME) was developed for selective determination of cobalt (Co) with electrothermal atomic absorption spectrometry (ETAAS) detection. Cobalt was initially complexed with 1-nitroso-2-naphtol (1N2N) reagent at pH 4.0. The IL-DLLME procedure was then performed by using a few microliters of the room temperature ionic liquid (RTIL) 1-hexyl-3-methylimidazolium hexafluorophosphate [C 6 mim][PF 6 ] as extractant while methanol was the dispersant solvent. After microextraction procedure, the Co-enriched RTIL phase was solubilized in methanol and directly injected into the graphite furnace. The effect of several variables on Co-1N2N complex formation, extraction with the dispersed RTIL phase, and analyte detection with ETAAS, was carefully studied in this work. An enrichment factor of 120 was obtained with only 6 mL of sample solution and under optimal experimental conditions. The resultant limit of detection (LOD) was 3.8 ng L -1 , while the relative standard deviation (RSD) was 3.4% (at 1 μg L -1 Co level and n = 10), calculated from the peak height of absorbance signals. The accuracy of the proposed methodology was tested by analysis of a certified reference material. The method was successfully applied for the determination of Co in environmental and biological samples.

  5. Venous catheterization with ultrasound navigation

    International Nuclear Information System (INIS)

    Kasatkin, A. A.; Nigmatullina, A. R.; Urakov, A. L.

    2015-01-01

    By ultrasound scanning it was determined that respiratory movements made by chest of healthy and sick person are accompanied by respiratory chest rise of internal jugular veins. During the exhalation of an individual diameter of his veins increases and during the breath it decreases down to the complete disappearing if their lumen. Change of the diameter of internal jugular veins in different phases can influence significantly the results of vein puncture and cauterization in patients. The purpose of this research is development of the method increasing the efficiency and safety of cannulation of internal jugular veins by the ultrasound visualization. We suggested the method of catheterization of internal jugular veins by the ultrasound navigation during the execution of which the puncture of venous wall by puncture needle and the following conduction of J-guide is carried out at the moment of patient’s exhalation. This method decreases the risk of complications development during catheterization of internal jugular vein due to exclusion of perforating wound of vein and subjacent tissues and anatomical structures

  6. Venous catheterization with ultrasound navigation

    Energy Technology Data Exchange (ETDEWEB)

    Kasatkin, A. A., E-mail: ant-kasatkin@yandex.ru; Nigmatullina, A. R. [Izhevsk State Medical Academy, Kommunarov street, 281, Izhevsk, Russia, 426034 (Russian Federation); Urakov, A. L., E-mail: ant-kasatkin@yandex.ru [Institute of Mechanics Ural Branch of Russian Academy of Sciences, T.Baramzinoy street 34, Izhevsk, Russia, 426067, Izhevsk (Russian Federation); Izhevsk State Medical Academy, Kommunarov street, 281, Izhevsk, Russia, 426034 (Russian Federation)

    2015-11-17

    By ultrasound scanning it was determined that respiratory movements made by chest of healthy and sick person are accompanied by respiratory chest rise of internal jugular veins. During the exhalation of an individual diameter of his veins increases and during the breath it decreases down to the complete disappearing if their lumen. Change of the diameter of internal jugular veins in different phases can influence significantly the results of vein puncture and cauterization in patients. The purpose of this research is development of the method increasing the efficiency and safety of cannulation of internal jugular veins by the ultrasound visualization. We suggested the method of catheterization of internal jugular veins by the ultrasound navigation during the execution of which the puncture of venous wall by puncture needle and the following conduction of J-guide is carried out at the moment of patient’s exhalation. This method decreases the risk of complications development during catheterization of internal jugular vein due to exclusion of perforating wound of vein and subjacent tissues and anatomical structures.

  7. Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation

    NARCIS (Netherlands)

    van Beest, Paul A.; van der Schors, Alice; Liefers, Henriette; Coenen, Ludo G. J.; Braam, Richard L.; Habib, Najib; Braber, Annemarije; Scheeren, Thomas W. L.; Kuiper, Michael A.; Spronk, Peter E.

    2012-01-01

    Objective:  The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients. Design:  Prospective observational controlled study. Setting:  Nonacademic university-affiliated

  8. Prevalence of lower extremity venous duplication

    Directory of Open Access Journals (Sweden)

    Simpson William

    2010-01-01

    Full Text Available Purpose: This retrospective study was performed to determine the prevalence of lower extremity venous duplication using duplex ultrasound in the patient population of a large urban medical center. Materials and Methods: The reports of all lower extremity venous ultrasound examinations performed at our institution between January 1, 2002 and December 31, 2002 were reviewed. Ultrasound examinations that were performed for purposes other than the detection of lower extremity deep vein thrombosis were excluded. The prevalence of duplication and its specific location were recorded. In addition, the prevalence of thrombus and its specific location were also recorded. Results: A total of 3118 exams were performed in 2664 patients. Of the 2664 patients, 2311 had only one examination performed during the study period; 353 patients had more than one examination performed. We found that 10.1% of patients (270/2664 had at least one venous segment duplicated and 5.4% of patients (143/2664 had a thrombus in at least one venous segment. There was a statistically significant difference in the prevalence of both duplication and thrombus with a change in venous segment. Only 0.4% of patients (11/2664 had thrombus within a duplicated segment. Of those who had more than one examination performed, 15.3% (54/353 had the same venous segment(s seen on one examination but not another. Conclusion: Lower extremity venous duplication is a frequent anatomic variant that is seen in 10.1% of patients, but it may not be as common as is generally believed. It can result in a false negative result for deep vein thrombosis.

  9. Alumina physically loaded by thiosemicarbazide for selective preconcentration of mercury(II) ion from natural water samples

    International Nuclear Information System (INIS)

    Ahmed, Salwa A.

    2008-01-01

    The multifunctional ligand, thiosemicarbazide, was physically loaded on neutral alumina. The produced alumina-modified solid phase (SP) extractor named, alumina-modified thiosemicarbazide (AM-TSC), experienced high thermal and medium stability. This new phase was identified based on surface coverage determination by thermal desorption method to be 0.437 ± 0.1 mmol g -1 . The selectivity of AM-TSC phase towards the uptake of different nine metal ions was checked using simple, fast and direct batch equilibration technique. AM-TSC was found to have the highest capacity in selective extraction of Hg(II) from aqueous solutions all over the range of pH used (1.0-7.0), compared to the other eight tested metal ions. So, Hg(II) uptake was 1.82 mmol g -1 (distribution coefficient log K d = 5.658) at pH 1.0 or 2.0 and 1.78, 1.73, 1.48, 1.28 and 1.28 mmol g -1 (log K d = 4.607, 4.265, 3.634, 3.372 and 3.372), at pH 3.0, 4.0, 5.0, 6.0 and 7.0, respectively. On the other hand, the metal ions Ca(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) showed low uptake values in range 0.009-0.720 mmol g -1 (log K d < 3.0) at their optimum pH values. A mechanism was suggested to explain the unique uptake of Hg(II) ions based on their binding as neutral and chloroanionic species predominate at pH values ≤3.0 of a medium rich in chloride ions. Application of the new phase for the preconcentration of ultratrace amounts of Hg(II) ions spiked natural water samples: doubly distilled water (DDW), drinking tap water (DTW) and Nile river water (NRW) using cold vapor atomic absorption spectroscopy (CV-AAS) was studied. The high recovery values obtained using AM-TSC (98.5 ± 0.5, 98.0 ± 0.5 and 103.0 ± 1.0) for DDW, DTW and NRW samples, respectively based on excellent enrichment factor 1000, along with a good precision (R.S.D.% 0.51-0.97%, n 3) demonstrate the accuracy and validity of the new modified alumina sorbent for preconcentrating ultratrace amounts of Hg(II) with no

  10. Racial differences in venous thromboembolism.

    Science.gov (United States)

    Zakai, N A; McClure, L A

    2011-10-01

    The incidence of venous thrombosis (VTE) varies by race, with African-Americans having over 5-fold greater incidence than Asian-ancestry populations, and an intermediate risk for European and Hispanic populations. Known racial differences in genetic polymorphisms associated with thrombosis do not account for this gradient of risk, nor do known racial variations in environmental risk factors. Data on the incidence of and risk factors for VTE outside of Europe and North America and in non-European ancestry populations are sparse. Common genetic polymorphisms in European-Ancestry populations, such as factor V Leiden and prothrombin G20210A, and environmental risk factors, such as obesity, may account for some of the increased risk in European populations, and high factor VIII, high von Willebrand factor and low protein C levels and increased prevalence of obesity may explain some of the increased risk in African-Americans. The low rates in Asian populations may be partially explained by low clinical suspicion in a perceived low-risk population and lack of access to healthcare in other populations. As risk factors for thrombosis, such as surgery and treatment for cancer, are applicable to more people, as obesity increases in prevalence in the developing world, and as surveillance systems for VTE improve, VTE may increase in previously low-risk populations. While differences in VTE by race due to genetic predisposition will probably always be present, understanding the reasons for racial differences in VTE will help providers develop strategies to minimize VTE in all populations. © 2011 International Society on Thrombosis and Haemostasis.

  11. Validation of the ANSR(®) Listeria monocytogenes Method for Detection of Listeria monocytogenes in Selected Food and Environmental Samples.

    Science.gov (United States)

    Caballero, Oscar; Alles, Susan; Le, Quynh-Nhi; Gray, R Lucas; Hosking, Edan; Pinkava, Lisa; Norton, Paul; Tolan, Jerry; Mozola, Mark; Rice, Jennifer; Chen, Yi; Ryser, Elliot; Odumeru, Joseph

    2016-01-01

    Work was conducted to validate performance of the ANSR(®) for Listeria monocytogenes method in selected food and environmental matrixes. This DNA-based assay involves amplification of nucleic acid via an isothermal reaction based on nicking enzyme amplification technology. Following single-step sample enrichment for 16-24 h for most matrixes, the assay is completed in 40 min using only simple instrumentation. When 50 distinct strains of L. monocytogenes were tested for inclusivity, 48 produced positive results, the exceptions being two strains confirmed by PCR to lack the assay target gene. Forty-seven nontarget strains (30 species), including multiple non-monocytogenes Listeria species as well as non-Listeria, Gram-positive bacteria, were tested, and all generated negative ANSR assay results. Performance of the ANSR method was compared with that of the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedure for detection of L. monocytogenes in hot dogs, pasteurized liquid egg, and sponge samples taken from an inoculated stainless steel surface. In addition, ANSR performance was measured against the U.S. Food and Drug Administration Bacteriological Analytical Manual reference method for detection of L. monocytogenes in Mexican-style cheese, cantaloupe, sprout irrigation water, and guacamole. With the single exception of pasteurized liquid egg at 16 h, ANSR method performance as quantified by the number of positives obtained was not statistically different from that of the reference methods. Robustness trials demonstrated that deliberate introduction of small deviations to the normal assay parameters did not affect ANSR method performance. Results of accelerated stability testing conducted using two manufactured lots of reagents predicts stability at the specified storage temperature of 4°C of more than 1 year.

  12. Preliminary evaluation of selected minerals in liver samples from springbok (Antidorcas marsupialis from the National Zoological Gardens of South Africa

    Directory of Open Access Journals (Sweden)

    Khanyisile R. Mbatha

    2012-04-01

    Full Text Available Limited information is available on the mineral nutrition of captive antelope in South Africa. Zoo animals are usually offered a very limited array of feeds, which may result in nutritional imbalances. As a pilot study to investigate the presence of myopathy in antelope at the National Zoological Gardens of South Africa (NZG, stored liver samples from six springbok (Antidorcas marsupialis and seven other antelopes from the NZG, as well as selected food items, were submitted for analysis of selenium, copper, manganese and zinc content by spectrophotometry. Springbok liver levels of copper were 23.07 mg/kg ± 0.72 mg/kg, whilst manganese, selenium and zinc levels were 6.73 mg/kg ± 0.22 mg/kg, 0.14 mg/kg ± 0.05 mg/kg and 135.02 mg/kg ± 1.26 mg/kg, respectively. Liver mineral levels in the other species were very variable. Food item copper levels ranged from 4.00 mg/kg (Eragrostis tef to 17.38 mg/kg (antelope cubes, lucerne (Medicago sativa and E. tef contained no detectable selenium. The highest zinc levels were in antelope cubes (147.00 mg/kg and the lowest were in lucerne (20.80 mg/kg. Interpretation of these results was hampered by the small number of samples and a paucity of information on liver mineral levels in free-ranging and captive antelope; however, results suggested that, in the springbok, whilst copper and manganese intake are likely adequate, selenium nutrition is probably insufficient and may account for the myopathy diagnosed. Zinc liver levels are possibly within the toxic range, perhaps as a result of the high levels of zinc in the antelope cubes. This pilot study highlighted the need to establish baseline mineral nutrition data for captive and freeranging antelope under South African conditions.

  13. Parathyroid aspiration directed by angiography: an alternative to venous sampling

    International Nuclear Information System (INIS)

    Krudy, A.G.; Doppman, J.L.; Marx, S.J.; Norton, J.A.; Spiegel, A.M.; Santora, A.C. II; Aurbach, G.D.

    1984-01-01

    Not all parathyroid glands can be visualized by CT or ultrasound and, therefore, cannot be aspirated using these techniques. The authors report the localization of a parathyroid gland by arteriography and needle aspiration under fluoroscopic guidance. This technique can be used to confirm a diagnosis of hypervascular parathyroid tissue that cannot otherwise be confirmed

  14. Lateral Nail Fold Incision Technique for Venous Anastomosis in Fingertip Replantation.

    Science.gov (United States)

    Jeon, Byung-Joon; Yang, Jae-Won; Roh, Si Young; Ki, Sae Hwi; Lee, Dong Chul; Kim, Jin Soo

    2016-01-01

    Successful venous anastomosis is one of the most important factors in fingertip replantation. Volar veins in the fingertip course proximally in a random pattern, which makes it difficult to find out the exact locations. Although dorsal veins in the lateral nail fold have constant location and adequate diameter for anastomosis, they have been known as hard to dissect from the immobile subcutaneous tissue. The authors present a new lateral nail fold incision technique for venous anastomosis in the fingertip amputations. From February 2010 to October 2010, 9 replantations using the new incision and venous anastomosis technique were performed in 9 patients. The levels of amputations were from the nail base to half of the nail bed. After repairing the proper digital arteries, a skin incision was made along the junction between the lateral nail fold and nail bed. Careful dissection was performed to isolate the veins in the lateral nail fold. After evaluation of the suitability of the vessel, venous anastomosis was performed. Seven male and 2 female patients were enrolled in this study. Appropriate dorsal veins for anastomosis could be found in 8 of 9 patients. All the replanted stumps survived without venous congestion and following additional procedures. A sizable volar or dorsal vein could not be found in 1 patient. The salvage technique was required in this patient. Dorsal veins in the lateral nail fold can be found easily because of the constant anatomical location. The new incision on the lateral nail fold provides not only sufficient operative field for anastomosis but also additional opportunity of successful venous anastomosis in the selected cases. The authors, therefore, propose this technique as an effective method for an alternative venous anastomosis in the zone I replantation.

  15. Ammonia concentrations in arterial blood, venous blood, and cerebrospinal fluid of dogs with and without congenital extrahepatic portosystemic shunts.

    Science.gov (United States)

    Or, Matan; Devriendt, Nausikaa; Kitshoff, Adriaan M; Peremans, Kathelijne; Vandermeulen, Eva; Paepe, Dominique; Polis, Ingeborgh; Martlé, Valentine; de Rooster, Hilde

    2017-11-01

    OBJECTIVE To compare ammonia concentrations in arterial blood, venous blood, and CSF samples of dogs with and without extrahepatic portosystemic shunts (EHPSS). ANIMALS 19 dogs with congenital EHPSS and 6 healthy control dogs. PROCEDURES All dogs underwent a physical examination and then were anesthetized for transsplenic portal scintigraphy to confirm the presence or absence of EHPSS. While dogs were anesthetized, arterial and venous blood samples and a CSF sample were simultaneously collected for determination of ammonia concentration, which was measured by use of a portable blood ammonia analyzer (device A) and a nonportable biochemical analyzer (device B). Results were compared between dogs with EHPSS and control dogs. RESULTS Arterial, venous, and CSF ammonia concentrations for dogs with EHPSS were significantly greater than those for control dogs. For dogs with EHPSS, ammonia concentrations in both arterial and venous blood samples were markedly increased from the reference range. There was a strong positive correlation between arterial and venous ammonia concentrations and between blood (arterial or venous) and CSF ammonia concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that blood and CSF ammonia concentrations in dogs with EHPSS were greater than those for healthy dogs and were strongly and positively correlated, albeit in a nonlinear manner. This suggested that the permeability of the blood-brain barrier to ammonia may be abnormally increased in dogs with EHPSS, but further investigation of the relationship between blood or CSF ammonia concentration and clinical signs of hepatic encephalopathy or the surgical outcome for dogs with EHPSS is warranted.

  16. Venous injury in abusive head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Choudhary, Arabinda K. [Nemours A. I. duPont Hospital for Children, Department of Radiology, Wilmington, DE (United States); Bradford, Ray; Thamburaj, K.; Boal, Danielle K.B. [Hershey Medical Center, Department of Radiology, Hershey, PA (United States); Dias, Mark S. [Hershey Medical Center, Department of Neurosurgery, Hershey, PA (United States)

    2015-11-15

    Abusive head trauma (AHT) is an important cause of serious brain injury in infants and young children who have characteristic clinical and imaging findings that are discordant with the clinical history provided. Recent attention has focused on abnormalities of the cranial venous sinuses and cortical veins, both on MRI and at autopsy. Although many have interpreted these to be secondary to the AHT, some have recently argued that these venous abnormalities represent primary cortical sinus and venous thrombosis that leads secondarily to subdural hemorrhage and secondary brain injury. Direct trauma to the veins and sinuses has been reported at autopsy in AHT, but there has been no systematic study of venous abnormalities in cases of AHT. The purpose of this study was to define the incidence and characteristics of venous and sinus abnormalities in AHT. We included all children <36 months of age who were diagnosed with abusive head trauma between 2001 and 2012 and who had MRI and magnetic resonance (MR) venography as part of their diagnostic workup. We analyzed age, gender and clinical findings. MRI and MR venography were analyzed independently by two neuroradiologists with a focus on abnormalities involving the intracranial veins and venous sinuses. A total of 45 children were included. The median age was 3 months (range 15 days to 31 months) and 28 were boys (62%). Clinical findings included retinal hemorrhage in 71% and extracranial fractures in 55%. CT or MRI demonstrated subdural hemorrhage in 41 (91%); none had subdural effusions. In 31 cases (69%) MR venography demonstrated mass effect on the venous sinuses or cortical draining veins, with either displacement or partial or complete effacement of the venous structures from an adjacent subdural hematoma or brain swelling. We also describe the lollipop sign, which represents direct trauma to the cortical bridging veins and was present in 20/45 (44%) children. Evidence of displacement or compression of cortical veins

  17. Venous injury in abusive head trauma

    International Nuclear Information System (INIS)

    Choudhary, Arabinda K.; Bradford, Ray; Thamburaj, K.; Boal, Danielle K.B.; Dias, Mark S.

    2015-01-01

    Abusive head trauma (AHT) is an important cause of serious brain injury in infants and young children who have characteristic clinical and imaging findings that are discordant with the clinical history provided. Recent attention has focused on abnormalities of the cranial venous sinuses and cortical veins, both on MRI and at autopsy. Although many have interpreted these to be secondary to the AHT, some have recently argued that these venous abnormalities represent primary cortical sinus and venous thrombosis that leads secondarily to subdural hemorrhage and secondary brain injury. Direct trauma to the veins and sinuses has been reported at autopsy in AHT, but there has been no systematic study of venous abnormalities in cases of AHT. The purpose of this study was to define the incidence and characteristics of venous and sinus abnormalities in AHT. We included all children <36 months of age who were diagnosed with abusive head trauma between 2001 and 2012 and who had MRI and magnetic resonance (MR) venography as part of their diagnostic workup. We analyzed age, gender and clinical findings. MRI and MR venography were analyzed independently by two neuroradiologists with a focus on abnormalities involving the intracranial veins and venous sinuses. A total of 45 children were included. The median age was 3 months (range 15 days to 31 months) and 28 were boys (62%). Clinical findings included retinal hemorrhage in 71% and extracranial fractures in 55%. CT or MRI demonstrated subdural hemorrhage in 41 (91%); none had subdural effusions. In 31 cases (69%) MR venography demonstrated mass effect on the venous sinuses or cortical draining veins, with either displacement or partial or complete effacement of the venous structures from an adjacent subdural hematoma or brain swelling. We also describe the lollipop sign, which represents direct trauma to the cortical bridging veins and was present in 20/45 (44%) children. Evidence of displacement or compression of cortical veins

  18. The Relationship between Multiple Substance Use, Perceived Academic Achievements, and Selected Socio-Demographic Factors in a Polish Adolescent Sample

    Science.gov (United States)

    Mazur, Joanna; Tabak, Izabela; Dzielska, Anna; Wąż, Krzysztof; Oblacińska, Anna

    2016-01-01

    Predictors of high-risk patterns of substance use are often analysed in relation to demographic and school-related factors. The interaction between these factors and the additional impact of family wealth are still new areas of research. The aim of this study was to find determinants of the most common patterns of psychoactive substance use in mid-adolescence, compared to non-users. A sample of 1202 Polish students (46.1% boys, mean age of 15.6 years) was surveyed in 2013/2014. Four patterns of psychoactive substance use were defined using cluster analysis: non-users—71.9%, mainly tobacco and alcohol users—13.7%, high alcohol and cannabis users—7.2%, poly-users—7.2%. The final model contained the main effects of gender and age, and one three-way (perceived academic achievement × gender × family affluence) interaction. Girls with poor perception of school performance (as compared to girls with better achievements) were at significantly higher risk of being poly-users, in both less and more affluent families (adjusted odds ratio (OR) = 5.55 and OR = 3.60, respectively). The impact of family affluence was revealed only in interaction with other factors. Patterns of substance use in mid-adolescence are strongly related to perceived academic achievements, and these interact with selected socio-demographic factors. PMID:28009806

  19. Effects of perceptual load and socially meaningful stimuli on crossmodal selective attention in Autism Spectrum Disorder and neurotypical samples.

    Science.gov (United States)

    Tyndall, Ian; Ragless, Liam; O'Hora, Denis

    2018-04-01

    The present study examined whether increasing visual perceptual load differentially affected both Socially Meaningful and Non-socially Meaningful auditory stimulus awareness in neurotypical (NT, n = 59) adults and Autism Spectrum Disorder (ASD, n = 57) adults. On a target trial, an unexpected critical auditory stimulus (CAS), either a Non-socially Meaningful ('beep' sound) or Socially Meaningful ('hi') stimulus, was played concurrently with the presentation of the visual task. Under conditions of low visual perceptual load both NT and ASD samples reliably noticed the CAS at similar rates (77-81%), whether the CAS was Socially Meaningful or Non-socially Meaningful. However, during high visual perceptual load NT and ASD participants reliably noticed the meaningful CAS (NT = 71%, ASD = 67%), but NT participants were unlikely to notice the Non-meaningful CAS (20%), whereas ASD participants reliably noticed it (80%), suggesting an inability to engage selective attention to ignore non-salient irrelevant distractor stimuli in ASD. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. The Relationship between Multiple Substance Use, Perceived Academic Achievements, and Selected Socio-Demographic Factors in a Polish Adolescent Sample

    Directory of Open Access Journals (Sweden)

    Joanna Mazur

    2016-12-01

    Full Text Available Predictors of high-risk patterns of substance use are often analysed in relation to demographic and school-related factors. The interaction between these factors and the additional impact of family wealth are still new areas of research. The aim of this study was to find determinants of the most common patterns of psychoactive substance use in mid-adolescence, compared to non-users. A sample of 1202 Polish students (46.1% boys, mean age of 15.6 years was surveyed in 2013/2014. Four patterns of psychoactive substance use were defined using cluster analysis: non-users—71.9%, mainly tobacco and alcohol users—13.7%, high alcohol and cannabis users—7.2%, poly-users—7.2%. The final model contained the main effects of gender and age, and one three-way (perceived academic achievement × gender × family affluence interaction. Girls with poor perception of school performance (as compared to girls with better achievements were at significantly higher risk of being poly-users, in both less and more affluent families (adjusted odds ratio (OR = 5.55 and OR = 3.60, respectively. The impact of family affluence was revealed only in interaction with other factors. Patterns of substance use in mid-adolescence are strongly related to perceived academic achievements, and these interact with selected socio-demographic factors.

  1. Selective Solid-Phase Extraction of Zinc(II) from Environmental Water Samples Using Ion Imprinted Activated Carbon.

    Science.gov (United States)

    Moniri, Elham; Panahi, Homayon Ahmad; Aghdam, Khaledeh; Sharif, Amir Abdollah Mehrdad

    2015-01-01

    A simple ion imprinted amino-functionalized sorbent was synthesized by coupling activated carbon with iminodiacetic acid, a functional compound for metal chelating, through cyanoric chloride spacer. The resulting sorbent has been characterized using FTIR spectroscopy, elemental analysis, and thermogravimetric analysis and evaluated for the preconcentration and determination of trace Zn(II) in environmental water samples. The optimum pH value for sorption of the metal ion was 6-7.5. The sorption capacity of the functionalized sorbent was 66.6 mg/g. The chelating sorbent can be reused for 10 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 100% was obtained for the metal ion with 0.5 M nitric acid as the eluent. Compared with nonimprinted polymer particles, the prepared Zn-imprinted sorbent showed high adsorption capacity, significant selectivity, and good site accessibility for Zn(II). Scatchard analysis revealed that the homogeneous binding sites were formed in the polymer. The equilibrium sorption data of Zn(II) by modified resin were analyzed by Langmuir, Freundlich, Temkin, and Redlich-Peterson models. Based on equilibrium adsorption data, the Langmuir, Freundlich, and Temkin constants were determined as 0.139, 12.82, and 2.34, respectively, at 25°C.

  2. Total arsenic in selected food samples from Argentina: Estimation of their contribution to inorganic arsenic dietary intake.

    Science.gov (United States)

    Sigrist, Mirna; Hilbe, Nandi; Brusa, Lucila; Campagnoli, Darío; Beldoménico, Horacio

    2016-11-01

    An optimized flow injection hydride generation atomic absorption spectroscopy (FI-HGAAS) method was used to determine total arsenic in selected food samples (beef, chicken, fish, milk, cheese, egg, rice, rice-based products, wheat flour, corn flour, oats, breakfast cereals, legumes and potatoes) and to estimate their contributions to inorganic arsenic dietary intake. The limit of detection (LOD) and limit of quantification (LOQ) values obtained were 6μgkg(-)(1) and 18μgkg(-)(1), respectively. The mean recovery range obtained for all food at a fortification level of 200μgkg(-)(1) was 85-110%. Accuracy was evaluated using dogfish liver certified reference material (DOLT-3 NRC) for trace metals. The highest total arsenic concentrations (in μgkg(-)(1)) were found in fish (152-439), rice (87-316) and rice-based products (52-201). The contribution to inorganic arsenic (i-As) intake was calculated from the mean i-As content of each food (calculated by applying conversion factors to total arsenic data) and the mean consumption per day. The primary contributors to inorganic arsenic intake were wheat flour, including its proportion in wheat flour-based products (breads, pasta and cookies), followed by rice; both foods account for close to 53% and 17% of the intake, respectively. The i-As dietary intake, estimated as 10.7μgday(-)(1), was significantly lower than that from drinking water in vast regions of Argentina. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Preparation and characterisation of core-shell CNTs@MIPs nanocomposites and selective removal of estrone from water samples.

    Science.gov (United States)

    Gao, Ruixia; Su, Xiaoqian; He, Xiwen; Chen, Langxing; Zhang, Yukui

    2011-01-15

    This paper reports the preparation of carbon nanotubes (CNTs) functionalized with molecularly imprinted polymers (MIPs) for advanced removal of estrone. CNTs@Est-MIPs nanocomposites with a well-defined core-shell structure were obtained using a semi-covalent imprinting strategy, which employed a thermally reversible covalent bond at the surface of silica-coated CNTs for a large-scale production. The morphology and structure of the products were characterised by transmission electron microscopy and Fourier transform infrared spectroscopy. The adsorption properties were demonstrated by equilibrium rebinding experiments and Scatchard analysis. The results demonstrate that the imprinted nanocomposites possess favourable selectivity, high capacity and fast kinetics for template molecule uptake, yielding an adsorption capacity of 113.5 μmol/g. The synthetic process is quite simple, and the different batches of synthesized CNTs@Est-MIPs nanocomposites showed good reproducibility in template binding. The feasibility of removing estrogenic compounds from environmental water using the CNTs@Est-MIPs nanocomposites was demonstrated using water samples spiked with estrone. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Testing the efficiency of rover science protocols for robotic sample selection: A GeoHeuristic Operational Strategies Test

    Science.gov (United States)

    Yingst, R. A.; Bartley, J. K.; Chidsey, T. C.; Cohen, B. A.; Gilleaudeau, G. J.; Hynek, B. M.; Kah, L. C.; Minitti, M. E.; Williams, R. M. E.; Black, S.; Gemperline, J.; Schaufler, R.; Thomas, R. J.

    2018-05-01

    The GHOST field tests are designed to isolate and test science-driven rover operations protocols, to determine best practices. During a recent field test at a potential Mars 2020 landing site analog, we tested two Mars Science Laboratory data-acquisition and decision-making methods to assess resulting science return and sample quality: a linear method, where sites of interest are studied in the order encountered, and a "walkabout-first" method, where sites of interest are examined remotely before down-selecting to a subset of sites that are interrogated with more resource-intensive instruments. The walkabout method cost less time and fewer resources, while increasing confidence in interpretations. Contextual data critical to evaluating site geology was acquired earlier than for the linear method, and given a higher priority, which resulted in development of more mature hypotheses earlier in the analysis process. Combined, this saved time and energy in the collection of data with more limited spatial coverage. Based on these results, we suggest that the walkabout method be used where doing so would provide early context and time for the science team to develop hypotheses-critical tests; and that in gathering context, coverage may be more important than higher resolution.

  5. An audit of pressure sores caused by intermittent compression devices used to prevent venous thromboembolism.

    Science.gov (United States)

    Skillman, Joanna; Thomas, Sunil

    2011-12-01

    When intermittent compression devices (ICDs) are used to prevent venous thromboembolism (VTE) they can cause pressure sores in a selected group of women, undergoing long operations. A prospective audit pre and post intervention showed a reduced risk with an alternative device, without increasing the risk of VTE.

  6. Do ready-made compression stockings fit the anatomy of the venous leg ulcer patient?

    DEFF Research Database (Denmark)

    Nørregaard, S; Bermark, S; Gottrup, F

    2014-01-01

    . CONCLUSION: These results demonstrate that there is a need to standardise measuring methods in the selection of ready-made below-knee compression stockings and a need for an evaluation of the present stocking sizes in relation to the anatomy of the venous leg ulcer patient. This study has shown that ready...

  7. Clinical significance of balloon dilatation angiography during cerebral venous sinus stenosis stenting

    Directory of Open Access Journals (Sweden)

    Xiang-yu CAO

    2016-12-01

    Full Text Available Objective To explore the clinical significance of balloon dilatation angiography during cerebral venous sinus stenosis stenting to predict the reflux of perforator veins after operation. Methods A total of 93 patients (including 51 with cerebral venous sinus stenosis and intracranial hypertension and 42 with intractable pulsatile tinnitus caused by cerebral venous sinus stenosis who were treated by stent implantation were analyzed retrospectively. Among those patients, the diameter of transverse and sigmoid sinuses of 63 cases were measured based on angiography, and stent was selected according to the measurement result. The other 30 cases were given angiography on ipsilateral carotid artery or vertebral artery when the balloon was dilated in the venous sinus to confirm the reflux of perforator veins. If the venous reflux decreased in the angiography, stent with diameter 1-2 mm less than that of venous sinus could be selected.  Results The success rate of stenting was 100% (93/93. In 63 cases, 45 cases were planted 9 mm × 40 mm stents, 15 were planted 8 mm × 40 mm stents, 3 were planted 7 mm × 40 mm stents. The average diameter of stents was (8.67 ± 0.68 mm. There were 11 cases (17.46% with slow perforator venous reflux after operation. In the other 30 cases, 3 cases were planted 8 mm × 40 mm stents, 11 were planted 7 mm × 40 mm stents, and 16 were planted 6 mm × 40 mm stents. The average diameter of stents was (7.57 ± 0.67 mm. There was only one case (3.33% with slow perforator venous reflux after operation. The difference of stent diameter between 2 groups was statistically significant (t = 15.632, P = 0.001. The occurrence rate of perforator vein occlusion after operation between 2 groups was significantly different (adjusted χ 2 = 60.065, P = 0.001.  Conclusions Perforator vein occlusion after cerebral venous sinus stenting is common complication. Balloon dilatation angiography could predict the possibility of perforator vein

  8. The effect of flight-related behaviour on the risk of venous thrombosis after air travel.

    Science.gov (United States)

    Schreijer, Anja J M; Cannegieter, Suzanne C; Doggen, Carine J M; Rosendaal, Frits R

    2009-02-01

    In a case-control study including 11,033 participants (The Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis study) on risk factors of venous thrombosis, we studied the effect of flight-related behaviour on the risk of venous thrombosis after air travel. Patients and control subjects received a questionnaire on risk factors for venous thrombosis, including recent travel history and details of their last flight. From this population, 80 patients and 108 control subjects were selected who had recently (1.1-4.4], particularly in those who were obese (OR 6.1; 95% CI: 0.5-76.2). Anxiety (OR 2.5; 95% CI: 0.9-7.0) and sleeping (OR 1.5; 95% CI: 0.7-3.1) may increase the risk slightly. The risk was not affected by alcohol consumption (OR 1.1; 95% CI: 0.5-2.4). Flying business class may lower the risk (OR 0.7; 95% CI: 0.2-1.8). We did not find a protective effect for several measures currently part of standard advice from airlines and clinicians, i.e. drinking non-alcoholic beverages, exercising or wearing stockings. The effect of behavioural factors during flying on the risk of venous thrombosis after air travel is limited. Current advice on prevention of travel-related thrombosis may have to be reconsidered.

  9. Intervention radiology for venous thrombosis: early thrombus removal using invasive methods.

    Science.gov (United States)

    Casanegra, Ana I; McBane, Robert D; Bjarnason, Haraldur

    2017-04-01

    The post thrombotic syndrome is one of the most dreaded complications of proximal deep vein thrombosis. This syndrome leads to pain and suffering with leg swelling, recalcitrant ulceration and venous claudication which greatly impairs mobility and quality of life. The prevalence can be high in patients with iliofemoral venous involvement particularly in the setting of a proximal venous stenosis, such as occurs in May Thurner syndrome. Anticoagulation alone does not reduce the likelihood of this outcome. Compression therapy may be effective but garment discomfort limits its implementation. Pharmacomechanical thrombectomy, which combines catheter-directed thrombolysis with mechanical thrombus dissolution, provides an attractive treatment strategy for such patients. The rationale and delivery of pharmacomechanical thrombectomy, including patient selection and adjunctive antithrombotic therapy, will be reviewed in addition to tips and tricks for managing difficult patient scenarios. © 2017 John Wiley & Sons Ltd.

  10. Endovascular Interventions for Acute and Chronic Lower Extremity Deep Venous Disease: State of the Art

    Science.gov (United States)

    Sista, Akhilesh K.; Vedantham, Suresh; Kaufman, John A.

    2015-01-01

    The societal and individual burden caused by acute and chronic lower extremity venous disease is considerable. In the past several decades, minimally invasive endovascular interventions have been developed to reduce thrombus burden in the setting of acute deep venous thrombosis to prevent both short- and long-term morbidity and to recanalize chronically occluded or stenosed postthrombotic or nonthrombotic veins in symptomatic patients. This state-of-the-art review provides an overview of the techniques and challenges, rationale, patient selection criteria, complications, postinterventional care, and outcomes data for endovascular intervention in the setting of acute and chronic lower extremity deep venous disease. Online supplemental material is available for this article. © RSNA, 2015 PMID:26101920

  11. Magnetic ion-imprinted and –SH functionalized polymer for selective removal of Pb(II) from aqueous samples

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Bin; Deng, Fang [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); Zhao, Yu [Technology Center of China Tobacco Hunan Industrial Corporation, Changsha 410007 (China); Luo, Xubiao, E-mail: luoxubiao@126.com [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); Luo, Shenglian, E-mail: sllou@hnu.edu.cn [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); Au, Chaktong [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China)

    2014-02-15

    A magnetic ion-imprinted polymer (Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP) functionalized with –SH groups for the selective removal of Pb(II) ions from aqueous samples was synthesized by surface imprinting technique combined with a sol–gel process using 3-mercaptopropyl trimethoxysilane as monomer, tetraethyl orthosilicate as cross-linking agent, and Pb(II) ion as template. The Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP was characterized by infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectrometry. Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP showed higher capacity and selectivity than that of Fe{sub 3}O{sub 4}@SiO{sub 2}-NIP. The effects of initial concentration of Pb(II) and pH of medium on adsorption capacity of Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP were studied. The experimental data fits well with the Langmuir adsorption isotherm. The maximum Pb(II)-sorption capacity calculated from Langmuir isotherm is 32.58 mg/g and 16.50 mg/g for Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP and Fe{sub 3}O{sub 4}@SiO{sub 2}-NIP, respectively. Kinetics studies show that the adsorption process obeys a pseudo-second-order kinetic model with high correlation coefficient (R{sup 2} = 0.9982). The separation factor of Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP for Pb(II)/Cu(II), Pb(II)/Zn(II), and Pb(II)/Co(II) are 50.54, 52.14, and 37.39, respectively. The adsorption thermodynamic parameters ΔG, ΔH and ΔS were −4.98 kJ/mol, 3.27 kJ/mol and 28.84 J/mol/K, respectively. In addition, the spent Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP can be refreshed by simple washing with aqueous HCl solution, and there is no significant decrease in adsorption capacity after a test of up to five cycles, demonstrating that the Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP is stable and reusable.

  12. Central venous obstruction in the thorax

    International Nuclear Information System (INIS)

    Collin, G.; Jones, R.G.; Willis, A.P.

    2015-01-01

    Central venous stenosis and occlusion can occur secondary to a spectrum of conditions ranging from aggressive malignancy to benign extrinsic anatomical compression in otherwise healthy individuals. Irrespective of aetiology, significant morbidity in the acute setting and long term can occur unless prompt accurate diagnosis and appropriate management is initiated, the radiologist being central to both. The present review will provide radiologists with a thorough illustration and explanation of the range of central venous conditions in the thorax (including deep vein thrombosis, thoracic outlet syndrome, haemodialysis, and malignancy related causes), the salient imaging findings and interventional management using case examples from the authors' practice. - Highlights: • We show a range of causes of central venous disease in the thorax. • We provide information about different imaging and management strategies. • We show several cases with successes and complications of endovascular management

  13. Complications of central venous stenosis due to permanent central venous catheters in children on hemodialysis.

    Science.gov (United States)

    Rinat, Choni; Ben-Shalom, Efrat; Becker-Cohen, Rachel; Feinstein, Sofia; Frishberg, Yaacov

    2014-11-01

    Central venous catheters are frequently used as access for hemodialysis (HD) in children. One of the known complications is central venous stenosis. Although this complication is not rare, it is often asymptomatic and therefore unacknowledged. Superior vena cava (SVC) stenosis is obviously suspected in the presence of upper body edema, but several other signs and symptoms are often unrecognized as being part of this syndrome. We describe four patients with various manifestations of central venous stenosis and SVC syndrome. These sometimes life- or organ-threatening conditions include obstructive sleep apnea, unresolving stridor, increased intracranial pressure, increased intraocular pressure, right-sided pleural effusion, protein-losing enteropathy and lymphadenopathy. The temporal relationship of these complications associated with the use of central venous catheters and documentation of venous stenosis, together with their resolution after alleviation of high venous pressure, points to a causal role. We suggest pathophysiological mechanisms for the formation of each of these complications. In patients with occlusion of the SVC, various unexpected clinical entities can be caused by high central venous pressure. As often the etiology is not obvious, a high index of suspicion is needed as in some cases prompt alleviation of the high pressure is mandatory.

  14. [Superficial venous thrombosis. A state of art].

    Science.gov (United States)

    Sándor, Tamás

    2017-01-01

    For a long time superficial thrombophlebitis has been thought to be a rather benign condition. Recently, when duplex ultrasound technique is used for the diagnosis more and more often, the disease is proved to be more dangerous than anticipated. Thrombosis propagates to the deep veins in 6-44% and pulmonary embolism was observed on the patients in 1,5-33%. We can calculate venous thromboembolic complications on every fourth patient. Diagnosis is clinical, but duplex ultrasound examination is mandatory, for estimation of the thrombus extent, for exclusion of the deep venous thrombosis and for follow up. Both legs should be checked with ultrasound, because simultaneous deep venous thrombosis can develop on the contralateral limb. Two different forms can be distinguished: superficial venous thrombosis with, or without varicose veins. In cases of spontaneous, non varicous form, especially when the process is migrating or recurrent, a careful clinical examination is necessery for exclusion of malignant diseases and thrombophilia. The treatment options are summarised on the basis of recent international consensus statements. The American and German guidelines are similar. Compression and mobilisation are cornerstones of the therapy. For a short segment thrombosis non steroidal antiinflammatory drugs are effective. For longer segments low molecular-weight heparins are preferred. Information on the effect of the novel oral anticoagulants for the therapy is lacking but they may appear to be effective in the future for this indication. When thrombus is close to the sapheno-femoral or sapheno-popliteal junction crossectomy (high ligation), or low molecular-weight heparin in therapeutic doses are indicated. The term superficial thrombophlebitis should be discouraged, because inflammation and infection is not the primary pathology. It should be called correctly superficial venous thrombosis in order to avoid the unnecessary administration of antibiotics and the misconception

  15. Hayabusa2 NIRS3’s Investigation to Characterize and Select Sampling and Landing Sites on Asteroid (25143) Ryugu

    Science.gov (United States)

    Takir, Driss; Hibbitts, Charles A.; Le Corre, Lucille; Emery, Joshua P.; Kitazato, Kohei; Sugita, Seiji; Nakauchi, Yusuke

    2017-10-01

    Following the visit of the spacecraft Hayabusa to (25143) Itokawa in 2005, the Japanese Space Agency (JAXA) launched a second spacecraft, Hayabusa2, in 2014 to the near-Earth Apollo asteroid (162173) Ryugu, a C-complex asteroid. Hayabusa2 will arrive at Ryugu in 2018. Near-Earth asteroids (NEAs) are important objects to study because of their possible role in the delivery of water and complex organic molecules to early Earth, and their threats to impact the Earth at irregular and unpredictable periods in the future. Hayabusa2 mission will provide exceptional science with a primary objective to illuminate the origin, evolution, and distribution of volatiles and organics on the surface of Ryugu and in the Solar System. Here we present our Near Infrared Spectrometer(NIRS3)-related strategy and plan to help the science team to characterize and select sampling and landing sites to collect carbonaceous samples from Ryugu and bring them back to Earth in 2020. Our plan includes, (1) measuring spectra of various carbonaceous chondrites and end-member hydrated silicates under asteroid-like conditions (vacuum and elevated temperatures) to develop spectral parameters of minerals and chemical compounds that we expect to detect on Ryugu, particularly around 2.8 to 3.2 µm, and (2) thermally and photometrically correcting Ryugu’s spectra to create site-specific and global maps of the mineralogical and chemical relative abundances across Ryugu’s surface, in addition to creating various albedo maps, including the geometric and bolometric Bond albedo. Previous 3-µm spectroscopic studies were conducted in ambient terrestrial environments, and hence were contaminated by atmospheric water. In our work, however, chondrite reflectance and hydrated mineral spectra are measured under asteroid-like conditions to remove adsorbed water and accurately compute the spectral parameters that will be used for Ryugu’s mineralogical and chemical mapping.AcknowledgementsWe wish to thank the

  16. Tripodal chelating ligand-based sensor for selective determination of Zn(II) in biological and environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Singh, Ashok; Mehtab, Sameena; Singh, Udai P.; Aggarwal, Vaibhave [Indian Institute of Technology-Roorkee, Department of Chemistry, Roorkee (India)

    2007-08-15

    Potassium hydrotris(N-tert-butyl-2-thioimidazolyl)borate [KTt{sup t-Bu}] and potassium hydrotris(3-tert-butyl-5-isopropyl-l-pyrazolyl)borate [KTp{sup t-Bu,i-Pr}] have been synthesized and evaluated as ionophores for preparation of a poly(vinyl chloride) (PVC) membrane sensor for Zn(II) ions. The effect of different plasticizers, viz. benzyl acetate (BA), dioctyl phthalate (DOP), dibutyl phthalate (DBP), tributyl phosphate (TBP), and o-nitrophenyl octyl ether (o-NPOE), and the anion excluders sodium tetraphenylborate (NaTPB), potassium tetrakis(p-chlorophenyl)borate (KTpClPB), and oleic acid (OA) were studied to improve the performance of the membrane sensor. The best performance was obtained from a sensor with a of [KTt{sup t-Bu}] membrane of composition (mg): [KTt{sup t-Bu}] (15), PVC (150), DBP (275), and NaTPB (4). This sensor had a Nernstian response (slope, 29.4 {+-} 0.2 mV decade of activity) for Zn{sup 2+} ions over a wide concentration range (1.4 x 10{sup -7} to 1.0 x 10{sup -1} mol L{sup -1}) with a limit of detection of 9.5 x 10{sup -8} mol L{sup -1}. It had a relatively fast response time (12 s) and could be used for 3 months without substantial change of the potential. The membrane sensor had very good selectivity for Zn{sup 2+} ions over a wide variety of other cations and could be used in a working pH range of 3.5-7.8. The sensor was also found to work satisfactorily in partially non-aqueous media and could be successfully used for estimation of zinc at trace levels in biological and environmental samples. (orig.)

  17. Probing BL Lac and Cluster Evolution via a Wide-angle, Deep X-ray Selected Sample

    Science.gov (United States)

    Perlman, E.; Jones, L.; White, N.; Angelini, L.; Giommi, P.; McHardy, I.; Wegner, G.

    1994-12-01

    The WARPS survey (Wide-Angle ROSAT Pointed Survey) has been constructed from the archive of all public ROSAT PSPC observations, and is a subset of the WGACAT catalog. WARPS will include a complete sample of >= 100 BL Lacs at F_x >= 10(-13) erg s(-1) cm(-2) . A second selection technique will identify ~ 100 clusters at 0.15 = 0.304 +/- 0.062 for XBLs but = 0.60 +/- 0.05 for RBLs. Models of the X-ray luminosity function (XLF) are also poorly constrained. WARPS will allow us to compute an accurate XLF, decreasing the error bars above by over a factor of two. We will also test for low-luminosity BL Lacs, whose non-thermal nuclear sources are dim compared to the host galaxy. Browne and Marcha (1993) claim the EMSS missed most of these objects and is incomplete. If their predictions are correct, 20-40% of the BL Lacs we find will fall in this category, enabling us to probe the evolution and internal workings of BL Lacs at lower luminosities than ever before. By removing likely QSOs before optical spectroscopy, WARPS requires only modest amounts of telescope time. It will extend measurement of the cluster XLF both to higher redshifts (z>0.5) and lower luminosities (LX<1x10(44) erg s(-1) ) than previous measurements, confirming or rejecting the 3sigma detection of negative evolution found in the EMSS, and constraining Cold Dark Matter cosmologies. Faint NELGs are a recently discovered major contributor to the X-ray background. They are a mixture of Sy2s, starbursts and galaxies of unknown type. Detailed classification and evolution of their XLF will be determined for the first time.

  18. Management of Peripheral and Truncal Venous Injuries

    Directory of Open Access Journals (Sweden)

    Triantafillos G. Giannakopoulos

    2017-08-01

    Full Text Available Civilian injuries are increasing according to the World Health Organization, and this is attributed mainly to road traffic accidents and urban interpersonal violence. Vascular injuries are common in these scenarios and are associated with high morbidity and mortality rates. Associated peripheral venous trauma is less likely to lead to death and controversy remains whether ligation or repair should be the primary approach. Conversely, non-compressible truncal venous insult can be lethal due to exsanguination, thus a high index of suspicion is crucial. Operative management is demanding with fair results but recent endovascular adjuncts demonstrate promising results and seem to be the way forward for these serious conditions.

  19. Assessment of Venous Thrombosis in Animal Models.

    Science.gov (United States)

    Grover, Steven P; Evans, Colin E; Patel, Ashish S; Modarai, Bijan; Saha, Prakash; Smith, Alberto

    2016-02-01

    Deep vein thrombosis and common complications, including pulmonary embolism and post-thrombotic syndrome, represent a major source of morbidity and mortality worldwide. Experimental models of venous thrombosis have provided considerable insight into the cellular and molecular mechanisms that regulate thrombus formation and subsequent resolution. Here, we critically appraise the ex vivo and in vivo techniques used to assess venous thrombosis in these models. Particular attention is paid to imaging modalities, including magnetic resonance imaging, micro-computed tomography, and high-frequency ultrasound that facilitate longitudinal assessment of thrombus size and composition. © 2015 American Heart Association, Inc.

  20. Admission Hyperglycemia and Clinical Outcome in Cerebral Venous Thrombosis

    NARCIS (Netherlands)

    Zuurbier, Susanna M.; Hiltunen, Sini; Tatlisumak, Turgut; Peters, Guusje M.; Silvis, Suzanne M.; Haapaniemi, Elena; Kruyt, Nyika D.; Putaala, Jukka; Coutinho, Jonathan M.

    2016-01-01

    Background and Purpose-Admission hyperglycemia is associated with poor clinical outcome in ischemic and hemorrhagic stroke. Admission hyperglycemia has not been investigated in patients with cerebral venous thrombosis. Methods-Consecutive adult patients with cerebral venous thrombosis were included

  1. Human cerebral venous outflow pathway depends on posture and central venous pressure

    DEFF Research Database (Denmark)

    Gisolf, J; van Lieshout, J J; van Heusden, K

    2004-01-01

    Internal jugular veins are the major cerebral venous outflow pathway in supine humans. In upright humans the positioning of these veins above heart level causes them to collapse. An alternative cerebral outflow pathway is the vertebral venous plexus. We set out to determine the effect of posture...... and during a Valsalva manoeuvre in both body positions, correlate highly with model simulation of the jugular cross-sectional area (R(2) = 0.97). The results suggest that the cerebral venous flow distribution depends on posture and CVP: in supine humans the internal jugular veins are the primary pathway...

  2. Correlation between arterial and venous blood gas analysis parameters in patients with acute exacerbation of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Novović Miloš

    2012-01-01

    Full Text Available Introduction. Arterial blood gas (ABG analyses have an important role in the assessment and monitoring of the metabolic and oxygen status of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD. Arterial puncture could have a lot of adverse effects, while sampling of venous blood is simpler and is not so invasive. Objective. The aim of this study was to evaluate whether venous blood gas (VBG values of pH, partial pressure of carbon dioxide (PCO2, partial oxygen pressure (PO2, bicarbonate (HCO3, and venous and arterial blood oxygen saturation (SO2 can reliably predict ABG levels in patients with acute exacerbation of COPD. Methods. Forty-seven patients with a prior diagnosis of COPD were included in this prospective study. The patients with acute exacerbation of this disease were examined at the General Hospital EMS Department in Prijepolje. ABG samples were taken immediately after venous sampling, and both were analyzed. Results. The Pearson correlation coefficients between arterial and venous parameters were 0.828, 0.877, 0.599, 0.896 and 0.312 for pH, PCO2, PO2, HCO3 and SO2, respectively. The statistically significant correlation between arterial and venous pH, PCO2 and HCO3, values was found in patients with acute exacerbation of COPD (p<0.001. Conclusion. When we cannot provide arterial blood for analysis, venous values of the pH, Pv,CO2 and HCO3 parameters can be an alternative to their arterial equivalents in the interpretation of the metabolic status in patients with acute exacerbation of COPD, while the values of venous Pv,O2 and Sv,O2 cannot be used as predictors in the assessment of oxygen status of such patients.

  3. Pregnancy-related venous thromboembolism and risk of occult cancer

    DEFF Research Database (Denmark)

    Hansen, Anette Tarp; Veres, Katalin; Horváth-Puhó, Erzsébet

    2017-01-01

    The cancer risk during the first year after a pregnancy-related venous thromboembolism episode is higher than expected. An aggressive search for cancer in women with pregnancy-related venous thromboembolism is probably not warranted, due to low absolute risk.......The cancer risk during the first year after a pregnancy-related venous thromboembolism episode is higher than expected. An aggressive search for cancer in women with pregnancy-related venous thromboembolism is probably not warranted, due to low absolute risk....

  4. Detailed examination of the adrenal glands by angiography and radioimmunologic measurement of hormones in adrenal venous blood

    International Nuclear Information System (INIS)

    Yugrinov, O.G.; Slavnov, V.N.; Komissarenko, I.V.; Olejnik, V.A.; Benikova, E.A.

    1984-01-01

    In 222 patients the adrenal glands were examined in detail by arteriography and venography, and if indicated also the ovaries, kidneys, bladder and other organs were checked up. Blood samples were taken from the adrenal glands, renal veins and the vena cava inferior in the bifurcational and subdiaphragmatic region. According to the clinical requirements cortisol, corticotropine, aldosterone, adrenaline, noradrenaline and renine activity were determined. Comprehensive angiographic and radioimmunologic studies revealed in 54 patients tumors of the adrenal cortex. Tumors of the adrenal medulla were detected in 43 of the cases. In 103 cases a morbus Icenko-Cushing was found. The basic examination of the diagnostic schedule was selective adrenal venography. Adrenal arteriography and measurement of venous hormone levels were complementary investigations and were rarely used as independent methods. (author)

  5. Congenital absence of infrarenal IVC and iliac venous system : Unusual collateral Pathways

    International Nuclear Information System (INIS)

    Lee, Jin Joo; Lee, Byung Hee; Kim, Kie Hwan; Do, Young Soo; Chin, Soo Yil

    1994-01-01

    We present a case with congenital absence of the infrarenal portion of inferior vena cava and iliac venous system, showing unusual venous collaterals including the left ovarian venous collateral via parametrial venous complex, and a mesenteric-periureteric venous connection. The venous collateral pathways were demonstrated by computed tomography and venography

  6. In Situ Pre-Selection of Return Samples with Bio-Signatures by Combined Laser Mass Spectrometry and Optical Microscopy

    Science.gov (United States)

    Wiesendanger, R.; Wurz, P.; Tulej, M.; Wacey, D.; Neubeck, A.; Grimaudo, V.; Riedo, A.; Moreno, P.; Cedeño-López, A.; Ivarsson, M.

    2018-04-01

    The University of Bern developed instrument prototypes that allow analysis of samples on Mars prior to bringing them back to Earth, allowing to maximize the scientific outcome of the returned samples. We will present the systems and first results.

  7. TEMPO DE VIABILIDADE DE AMOSTRAS DE SANGUE VENOSO BOVINO DESTINADAS AO EXAME HEMOGASOMÉTRICO, QUANDO MANTIDAS SOB CONSERVAÇÃO EM ÁGUA GELADA VIABILITY TIME OF BLOOD GAS ANALYSIS IN BOVINE VENOUS BLOOD SAMPLES STORED IN ICE WATER BATH

    Directory of Open Access Journals (Sweden)

    Júlio Augusto Naylor Lisbôa

    2001-04-01

    adequadamente conservadas em banho de água gelada, mantendo, assim, o seu valor diagnóstico.In order to verify the viability of blood gas analysis in bovine venous blood stored on ice water bath, two samples (10ml each were taken from the jugular vein of 14 healthy animals (7 males and 7 females, 1- to 5-year-old, using plastic syringes and attached needles filled with sodium heparin (1,000IU. The blood samples were obtained anaerobically, the air bubbles observed were immediately removed, and the needle was maintened capped with a rubber stopper. Each syringe of the pair was distinctally stored at room temperature (23-30ºC or in ice water bath (0-4ºC during the experimental period. Values of pH, carbon dioxide (PvCO2 and oxigen (PvO2 tensions, bicarbonate (HCO3-, total carbon dioxide (TCO2, base excess (BE, standard bicarbonate (StB, oxigen saturation (SatO2, and oxigen content (O2 were determined soon after sampling and after 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours. According to the type of storage temperature, the results were analysed through repeated measurements ANOVA, considering the contrast between the mean value of each time and the initial one. On the storage at room temperature, the in vitro changes were characterized from continuous decreases in pH, PvO2, BE, StB, SatO2, and O2 values, and gradual increase in PvCO2, starting at 2- or 3-hour after the collection. In the samples stored at 0-4ºC, on the other hand, the changes in pH occurred only at the 4th hour, and the stability of the PvCO2, BE, and StB values were maintened for up to the 6th hour. These results indicated that the diagnostic utility of blood gas analysis is conserved in bovine venous blood samples adequately stored up to 6 hours in ice water bath, at 0-4ºC.

  8. Mechanochemical endovenous ablation and new frontiers in venous intervention

    NARCIS (Netherlands)

    Boersma, D

    2017-01-01

    Venous insufficiency of the lower extremities is a common condition and related to various symptoms, including venous ulcers. The effect of venous insufficiency on patients’ health-related quality of life is substantial and comparable with other chronic diseases such as arthritis, diabetes, and

  9. Erythrocytes and von Willebrand factor in venous thrombosis

    NARCIS (Netherlands)

    Smeets, M.W.J.

    2018-01-01

    Venous thromboembolism represents the third leading vascular disease after myocardial infarction and stroke. Erythrocytes, the most abundant cells in venous thrombi, were thought to be innocent bystanders that become tangled up in the fibrin mesh of venous thrombi. However, this thesis describes

  10. Contribution of MRI in supracardiac total anomalous pulmonary venous drainage

    International Nuclear Information System (INIS)

    Kastler, B.; Germain, P.; Gangi, A.; Klinkert, A.; Dietemann, J.L.; Wackenheim, A.; Livolsi, A.; Willard, D.

    1992-01-01

    A case of supracardiac total anomalous pulmonary venous drainage (TAPVD) in an infant aged 2 1/2 months is presented. Diagnosis was established non invasively by magnetic resonance image (MRI). Not only did MRI precisely depict the anomalous venous pathway but it moreover securely excluded pulmonary venous obstruction. (orig.)

  11. Diagnostics of defeats of venous collectors of brain

    International Nuclear Information System (INIS)

    Timofeeva, T.V.; Polunina, I.S.; Shcherbakova, E.Ya.; Kuldakova, S.V.

    1997-01-01

    Comparative data of transcranial ultrasonic dopplerography (170 patients) and radionuclidous antroscintigraphy (124), received during diagnostics of defects of venous collectors of brain are analyzed. Five variants of defeats of venous collectors (cross, sigmoid, internal of jugular of jugular vein), but also unpaired sine (direct, confluent) are described. Received results permit to reveal interrelation of infringements of venous outflow and increase of intracranial pressure

  12. Metastatic Carcinoma of Unknown Primary Presenting as Jugular Venous Thrombosis

    Directory of Open Access Journals (Sweden)

    Prince Cheriyan Modayil

    2009-01-01

    Full Text Available Jugular venous thrombosis is unusual and is associated with central venous catheterisation, intravenous drug abuse and head and neck sepsis. It is rarely associated with malignancy. We report a case of metastatic carcinoma of unknown primary in a forty year old female which presented with jugular venous thrombosis. The discussion includes investigation and treatment options for this condition.

  13. A Novel Stretch Sensor to Measure Venous Hemodynamics

    Directory of Open Access Journals (Sweden)

    Syrpailyne Wankhar

    2018-07-01

    Full Text Available Chronic venous insufficiency is a debilitating condition causing varicose veins and venous ulcers. The pathophysiology includes reflux and venous obstruction. The diagnosis is often made by clinical examination and confirmed by Venous Doppler studies. Plethysmography helps to quantitatively examine the reflux and diagnose the burden of deep venous pathology to better understand venous hemodynamics, which is not elicited by venous duplex examination alone. However, most of these tests are qualitative, expensive, and not easily available. In this paper, we demonstrate the potential use of a novel stretch sensor in the assessment of venous hemodynamics during different maneuvers by measuring the change in calf circumference. We designed the stretch sensor by using semiconductor strain gauges pasted onto a small metal bar to form a load cell. The elastic and Velcro material attached to the load cell form a belt. It converts the change in limb circumference to a proportional tension (force of distension when placed around the calf muscle. We recorded the change in limb circumference from arrays of stretch sensors by using an in-house data acquisition system. We calculated the venous volume (VV, venous filling index (VFI, ejection fraction (EF and residual venous volume (RVV on two normal subjects and on two patients to assess venous hemodynamics. The values (VV > 60 ml, VFI 60%, RVV 2ml/s, EF 35% in patients were comparable to those reported in the literature.

  14. High sensitivity and selectivity in quantitative analysis of drugs in biological samples using 4-column multidimensional micro-UHPLC-MS enabling enhanced sample loading capacity.

    Science.gov (United States)

    de Vries, Ronald; Vereyken, Liesbeth; François, Isabelle; Dillen, Lieve; Vreeken, Rob J; Cuyckens, Filip

    2017-10-09

    Sensitivity is often a critical parameter in quantitative bioanalyses in drug development. For liquid-chromatography-based methods, sensitivity can be improved by reducing the column diameter, but practical sensitivity gains are limited by the reduced sample loading capacity on small internal diameter (I.D.) columns. We developed a set-up that has overcome these limitations in sample loading capacity. The set-up uses 4 columns with gradually decreasing column diameters along the flow-path (2.1 → 1 → 0.5 → 0.15 mm). Samples are pre-concentrated on-line on a 2.1 mm I.D. trapping column and back flushed to a 1 mm I.D. UHPLC analytical column and separated. The peak(s) of interest are transferred using heartcutting to a second trapping column (0.5 mm I.D.), which is back-flushed to a 0.15 mm I.D. micro-UHPLC analytical column for orthogonal separation. The proof of concept of the set-up was demonstrated by the simultaneous analysis of midazolam and 1'-hydroxy midazolam in plasma by injection of 80 μL of protein precipitated plasma. The 4-column funnel set-up proved to be robust and resulted in a 10-50 times better sensitivity compared to a trap-elute approach and 250-500 fold better compared to direct micro-UHPLC analysis. A lower limit of quantification of 100 fg/mL in plasma was obtained for both probe compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Does the preference of peripheral versus central venous access in peripheral blood stem cell collection/yield change stem cell kinetics in autologous stem cell transplantation?

    Science.gov (United States)

    Dogu, Mehmet Hilmi; Kaya, Ali Hakan; Berber, Ilhami; Sari, İsmail; Tekgündüz, Emre; Erkurt, Mehmet Ali; Iskender, Dicle; Kayıkçı, Ömur; Kuku, Irfan; Kaya, Emin; Keskin, Ali; Altuntaş, Fevzi

    2016-02-01

    Central venous access is often used during apheresis procedure in stem cell collection. The aim of the present study was to evaluate whether central or peripheral venous access has an effect on stem cell yield and the kinetics of the procedure and the product in patients undergoing ASCT after high dose therapy. A total of 327 patients were retrospectively reviewed. The use of peripheral venous access for stem cell yield was significantly more frequent in males compared to females (p = 0.005). Total volume of the product was significantly lower in central venous access group (p = 0.046). As being a less invasive procedure, peripheral venous access can be used for stem cell yield in eligible selected patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Distribution of Gas Phase Polycyclic Aromatic Hydrocarbons (PAHs in Selected Indoor and Outdoor Air Samples of Malaysia: a Case Study in Serdang, Selangor and Bachang, Malacca

    Directory of Open Access Journals (Sweden)

    Haris Hafizal Abd Hamid

    2017-07-01

    Full Text Available Distribution of 10 polycyclic aromatic hydrocarbons (PAHs in the gas phase of air from selected indoor and outdoor areas of Selangor and Malacca, Malaysia has been investigated. A locally designed Semi Permeable Membrane Device (SPMD was applied for passive air sampling for 37 days at selected locations. Cleanup was carried out with Gas Purge - Micro Syringe Extraction (GP-MSE and the final analysis was using Gas Chromatography-Mass Spectrometry (GC-MS. In this study, 6 indoor and 12 outdoor locations were selected for air sampling. A total of 10 compounds of PAHs (Ʃ10PAHs were determined in the range of 0.218 ng/m3 - 1.692 ng/m3 and 0.378 ng/m3 - 1.492 ng/m3 in outdoor and indoor samples respectively. In the outdoor samples, locations such as near a petrol station and heavy traffic showed the maximum levels of Ʃ10PAHs, while rooftop samples showed the lowest Ʃ10PAHs. The distribution of gas phase Ʃ10PAHs was influenced by vehicular emission. Low molecular weight (LMW compounds (2-3 rings were dominant in all samples (>70% indicating that SPMD has successfully sampled the gas phase of the air.

  17. Investigation of cerebral venous outflow in microgravity.

    Science.gov (United States)

    Taibi, A; Gadda, G; Gambaccini, M; Menegatti, E; Sisini, F; Zamboni, P

    2017-10-31

    The gravitational gradient is the major component to face when considering the physiology of venous return, and there is a growing interest in understanding the mechanisms ensuring the heart filling, in the absence of gravity, for astronauts who perform long-term space missions. The purpose of the Drain Brain project was to monitor the cerebral venous outflow of a crew member during an experiment on the International Space Station (ISS), so as to study the compensatory mechanisms that facilitate this essential physiological action in subjects living in a microgravity environment. Such venous function has been characterized by means of a novel application of strain-gauge plethysmography which uses a capacitive sensor. In this contribution, preliminary results of our investigation have been presented. In particular, comparison of plethysmography data confirmed that long duration spaceflights lead to a redistribution of venous blood volume, and showed interesting differences in the amplitude of cardiac oscillations measured at the level of the neck veins. The success of the experiment has also demonstrated that thanks to its easy portability, non-invasiveness, and non-operator dependence, the proposed device can be considered as a novel tool for use aboard the ISS. Further trials are now under way to complete the investigation on the drainage function of the neck veins in microgravity.

  18. Pediatric central venous access devices: nursing interventions

    Directory of Open Access Journals (Sweden)

    Duffy EA

    2017-05-01

    Full Text Available Elizabeth A Duffy, Kathryn N Nelson Department of Health Behavior and Biological Sciences, The University of Michigan School of Nursing, Ann Arbor, MI, USA Abstract: A central venous catheter (CVC is an indwelling catheter that provides permanent or temporary stable venous access for both acute and chronically ill pediatric patients. These catheters provide stable venous access that can be used for a variety of medical purposes including drawing blood, hemodynamic monitoring, infusion of intravenous medications, infusion of intravenous fluids, chemotherapy, blood products, and parenteral nutrition. Each day, nurses access and care for CVCs in infants, children, and adolescents; the precision of this care can prevent life-threatening complications. The purpose of this review and the case study is to highlight the importance and components of evidence-based nursing practice in pediatric CVC care. A historical perspective of CVC care is provided in conjunction with current national initiatives to improve patient outcomes for children with CVCs. Infection prevention, clinical practice guidelines, quality improvement, and evidence-based care bundles are discussed. Keywords: pediatric nursing, central venous catheters, central line-associated bloodstream infection, care bundles, pediatric case study 

  19. Thermodilution-determined Internal Jugular Venous Flow

    DEFF Research Database (Denmark)

    Rasmussen, Peter; Widmer, Mario; Hilty, Matthias P

    2017-01-01

    PURPOSE: Cerebral blood flow (CBF) increases ~20% during whole body exercise although a Kety-Schmidt-determined CBF is reported to remain stable; a discrepancy that could reflect evaluation of arterial vs. internal jugular venous (IJV) flow and/or that CBF is influenced by posture. Here we test...

  20. Global public awareness of venous thromboembolism

    NARCIS (Netherlands)

    Wendelboe, A. M.; McCumber, M.; Hylek, E. M.; Buller, H.; Weitz, J. I.; Raskob, G.; Angchaisuksiri, P.; Blanco, A. N.; Hunt, B. J.; Kakkar, A.; Konstantinides, S. V.; McLintock, C.; Ozaki, Y.

    2015-01-01

    Data on public awareness about thrombosis in general and venous thromboembolism (VTE) in particular are limited. We aimed to measure the global awareness of thrombosis to address this gap. With Ipsos-Reid, from 22 July to 5 August 2014, we surveyed 800 respondents in their native language from each

  1. Central Venous Occlusion in the Hemodialysis Patient.

    Science.gov (United States)

    Krishna, Vinay Narasimha; Eason, Joseph B; Allon, Michael

    2016-11-01

    Central venous stenosis (CVS) is encountered frequently among hemodialysis patients. Prior ipsilateral central venous catheterization and cardiac rhythm device insertions are common risk factors, but CVS can also occur in the absence of this history. Chronic CVS can cause thrombosis with partial or complete occlusion of the central vein at the site of stenosis. CVS is frequently asymptomatic and identified as an incidental finding during imaging studies. Symptomatic CVS presents most commonly as an upper- or lower-extremity edema ipsilateral to the CVS. Previously unsuspected CVS may become symptomatic after placement of an ipsilateral vascular access. The likelihood of symptomatic CVS may be affected by the central venous catheter (CVC) location; CVC side; duration of CVC dependence; type, location, and blood flow of the ipsilateral access; and extent of collateral veins. Venous angiography is the gold standard for diagnosis. Percutaneous transluminal angioplasty and stent placement can improve the stenosis and alleviate symptoms, but CVS typically recurs frequently, requiring repeated interventions. Refractory symptomatic CVS may require ligation of the ipsilateral vascular access. Because no available treatment option is curative, the goal should be to prevent CVS by minimizing catheters and central vein instrumentation in patients with chronic kidney disease and dialysis patients. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  2. Travel and venous thrombosis: a systematic review

    NARCIS (Netherlands)

    Kuipers, S.; Schreijer, A. J. M.; Cannegieter, S. C.; Bueller, H. R.; Rosendaal, F. R.; Middeldorp, S.

    2007-01-01

    In the past decade, numerous publications on the association between venous thrombosis (VT) and travel have been published. Relative and absolute risks of VT after travel, and particularly after travel by air, have been studied in case-control and observational follow-up studies, whereas the effect

  3. Venous thromboembolism: Risk profile and management of ...

    African Journals Online (AJOL)

    Objectives. This study aims to describe the venous thromboembolism (VTE) risk profile of women undergoing elective gynaecological surgery in a tertiary hospital and to audit the VTE prophylaxis prescribed. Methods. One hundred and nine women who underwent elective gynaecological surgery at Kalafong Provincial ...

  4. Urethro-venous intravasation during urethrography

    African Journals Online (AJOL)

    J.M. Ratkal

    Abstract. Retrograde urethrography is a procedure used to evaluate urethral strictures. Urethro-venous intravasation, rarely seen during retrograde urethrography, can result in bacteremia, adverse reactions to contrast agents, renal failure and even pulmonary embolism. We report one such case of a male patient who ...

  5. REVIEW ARTICLE Venous thromboembolism associated with ...

    Indian Academy of Sciences (India)

    Navya

    2017-03-24

    Mar 24, 2017 ... It has been long recognized that reduced PS activity is a risk factor for venous .... individual had PS deficiency type I but was unavailable for DNA .... Influence of PROS1 gene mutations affecting protein S amino-acid 275 on ...

  6. Knowledge, attitude and practice of venous thromboembolism ...

    African Journals Online (AJOL)

    USER

    We aimed to assess the knowledge, attitude and practice of prophylaxis in venous thromboembolism among medical doctors in Usmanu Danfodiyo University Teaching Hospital,. Sokoto, North-West Nigeria. Methodology: The knowledge, attitude and practice of VTE prophylaxis among medical doctors was assessed using ...

  7. Venous infraction of developmental venous anomaly: A case report with perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Youn; Kim, Hye Jeong; Hyun, Su Jeong; Kim, Hee Yeong; Kim, Han Myun; Hwang, Ji Young; Hong, Hye Suk; Woo, Ji Young; Yang, Ik [Dept. of Radiology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of); Kim, Eun Soo [Dept. of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

    2017-06-15

    Developmental venous anomaly (DVA) is a common congenital venous malformation characterized by dilated medullary veins in caput medusa configuration and a draining vein. Despite the high incidence of DVAs, they are benign anatomic variations and rarely cause symptoms. Here, we report computed tomography and magnetic resonance imaging findings with perfusion images of acute infarction from underlying DVA in a 63-year-old female patient who presented with acute onset of neurologic symptoms and recovered without any neurologic deficit.

  8. CT findings of posterior fossa venous angiomas

    International Nuclear Information System (INIS)

    Satoh, Toru; Kinugasa, Kazushi; Nishimoto, Akira; Nishimoto, Ken.

    1986-01-01

    Three cases of posterior fossa venous angiomas were reported, with some comments on the CT findings. Case 1: A 53-year-old woman was admitted for the further examination of a viral meningitis which had appeared three months before. Neurological examination revealed no abnormality. Vertebral angiography, however, demonstrated numerous fine medullary veins, with an enlarged intraparenchymal draining vein, in the right cerebellum; they drained into the petrosal vein, which was characteristic of venous angioma. On the plain CT, part of the draining vein was identified as a slightly high-density node. A curvilinear draining vein was demonstrated by the enhanced CT. Case 2: A 29-year-old man was admitted complaining of headache, vomiting, and atxia. Neurological examination disclosed truncal ataxia. The enhanced CT demonstrated two distinct nodules on the anterior border of the hematoma in the deep median cerebellum, probably corresponding to the draining veins. On the angiogram, a venous angioma was found in the bilateral cerebellum; it drained into the precentral cerebellar veins and ultimately joined the straight sinus via the precentro-vermo-rectal vein. Case 3: A 4-year-old boy was admitted suffering from headache, vomiting, and ataxia. Neurological examination disclosed a co-ordination disturbance of the left side. The enhanced CT demonstrated a curvilinear structure inside the hematoma. Angiography showed a venous angioma in the left cerebellum which drained into the petrosal vein. Computerized angiotomography delineated the characteristic venous structure on the angiogram as many fine, high-density lines (medullary veins) converging to a large intraparenchymal linear structure (central medullary vein) and then to a superficial cortical vein. In all cases, large intraparenchymal draining veins were identified by the conventional CT. (J.P.N.)

  9. Anticoagulation period in idiopathic venous thromboembolism

    International Nuclear Information System (INIS)

    Farraj, Rami S.

    2004-01-01

    The period of anticoagulation of a first episode of idiopathic venous thromboembolism has been 6 months. It is unclear if such patients would benefit from longer treatment, as there appears to be an increased risk of recurrence after anticoagulation is stopped. In a randomized prospective study of 64 patients admitted to King Hussein Medical city, Amman, Jordan, who developed a first episode of venous thromboembolism, 32 patients were given warfarin for 24-months, while 32 patients stopped anticoagulation after completion of 6-months of therapy. Our goal was to determine the effects of extended anticoagulation on rates of recurrence of symptomatic venous thromboembolism and bleeding. The patients were followed for 12-months after stopping anticoagulation. After 24-months, 7 of the 32 patients (21%) who had standard anticoagulation for 6-months had a recurrent episode of thromboembolism compared to one of the 32 patients who received anticoagulation for 24 months (3%). Extended warfarin therapy for 24-months has resulted in an absolute risk reduction of 0.1% (p<0.05). This translates into 8 patients having to be treated for 24-months to avoid one recurrence without increasing the risk of major bleeding. Two patients in each group (6%) had major nonfatal bleeding, all 4 bleeding episodes occurring within the first 3-months of anticoagulation. After 36-months of follow up, the recurrence rate of extended warfarin therapy was only 3 patients (9%), which is a 43% relative reduction in recurrence of thromboembolism compared to standard therapy for 6-months. Patients with first episodes of idiopathic venous thromboembolism have an increased risk of recurrent venous thromboembolism and should be treated with oral anticoagulants for longer than 6-months, probably 24-months. (author)

  10. The Atacama Cosmology Telescope: Physical Properties and Purity of a Galaxy Cluster Sample Selected Via the Sunyaev-Zel'Dovich Effect

    Science.gov (United States)

    Menanteau, Felipe; Gonzalez, Jorge; Juin, Jean-Baptiste; Marriage, Tobias; Reese, Erik D.; Acquaviva, Viviana; Aguirre, Paula; Appel, John Willam; Baker, Andrew J.; Barrientos, L. Felipe; hide

    2010-01-01

    We present optical and X-ray properties for the first confirmed galaxy cluster sample selected by the Sunyaev-Zel'dovich Effect from 148 GHz maps over 455 square degrees of sky made with the Atacama Cosmology Telescope. These maps. coupled with multi-band imaging on 4-meter-class optical telescopes, have yielded a sample of 23 galaxy clusters with redshifts between 0.118 and 1.066. Of these 23 clusters, 10 are newly discovered. The selection of this sample is approximately mass limited and essentially independent of redshift. We provide optical positions, images, redshifts and X-ray fluxes and luminosities for the full sample, and X-ray temperatures of an important subset. The mass limit of the full sample is around 8.0 x 10(exp 14) Stellar Mass. with a number distribution that peaks around a redshift of 0.4. For the 10 highest significance SZE-selected cluster candidates, all of which are optically confirmed, the mass threshold is 1 x 10(exp 15) Stellar Mass and the redshift range is 0.167 to 1.066. Archival observations from Chandra, XMM-Newton. and ROSAT provide X-ray luminosities and temperatures that are broadly consistent with this mass threshold. Our optical follow-up procedure also allowed us to assess the purity of the ACT cluster sample. Eighty (one hundred) percent of the 148 GHz candidates with signal-to-noise ratios greater than 5.1 (5.7) are confirmed as massive clusters. The reported sample represents one of the largest SZE-selected sample of massive clusters over all redshifts within a cosmologically-significant survey volume, which will enable cosmological studies as well as future studies on the evolution, morphology, and stellar populations in the most massive clusters in the Universe.

  11. Computed tomographic manifestations of abdominal and pelvic venous collaterals

    International Nuclear Information System (INIS)

    Pagani, J.J.; Thomas, J.L.; Bernardino, M.E.

    1982-01-01

    Obstruction of blood flow through the inferior vena cava and portal vein may produce venous collaterals. These include the paravertebral venous system and its communications with the ascending lumbar veins and azygous/hemiazygous system; gonadal, periureteric, and other retroperitoneal veins; abdominal wall veins; hemorrhoidal venous plexus; and the portal venous system. The anatomic location of these vessels is discussed. Computed tomography demonstrates them as round or tubular structures that are isodens when compared with other venous structures following contrast material administration. Techniques of examination and methods of differentiation of these vascular structures from other abnormalities, especially lymphadenopathy, are discussed

  12. RECRUITMENT AND SELECTION PROCESS OF HUMAN RESOURCES: A SAMPLE OF TRAVEL AGENCIES OPERATING IN FETHİYE

    OpenAIRE

    ERGÜN, Emre; GAVCAR, Erdoğan

    2013-01-01

    The purpose of the study was to understand the recruitment and selection process of travel agencies' employees operating in Fethiye. The data was collected from the department managers hired in travel agencies operating in Fethiye and analyzed using the statistical package programs.According to the results, the selection criteria were different between incoming agencies and the agencies that were not incoming. Besides, there was another difference on the agencies that have human resource...

  13. Selectivity in the sample preparation for the analysis of drug residues in products of animal origin using LC-MS

    NARCIS (Netherlands)

    Berendsen, B.J.A.; Stolker, A.A.M.; Nielen, M.W.F.

    2013-01-01

    Sample preparation is critical in relation to analysis time, sample throughput and therefore analysis costs. Due to recent advances in liquid chromatography-mass spectrometry (LC-MS) instrumentation, the detection of many compounds within one run became possible, and methods for the simultaneous

  14. Normal venous anatomy and physiology of the lower extremity.

    Science.gov (United States)

    Notowitz, L B

    1993-06-01

    Venous disease of the lower extremities is common but is often misunderstood. It seems that the focus is on the exciting world of arterial anatomy and pathology, while the topic of venous anatomy and pathology comes in second place. However, venous diseases such as chronic venous insufficiency, leg ulcers, and varicose veins affect much of the population and may lead to disability and death. Nurses are often required to answer complex questions from the patients and his or her family about the patient's disease. Patients depend on nurses to provide accurate information in terms they can understand. Therefore it is important to have an understanding of the normal venous system of the legs before one can understand the complexities of venous diseases and treatments. This presents an overview of normal venous anatomy and physiology.

  15. Gas6 Promotes Inflammatory (CCR2hiCX3CR1lo) Monocyte Recruitment in Venous Thrombosis.

    Science.gov (United States)

    Laurance, Sandrine; Bertin, François-René; Ebrahimian, Talin; Kassim, Yusra; Rys, Ryan N; Lehoux, Stéphanie; Lemarié, Catherine A; Blostein, Mark D

    2017-07-01

    Coagulation and inflammation are inter-related. Gas6 (growth arrest-specific 6) promotes venous thrombosis and participates to inflammation through endothelial-innate immune cell interactions. Innate immune cells can provide the initiating stimulus for venous thrombus development. We hypothesize that Gas6 promotes monocyte recruitment during venous thrombosis. Deep venous thrombosis was induced in wild-type and Gas6-deficient (-/-) mice using 5% FeCl 3 and flow reduction in the inferior vena cava. Total monocyte depletion was achieved by injection of clodronate before deep venous thrombosis. Inflammatory monocytes were depleted using an anti-C-C chemokine receptor type 2 (CCR2) antibody. Similarly, injection of an anti-chemokine ligand 2 (CCL2) antibody induced CCL2 depletion. Flow cytometry and immunofluorescence were used to characterize the monocytes recruited to the thrombus. In vivo, absence of Gas6 was associated with a reduction of monocyte recruitment in both deep venous thrombosis models. Global monocyte depletion by clodronate leads to smaller thrombi in wild-type mice. Compared with wild type, the thrombi from Gas6 -/- mice contain less inflammatory (CCR2 hi CX 3 CR1 lo ) monocytes, consistent with a Gas6-dependent recruitment of this monocyte subset. Correspondingly, selective depletion of CCR2 hi CX 3 CR1 lo monocytes reduced the formation of venous thrombi in wild-type mice demonstrating a predominant role of the inflammatory monocytes in thrombosis. In vitro, the expression of both CCR2 and CCL2 were Gas6 dependent in monocytes and endothelial cells, respectively, impacting monocyte migration. Moreover, Gas6-dependent CCL2 expression and monocyte migration were mediated via JNK (c-Jun N-terminal kinase). This study demonstrates that Gas6 specifically promotes the recruitment of inflammatory CCR2 hi CX 3 CR1 lo monocytes through the regulation of both CCR2 and CCL2 during deep venous thrombosis. © 2017 American Heart Association, Inc.

  16. Microbiological testing of devices used in maintaining peripheral venous catheters

    Directory of Open Access Journals (Sweden)

    Fernanda de Paula Rossini

    Full Text Available ABSTRACT Objective: to evaluate the use of peripheral venous catheters based on microbiological analysis of devices (dressing and three-way stopcocks and thus contribute to the prevention and infection control. Methods: this was a prospective study of microbiological analysis of 30 three-way stopcocks (external surfaces and lumens and 30 dressing used in maintaining the peripheral venous catheters of hospitalized adult patients. Results: all external surfaces, 40% of lumens, and 86.7% of dressing presented bacterial growth. The main species isolated in the lumen were 50% coagulase-negative Staphylococcus, 14.3% Staphylococcus aureus, and 14.3% Pseudomonas aeruginosa. Fifty nine percent of multidrug-resistant bacteria were isolated of the three-way stopcocks, 42% of the lumens, and 44% of the dressing with a predominance of coagulase-negative Staphylococcus resistant to methicillin. Besides, 18% gram-negative bacteria with resistance to carbapenems were identified from multidrug-resistant bacteria on the external surfaces of the three-way stopcocks. Conclusion: it is important to emphasize the isolation of coagulase-negative Staphylococcus and gram-negative bacteria resistant to methicillin and carbapenems in samples of devices, respectively, which reinforces the importance of nursing care in the maintenance of the biologically safe environment as well as prevention and infection control practices.

  17. Vibration and acoustic frequency spectra for industrial process modeling using selective fusion multi-condition samples and multi-source features

    Science.gov (United States)

    Tang, Jian; Qiao, Junfei; Wu, ZhiWei; Chai, Tianyou; Zhang, Jian; Yu, Wen

    2018-01-01

    Frequency spectral data of mechanical vibration and acoustic signals relate to difficult-to-measure production quality and quantity parameters of complex industrial processes. A selective ensemble (SEN) algorithm can be used to build a soft sensor model of these process parameters by fusing valued information selectively from different perspectives. However, a combination of several optimized ensemble sub-models with SEN cannot guarantee the best prediction model. In this study, we use several techniques to construct mechanical vibration and acoustic frequency spectra of a data-driven industrial process parameter model based on selective fusion multi-condition samples and multi-source features. Multi-layer SEN (MLSEN) strategy is used to simulate the domain expert cognitive process. Genetic algorithm and kernel partial least squares are used to construct the inside-layer SEN sub-model based on each mechanical vibration and acoustic frequency spectral feature subset. Branch-and-bound and adaptive weighted fusion algorithms are integrated to select and combine outputs of the inside-layer SEN sub-models. Then, the outside-layer SEN is constructed. Thus, "sub-sampling training examples"-based and "manipulating input features"-based ensemble construction methods are integrated, thereby realizing the selective information fusion process based on multi-condition history samples and multi-source input features. This novel approach is applied to a laboratory-scale ball mill grinding process. A comparison with other methods indicates that the proposed MLSEN approach effectively models mechanical vibration and acoustic signals.

  18. A Multiwavelength Study of a Sample of 70 μm Selected Galaxies in the COSMOS Field : I. Spectral Energy Distributions and Luminosities

    NARCIS (Netherlands)

    Kartaltepe, Jeyhan S.; Sanders, D. B.; Le Floc'h, E.; Frayer, D. T.; Aussel, H.; Arnouts, S.; Ilbert, O.; Salvato, M.; Scoville, N. Z.; Surace, J.; Yan, L.; Brusa, M.; Capak, P.; Caputi, K.; Carollo, C. M.; Civano, F.; Elvis, M.; Faure, C.; Hasinger, G.; Koekemoer, A. M.; Lee, N.; Lilly, S.; Liu, C. T.; McCracken, H. J.; Schinnerer, E.; Smolčić, V.; Taniguchi, Y.; Thompson, D. J.; Trump, J.

    We present a large robust sample of 1503 reliable and unconfused 70 μm selected sources from the multiwavelength data set of the Cosmic Evolution Survey. Using the Spitzer IRAC and MIPS photometry, we estimate the total infrared (IR) luminosity, L IR (8-1000 μm), by finding the best-fit template

  19. A novel knot selection method for the error-bounded B-spline curve fitting of sampling points in the measuring process

    International Nuclear Information System (INIS)

    Liang, Fusheng; Zhao, Ji; Ji, Shijun; Zhang, Bing; Fan, Cheng

    2017-01-01

    The B-spline curve has been widely used in the reconstruction of measurement data. The error-bounded sampling points reconstruction can be achieved by the knot addition method (KAM) based B-spline curve fitting. In KAM, the selection pattern of initial knot vector has been associated with the ultimate necessary number of knots. This paper provides a novel initial knots selection method to condense the knot vector required for the error-bounded B-spline curve fitting. The initial knots are determined by the distribution of features which include the chord length (arc length) and bending degree (curvature) contained in the discrete sampling points. Firstly, the sampling points are fitted into an approximate B-spline curve Gs with intensively uniform knot vector to substitute the description of the feature of the sampling points. The feature integral of Gs is built as a monotone increasing function in an analytic form. Then, the initial knots are selected according to the constant increment of the feature integral. After that, an iterative knot insertion (IKI) process starting from the initial knots is introduced to improve the fitting precision, and the ultimate knot vector for the error-bounded B-spline curve fitting is achieved. Lastly, two simulations and the measurement experiment are provided, and the results indicate that the proposed knot selection method can reduce the number of ultimate knots available. (paper)

  20. Selection of blood sampling times for determination of 51Cr-EDTA clearance in a screeening procedure

    International Nuclear Information System (INIS)

    Gullquist, R.; Askergren, A.; Brandt, R.; Silk, B.; Strandell, T.; Huddinge University Hospital

    1983-01-01

    In a group of 44 construction workers various blood sampling protocols were compared with regard to variability of the 51 Cr-EDTA clearance on repeated determinations. A comparison was also made among the different blood sampling protocols with a reference method using Simpson's formula in the area calculation. A double slope method lasting for two and a half hours was finally choosen and suggested as a screening procedure in industrial environment with blood sampling at 5, 15, 90, 120, 135 and 150 minutes after injection and with the patient resting in a semirecumbent position. (orig.) [de