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Sample records for alcohol copolymer onyx

  1. Left Gastric Artery Aneurysm: Successful Embolization with Ethylene Vinyl Alcohol Copolymer (Onyx)

    SciTech Connect

    Vargas, Hebert Alberto Cousins, Claire; Higgins, J. Nicholas; See, Teik Choon

    2008-03-15

    Patients with left gastric artery aneurysms present with hemorrhagic shock due to rupture or occasionally it is an incidental finding on abdominal CT examinations. Due to the increased morbidity and mortality from this condition, adequate diagnosis and treatment are essential. In this article we present a patient with a left gastric artery aneurysm treated with a new embolization agent, ethylene vinyl alcohol copolymer (Onyx)

  2. Onyx (Ethylene-vinyl Alcohol Copolymer) in Peripheral Applications

    PubMed Central

    Guimaraes, Marcelo; Wooster, Mathew

    2011-01-01

    Onyx is a nonadhesive liquid embolic agent approved for the treatment of brain arteriovenous malformations. Here, the use of Onyx is discussed in different peripheral procedures. The Onyx's features, its manipulation, technical details, tips, and tricks are presented followed by illustrative cases. PMID:22942553

  3. Endovascular Treatment of Acute Arterial Hemorrhage in Trauma Patients Using Ethylene Vinyl Alcohol Copolymer (Onyx)

    SciTech Connect

    Mueller-Wille, R. Heiss, P.; Herold, T.; Jung, E. M. Schreyer, A. G. Hamer, O. W. Rennert, J. Hoffstetter, P. Stroszczynski, C.; Zorger, N.

    2012-02-15

    Purpose: This study was designed to determine the feasibility and efficacy of endovascular embolization with liquid embolic agent ethylene vinyl alcohol copolymer (Onyx) in patients with acute traumatic arterial bleeding. Methods: This is a retrospective review of 13 patients (9 men and 4 women; mean age 45 years) with severe trauma who underwent embolotherapy using Onyx from November 2003 to February 2009. Bleeding was located in the pelvis (5 patients), kidney (3 patients), mesenteric region (2 patients), retroperitoneal space (2 patients), neck (1 patient), and thigh (1 patient). In three cases (23.1%), Onyx was used in conjunction with coils. We evaluate the technical and clinical success, procedural and embolization time, occurrence of rebleeding, and embolotherapy-related complications, such as necrosis or migration of Onyx into nontarget vessels. Results: In all patients, embolotherapy was technically and clinically successful on the first attempt. Control of bleeding could be reached with a mean time of 19 (range, 4-63) min after correct placement of the microcatheter in the feeding artery. No recurrent bleeding was detected. No unintended necrosis or migration of Onyx into a nontarget region was observed. During the follow-up period, three patients (23.1%) died due to severe intracranial hemorrhage, cardiac arrest, and sepsis. Conclusions: Transcatheter embolization with new liquid embolic agent Onyx is technically feasible and effective in trauma patients with acute arterial hemorrhage.

  4. Transsinusoidal Portal Vein Embolization with Ethylene Vinyl Alcohol Copolymer (Onyx): A Feasibility Study in Pigs

    SciTech Connect

    Smits, Maarten L. J.; Vanlangenhove, Peter Sturm, Emiel J. C.; Bosch, Maurice A. A. J. van den; Hav, Monirath Praet, Marleen; Vente, Maarten A. D.; Snaps, Frederic R.; Defreyne, Luc

    2012-10-15

    Purpose: Portal vein embolization is performed to increase the future liver remnant before liver surgery in patients with liver malignancies. This study assesses the feasibility of a transsinusoidal approach for portal vein embolization (PVE) with the ethylene vinyl alcohol copolymer, Onyx. Methods: Indirect portography through contrast injection in the cranial mesenteric artery was performed in eight healthy pigs. Onyx was slowly injected through a microcatheter from a wedged position in the hepatic vein and advanced through the liver lobules into the portal system. The progression of Onyx was followed under fluoroscopy, and the extent of embolization was monitored by indirect portography. The pigs were euthanized immediately (n = 2), at 7 days (n = 4), or at 21 days postprocedure (n = 2). All pigs underwent necropsy and the ex vivo livers were grossly and histopathologically analyzed. Results: Transsinusoidal PVE was successfully performed in five of eight pigs (63%). In 14 of 21 injections (67%), a segmental portal vein could be filled completely. A mean of 1.6 liver lobes per pig was embolized (range 1-2 lobes). There were no periprocedural adverse events. Focal capsular scarring was visible on the surface of two resected livers, yet the capsules remained intact. Histopathological examination showed no signs of recanalization or abscess formation. Mild inflammatory reaction to Onyx was observed in the perivascular parenchyma. Conclusions: The porcine portal vein can be embolized through injection of Onyx from a wedged position in the hepatic vein. Possible complications of transsinusoidal PVE and the effect on contralateral hypertrophy need further study.

  5. Transarterial Embolization of Type II Endoleaks after EVAR: The Role of Ethylene Vinyl Alcohol Copolymer (Onyx)

    SciTech Connect

    Mueller-Wille, Rene Wohlgemuth, Walter A. Heiss, Peter Wiggermann, Philipp Guentner, Oliver Schreyer, Andreas G. Hoffstetter, Patrick Stroszczynski, Christian; Zorger, Niels

    2013-10-15

    Purpose: To determine the feasibility and efficacy of transarterial endoleak embolization using the liquid embolic agent ethylene vinyl alcohol copolymer (Onyx). Methods: Over a 7-year period eleven patients (6 women, 5 men; mean age 68 years, range 37-83 years) underwent transarterial embolization of a type II endoleak after endovascular aortic aneurysm repair using the liquid embolic agent Onyx. Two patients (18 %) had a simple type II endoleak with only one artery in communication with the aneurysm sac, whereas 9 patients (82 %) had a complex type II endoleak with multiple communicating vessels. We retrospectively analyzed the technical and clinical success of transarterial type II endoleak embolization with Onyx. Complete embolization of the nidus was defined as technical success. Embolization was considered clinically successful when volume of the aneurysm sac was stable or decreased on follow-up CT scans. Result: Mean follow-up time was 26.0 (range 6-50) months. Clinical success was achieved in 8 of 11 patients (73 %). Transarterial nidus embolization with Onyx was technically successful in 6 of 11 patients (55 %). In three cases the nidus was embolized without direct catheterization from a more distal access through the network of collateral vessels. Conclusion: Onyx is a favorable embolic agent for transarterial endoleak embolization. To achieve the best clinical results, complete occlusion of the nidus is mandatory.

  6. Endovascular Treatment of a Superior Mesenteric Artery Aneurysm Secondary to Behcet's Disease with Onyx (Ethylene Vinyl Alcohol Copolymer)

    SciTech Connect

    Gueven, Koray Rozanes, Izzet; Kayabali, Murat; Minareci, Ozenc

    2009-01-15

    Behcet's disease is a complex multisystemic chronic inflammatory disease that is characterized by oral and genital aphtous ulcers and vasculitis. Aneurysms of major arteries are the most important cause of mortality in Behcet's disease. Four patients with superior mesenteric artery (SMA) aneurysms related to Behcet's disease have been reported in the literature. We report here the first successful endovascular treatment of a giant, wide-necked SMA aneurysm secondary to Behcet's disease. We performed a balloon-assisted embolization technique using ethylene vinyl alcohol copolymer (Onyx, ev3, Irvine, CA, USA). There were no signs of recurrence during 2-year follow-up.

  7. Ethylene vinyl alcohol copolymer (Onyx®) in peripheral interventional radiology: indications, advantages and limitations.

    PubMed

    Saeed Kilani, M; Izaaryene, J; Cohen, F; Varoquaux, A; Gaubert, J Y; Louis, G; Jacquier, A; Bartoli, J M; Moulin, G; Vidal, V

    2015-04-01

    Onyx(®) is a remarkable liquid embolizing agent that may allow a well-trained operator to undertake challenging embolization procedures. In multiple interventional radiology indications, the physico-chemical properties of Onyx(®) allow safe embolization. The purpose of this article is to review the advantages and disadvantages of Onyx(®) and identify its main indications.

  8. Ethylene-vinyl alcohol copolymer (Onyx(®)) transarterial embolization for post-traumatic high-flow priapism.

    PubMed

    Chevallier, Olivier; Gehin, Sophie; Foahom-Kamwa, Alain; Pottecher, Pierre; Favelier, Sylvain; Loffroy, Romaric

    2016-06-01

    We report a case of high-flow priapism treated successfully with superselective embolization of the cavernous artery. A 16-year-old male developed post-traumatic priapism subsequent to a fall causing blunt perineal trauma. He presented to our hospital four days after trauma. Immediately after the injury, he suffered painless sustained incomplete erection. High-flow priapism was diagnosed on the basis of color doppler ultrasonography findings. Computed tomography scan showed a high-flow arterio-venous fistula with feeders from branches of the right internal iliac artery. Selective arteriography of the right internal pudendal artery demonstrated an arterio-cavernous fistula. The fistula was superselectively embolized with ethylene-vinyl alcohol copolymer (Onyx(®)) liquid agent and disappeared completely. Improvement was noted, with significant detumescence on table. This was later confirmed on repeat color Doppler imaging. At follow-up 3 months later, he had normal erectile function. To our knowledge, transarterial embolization of high-flow priapism with Onyx(®) has never been reported and appears to be a safe and effective treatment for managing patients with such a condition.

  9. Ethylene-vinyl alcohol copolymer (Onyx(®)) transarterial embolization for post-traumatic high-flow priapism.

    PubMed

    Chevallier, Olivier; Gehin, Sophie; Foahom-Kamwa, Alain; Pottecher, Pierre; Favelier, Sylvain; Loffroy, Romaric

    2016-06-01

    We report a case of high-flow priapism treated successfully with superselective embolization of the cavernous artery. A 16-year-old male developed post-traumatic priapism subsequent to a fall causing blunt perineal trauma. He presented to our hospital four days after trauma. Immediately after the injury, he suffered painless sustained incomplete erection. High-flow priapism was diagnosed on the basis of color doppler ultrasonography findings. Computed tomography scan showed a high-flow arterio-venous fistula with feeders from branches of the right internal iliac artery. Selective arteriography of the right internal pudendal artery demonstrated an arterio-cavernous fistula. The fistula was superselectively embolized with ethylene-vinyl alcohol copolymer (Onyx(®)) liquid agent and disappeared completely. Improvement was noted, with significant detumescence on table. This was later confirmed on repeat color Doppler imaging. At follow-up 3 months later, he had normal erectile function. To our knowledge, transarterial embolization of high-flow priapism with Onyx(®) has never been reported and appears to be a safe and effective treatment for managing patients with such a condition. PMID:27429919

  10. Ethylene-vinyl alcohol copolymer (Onyx®) transarterial embolization for post-traumatic high-flow priapism

    PubMed Central

    Chevallier, Olivier; Gehin, Sophie; Foahom-Kamwa, Alain; Pottecher, Pierre; Favelier, Sylvain

    2016-01-01

    We report a case of high-flow priapism treated successfully with superselective embolization of the cavernous artery. A 16-year-old male developed post-traumatic priapism subsequent to a fall causing blunt perineal trauma. He presented to our hospital four days after trauma. Immediately after the injury, he suffered painless sustained incomplete erection. High-flow priapism was diagnosed on the basis of color doppler ultrasonography findings. Computed tomography scan showed a high-flow arterio-venous fistula with feeders from branches of the right internal iliac artery. Selective arteriography of the right internal pudendal artery demonstrated an arterio-cavernous fistula. The fistula was superselectively embolized with ethylene-vinyl alcohol copolymer (Onyx®) liquid agent and disappeared completely. Improvement was noted, with significant detumescence on table. This was later confirmed on repeat color Doppler imaging. At follow-up 3 months later, he had normal erectile function. To our knowledge, transarterial embolization of high-flow priapism with Onyx® has never been reported and appears to be a safe and effective treatment for managing patients with such a condition. PMID:27429919

  11. Pancreatic Arteriovenous Malformation Involving the Duodenum Embolized with Ethylene-Vinyl Alcohol Copolymer (Onyx)

    SciTech Connect

    Grasso, Rosario Francesco Cazzato, Roberto Luigi; Luppi, Giacomo; Faiella, Eliodoro; Del Vescovo, Riccardo; Giurazza, Francesco; Borzomati, Domenico; Coppola, Roberto; Beomonte Zobel, Bruno

    2012-08-15

    Arteriovenous malformation (AVM) of the pancreas is a rare condition. Most patients are asymptomatic or alternatively may present with a wide spectrum of symptoms. Traditionally, surgery has been considered the treatment of choice; however, alternative approaches, such as transcatheter embolization (TAE), may be proposed. We report a case of a 48-year-old man with a pancreatic head AVM, presenting with upper abdominal pain and slight anemia. The patient refused surgery and underwent TAE by means of ethylene-vinyl alcohol copolymer (EVOH). At 3 months follow-up, the patient was able to eat regularly, with no residual pain and no signs of anemia.

  12. Transarterial Onyx Embolization of an Orbital Solitary Fibrous Tumor.

    PubMed

    Hashemi, Nafiseh; Ling, Jeanie D; Soparkar, Charles; Sami, Mirwat; Ellezam, Benjamin; Klucznik, Richard; Lee, Andrew G; Chévez-Barrios, Patricia

    2015-02-01

    Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm sometimes found in the orbit. We report a case of an aggressive orbital SFT with enlarged feeding vessels that was successfully resected immediately after transarterial embolization with Onyx (ethylene vinyl alcohol copolymer). To our knowledge, this is the first report showing the histopathology of Onyx embolization material in an orbital SFT.

  13. Endovascular Embolization of Visceral Artery Aneurysms with Ethylene-vinyl Alcohol (Onyx): A Case Series

    SciTech Connect

    Bratby, M.J.; Lehmann, E.D.; Bottomley, J.; Kessel, D.O.; Nicholson, A.A.; McPherson, S.J.; Morgan, R.A.; Belli, A.-M.

    2006-12-15

    We report the application of the liquid embolic agent ethylene-vinyl alcohol (Onyx; MicroTherapeutics, Irvine, CA, USA) in the management of visceral artery aneurysms. The technique and indications for using Onyx are discussed with emphasis on the management of wide-necked aneurysms and maintenance of patency of the parent vessel. None of the cases was considered suitable for stent-grafting or embolization with conventional agents. Two aneurysms of the renal artery bifurcation and one aneurysm of the inferior pancreaticoduodenal artery were treated. Following treatment there was complete exclusion of all aneurysms. There was no evidence of end-organ infarction. Follow-up with intervals up to 6 months has shown sustained aneurysm exclusion. Onyx is known to be effective in the management of intracranial aneurysms. Our experience demonstrates the efficacy and applicability of the use of Onyx in the treatment of complex visceral artery aneurysms.

  14. CT and radiographic appearance of extracranial Onyx(®) embolization.

    PubMed

    Jia, J B; Green, C S; Cohen, A J; Helmy, M

    2015-03-01

    Onyx(®) (ev3, Irvine, CA, USA) is a liquid embolic agent composed of ethylene vinyl alcohol copolymer dissolved in dimethyl sulphoxide used for the treatment of intracranial arteriovenous malformations. Onyx is a preferred embolizing agent due to its unique properties, non-adhesive nature, and durability. In addition to its approved intracranial application, Onyx is also being used successfully in extracranial embolization in areas including extracranial aneurisms and vascular malformations, trauma, gastrointestinal bleeding, and neoplasms. Because of its increasing utilization, it is important for reporting radiologists to be able to recognize its extracranial appearance across different imaging techniques and to be familiar with its uses. The goal of this review is to describe the extracranial uses of Onyx and its appearance in various extracranial locations at radiography and CT, while providing didactic examples. Onyx appears radiodense at CT and plain radiography and has a curvilinear pattern following the expected path of the vessel embolized. At CT, Onyx creates streak artefact that may obstruct the view of surrounding tissues consistent with descriptions of other tantalum devices.

  15. Transcatheter Embolization of a Renal Artery Aneurysm Using Ethylene Vinyl Alcohol Copolymer

    SciTech Connect

    Rautio, Riitta Haapanen, Arto

    2007-04-15

    Our aim was to treat a clinically silent renal artery aneurysm. The patient was a 76-year-old man with elevated prostate-specific antigen and prostata biopsies with a gradus II-III adenocarcinoma who was incidentally found to have an aneurysm in his right renal artery. We performed a successful transcatheter embolization of the aneurysm using ethylene vinyl alcohol copolymer (Onyx). To avoid migration of the liquid material into the parent artery, a balloon was inflated in the orifice of the neck of the aneurysm while the liquid was injected. Five-month follow-up computed tomography (CT) imaging confirmed total occlusion of the aneurysm.

  16. Endovascular balloon-assisted embolization of high-flow peripheral vascular lesions using dual-lumen coaxial balloon microcatheter and Onyx: initial experience.

    PubMed

    Jagadeesan, Bharathi D; Mortazavi, Shabnam; Hunter, David W; Duran-Castro, Olga L; Snyder, Gregory B; Siedel, Glen F; Golzarian, Jafar

    2014-04-01

    Balloon-assisted embolization performed by delivering Onyx ethylene vinyl alcohol copolymer through a dual-lumen coaxial balloon microcatheter is a new technique for the management of peripheral vascular lesions. This technique does not require an initial reflux of Onyx to form around the tip of the microcatheter before antegrade flow of Onyx can commence. In a series of four patients who were treated with the use of this technique, the absence of significant reflux of Onyx was noted, as were excellent navigability and easy retrieval of the balloon microcatheter. However, in one patient, there was inadvertent adverse embolization of a digital artery, which was not caused by reflux of Onyx but could still be related to balloon inflation. PMID:24674217

  17. Endovascular balloon-assisted embolization of high-flow peripheral vascular lesions using dual-lumen coaxial balloon microcatheter and Onyx: initial experience.

    PubMed

    Jagadeesan, Bharathi D; Mortazavi, Shabnam; Hunter, David W; Duran-Castro, Olga L; Snyder, Gregory B; Siedel, Glen F; Golzarian, Jafar

    2014-04-01

    Balloon-assisted embolization performed by delivering Onyx ethylene vinyl alcohol copolymer through a dual-lumen coaxial balloon microcatheter is a new technique for the management of peripheral vascular lesions. This technique does not require an initial reflux of Onyx to form around the tip of the microcatheter before antegrade flow of Onyx can commence. In a series of four patients who were treated with the use of this technique, the absence of significant reflux of Onyx was noted, as were excellent navigability and easy retrieval of the balloon microcatheter. However, in one patient, there was inadvertent adverse embolization of a digital artery, which was not caused by reflux of Onyx but could still be related to balloon inflation.

  18. Onyx in Brain Arteriovenous Malformation Embolisation

    PubMed Central

    Hashim, Hilwati; Muda, A Sobri; Abdul Aziz, Aida; Abdul Hamid, Zuhanis

    2016-01-01

    Introduction Embolisation has long been used as an adjunct to surgical resection in the treatment of brain arteriovenous malformation (bAVM). The most commonly used embolic material, n-butylcyanoacrylate glue, requires experience and skill to handle its quick and unpredictable flow and polymerisation. A new liquid embolic agent, ethylene vinyl alcohol copolymer (Onyx), is less adhesive and polymerises slowly, which provides better control for radiologists performing embolisation. Objective To report our experience in embolisation using Onyx alone or in combination with histoacryl for bAVM embolisation in our tertiary referral centre. Methods We retrospectively reviewed the anatomy, technical conditions, complications and clinical outcome of all bAVM patients embolised at our centre using Onyx alone or in combination with n-butylcyanoacrylate glue. Results Between 2010 and 2013, 13 patients [6 (46.2%) male; 7 (53.8%) female; aged, 14–57 years] were included, and a total of 31 embolisations were performed. Clinical presentation included hemorrhage [9 (69.2%)], seizures [2 (15.4%)], and headache [2 (15.4%)]. Most AVMs were located in the brain hemispheres [12 (92.3%)] and measured <3 cm [7 (53.8%]. Complete occlusion of the AVM was obtained in 2 (15.4%) patients; 11 (84.6%) patients had partial occlusion [6 (54.5%) had <50% nidus occlusion]. Complications occurred in four procedures involving 3 patients (morbidity, 23.1%). This resulted in the death of 1 patient (mortality, 7.7%) and complete recovery with no disability in 2 patients. Conclusion The total nidal occlusion achieved herein is comparable to other similar studies. Our morbidity and mortality were higher compared to other studies which may be attributed to the small number of patients. More data is being collected which may better reflect on our experience. PMID:27660546

  19. Onyx in Brain Arteriovenous Malformation Embolisation

    PubMed Central

    Hashim, Hilwati; Muda, A Sobri; Abdul Aziz, Aida; Abdul Hamid, Zuhanis

    2016-01-01

    Introduction Embolisation has long been used as an adjunct to surgical resection in the treatment of brain arteriovenous malformation (bAVM). The most commonly used embolic material, n-butylcyanoacrylate glue, requires experience and skill to handle its quick and unpredictable flow and polymerisation. A new liquid embolic agent, ethylene vinyl alcohol copolymer (Onyx), is less adhesive and polymerises slowly, which provides better control for radiologists performing embolisation. Objective To report our experience in embolisation using Onyx alone or in combination with histoacryl for bAVM embolisation in our tertiary referral centre. Methods We retrospectively reviewed the anatomy, technical conditions, complications and clinical outcome of all bAVM patients embolised at our centre using Onyx alone or in combination with n-butylcyanoacrylate glue. Results Between 2010 and 2013, 13 patients [6 (46.2%) male; 7 (53.8%) female; aged, 14–57 years] were included, and a total of 31 embolisations were performed. Clinical presentation included hemorrhage [9 (69.2%)], seizures [2 (15.4%)], and headache [2 (15.4%)]. Most AVMs were located in the brain hemispheres [12 (92.3%)] and measured <3 cm [7 (53.8%]. Complete occlusion of the AVM was obtained in 2 (15.4%) patients; 11 (84.6%) patients had partial occlusion [6 (54.5%) had <50% nidus occlusion]. Complications occurred in four procedures involving 3 patients (morbidity, 23.1%). This resulted in the death of 1 patient (mortality, 7.7%) and complete recovery with no disability in 2 patients. Conclusion The total nidal occlusion achieved herein is comparable to other similar studies. Our morbidity and mortality were higher compared to other studies which may be attributed to the small number of patients. More data is being collected which may better reflect on our experience.

  20. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethylene-vinyl acetate-vinyl alcohol copolymers... acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2... accordance with the following prescribed conditions: (a) Ethylene-vinyl acetate-vinyl alcohol copolymers...

  1. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate-vinyl alcohol copolymers... acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2... accordance with the following prescribed conditions: (a) Ethylene-vinyl acetate-vinyl alcohol copolymers...

  2. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethylene-vinyl acetate-vinyl alcohol copolymers... acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2... accordance with the following prescribed conditions: (a) Ethylene-vinyl acetate-vinyl alcohol copolymers...

  3. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene-vinyl acetate-vinyl alcohol copolymers... acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2... accordance with the following prescribed conditions: (a) Ethylene-vinyl acetate-vinyl alcohol copolymers...

  4. Dosimetric measurements of Onyx embolization material for stereotactic radiosurgery

    SciTech Connect

    Roberts, Donald A.; Balter, James M.; Chaudhary, Neeraj; Gemmete, Joseph J.; Pandey, Aditya S.

    2012-11-15

    Purpose: Arteriovenous malformations are often treated with a combination of embolization and stereotactic radiosurgery. Concern has been expressed in the past regarding the dosimetric properties of materials used in embolization and the effects that the introduction of these materials into the brain may have on the quality of the radiosurgery plan. To quantify these effects, the authors have taken large volumes of Onyx 34 and Onyx 18 (ethylene-vinyl alcohol copolymer doped with tantalum) and measured the attenuation and interface effects of these embolization materials. Methods: The manufacturer provided large cured volumes ({approx}28 cc) of both Onyx materials. These samples were 8.5 cm in diameter with a nominal thickness of 5 mm. The samples were placed on a block tray above a stack of solid water with an Attix chamber at a depth of 5 cm within the stack. The Attix chamber was used to measure the attenuation. These measurements were made for both 6 and 16 MV beams. Placing the sample directly on the solid water stack and varying the thickness of solid water between the sample and the Attix chamber measured the interface effects. The computed tomography (CT) numbers for bulk material were measured in a phantom using a wide bore CT scanner. Results: The transmission through the Onyx materials relative to solid water was approximately 98% and 97% for 16 and 6 MV beams, respectively. The interface effect shows an enhancement of approximately 2% and 1% downstream for 16 and 6 MV beams. CT numbers of approximately 2600-3000 were measured for both materials, which corresponded to an apparent relative electron density (RED) {rho}{sub e}{sup w} to water of approximately 2.7-2.9 if calculated from the commissioning data of the CT scanner. Conclusions: We performed direct measurements of attenuation and interface effects of Onyx 34 and Onyx 18 embolization materials with large samples. The introduction of embolization materials affects the dose distribution of a MV

  5. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethylene-vinyl acetate-vinyl alcohol copolymers... Repeated Use Food Contact Surfaces § 177.1360 Ethylene-vinyl acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2) may be safely used as articles...

  6. Complete preoperative embolization of hemangioblastoma vessels with Onyx 18.

    PubMed

    Horvathy, Denes B; Hauck, Erik F; Ogilvy, Christopher S; Hopkins, L Nelson; Levy, Elad I; Siddiqui, Adnan H

    2011-03-01

    The authors present a preliminary experience with ethyl-enevinylalcohol copolymer (Onyx) for hemangioblastoma vessel embolization before surgical resection. The patient presented with neck pain, dizziness, blurred vision, vomiting, and loss of balance. Diagnostic imaging revealed a posterior fossa cystic mass with a nodular component. Angiography demonstrated a significant vascular blush with arteriovenous shunting that was characteristic of a hemangioblastoma. Tumor vessels originating off the left posterior inferior cerebellar artery were embolized before surgery using Onyx 18 (ev3, Covidien Vascular Therapies, Mansfield, MA, USA). This resulted in complete obliteration of all tumor vessels, transforming a highly vascular tumor into an avascular mass. A safe and uneventful surgical resection was performed the next day. Onyx is a valuable embolic agent for preoperative hemangioblastoma vessel embolization. Because of its low viscosity, Onyx penetrates deeply into the tumor vasculature and allows complete obliteration of tumor vessels. Risks of the intervention have to be carefully weighed against the benefits. If preoperative embolization is indicated, the use of Onyx should be strongly considered. PMID:21237650

  7. Biodegradable poly(ethylene-g-vinyl alcohol) copolymer

    SciTech Connect

    Watanabe, T.; Huang, S.J.

    1993-12-31

    A graft reaction of poly(vinyl alcohol), PVA, and polyethylene grafted width maleic anhydride has been carried out in order to add hydrophobicity to PVA. Biodegradabilities of PVA and the polyethylene derivative are well-known. The graft reaction product that was prepared by a simple procedure was characterized with FTIR, DSC, and TGA. The FTIR spectra indicated that ester bonds were formed in the product. It was also found from the thermal analysis that the graft compound was less crystalline that raw PVA and the thermal properties of the graft copolymer remarkably depended on molar ratio of succinic anhydride group in the polyethylene derivative that was used in the graft reaction. The degradation of the material will be discussed.

  8. Preoperative Embolization of Extra-axial Hypervascular Tumors with Onyx

    PubMed Central

    Fusco, Matthew R.; Salem, Mohamed M.; Reddy, Arra S.; Ogilvy, Christopher S.; Kasper, Ekkehard M.; Thomas, Ajith J.

    2016-01-01

    Objective Preoperative endovascular embolization of intracranial tumors is performed to mitigate anticipated intraoperative blood loss. Although the usage of a wide array of embolic agents, particularly polyvinyl alcohol (PVA), has been described for a variety of tumors, literature detailing the efficacy, safety and complication rates for the usage of Onyx is relatively sparse. Materials and Methods We reviewed our single institutional experience with pre-surgical Onyx embolization of extra-axial tumors to evaluate its efficacy and safety and highlight nuances of individualized cases. Results Five patients underwent pre-surgical Onyx embolization of large or giant extra-axial tumors within 24 hours of surgical resection. Four patients harbored falcine or convexity meningiomas (grade I in 2 patients, grade II in 1 patient and grade III in one patient), and one patient had a grade II hemangiopericytoma. Embolization proceeded uneventfully in all cases and there were no complications. Conclusion This series augments the expanding literature confirming the safety and efficacy of Onyx in the preoperative embolization of extra-axial tumors, underscoring its advantage of being able to attain extensive devascularization via only one supplying pedicle. PMID:27114961

  9. Ping-pong polymerization by allylation and hydroformylation for alternating vinyl alcohol-vinyl monomer copolymers.

    PubMed

    Ito, Shingo; Noguchi, Masaki; Nozaki, Kyoko

    2012-11-01

    Inspired by the enzymatic ping-pong mechanism, we designed a novel "ping-pong polymerization", which employs allylation and hydroformylation in an iterative and alternating manner. Thus, alternating and regioregular vinyl alcohol-vinyl monomer copolymers possessing multiple hydroxy groups in a periodical manner were successfully synthesized.

  10. Radiation cross-linking of ethylene vinyl alcohol copolymer functionalized with m-isopropenyl-{alpha},{alpha}-dimethyl benzyl isocyanate

    SciTech Connect

    Ekman, K.B.; Naesman, J.H.

    1993-12-31

    In order to allow radiation cross-linking at low radiation doses, pendant unsaturation was introduced by reactive processing of ethylene vinyl alcohol copolymer and m-isopropenyl-{alpha},{alpha}-dimethyl benzyl isocyanate. Oxygen permeability of ethylene vinyl alcohol copolymer decreased with increasing degree of functionalization, while irradiation of the samples form trapped radicals, which act as oxygen scavengers and consequently no oxygen permeability was detected. However, radical activity was inhibited by annealing the samples at 110{degrees}C for 2.5 h, resulting in a 24% higher oxygen permeability value for the irradiated unfunctionalized copolymer, while the oxygen permeability values of the irradiated functionalized samples were 13% lower. Laminates, of m-isopropenyl-{alpha},{alpha}-dimethyl benzyl isocyanate functionalized ethylene vinyl alcohol copolymer and m-isopropenyl-{alpha},{alpha}-dimethyl benzyl isocyanate functionalized ethylene hydroxyethyl methacrylate copolymer acquired improved adhesive strength both at dry and wet conditions as well as at elevated temperatures upon exposure to radiation.

  11. Alkaline battery containing a separator of a cross-linked copolymer of vinyl alcohol and unsaturated carboxylic acid

    NASA Technical Reports Server (NTRS)

    Hsu, L. C.; Philipp, W. H.; Sheibley, D. W.; Gonzalez-Sanabria, O. D. (Inventor)

    1985-01-01

    A battery separator for an alkaline battery is described. The separator comprises a cross linked copolymer of vinyl alcohol units and unsaturated carboxylic acid units. The cross linked copolymer is insoluble in water, has excellent zincate diffusion and oxygen gas barrier properties and a low electrical resistivity. Cross linking with a polyaldehyde cross linking agent is preferred.

  12. Polyethylene glycol-g-polyvinyl alcohol grafted copolymer: reproductive toxicity study in Wistar rats.

    PubMed

    Heuschmid, Franziska F; Schneider, Steffen; Schuster, Paul; Lauer, Birthe; van Ravenzwaay, Bennard

    2013-07-01

    Polyethylene glycol-g-polyvinyl alcohol (PEG-PVA) grafted copolymer was administered by gavage to groups of 25 male and 25 female young Wistar rats at doses of 0 (vehicle control), 100, 300, or 1000 mg/kg bw/day for one generation (F0). The study followed the treated F0 generation through mating, gestation, lactation, and weaning of the F1 generation. F1 animals were mated and followed to gestation day (GD) 15-17 at which time F2 implants were evaluated. There were no indications from the various clinical and gross pathological examinations that the oral administration of PEG-PVA grafted copolymer to the F0-parental rats produced any signs of general, reproductive, or developmental toxicity in the F0 or F1 animals or F2 implants. Based on the lack of any dose-related or biologically relevant effects on fertility, reproduction, development, and overall health of rats gavaged with PEG-PVA grafted copolymer and their progeny, the no-observed-adverse effect level (NOAEL) was determined to be the highest dose tested of 1000 mg/kg bw/day.

  13. Subchronic toxicity of polyethylene glycol-g-polyvinyl alcohol grafted copolymer.

    PubMed

    Heuschmid, Franziska F; Schuster, Paul; Lauer, Birthe; Buesen, Roland; Mellert, Werner; Groeters, Sibylle; van Ravenzwaay, Bennard

    2013-07-01

    The safety of polyethylene glycol-g-polyvinyl alcohol (PEG-PVA) grafted copolymer was evaluated in a 13-week oral toxicity study in rats and in a 9-month oral toxicity study in dogs. Wistar rats were administered 600, 3000, or 15,000 ppm PEG-PVA grafted copolymer in their drinking water whereas beagle dogs were fed 3000, 10,000, or 30,000 ppm PEG-PVA grafted copolymer in the diet. There were no mortalities, no adverse clinical signs, no toxicologically adverse effects on body weight or body weight gain, feed consumption, hematological, clinical chemistry or urinary parameters, or histopathology in either species. In rats, no treatment-related effects were observed in the functional observational battery (FOB) or related measurements of motor activity. Increased water consumption observed in rats at the highest dose was the only test substance-induced effect noted. The no-observed-adverse-effect level (NOAEL) was the highest concentration tested in both species: 15,000 ppm in rats (corresponding to a daily intake of 1611 mg/kg bw for males and 2191 mg/kg bw for females) and 30,000 ppm in dogs (corresponding to a mean daily intake of 783 mg/kg bw for males and 811 mg/kg bw for females).

  14. Developmental toxicity of polyethylene glycol-g-polyvinyl alcohol grafted copolymer in rats and rabbits.

    PubMed

    Heuschmid, Franziska F; Schneider, Steffen; Schuster, Paul; Lauer, Birthe; van Ravenzwaay, Bennard

    2013-07-01

    Polyethylene glycol-g-polyvinyl alcohol (PEG-PVA) grafted copolymer was evaluated in developmental toxicity studies with Wistar rats and Himalayan rabbits. Pregnant Wistar rats were gavaged with 0 (vehicle control), 100, 300, or 1000 mg PEG-PVA grafted copolymer/kg bw/day from gestation day (GD) 6-15. Pregnant Himalayan rabbits received the same treatment from GD 6 to 19. On GD 20 and 29 for rats and rabbits, respectively, the animals were euthanized and were examined grossly. For each dam, corpora lutea were counted and number and distribution of implantation sites were determined. The fetuses were removed, sexed, weighed, and evaluated for any external, soft tissue, and skeletal findings. No significant findings were found that could be attributed to administration of PEG-PVA grafted copolymer. Under the conditions of these studies, the no-observed-adverse-effect level (NOAEL) for maternal and developmental toxicity in both species was the highest dose tested of 1000 mg/kg bw/day.

  15. 75 FR 42431 - Onyx Specialty Papers, Inc; Notice Soliciting Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... Energy Regulatory Commission Onyx Specialty Papers, Inc; Notice Soliciting Applications July 14, 2010. On April 29, 2009, Onyx Specialty Papers, Inc. (Onyx), licensee for the Willow Mill Project No. 2985, filed... Housatonic River. The turbine generating unit is located in the basement of MeadWestvaco's paper mill....

  16. Polyethylene glycol-polyvinyl alcohol grafted copolymer: study of the bioavailability after oral administration to rats.

    PubMed

    Heuschmid, Franziska F; Schuster, Paul; Lauer, Birthe; Fabian, Eric; Leibold, Edgar; van Ravenzwaay, Bennard

    2013-07-01

    The absorption, urinary excretion, and the biliary excretion of a single oral dose of 10 or 1000 mg/kg bw of (14)C-polyethylene glycol-polyvinyl alcohol (PEG-PVA) grafted copolymer were studied in adult male and female rats. In a balance/excretion experiment, the total excretion of ingested radioactivity was determined over a period of 168 h and residual radioactivity was detected in selected tissues and the carcass. In a biliary excretion experiment, excretion of radioactivity via the bile duct was determined over a period of 48 h after administration of the substance to cannulated rats. Most, if not all, of the radioactivity (>100%) was excreted within 48 h via the feces regardless of sex or dose. Urinary excretion was very limited: 0.45-0.50% of dose at the low dose and 0.22-0.27% of dose at the high dose. At both dose levels, residual radioactivity in the carcass and all organs and tissues after 168 h was ≤ 0.02% of dose. Biliary excretion was 0.01-0.02% of dose. Based on these findings, the bioavailability of PEG-PVA grafted copolymer was determined to be <1% demonstrating that absorption was virtually negligible following a single oral administration to male and female rats. PMID:23321424

  17. Polyethylene glycol-polyvinyl alcohol grafted copolymer: study of the bioavailability after oral administration to rats.

    PubMed

    Heuschmid, Franziska F; Schuster, Paul; Lauer, Birthe; Fabian, Eric; Leibold, Edgar; van Ravenzwaay, Bennard

    2013-07-01

    The absorption, urinary excretion, and the biliary excretion of a single oral dose of 10 or 1000 mg/kg bw of (14)C-polyethylene glycol-polyvinyl alcohol (PEG-PVA) grafted copolymer were studied in adult male and female rats. In a balance/excretion experiment, the total excretion of ingested radioactivity was determined over a period of 168 h and residual radioactivity was detected in selected tissues and the carcass. In a biliary excretion experiment, excretion of radioactivity via the bile duct was determined over a period of 48 h after administration of the substance to cannulated rats. Most, if not all, of the radioactivity (>100%) was excreted within 48 h via the feces regardless of sex or dose. Urinary excretion was very limited: 0.45-0.50% of dose at the low dose and 0.22-0.27% of dose at the high dose. At both dose levels, residual radioactivity in the carcass and all organs and tissues after 168 h was ≤ 0.02% of dose. Biliary excretion was 0.01-0.02% of dose. Based on these findings, the bioavailability of PEG-PVA grafted copolymer was determined to be <1% demonstrating that absorption was virtually negligible following a single oral administration to male and female rats.

  18. How Do Spherical Diblock Copolymer Nanoparticles Grow during RAFT Alcoholic Dispersion Polymerization?

    PubMed Central

    2015-01-01

    A poly(2-(dimethylamino)ethyl methacrylate) (PDMA) chain transfer agent (CTA) is used for the reversible addition–fragmentation chain transfer (RAFT) alcoholic dispersion polymerization of benzyl methacrylate (BzMA) in ethanol at 70 °C. THF GPC analysis indicated a well-controlled polymerization with molecular weight increasing linearly with conversion. GPC traces also showed high blocking efficiency with no homopolymer contamination apparent and Mw/Mn values below 1.35 in all cases. 1H NMR studies confirmed greater than 98% BzMA conversion for a target PBzMA degree of polymerization (DP) of up to 600. The PBzMA block becomes insoluble as it grows, leading to the in situ formation of sterically stabilized diblock copolymer nanoparticles via polymerization-induced self-assembly (PISA). Fixing the mean DP of the PDMA stabilizer block at 94 units and systematically varying the DP of the PBzMA block enabled a series of spherical nanoparticles of tunable diameter to be obtained. These nanoparticles were characterized by TEM, DLS, MALLS, and SAXS, with mean diameters ranging from 35 to 100 nm. The latter technique was particularly informative: data fits to a spherical micelle model enabled calculation of the core diameter, surface area occupied per copolymer chain, and the mean aggregation number (Nagg). The scaling exponent derived from a double-logarithmic plot of core diameter vs PBzMA DP suggests that the conformation of the PBzMA chains is intermediate between the collapsed and fully extended state. This is in good agreement with 1H NMR studies, which suggest that only 5−13% of the BzMA residues of the core-forming chains are solvated. The Nagg values calculated from SAXS and MALLS are in good agreement and scale approximately linearly with PBzMA DP. This suggests that spherical micelles grow in size not only as a result of the increase in copolymer molecular weight during the PISA synthesis but also by exchange of individual copolymer chains between micelles

  19. Modifying theophylline microparticle surfaces via the sequential deposition of poly(vinyl alcohol-co-vinyl acetate) copolymers.

    PubMed

    Zhao, Yanjun; Alas'ad, Mannar A; Jones, Stuart A

    2014-03-10

    The aim of this study was to investigate the manner in which amphiphilic poly(vinyl alcohol-co-vinyl acetate) copolymers (PVA-Ac) assembled on drug surfaces and use this information to generate a novel bi-layer polymer coating for a theophylline microparticle. Three grades of PVA-Ac, differing in hydrolysis degree and monomer distribution, were synthesised, characterised by nuclear magnetic resonance and shown to interact with theophylline when suspended in water. PVA-Ac deposition at the solid/liquid interface was driven by polymer hydrogen bond formation in a process that induced consequential structural changes in the macromolecule architecture. The most hydrophobic grades of the copolymer appeared to adsorb in a multistage process that passed through a series of equilibrium points. The PVA-Ac surface allowed two grades of the copolymer to be sequentially adsorbed and this resulted in the fabrication of a microparticle with desirable characteristics for pharmaceutical formulation production. PMID:24355619

  20. Modifying theophylline microparticle surfaces via the sequential deposition of poly(vinyl alcohol-co-vinyl acetate) copolymers.

    PubMed

    Zhao, Yanjun; Alas'ad, Mannar A; Jones, Stuart A

    2014-03-10

    The aim of this study was to investigate the manner in which amphiphilic poly(vinyl alcohol-co-vinyl acetate) copolymers (PVA-Ac) assembled on drug surfaces and use this information to generate a novel bi-layer polymer coating for a theophylline microparticle. Three grades of PVA-Ac, differing in hydrolysis degree and monomer distribution, were synthesised, characterised by nuclear magnetic resonance and shown to interact with theophylline when suspended in water. PVA-Ac deposition at the solid/liquid interface was driven by polymer hydrogen bond formation in a process that induced consequential structural changes in the macromolecule architecture. The most hydrophobic grades of the copolymer appeared to adsorb in a multistage process that passed through a series of equilibrium points. The PVA-Ac surface allowed two grades of the copolymer to be sequentially adsorbed and this resulted in the fabrication of a microparticle with desirable characteristics for pharmaceutical formulation production.

  1. Inverse gas chromatography study on the effect of humidity on the mass transport of alcohols in an ethylene-vinyl alcohol copolymer near the glass transition temperature.

    PubMed

    Cava, David; Lagarón, José M; Martínez-Giménez, Félix; Gavara, Rafael

    2007-12-21

    Inverse gas chromatography (IGC) was used to study the effect of moisture on transport properties of three low molecular weight alcohols (methanol, ethanol, and 1-butanol) through high barrier copolymers of ethylene-vinyl alcohol with an ethylene content of 38%mol (EVOH38) at 40 degrees C. The value of the partition coefficient (K) was obtained by using two approaches: (a) the fit of the slope of sorption isotherms obtained through the method of Kiselev and Yashin; and (b) the solution to the model of Romdhane and Danner obtained by using the law of moments. The second method also allowed the estimation of the diffusion coefficient (D(p)) at the different humidity conditions. None of these two methods were applicable at low values of relative humidity. With the first method, the diffusion of the permeants through the copolymer was not fast enough to allow them to reach the core of the EVOH particles used as stationary phase resulting in sorption values unrealistically low. The fit of the chromatograms obtained by using the second method also suggested questionable values of the mass transport parameters. Although the theoretical curve perfectly described the chromatogram, the low extent of the interaction and the slow diffusion resulted in interdependent values of the coefficients K and D(p), with infinite pairs of values providing the same curve profile. As the relative humidity of the carrier gas increased, the diffusivity and the sorption of the alcohols also increased, making both methods applicable. In the case of the partition coefficient, the sorption of the biggest molecules (ethanol and 1-butanol) was the most affected, the increment of K for methanol being moderate. As regards the D(p) value, methanol was the most influenced compound and 1-butanol the least. Finally, a sharp increment of the D(p) of the three alcohols was observed between 35 and 47% RH and attributed to the plasticization of the copolymer.

  2. Transcatheter arterial embolization of a uterine artery pseudoaneurysm with Onyx® following D&C for uterine bleeding.

    PubMed

    Wendel, Mark; Beheshti, Michael; Yousaf, Muhammad; Erdem, Eren

    2013-01-01

    Transcatheter uterine artery embolization is well described and performed for treatment of symptomatic uterine leiomyomas, for postpartum hemorrhage, and for hemorrhage following hysterectomy. Embolic agents have included polyvinyl alcohol, gelfoam, coils, and Embospheres®. We present a case of severe uterine hemorrhage after a missed abortion (after two instances of dilatation and curettage), which could not be managed with traditional embolic techniques but was successfully controlled with Onyx®.

  3. Linear programming computational experience with onyx

    SciTech Connect

    Atrek, E.

    1994-12-31

    ONYX is a linear programming software package based on an efficient variation of the gradient projection method. When fully configured, it is intended for application to industrial size problems. While the computational experience is limited at the time of this abstract, the technique is found to be robust and competitive with existing methodology in terms of both accuracy and speed. An overview of the approach is presented together with a description of program capabilities, followed by a discussion of up-to-date computational experience with the program. Conclusions include advantages of the approach and envisioned future developments.

  4. Onyx embolization of anterior condylar confluence dural arteriovenous fistula.

    PubMed

    Takemoto, Koichiro; Tateshima, Satoshi; Rastogi, Sachin; Gonzalez, Nestor; Jahan, Reza; Duckwiler, Gary; Vinuela, Fernando

    2014-03-01

    The anterior condylar confluence (ACC) is a small complex venous structure located medial to the jugular vein and adjacent to the hypoglossal canal. To our knowledge, this is the first report of transvenous Onyx embolization for ACC dural arteriovenous fistula (DAVF). Three patients with ACC DAVF were treated using the Onyx liquid embolic agent with or without detachable coils. Complete angiographic obliteration of the fistulas was achieved in all cases without permanent lower cranial neuropathy. This report suggests that the controlled penetration of Onyx is advantageous in order to obliterate ACC DAVFs with a small amount of embolic material.

  5. Onyx embolization of anterior condylar confluence dural arteriovenous fistula.

    PubMed

    Takemoto, Koichiro; Tateshima, Satoshi; Rastogi, Sachin; Gonzalez, Nestor; Jahan, Reza; Duckwiler, Gary; Vinuela, Fernando

    2013-01-01

    The anterior condylar confluence (ACC) is a small complex venous structure located medial to the jugular vein and adjacent to the hypoglossal canal. To our knowledge, this is the first report of transvenous Onyx embolization for ACC dural arteriovenous fistula (DAVF). Three patients with ACC DAVF were treated using the Onyx liquid embolic agent with or without detachable coils. Complete angiographic obliteration of the fistulas was achieved in all cases without permanent lower cranial neuropathy. This report suggests that the controlled penetration of Onyx is advantageous in order to obliterate ACC DAVFs with a small amount of embolic material.

  6. Onyx-Advanced Aeropropulsion Simulation Framework Created

    NASA Technical Reports Server (NTRS)

    Reed, John A.

    2001-01-01

    The Numerical Propulsion System Simulation (NPSS) project at the NASA Glenn Research Center is developing a new software environment for analyzing and designing aircraft engines and, eventually, space transportation systems. Its purpose is to dramatically reduce the time, effort, and expense necessary to design and test jet engines by creating sophisticated computer simulations of an aerospace object or system (refs. 1 and 2). Through a university grant as part of that effort, researchers at the University of Toledo have developed Onyx, an extensible Java-based (Sun Micro-systems, Inc.), objectoriented simulation framework, to investigate how advanced software design techniques can be successfully applied to aeropropulsion system simulation (refs. 3 and 4). The design of Onyx's architecture enables users to customize and extend the framework to add new functionality or adapt simulation behavior as required. It exploits object-oriented technologies, such as design patterns, domain frameworks, and software components, to develop a modular system in which users can dynamically replace components with others having different functionality.

  7. Double-lumen arterial balloon catheter technique for Onyx embolization of dural arteriovenous fistulas: initial experience

    PubMed Central

    Chiu, Albert Ho Yuen; Aw, Grace; Wenderoth, Jason David

    2014-01-01

    Background Dural arteriovenous fistulas are vascular malformations with variable clinical symptoms that range in severity from completely asymptomatic to seizures, dementia, loss of vision and intracranial hemorrhage. Historically, surgical obliteration was the treatment of choice but, more recently, endovascular embolization has become the first-line treatment. The liquid embolic agent Onyx (ethyl vinyl copolymer) has become the agent of choice, but problems with reflux around the delivery microcatheter and inadvertent venous penetration have arisen. Methods and results We present six cases in which the double-lumen balloon microcatheter was used to transarterially embolize dural arteriovenous fistulas via injection of Onyx through the wire lumen. Depending on the individual pathology a venous balloon was also used in some cases. The advantages and disadvantages of the use of these devices are discussed. Conclusions We consider that the use of the double-lumen balloon technique for fistula embolization has the potential for reducing overall procedural times, procedural failures and catheter retention in certain situations. In such cases we would advocate this as a first-line technique. When lower profile, more navigable balloon catheters become available, this may become the standard of care. PMID:23749795

  8. 76 FR 43680 - Onyx Specialty Papers, Inc.; Notice of Application Accepted for Filing, Soliciting Motions To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ... Energy Regulatory Commission Onyx Specialty Papers, Inc.; Notice of Application Accepted for Filing... License. b. Project No.: 2985-008. c. Date Filed: June 1, 2010. d. Applicant: Onyx Specialty Papers, Inc... Clements, Counsel for Onyx Specialty Papers, Inc., Van Ness Feldman, PC, 1050 Jefferson Street, NW.,...

  9. Mechanical Removal of Migrated Onyx Due to Microcatheter Rupture During AVM Embolization: A Technical Case Report.

    PubMed

    Senturk, Cagin

    2015-12-01

    We report a case where migrated Onyx could be removed safely with a mechanical thrombectomy device after withdrawal of the damaged microcatheter. A microcatheter was retained in the superior cerebellar artery with attached Onyx fragments on its tip during embolization of a bled cerebellar AVM. During retrieval maneuvers microcatheter shaft was ruptured and Onyx fragments were released into the vertebrobasilar system causing occlusion. Finally, Onyx fragment on tip of the microcatheter could be detached with dimethyl sulfoxide injection and the microcatheter could be withdrawn. A Merci retriever device (Concentric Medical, Mountain View, CA, USA) was successfully used to retrieve most of the dislodged Onyx material and recanalize the vertebrobasilar circulation.

  10. Periprocedural Bleeding Complications of Brain AVM Embolization with Onyx

    PubMed Central

    Liu, L.; Jiang, C.; He, H.; Li, Y.; Wu, Z.

    2010-01-01

    Summary The advent of Onyx has provided a new method for neurointerventional therapists to treat brain AVMs. Although some retrospective studies have reported complications for AVM embolization with Onyx, periprocedural bleeding complications with Onyx embolization have not yet been described in detail. The aim of this retrospective study was to analyze the factors of Onyx-related bleeding complications and to find a way to avoid and manage these complications. From January 2003, patients with AVMs recruited in our institution started to be treated by Onyx embolization. From January 2007 to July 2009, 143 consecutive interventions were performed in 126 patients using flow-independent microcatheters and Onyx as embolic agents. Seven patients encountered bleeding complications (5.4% per patients and 4.7% per procedures) during or after the endovascular procedures. Among them, five bleeding episodes occurred during procedures, the other two after procedures. Details of the seven patients' clinical presentations, imaging presentations, speculative reasons and management of these complications were recorded. Follow-up data, including postoperative course, clinical symptoms and duration of follow-up were documented. The five active bleedings discovered in procedures were managed in time, and the patients recovered without any new neurological symptoms compared with preoperation. However, of the two bleeding episodes that occurred after interventional procedures, one was detected half an hour later: the patient was remained comatose two months later after resection of right occipital hematoma; the other who encountered intraventricular and midbrain hemorrhage was treated conservatively and suffered Parinaud syndrome and hemianesthesia. Conclusion: Periprocedural bleeding of AVMs embolization is considered a severe and devastating complication. The clinical course and prognosis of bleeding mostly depends on prompt detection and management. Interventional embolization is an

  11. Sonic Onyx: Case Study of an Interactive Artwork

    NASA Astrophysics Data System (ADS)

    Ahmed, Salah Uddin; Jaccheri, Letizia; M'kadmi, Samir

    Software supported art projects are increasing in numbers in recent years as artists are exploring how computing can be used to create new forms of live art. Interactive sound installation is one kind of art in this genre. In this article we present the development process and functional description of Sonic Onyx, an interactive sound installation. The objective is to show, through the life cycle of Sonic Onyx, how a software dependent interactive artwork involves its users and raises issues related to its interaction and functionalities.

  12. Tentorial Dural Arteriovenous Fistula Treated Using Transarterial Onyx Embolization.

    PubMed

    Kim, Hyun-Jung; Yang, Ji-Ho; Lee, Hong-Jae; Lee, Hyung-Jin

    2015-09-01

    Tentorial dural arteriovenous fistula (DAVF) is a rare vascular disease, which has high risk of intracranial hemorrhage. We present two cases of tentorial DAVF which were successfully treated with single trial of transarterial embolization using Onyx. We briefly reviewed the types of the tentorial DAVF and strategies of treatment. PMID:26539273

  13. Onyx resorbtion with AVM recanalization after complete AVM obliteration.

    PubMed

    Bauer, Andrew M; Bain, Mark D; Rasmussen, Peter A

    2015-06-01

    Brain arteriovenous malformations (BAVM) are some of the most complex lesions treated by clinical neuroscientists. The recent publication of the ARUBA trial, showing higher complication rates with treatment compared with the natural history over a short period of follow-up, puts even more pressure on the physician to achieve complete BAVM eradication without complication. These lesions are often treated by multimodality therapy with some combination of endovascular embolization, radiosurgery, and microsurgical resection; however, multimodality therapy involves the additive risk of procedural complication with each procedure. While surgical resection has long been accepted as monotherapy with good cure rates, staged pre-operative endovascular embolization has facilitated microsurgical resection with lower blood loss. Endovascular embolization is more often utilized in conjunction with surgical resection, and often the portions of the AVM and feeders that are completely embolized with Onyx or glue may not be surgically resected since they have been "internally obliterated." We present a case where the AVM was preoperatively embolized with Onyx and subsequently partially surgically resected. Post-operative angiography showed complete obliteration or "cure" of the AVM with no filling of the nidus or early venous drainage. The patient presented 12 months later with seizures and imaging showed volume loss in the residual Onyx cast and recanalization of the AVM nidus. The patient subsequently underwent repeat resection with complete removal of the residual AVM and Onyx cast. To our knowledge this is the first published report of volume loss within the Onyx cast leading to recanalization of the AVM nidus. This suggests that extreme care should be taken with partial resection of the AVM nidus or with embolization for cure, as late recanalization may occur.

  14. Transarterial Ethylene Vinyl Alcohol Copolymer Visualization and Penetration After Embolization of Life-Threatening Hemoptysis: Technical and Clinical Outcomes

    SciTech Connect

    Bommart, Sebastien; Bourdin, Arnaud; Giroux, Marie France; Klein, Francois; Micheau, Antoine; Bares, Valerie Monnin; Kovacsik, Helene

    2012-06-15

    Objectives: This study was designed to evaluate the feasibility of using ethylene vinyl alcohol copolymer (EVAC) for bronchial artery embolization (BAE) in patients with life-threatening hemoptysis and to compare the visualization and transarterial penetration of EVAC under fluoroscopy and computed tomography (CT). Methods: Fifteen patients (mean age, 62.9 (range, 24-82) years) who were referred for life-threatening hemoptysis (27 month period) underwent BAE using EVAC. All patients had thoracic CT examination before and after BAE. Technical and clinical results were evaluated. Visibility and extent of cast penetration (graded 1-4) on fluoroscopy and postprocedure CT were assessed and compared. Results: BAE was feasible in all but one artery (due to spasm; n = 27; 96.4%). No procedure-related complications or deaths were detected. Two patients had recurrent bleeding in the following day (13.3%). Immediate clinical success was achieved in 14 cases (93.3%) after reembolization of pulmonary artery pseudoaneurysm in one patient (mean follow-up, 43.5 (range, 14-148) days). Visibility of the cast was possible in 73.3% of patients (n = 11) under fluoroscopy (mean cast penetration 1.66) and in all patients under CT (mean cast penetration 2.06). The postinjection fluoroscopic visibility in 6 of 15 (40%) patients was inferior to CT (P < 0.02). Conclusions: BAE with EVAC seems to be feasible and safe with immediate control of hemoptysis in most patients. The postinjection fluoroscopic visibility of EVAC under fluoroscopy was inferior to CT.

  15. Onyx injection by direct puncture for the treatment of hypervascular spinal metastases close to the anterior spinal artery: initial experience.

    PubMed

    Clarençon, Frédéric; Di Maria, Federico; Cormier, Evelyne; Sourour, Nader-Antoine; Enkaoua, Eric; Sailhan, Frédéric; Iosif, Christina; Le Jean, Lise; Chiras, Jacques

    2013-06-01

    Presurgical devascularization of hypervascular spinal metastases has been shown to be effective in preventing major blood loss during open surgery. Most often, embolization can be performed using polyvinyl alcohol (PVA) microparticles. However, in some cases, the close relationship between the feeders of the metastases and the feeders of the anterior spinal artery (ASA) poses a risk of spinal cord ischemia when PVA microparticle embolization is performed. The authors present their early experience in the treatment of spinal metastases close to the ASA; in 2 cases they injected Onyx-18, by direct puncture, into hypervascular posterior arch spinal metastases situated close to the ASA. Two women, one 36 and the other 55 years of age, who presented with spinal lesions (at the posterior arch of C-4 and T-6, respectively) from thyroid and a kidney tumors, were sent to the authors' department to undergo presurgical embolization. After having performed a complete spinal digital subtraction angiography study, a regular angiography catheter was positioned at the ostium of the artery that mainly supplied the lesion. Then, with the patient in the left lateral decubitus position, direct puncture with 18-gauge needles of the lesion was performed using roadmap guidance. Onyx-18 was injected through the needles under biplanar fluoroscopy. Satisfactory devascularization of the lesions was obtained; the ASA remained patent in both cases. The metastases were surgically removed in both cases within the 48 hours after the embolization and major blood loss did not occur. Presurgical devascularization of hypervascular spinal metastases close the ASA by direct puncture with Onyx-18 seems to be an effective technique and appears to be safe in terms of the preserving the ASA's patency. PMID:23600580

  16. Thermoluminescence glow curve analysis of natural onyx from Turkey.

    PubMed

    Dogan, Tamer; Toktamış, Hüseyin; Yüksel, Mehmet; Topaksu, Mustafa; Yazici, A Necmeddin

    2015-02-01

    In this study, the thermoluminesce (TL) properties of natural onyx were determined after β-irradiation ((90)Sr/(90)Y) at room temperature. The effect of the additive dose and variable heating rate for TL glow peaks of the sample were investigated. Computerized glow curve deconvolution (CGCD) methods were used to determine the number of peaks and kinetic parameters related to the TL glow peaks in natural onyx from Turkey. It was also determined kinetic parameters of onyx by means of the variable heating rate (VHR) method. The sample was exposed to β-irradiation between 2.4 Gy and 2.457 kGy. The CGCD methods showed that the glow curve of sample is the superposition of at least six first order components which were ascribed as P1-P6. The dose responses of some peaks have similar patterns and they follow linearity. The effect of heating rates on the response of dosimetric glow peaks of sample was studied. The maximum TL peak intensities of glow curve are decreasing with increasing heating rate and maximum TL peak intensities at 1 °C/s drops to 20% of the initial value when the sample is read at 6 °C/s.

  17. Liver Hypertrophy After Percutaneous Portal Vein Embolization: Comparison of N-Butyl-2-Cyanocrylate Versus Sodium Acrylate-Vinyl Alcohol Copolymer Particles in a Swine Model

    SciTech Connect

    Tsoumakidou, Georgia; Theocharis, Stamatis; Ptohis, Nikolaos Alexopoulou, Efthimia; Mantziaras, George; Kelekis, Nikolaos L. Brountzos, Elias N.

    2011-10-15

    Purpose: Percutaneous portal vein embolization (PPVE) induces hypertrophy of the future liver remnant before hepatic resection. The ideal embolic material has not yet been determined. We compared N-butyl-2-cyanocrylate (NBCA) with sodium acrylate-vinyl alcohol copolymer particles using a swine model. Materials and Methods: Twelve pigs underwent PPVE. Six pigs (group A) were embolized with NBCA, and 6 pigs (group B) were embolized with sodium acrylate-vinyl alcohol copolymer particles. Computed tomographic volumetry of the embolized lobe (EL) and the nonembolized lobe (NEL), along with liver function tests, was performed before and at 14 and 28 days after embolization. Tissue samples from both lobes were taken 14 and 28 days after PPVE. Results: NEL-volume and NEL-ratio increases were significantly higher in group A at 14 and 28 days after PPVE (78 and 52% and 91 and 66%, respectively) than in group B (32 and 12% and 28 and 10%, respectively) (p < 0.05). Percent change of the EL-volume was significantly higher for group A at 28 days after PPVE. No statistically significant difference was found between the groups regarding hepatocyte proliferation on the NEL and apoptosis on the EL at both time intervals. Conclusion: PPVE using NBCA is more efficient and causes more NEL hypertrophy than microspheres.

  18. 77 FR 40353 - Onyx Specialty Papers, Inc; Notice of Availability of Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-09

    ..., 52 FR 47897), Commission staff has reviewed the Onyx Specialty Papers, Inc.'s application for... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Onyx Specialty Papers, Inc; Notice of Availability of...

  19. Alcohol

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Alcohol KidsHealth > For Teens > Alcohol Print A A A ... you can make an educated choice. What Is Alcohol? Alcohol is created when grains, fruits, or vegetables ...

  20. Successful embolization of iatrogenic ruptured coronary artery using Onyx: a new technique.

    PubMed

    Asouhidou, I; Katsaridis, V

    2014-12-01

    Iatrogenic perforation of coronary artery is rare during percutaneous coronary intervention (PCI); however the complications are life-threatening. Patients in this clinical setting may be treated either by stent placement, closure of the perforation with fibrin glue or coils, or with emergency bypass surgery. Onyx, a new material that has been used successfully in cerebral arteries, represents a new and safe alternative. The advantage of Onyx is that it is easily injected through a microcatheter and it allows for a longer injection time having also the ability to reach difficult anatomical locations. We present the first case of successful embolization of a right coronary artery perforation during coronary angiography using Onyx.

  1. Endovascular Treatment of Cerebral AVM: Our Experience with Onyx

    PubMed Central

    Pérez-Higueras, A.; Rossi López, R.; Quiñones Tapia, D.

    2005-01-01

    Summary We have been using Onyx, a non-adhesive liquid polymer, to treat cerebral AVMs endovascularly since 1999. During this time we have treated 45 consecutive, unselected patients. From the outset this product brought about a change in our approach to treating this type of lesion because of the different injection behaviour observed for this material compared with the adhesive Histoacryl that had been employed until then. The object of this article is to assess the results achieved by our team using this new embolic agent, following angiographic and clinical follow-up of cases for a minimum of six months and a maximum of five years (mean: two years). We propose new categories of cerebral AVM based on the expected behaviour of Onyx within the nidus. Our appraisal indicates that we have improved our angiographic results, achieving complete occlusion of the malformation in 22% of cases and over 80-% closure in 69% of cases. The morbimortality rate for the procedure was 18%. PMID:20584469

  2. Benzyl alcohol and block copolymer micellar lithography: a versatile route to assembling gold and in situ generated titania nanoparticles into uniform binary nanoarrays.

    PubMed

    Polleux, Julien; Rasp, Matthias; Louban, Ilia; Plath, Nicole; Feldhoff, Armin; Spatz, Joachim P

    2011-08-23

    Simultaneous synthesis and assembly of nanoparticles that exhibit unique physicochemical properties are critically important for designing new functional devices at the macroscopic scale. In the present study, we report a simple version of block copolymer micellar lithography (BCML) to synthesize gold and titanium dioxide (TiO(2)) nanoarrays by using benzyl alcohol (BnOH) as a solvent. In contrast to toluene, BnOH can lead to the formation of various gold nanopatterns via salt-induced micellization of polystyrene-block-poly(vinylpyridine) (PS-b-P2VP). In the case of titania, the use of BCML with a nonaqueous sol-gel method, the "benzyl alcohol route", enables the fabrication of nanopatterns made of quasi-hexagonally organized particles or parallel wires upon aging a (BnOH-TiCl(4)-PS(846)-b-P2VP(171))-containing solution for four weeks to grow TiO(2) building blocks in situ. This approach was found to depend mainly on the relative lengths of the polymer blocks, which allows nanoparticle-induced micellization and self-assembly during solvent evaporation. Moreover, this versatile route enables the design of uniform and quasi-ordered gold-TiO(2) binary nanoarrays with a precise particle density due to the absence of graphoepitaxy during the deposition of TiO(2) onto gold nanopatterns.

  3. Direct Tumor Embolization of Sinonasal Unclassified Spindle Cell Sarcoma with Onyx

    PubMed Central

    Kansal, Ankit; Srinet, Prateek; Manes, Richard Peter

    2016-01-01

    Objectives  To evaluate the use of a new tumor embolization agent, Onyx (Covidien, Dublin, Ireland), for the use of intraoperative embolization of a sinonasal unclassified spindle cell sarcoma. Methods  A 45-year-old female patient presented to the rhinology clinic with a nasal mass. A biopsy revealed a highly vascular mass consistent with a sinonasal unclassified spindle cell sarcoma. Secondary to its extensive vascularity, the patient underwent preoperative transarterial embolization (TAE) before definitive resection. Due to complex vascular anatomy including feeding vessels emanating from intracranial circulation, incomplete embolization was achieved. Subsequently, intraoperative embolization with Onyx at the time of resection was performed. Results  Intraoperative Onyx use resulted in almost complete devascularization of the tumor with decreased risk of intracranial embolization. Conclusions  Intraoperative embolization with Onyx after an incomplete TAE can be a safe and effective method of achieving near-total embolization of sinonasal tumors. PMID:27652195

  4. Direct Tumor Embolization of Sinonasal Unclassified Spindle Cell Sarcoma with Onyx

    PubMed Central

    Kansal, Ankit; Srinet, Prateek; Manes, Richard Peter

    2016-01-01

    Objectives  To evaluate the use of a new tumor embolization agent, Onyx (Covidien, Dublin, Ireland), for the use of intraoperative embolization of a sinonasal unclassified spindle cell sarcoma. Methods  A 45-year-old female patient presented to the rhinology clinic with a nasal mass. A biopsy revealed a highly vascular mass consistent with a sinonasal unclassified spindle cell sarcoma. Secondary to its extensive vascularity, the patient underwent preoperative transarterial embolization (TAE) before definitive resection. Due to complex vascular anatomy including feeding vessels emanating from intracranial circulation, incomplete embolization was achieved. Subsequently, intraoperative embolization with Onyx at the time of resection was performed. Results  Intraoperative Onyx use resulted in almost complete devascularization of the tumor with decreased risk of intracranial embolization. Conclusions  Intraoperative embolization with Onyx after an incomplete TAE can be a safe and effective method of achieving near-total embolization of sinonasal tumors.

  5. Direct Endoscopic Intratumoral Injection of Onyx for the Preoperative Embolization of a Recurrent Juvenile Nasal Angiofibroma

    PubMed Central

    Hira, A.; Chao, K.

    2011-01-01

    Summary Percutaneous injection of embolization material within head and neck tumors is being described as an alternative or adjunct to transarterial embolization. Access in these reports is by computed tomography (CT) guidance, which is cumbersome given the need to transport the patient from the CT scanner to angiography suite. We describe a case of direct percutaneous onyx embolization of juvenile nasal angiofibroma following endoscopic access in the angiography suite including self-sustained onyx combustion during surgical electrocautery. PMID:22192553

  6. Alcohol

    MedlinePlus

    ... Text Size: A A A Listen En Español Alcohol Wondering if alcohol is off limits with diabetes? Most people with diabetes can have a moderate amount of alcohol. Research has shown that there can be some ...

  7. Alcohol

    MedlinePlus

    If you are like many Americans, you drink alcohol at least occasionally. For many people, moderate drinking ... risky. Heavy drinking can lead to alcoholism and alcohol abuse, as well as injuries, liver disease, heart ...

  8. Alcohol

    MedlinePlus

    ... Got Homework? Here's Help White House Lunch Recipes Alcohol KidsHealth > For Kids > Alcohol Print A A A Text Size What's in ... What Is Alcoholism? Say No en español El alcohol Getting the Right Message "Hey, who wants a ...

  9. Formulation and in vitro characterization of novel sildenafil citrate-loaded polyvinyl alcohol-polyethylene glycol graft copolymer-based orally dissolving films.

    PubMed

    Xu, Li-Li; Shi, Li-Li; Cao, Qing-Ri; Xu, Wei-Juan; Cao, Yue; Zhu, Xiao-Yin; Cui, Jing-Hao

    2014-10-01

    This work was aimed to develop novel sildenafil citrate (SC)-loaded polyvinyl alcohol (PVA)-polyethylene glycol (PEG) graft copolymer (Kollicoat(®) IR)-based orally dissolving films (ODFs) using a solvent casting method. Formulation factors such as plasticizers and disintegrants were optimized on the basis of characteristics of blank ODFs. The SC-loaded ODF with a loading capacity up to 6.25mg in an area of 6 cm(2) was prepared and evaluated in terms of mechanical properties, disintegration time and dissolution rate. The physicochemical properties of drug-loaded ODF were also investigated using the scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The blank ODF composed of Kollicoat(®) IR, sodium alginate (ALG-Na) and glycerol (10:2:1.5, w/w) had a remarkably short disintegration time of about 20s. The SC-loaded ODF showed a delayed disintegration time (about 25s), but exhibited improved mechanical properties when compared to the blank ODF. SC was homogeneously dispersed throughout the ODF and the crystalline form of drug had been partly changed, existing strong hydrogen bonding between the drug and carriers. The Kollicoat(®) IR/ALG-Na based ODFs containing SC might be an alternative to conventional tablet for the treatment of male erectile dysfunction.

  10. Novel hydrogels of chitosan and poly(vinyl alcohol)-g-glycolic acid copolymer with enhanced rheological properties.

    PubMed

    Lejardi, A; Hernández, R; Criado, M; Santos, Jose I; Etxeberria, A; Sarasua, J R; Mijangos, C

    2014-03-15

    Poly(vinyl alcohol) (PVA) has been grafted with glycolic acid (GL), a biodegradable hydroxyl acid to yield modified poly(vinyl alcohol) (PVAGL). The formation of hydrogels at pH = 6.8 and physiological temperature through blending chitosan (CS) and PVAGL at different concentrations has been investigated. FTIR, DOSY NMR and oscillatory rheology measurements have been carried out on CS/PVAGL hydrogels and the results have been compared to those obtained for CS/PVA hydrogels prepared under the same conditions. The experimental results point to an increase in the number of interactions between chitosan and PVAGL in polymer hydrogels prepared with modified PVA. The resulting materials with enhanced elastic properties and thixotropic behavior are potential candidates to be employed as injectable materials for biomedical applications.

  11. Alcoholism

    PubMed Central

    Girard, Donald E.; Carlton, Bruce E.

    1978-01-01

    There are important measurements of alcoholism that are poorly understood by physicians. Professional attitudes toward alcoholic patients are often counterproductive. Americans spend about $30 billion on alcohol a year and most adults drink alcohol. Even though traditional criteria allow for recognition of the disease, diagnosis is often made late in the natural course, when intervention fails. Alcoholism is a major health problem and accounts for 10 percent of total health care costs. Still, this country's 10 million adult alcoholics come from a pool of heavy drinkers with well defined demographic characteristics. These social, cultural and familial traits, along with subtle signs of addiction, allow for earlier diagnosis. Although these factors alone do not establish a diagnosis of alcoholism, they should alert a physician that significant disease may be imminent. Focus must be directed to these aspects of alcoholism if containment of the problem is expected. PMID:685264

  12. Embolization of traumatic and non-traumatic peripheral vascular lesions with Onyx

    PubMed Central

    Regine, Renato; De Siero, Michele; Rescigno, Antonio; Sica, Vincenzo; Cantarela, Raffaele; Villari, Vincenzo

    2015-01-01

    Purpose The aim of our study is to verify the feasibility and the efficacy of Onyx as embolization agent in the treatment of traumatic and non-traumatic peripheral vascular lesions. Materials and Methods In the period between September 2006 and March 2012, we treated with Onyx 26 patients (14 males/12 females; age range, 18–85 years old; mean age, 65 years old), 11 of which with traumatic peripheral vascular lesions and 15 with non-traumatic vascular lesions (9 neoplastic hemorrhagic lesions, 3 arteriovenous malformations (AVMs) and 3 aneurysms). Follow-up controls were performed with clinical examination and by multidetector computed tomography (MDCT) imaging 1, 6, and 12 months after the procedure. Results All peripheral vascular lesions were embolized with Onyx; 3 patients with aneurysms were treated with Onyx associated with endovascular coils. Four elective and 22 emergency embolization procedures were performed. In all patients, we obtained cessation of bleeding and the complete and permanent embolization of all vascular lesions. Conclusions Onyx is an effective and safe embolization agent for peripheral vascular lesions. PMID:25838923

  13. Onyx extrusion through the scalp after embolization of dural arteriovenous fistula.

    PubMed

    Singla, Amit; Fargen, Kyle Michael; Hoh, Brian

    2016-09-01

    A man in his sixties referred with symptoms of episodic left lip numbness and left arm weakness was diagnosed with a Borden type 3 dural arteriovenous fistula (DAVF) on DSA. Successful Onyx embolization of the DAVF was performed via the distal left occipital artery using an ev3 Apollo detachable tip microcatheter. He underwent surgical obliteration for the residual DAVF 3 days later. Three months later during a routine postoperative clinic visit, the patient produced a plastic bag containing multiple small pieces of Onyx cast and the detached tip of the Apollo microcatheter that had extruded out from his scalp through small spontaneous holes about 5 weeks after the embolization procedure. This spontaneous extrusion of Onyx can be alarming to the patient not expecting it; however, prior knowledge and discussion can lessen the anxiety of both the treating physician and the patient dealing with such a situation.

  14. Onyx extrusion through the scalp after embolization of dural arteriovenous fistula.

    PubMed

    Singla, Amit; Fargen, Kyle Michael; Hoh, Brian

    2015-01-01

    A man in his sixties referred with symptoms of episodic left lip numbness and left arm weakness was diagnosed with a Borden type 3 dural arteriovenous fistula (DAVF) on DSA. Successful Onyx embolization of the DAVF was performed via the distal left occipital artery using an ev3 Apollo detachable tip microcatheter. He underwent surgical obliteration for the residual DAVF 3 days later. Three months later during a routine postoperative clinic visit, the patient produced a plastic bag containing multiple small pieces of Onyx cast and the detached tip of the Apollo microcatheter that had extruded out from his scalp through small spontaneous holes about 5 weeks after the embolization procedure. This spontaneous extrusion of Onyx can be alarming to the patient not expecting it; however, prior knowledge and discussion can lessen the anxiety of both the treating physician and the patient dealing with such a situation.

  15. Roman onyx glass: A study of production recipes and colorants, using PIXE spectrometry

    NASA Astrophysics Data System (ADS)

    Fleming, S. J.; Swann, C. P.

    1994-03-01

    The most attractive Roman glass produced during the latter half of the 1st century B.C. was mosaic ware — vessels and dishes molded from arrays of composite, multi-colored canes which create abstract floral and geometric designs. We have studied a range of such vessels, all of them colored amber and white in a way which was intended to imitate elite vessels that were carved from onyx stone. We have differentiated three ways in which onyx patterns were achieved in this glass. Taking advantage of the spatial resolution and detection sensitivity of PIXE spectrometry, we have studied the "recipes" for colorants used in these onyx patterns, thus raising the notion that each one may have been fashionable in just certain regions of the Roman World, and/or in vogue only during a certain time period.

  16. Curative Transvenous Onyx Embolization of a Maxillary Arteriovenous Malformation in a Child: Report of a New Technique.

    PubMed

    Limbucci, Nicola; Spinelli, Giuseppe; Nappini, Sergio; Renieri, Leonardo; Consoli, Arturo; Rosi, Andrea; Mangiafico, Salvatore

    2016-03-01

    Endovascular management of maxillary arteriovenous malformation (AVMs) can be complex. Transarterial, transvenous, and direct puncture embolization has been described. The authors report the case of a 9-year-old girl with a hemorrhagic maxillary AVM, which has been treated by transvenous embolization after failure of transarterial embolization. The venous pouch was catheterized with a detachable tip microcatheter and occluded by slow Onyx injection. Onyx filled the pouch and retrogradely reached some arterial feeders, achieving complete occlusion. Bleeding episode ceased and at 6 months follow-up no recurrence was found. Maxillary AVMs can be successfully treated by transvenous Onyx embolization.

  17. Curative Transvenous Onyx Embolization of a Maxillary Arteriovenous Malformation in a Child: Report of a New Technique.

    PubMed

    Limbucci, Nicola; Spinelli, Giuseppe; Nappini, Sergio; Renieri, Leonardo; Consoli, Arturo; Rosi, Andrea; Mangiafico, Salvatore

    2016-03-01

    Endovascular management of maxillary arteriovenous malformation (AVMs) can be complex. Transarterial, transvenous, and direct puncture embolization has been described. The authors report the case of a 9-year-old girl with a hemorrhagic maxillary AVM, which has been treated by transvenous embolization after failure of transarterial embolization. The venous pouch was catheterized with a detachable tip microcatheter and occluded by slow Onyx injection. Onyx filled the pouch and retrogradely reached some arterial feeders, achieving complete occlusion. Bleeding episode ceased and at 6 months follow-up no recurrence was found. Maxillary AVMs can be successfully treated by transvenous Onyx embolization. PMID:26872284

  18. The Incidence of Trigeminocardiac Reflex in Endovascular Treatment of Dural Arteriovenous Fistula with Onyx

    PubMed Central

    Lv, X.; Li, Y.; Jiang, C.; Wu, Z.

    2010-01-01

    Summary This paper reports the incidence of trigeminocardiac reflex (TCR) in endovascular treatment of dural arteriovenous fistulas (DAVFs) with Onyx. The consecutive case histories of 45 patients with DAVFs, treated with Onyx transarterially and transvenously, from February 2005 to February 2008 at Beijing Tiantan Hospital, China, were retrospectively reviewed. The time period was limited as the anesthetic and intravascular procedure was performed under the same standardized anesthetic protocol and by the same team. The TCR rate was subsequently calculated. Of the 45 patients, five showed evidence of TCR during transarterial Onyx injection and transvenous DMSO injection. Their HR fell 50% during intravascular procedures compared with levels immediately before the stimulus. However, blood pressure values were stable in all cases. The TCR rate for all patients was 11.1% (95% CI, 4 to 24%), 7.7% (95% CI, 2 to 21%) in patients treated intraarterially and 33.3% (4 to 78%) in patients treated intravenously. Once HR has fallen, intravenous atropine is indicated to block the depressor response and prevention further TCR episodes. TCR may occur due to chemical stimulus of DMSO and Onyx cast formation under a standardized anesthetic protocol and should be blunted by atropine. PMID:20377980

  19. 75 FR 6377 - Onyx Specialty Papers, Inc.; Notice of Availability of Draft Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ... Energy Regulatory Commission's regulations, 18 CFR Part 380 (Order No. 486,52 FR 47897), the Office of... Energy Regulatory Commission Onyx Specialty Papers, Inc.; Notice of Availability of Draft Environmental... filed electronically via Internet in lieu of paper. The Commission strongly encourages...

  20. Onyx removal after embolization of a superior sagittal sinus dural arteriovenous fistula involving scalp artery

    PubMed Central

    Watanabe, Jun; Maruya, Jun; Nishimaki, Keiichi; Ito, Yasushi

    2016-01-01

    Background: Most dural arteriovenous fistula (DAVF) in superior sagittal sinus (SSS) requires multimodal treatment. Onyx embolization is useful for DAVF; however, scalp artery embolization has cast extrusion risk. Case Description: A 59-year-old male presented with involuntary movements of both legs and progressive dementia. Cerebral angiography demonstrated the DAVF in the SSS fed by bilateral superficial temporal, occipital, and middle meningeal arteries. The posterior SSS was thrombosed, and the main drainers were cortical veins. Combined treatment with transarterial embolization using Onyx and transvenous embolization using coils was performed. Although symptoms were improved, a small DAVF remained. Two months later, Onyx cast extrusion through the scalp was observed, requiring removal and debridement because of infection at the extrusion sites. Surgery for the residual DAVF would be difficult because of scalp condition; therefore, an additional endovascular treatment was conducted, completely occluding DAVF. Conclusion: Onyx embolization is useful for DAVF; however, scalp artery embolization has cast extrusion risk. Therefore, scalp infection should be considered because it may preclude additional surgical procedures. PMID:27313969

  1. Alcohol.

    ERIC Educational Resources Information Center

    Schibeci, Renato

    1996-01-01

    Describes the manufacturing of ethanol, the effects of ethanol on the body, the composition of alcoholic drinks, and some properties of ethanol. Presents some classroom experiments using ethanol. (JRH)

  2. Onyx HD-500 embolization of intracranial aneurysms: modified technique using continuous balloon inflation under conscious sedation.

    PubMed

    Rahme, Ralph; Grande, Andrew; Jimenez, Lincoln; Abruzzo, Todd A; Ringer, Andrew J

    2014-08-01

    The conventional technique of intracranial aneurysm embolization using Onyx HD-500 (ev3 Neurovascular, Irvine, CA, USA) involves repetitive balloon inflation-deflation cycles under general anesthesia. By limiting parent artery occlusion to 5 minutes, this cyclic technique is thought to minimize cerebral ischemia. However, intermittent balloon deflation may lengthen procedure time and allow balloon migration, resulting in intimal injury or Onyx leakage. We report our experience using a modified technique of uninterrupted Onyx injection with continuous balloon occlusion under conscious sedation. All Onyx embolization procedures for unruptured aneurysms performed by the senior author (A.J.R.) between September 2008 and April 2010 were retrospectively reviewed. Demographic, clinical, angiographic, and procedural data were recorded. Twenty-four embolization procedures were performed in 21 patients with 23 aneurysms, including four recurrences. Twenty aneurysms (87%) involved the paraclinoid or proximal supraclinoid internal carotid artery. Size ranged from 2.5 to 24mm and neck diameter from 2 to 8mm. The modified technique was employed in 19 cases. All but one patient (94.4%) tolerated continuous balloon inflation. Complete occlusion was achieved in 20 aneurysms (83.3%) and subtotal occlusion in three (12.5%). Stable angiographic results were seen in 85%, 94%, 94%, and 100% of patients at 6, 12, 24, and 36months, respectively. There were no deaths. Permanent non-disabling neurological morbidity occurred in one patient (4.2%). Minor, transient, and/or angiographic complications were seen in three patients (12.5%), none related to the technique itself. Onyx embolization of unruptured intracranial aneurysms can be safely and effectively performed using continuous balloon inflation under conscious sedation.

  3. Initial experience with dual-lumen balloon catheter injection for preoperative Onyx embolization of skull base paragangliomas.

    PubMed

    Ladner, Travis R; He, Lucy; Davis, Brandon J; Yang, George L; Wanna, George B; Mocco, J

    2016-06-01

    OBJECT Paragangliomas are highly vascular head and neck tumors for which preoperative embolization is often considered to facilitate resection. The authors evaluated their initial experience using a dual-lumen balloon to facilitate preoperative embolization in 5 consecutive patients who underwent preoperative transarterial Onyx embolization assisted by the Scepter dual-lumen balloon catheter between 2012 and 2014. OBJECT The authors reviewed the demographic and clinical records of 5 patients who underwent Scepter-assisted Onyx embolization of a paraganglioma followed by resection between 2012 and 2014. Descriptive statistics of clinical outcomes were assessed. RESULTS Five patients (4 with a jugular and 1 with a vagal paraganglioma) were identified. Three paragangliomas were embolized in a single session, and each of the other 2 were completed in 3 staged sessions. The mean volume of Onyx used was 14.3 ml (range 6-30 ml). Twenty-seven vessels were selectively catheterized for embolization. All patients required selective embolization via multiple vessels. Two patients required sacrifice of parent vessels (1 petrocavernous internal carotid artery and 1 vertebral artery) after successful balloon test occlusion. One patient underwent embolization with Onyx-18 alone, 2 with Onyx-34 alone, and 1 with Onyx-18 and -34. In each case, migration of Onyx was achieved within the tumor parenchyma. The mean time between embolization and resection was 3.8 days (range 1-8 days). Gross-total resection was achieved in 3 (60%) patients, and the other 2 patients had minimal residual tumor. The mean estimated blood loss during the resections was 556 ml (range 200-850 ml). The mean postoperative hematocrit level change was -17.3%. Two patients required blood transfusions. One patient, who underwent extensive tumor penetration with Onyx, developed a temporary partial cranial nerve VII palsy that resolved to House-Brackmann Grade I (out of VI) at the 6-month follow-up. One patient

  4. Initial experience with dual-lumen balloon catheter injection for preoperative Onyx embolization of skull base paragangliomas.

    PubMed

    Ladner, Travis R; He, Lucy; Davis, Brandon J; Yang, George L; Wanna, George B; Mocco, J

    2016-06-01

    OBJECT Paragangliomas are highly vascular head and neck tumors for which preoperative embolization is often considered to facilitate resection. The authors evaluated their initial experience using a dual-lumen balloon to facilitate preoperative embolization in 5 consecutive patients who underwent preoperative transarterial Onyx embolization assisted by the Scepter dual-lumen balloon catheter between 2012 and 2014. OBJECT The authors reviewed the demographic and clinical records of 5 patients who underwent Scepter-assisted Onyx embolization of a paraganglioma followed by resection between 2012 and 2014. Descriptive statistics of clinical outcomes were assessed. RESULTS Five patients (4 with a jugular and 1 with a vagal paraganglioma) were identified. Three paragangliomas were embolized in a single session, and each of the other 2 were completed in 3 staged sessions. The mean volume of Onyx used was 14.3 ml (range 6-30 ml). Twenty-seven vessels were selectively catheterized for embolization. All patients required selective embolization via multiple vessels. Two patients required sacrifice of parent vessels (1 petrocavernous internal carotid artery and 1 vertebral artery) after successful balloon test occlusion. One patient underwent embolization with Onyx-18 alone, 2 with Onyx-34 alone, and 1 with Onyx-18 and -34. In each case, migration of Onyx was achieved within the tumor parenchyma. The mean time between embolization and resection was 3.8 days (range 1-8 days). Gross-total resection was achieved in 3 (60%) patients, and the other 2 patients had minimal residual tumor. The mean estimated blood loss during the resections was 556 ml (range 200-850 ml). The mean postoperative hematocrit level change was -17.3%. Two patients required blood transfusions. One patient, who underwent extensive tumor penetration with Onyx, developed a temporary partial cranial nerve VII palsy that resolved to House-Brackmann Grade I (out of VI) at the 6-month follow-up. One patient

  5. Onyx embolization of a ruptured aneurysm in a patient with moyamoya disease.

    PubMed

    Daou, Badih; Chalouhi, Nohra; Tjoumakaris, Stavropoula; Rosenwasser, Robert H; Jabbour, Pascal

    2015-10-01

    We report a woman who presented with an intraparenchymal hemorrhage. Her cerebral angiogram showed a middle cerebral artery (MCA) M1 occlusion with multiple collaterals supplying the distal MCA territory, compatible with moyamoya disease. Also, an associated 8 mm dysplastic distal aneurysm fed by a left-sided P2 perforator was seen, collateral from the posterior cerebral artery. The aneurysm was successfully occluded with Onyx (ev3 Endovascular, Plymouth, MN, USA) embolization. The woman had an uneventful postoperative course. Aneurysm formation in patients with moyamoya disease represents a major hemorrhagic risk. Several treatment strategies exist including endovascular and surgical approaches. Patients with moyamoya disease who present with aneurysmal intracerebral hemorrhage should be treated to prevent rebleeding. Onyx embolization can be an effective treatment of aneurysms that are associated with moyamoya disease and would otherwise be difficult to treat surgically.

  6. Trigeminal Cardiac Reflex Caused by Onyx Embolization of Intracranial Dural Arteriovenous Fistula.

    PubMed

    Wang, Jian; Wu, Huan-Cheng; Wang, Wei-Wei; Zhao, Hong-Sen; Dao, Ri-Na; Liu, Wei-Min; Zhou, Dong-Zhe; Wang, Hui-Yu; DU, Chao

    2016-01-01

    Trigeminocardiac reflex (TCR) is a reflexive response of bradycardia, hypotension and gastric hypermotility which is observed upon mechanical stimulation in the distribution of the trigeminal nerve. Previous articles have described TCR during intracranial operations, ophthalmic surgery, microcompression of the trigeminal ganglion and radiofrequency lesioning of the trigeminal ganglion. TCR may occur during transarterial embolization of dural arteriovenous fistula (DAVF) with Onyx, leading to a significant decrease in heart rate under a standard anesthetic protocol. TCR may also occur due to chemical stimulus of dimethyl sulfoxide (DMSO) in transvenous Onyx embolization of dural cavernous sinus fistula. Slow rate of injection may give DMSO enough time to dissipate in the blood stream which is important for the prevention of toxicity. This report confirms that the reflex was blunted by the anticholinergic effects of atropine and there was no harm to patients if stopped immediately.

  7. Trigeminal Cardiac Reflex Caused by Onyx Embolization of Intracranial Dural Arteriovenous Fistula.

    PubMed

    Wang, Jian; Wu, Huan-Cheng; Wang, Wei-Wei; Zhao, Hong-Sen; Dao, Ri-Na; Liu, Wei-Min; Zhou, Dong-Zhe; Wang, Hui-Yu; DU, Chao

    2016-01-01

    Trigeminocardiac reflex (TCR) is a reflexive response of bradycardia, hypotension and gastric hypermotility which is observed upon mechanical stimulation in the distribution of the trigeminal nerve. Previous articles have described TCR during intracranial operations, ophthalmic surgery, microcompression of the trigeminal ganglion and radiofrequency lesioning of the trigeminal ganglion. TCR may occur during transarterial embolization of dural arteriovenous fistula (DAVF) with Onyx, leading to a significant decrease in heart rate under a standard anesthetic protocol. TCR may also occur due to chemical stimulus of dimethyl sulfoxide (DMSO) in transvenous Onyx embolization of dural cavernous sinus fistula. Slow rate of injection may give DMSO enough time to dissipate in the blood stream which is important for the prevention of toxicity. This report confirms that the reflex was blunted by the anticholinergic effects of atropine and there was no harm to patients if stopped immediately. PMID:27161455

  8. Modified pressure cooker technique: An easier way to control onyx reflux.

    PubMed

    Abud, Daniel Giansante; de Castro-Afonso, Luis Henrique; Nakiri, Guilherme Seizem; Monsignore, Lucas Moretti; Colli, Benedicto Oscar

    2016-06-01

    The use of onyx enabled the treatment of various intracranial vascular diseases more effectively than cyanoacrylate. The pressure cooker technique allowed definitive control of reflux and was made possible via detachable microcatheters. We present a variation of this technique called the modified pressure cooker to make reflux control easier and more reproducible and thus simplifying the procedure. We also extended the application of the technique to other diseases beyond arteriovenous malformations including dural arteriovenous fistulas and hypervascular tumors.

  9. Middle meningeal artery: Gateway for effective transarterial Onyx embolization of dural arteriovenous fistulas.

    PubMed

    Griessenauer, Christoph J; He, Lucy; Salem, Mohamed; Chua, Michelle H; Ogilvy, Christopher S; Thomas, Ajith J

    2016-09-01

    Curative transarterial embolization of noncavernous sinus dural arteriovenous fistulas (dAVFs) is challenging. We sought to evaluate the role of the middle meningeal artery (MMA) in endovascular treatment of these lesions. We performed a retrospective cohort study on patients who underwent transarterial Onyx embolization of a noncavernous sinus dAVFs with contribution from the MMA at a major academic institution in the United States from January 2009 to January 2015. Twenty consecutive patients who underwent transarterial Onyx embolization of a noncavernous sinus dAVF were identified. One patient was excluded as there was no MMA contribution to the dAVF. All of the remaining 19 patients (61.3 ± 13.8 years of age) underwent transarterial embolization through the MMA. Six patients (31.6%) presented with intraparenchymal or subarachnoid hemorrhage from the dAVF. The overall angiographic cure rate was 73.7% upon last follow up. In 71.4% of successfully treated patients transarterial embolization of the MMA alone was sufficient to achieve angiographic cure. When robust MMA supply was present, MMA embolization resulted in angiographic cure even after embolization of other arterial feeders had failed in 92.9% of patients. A robust contribution of the MMA to the fistula was the single most important predictor for successful embolization (P = 0.00129). We attribute our findings to the fairly straight, non-tortuous course of the MMA that facilitates microcatheter access, navigation, and Onyx penetration. Noncavernous sinus dAVF can be successfully embolized with transarterial Onyx through the MMA, as long as supply is robust. A transvenous approach is rarely necessary. Clin. Anat. 29:718-728, 2016. © 2016 Wiley Periodicals, Inc.

  10. Middle meningeal artery: Gateway for effective transarterial Onyx embolization of dural arteriovenous fistulas.

    PubMed

    Griessenauer, Christoph J; He, Lucy; Salem, Mohamed; Chua, Michelle H; Ogilvy, Christopher S; Thomas, Ajith J

    2016-09-01

    Curative transarterial embolization of noncavernous sinus dural arteriovenous fistulas (dAVFs) is challenging. We sought to evaluate the role of the middle meningeal artery (MMA) in endovascular treatment of these lesions. We performed a retrospective cohort study on patients who underwent transarterial Onyx embolization of a noncavernous sinus dAVFs with contribution from the MMA at a major academic institution in the United States from January 2009 to January 2015. Twenty consecutive patients who underwent transarterial Onyx embolization of a noncavernous sinus dAVF were identified. One patient was excluded as there was no MMA contribution to the dAVF. All of the remaining 19 patients (61.3 ± 13.8 years of age) underwent transarterial embolization through the MMA. Six patients (31.6%) presented with intraparenchymal or subarachnoid hemorrhage from the dAVF. The overall angiographic cure rate was 73.7% upon last follow up. In 71.4% of successfully treated patients transarterial embolization of the MMA alone was sufficient to achieve angiographic cure. When robust MMA supply was present, MMA embolization resulted in angiographic cure even after embolization of other arterial feeders had failed in 92.9% of patients. A robust contribution of the MMA to the fistula was the single most important predictor for successful embolization (P = 0.00129). We attribute our findings to the fairly straight, non-tortuous course of the MMA that facilitates microcatheter access, navigation, and Onyx penetration. Noncavernous sinus dAVF can be successfully embolized with transarterial Onyx through the MMA, as long as supply is robust. A transvenous approach is rarely necessary. Clin. Anat. 29:718-728, 2016. © 2016 Wiley Periodicals, Inc. PMID:27148680

  11. Modified pressure cooker technique: An easier way to control onyx reflux.

    PubMed

    Abud, Daniel Giansante; de Castro-Afonso, Luis Henrique; Nakiri, Guilherme Seizem; Monsignore, Lucas Moretti; Colli, Benedicto Oscar

    2016-06-01

    The use of onyx enabled the treatment of various intracranial vascular diseases more effectively than cyanoacrylate. The pressure cooker technique allowed definitive control of reflux and was made possible via detachable microcatheters. We present a variation of this technique called the modified pressure cooker to make reflux control easier and more reproducible and thus simplifying the procedure. We also extended the application of the technique to other diseases beyond arteriovenous malformations including dural arteriovenous fistulas and hypervascular tumors. PMID:26944607

  12. Transarterial Onyx Embolization for Patients with Cavernous Sinus Dural Arteriovenous Fistulas Who Have Failed Transvenous Embolization.

    PubMed

    Wen, Jun; Duan, Chuan-Zhi; Huang, Li-Jing; Zhang, Xin; He, Xu-Ying; Li, Xi-Feng

    2015-09-01

    Transvenous embolization is the treatment of choice for cavernous sinus dural arteriovenous fistulas (csDAVFs) despite occasional difficulty in transvenous catheterization. We reported our experience in the treatment of csDAVFs by transarterial Onyx embolization in patients who had failed transvenous catheterization. We reviewed the clinical and radiographic records of csDAVFs patients receiving transarterial Onyx embolization after failed transvenous Onyx embolization at our institution over a period of 31 months. Success was defined as complete or near complete occlusion upon angiographic examination. In seven cases, the microcatheter failed to reach the cavernous sinus; in the remaining case, the internal jugular vein was occlusive. Eight sessions of the embolization and catheterization procedures via the arterial routes were conducted. Among them, five cases via the middle meningeal artery and the other three via the accessory meningeal artery. Angiography, immediately after embolization, revealed complete occlusion in seven cases (87.5 %) and partial occlusion in the remaining case. Angiographic follow-up (range, 6-10 months) showed that all patients achieved complete embolization. In cases where transvenous embolization of the cavernous sinus is difficult, transarterial embolization of the fistulas offers a safe and effective alternative.

  13. Embolisation of a Proximal Type I Endoleak Post-Nellix Aortic Aneurysm Repair Complicated by Reflux of Onyx into the Nellix Endograft Limb

    SciTech Connect

    Ameli-Renani, S. Das, R. Weller, A. Chung, R. Morgan, R. A.

    2015-06-15

    We report the first case of intervention for a proximal type 1 endoleak following Nellix endovascular aneurysm sealing repair of an aortic aneurysm. This was complicated by migration of Onyx into one of the Nellix graft limbs causing significant stenosis. Subsequent placement of a covered stent to affix the Onyx between the stent and the wall of the Nellix endograft successfully restored stent patency.

  14. Onyx, a New Liquid Embolic Material for Peripheral Interventions: Preliminary Experience in Aneurysm, Pseudoaneurysm, and Pulmonary Arteriovenous Malformation Embolization

    SciTech Connect

    Vanninen, Ritva L. Manninen, I.

    2007-04-15

    Purpose. To describe our preliminary experience with a new liquid embolization agent, Onyx, in peripheral interventions. Methods and results. We successfully treated two peripheral aneurysms (one in an internal iliac artery, one in a thoracic collateral artery of an aortic coarctation), two peripheral pseudoaneurysms (one in a lumbar artery, one in a renal artery), and one pulmonary arteriovenous malformation. Conclusion. Onyx is a promising alternative embolic material for peripheral interventions. It can be combined with coils in selected cases, and balloon catheters can be effectively used during slow injection of embolic material to control flow and protect the aneurysm neck.

  15. Effect of poly(vinyl alcohol-co-vinyl acetate) copolymer blockiness on the dynamic interfacial tension and dilational viscoelasticity of polymer-anionic surfactant complex at the water-1-chlorobutane interface.

    PubMed

    Atanase, Leonard Ionut; Bistac, Sophie; Riess, Gérard

    2015-04-01

    Poly(vinyl alcohol-co-vinyl acetate) (PVA) copolymers obtained by partial hydrolysis of poly(vinyl acetate) (PVAc) are of practical importance for many applications, including emulsion and suspension polymerization processes. Their molecular characteristics have a major influence on the colloidal and interfacial properties. The most significant characteristics are represented by the average degree of hydrolysis D̅H̅, average degree of polymerization D̅P̅w̅ but also by the average acetate sequence length n(VAc)(0) which designates the so-called blockiness. Colloidal aggregates were observed in the aqueous PVA solutions having a D̅H̅ value of 73 mol%. The volume fraction of these aggregates at a given D̅H̅ value is directly correlated to the blockiness. Three PVA samples with identical D̅H̅ and D̅P̅w̅ but different blockiness were examined. By pendant drop and oscillating pendant drop techniques it was shown that the PVA sample having the lowest blockiness and thus the lowest volume fraction of colloidal aggregates has lower interfacial tension and elastic modulus E' values. On the contrary, the corresponding values are highest for PVA sample of higher blockiness. In the presence of sodium dodecyl sulfate (SDS), the colloidal aggregates are disaggregated by complex formation due to the hydrophobic-hydrophobic interactions. The PVA-SDS complex acts as a partial polyelectrolyte that induces the stretching of the chains and thus a reduction of the interface thickness. In this case, the interfacial tension and the elastic modulus both increase with increasing SDS concentration for all three PVA samples and the most significant effect was noticed for the most "blocky" copolymer sample.

  16. Spinal intraosseous epidural arteriovenous fistula with perimedullary drainage obliterated with Onyx embolization: case report.

    PubMed

    Ou, Chang-Hsien; Wang, Hao-Kuang; Yang, Tzu-Hsien; Liang, Cheng-Loong; Wong, Ho-Fai

    2015-08-01

    The authors report an extremely rare case of spinal intraosseous epidural arteriovenous fistula (AVF) with perimedullary vein reflux causing symptoms of myelopathy. The intraosseous fistula tracts were completely obliterated with Onyx embolic agent, resulting in a total resolution of symptoms. The unique features of this case include the rare location of the fistula in the vertebral body and the association of the fistula with a compressive fracture. Imaging studies confirmed these hemodynamic findings and provided clarity and direct evidence regarding the association of epidural AVF formation with the vertebral compressive fracture. The authors also propose a possible disease evolution based on the previously adduced reflux-impending mechanism.

  17. Polybrominated diphenyl ethers do not affect metamorphosis but alter the proteome of the invasive slipper limpet Crepidula onyx.

    PubMed

    Mukherjee, Joy; Po, Beverly H K; Chiu, Jill M Y; Wu, Rudolf S S; Qian, Pei-Yuan; Thiyagarajan, Vengatesen

    2013-08-15

    Man-made polybrominated diphenyl ethers (PBDEs) used as flame retardants in various consumer products may be harmful to marine organisms. Larvae of some marine invertebrates, especially invasive species, can develop resistance to PBDEs through altered protein expression patterns or proteome plasticity. This is the first report of a proteomics approach to study BDE-47 induced molecular changes in the invasive limpet Crepidula onyx. Larvae of C. onyx were cultured for 5 days (hatching to metamorphosis) in the presence of BDE-47 (1 μg L(-1)). Using a 2-DE proteomics approach with triple quadrupole and high-resolution TOF-MS, we showed that BDE-47 altered the proteome structure but not the growth or metamorphosis of C. onyx larvae. We found eight significant differentially expressed proteins in response to BDE-47, deemed the protein expression signature, consisting of cytoskeletal, stress tolerance, metabolism and energy production related proteins. Our data suggest C. onyx larvae have adequate proteome plasticity to tolerate BDE-47 toxicity. PMID:23743271

  18. Polybrominated diphenyl ethers do not affect metamorphosis but alter the proteome of the invasive slipper limpet Crepidula onyx.

    PubMed

    Mukherjee, Joy; Po, Beverly H K; Chiu, Jill M Y; Wu, Rudolf S S; Qian, Pei-Yuan; Thiyagarajan, Vengatesen

    2013-08-15

    Man-made polybrominated diphenyl ethers (PBDEs) used as flame retardants in various consumer products may be harmful to marine organisms. Larvae of some marine invertebrates, especially invasive species, can develop resistance to PBDEs through altered protein expression patterns or proteome plasticity. This is the first report of a proteomics approach to study BDE-47 induced molecular changes in the invasive limpet Crepidula onyx. Larvae of C. onyx were cultured for 5 days (hatching to metamorphosis) in the presence of BDE-47 (1 μg L(-1)). Using a 2-DE proteomics approach with triple quadrupole and high-resolution TOF-MS, we showed that BDE-47 altered the proteome structure but not the growth or metamorphosis of C. onyx larvae. We found eight significant differentially expressed proteins in response to BDE-47, deemed the protein expression signature, consisting of cytoskeletal, stress tolerance, metabolism and energy production related proteins. Our data suggest C. onyx larvae have adequate proteome plasticity to tolerate BDE-47 toxicity.

  19. Occurrence and Management Strategies for Catheter Entrapment with Onyx Liquid Embolization.

    PubMed

    Qureshi, Adnan I; Mian, Nidaullah; Siddiqi, Harris; Qureshi, Mushtaq H; Malik, Adil M; Rauf Afzal, Mohammad; Khan, Asif A; Suri, M Fareed K

    2015-07-01

    In June 2012, Food and Drug Administration (FDA) issued a warning about the risk of catheter entrapment associated with Onyx embolization. We used our experience, literature review, and FDA Manufacturer and User Facility Device Experience (MAUDE) data review to identify five strategies to address catheter entrapment: 1/. Surgical resection of vessel at point of entrapment of catheter and retraction from exterior portion at the femoral region; 2/. Advancing and closing the loop of snare over the entrapped catheter followed by retraction; 3/. Advancing the distal access catheter over the entrapped catheter and retraction with forward movement of the distal access catheters; 4/. Inflation of balloon catheter coaxial to the entrapped catheter with subsequent retraction; and 5/. Intravascular retention and internalization of microcatheter. In the MAUDE data, there were 77 reports of catheter entrapment with Onyx embolization; microcatheter was retracted by surgical excision in 15, endovascular snare or other retriever devices in 5, deliberately entrapped inside the vessel using stent in 1, and left without intervention within intravascular compartment in 27 patients.

  20. Phase separations in a copolymer copolymer mixture

    NASA Astrophysics Data System (ADS)

    Zhang, Jin-Jun; Jin, Guojun; Ma, Yuqiang

    2006-01-01

    We propose a three-order-parameter model to study the phase separations in a diblock copolymer-diblock copolymer mixture. The cell dynamical simulations provide rich information about the phase evolution and structural formation, especially the appearance of onion-rings. The parametric dependence and physical reason for the domain growth of onion-rings are discussed.

  1. Brain AVM Embolization with Onyx®: Analysis of Treatment in 34 Patients

    PubMed Central

    Leonardi, M.; Simonetti, L.; Cenni, P.; Raffi, L.

    2005-01-01

    Summary The endovascular approach to arteriovenous malformations (AVM) using different embolizing agents is a well-established treatment option. This report assesses the results of our experience using a non "glueing" embolic material available for several years, commercially known as Onyx®. We used Onyx to treat 34 consecutive patients in the last four years. All patients were treated in the same department by the same neuroradiological team, with a strictly repetitive technical strategy and procedural protocol. All our patients presented AVMs with Spetzler Grade 3 or more, because in our Institution Grade 1 or 2 AVMs are directly treated by surgical approach. We adopt a multidisciplinary treatment approach (embolization, surgery, radiotherapy) by which embolization is construed as work in progress offering definitive treatment of AVMs without severe risks. Embolization is mainly undertaken as the first step before surgery, to reduce flow and size of the AVM by a "targeted" technique. In addition to reducing lesion size, endovascular treatment aims to seal off AVM areas anatomically or haemodynamically complex for surgical treatment. Occasionally, the reduction in size allows a radiosurgical approach. Embolization seldom results in a definitive cure of AVMs. At the end of multimodal approach, we obtained the complete and definitive cure of AVM in 21/34 patients (two complete obliteration with interventional technique, 19 in combination with surgery); to these were added 5/34 patients who received radiosurgical therapy. No major complications arose during endovascular treatment. One patient had transitory (36 hour) impaired right arm pronation. The CT scan disclosed an asymptomatic mild SAH in the left sylvian fissure but no ischaemic areas. One patient still in treatment died from fatal rebleeding (the clinical onset had been with haemorrhage two weeks before the session) 12 days after the embolization. Excellent or good clinical outcome was obtained in 23

  2. Use of intermediate guide catheters as an adjunct in extracranial embolization to avoid onyx reflux into the anastomotic vasculature. A technical note.

    PubMed

    Puri, Ajit S; Kühn, Anna L; Hou, Samuel Y; Wakhloo, Ajay K

    2014-01-01

    Onyx is a non-adhesive polymer used for embolization of arteriovenous malformations and dural arteriovenous fistulas (DAVFs). The limiting factor for Onyx embolization is usually the amount of microcatheter reflux, which can be safely tolerated. The dual microcatheter technique, compliant balloon use proximally and the use of the dual lumen Scepter balloon have been described to prevent and limit proximal Onyx reflux. We describe the use the Navien 058 intermediate guide catheter to accept the Onyx reflux in its lumen and possibly also serve as a mechanical barrier to avoid reflux into the anastomotic channel connecting the occipital artery to the vertebral artery during DAVF embolization via the occipital artery. Complete embolization of the DAVF was achieved using the lumen of the Navien catheter to accept aggressive Onyx reflux. Complete cure of the DAVF was obtained with Onyx cast filling the entire venous pouch. Besides providing distal access support, intermediate guide catheters can also prevent embolic material reflux by accepting reflux into the lumen and providing a mechanical barrier.

  3. Selecting and implementing the PBS scheduler on an SGI Onyx 2/Orgin 2000.

    SciTech Connect

    Bittner, S.

    1999-06-28

    In the Mathematics and Computer Science Division at Argonne, the demand for resources on the Onyx 2 exceeds the resources available for consumption. To distribute these scarce resources effectively, we need a scheduling and resource management package with multiple capabilities. In particular, it must accept standard interactive user logins, allow batch jobs, backfill the system based on available resources, and permit system activities such as accounting to proceed without interruption. The package must include a mechanism to treat the graphic pipes as a schedulable resource. Also required is the ability to create advance reservations, offer dedicated system modes for large resource runs and benchmarking, and track the resources consumed for each job run. Furthermore, our users want to be able to obtain repeatable timing results on job runs. And, of course, package costs must be carefully considered. We explored several options, including NQE and various third-party products, before settling on the PBS scheduler.

  4. Onyx Embolization of a Meningioma with a Dysplastic Aneurysmal Anterior Cerebral Artery Vessel

    PubMed Central

    Felbaum, Daniel R; Liu, Ai-Hsi; Armonda, Rocco A

    2016-01-01

    Preoperative embolization of meningiomas can be safely performed using a variety of embolic agents. Most commonly, the vascular supply from branches of the external carotid artery is the target of embolization. In our report, we detail the treatment of a patient with a parafalcine meningioma that received its supply via branches of the anterior cerebral artery. One of the feeder vessels appeared to contain a dysplastic aneurysmal dilatation of the vessel. Due to patient circumstances, embolization was performed using standard microcatheterization techniques to minimize intraoperative blood loss. We report a rare instance of endovascular treatment of a pial vessel to treat an intracranial meningioma using Onyx. PMID:27738575

  5. Geochemical processes in the Onyx River, Wright Valley, Antarctica: Major ions, nutrients, trace metals

    NASA Astrophysics Data System (ADS)

    Green, William J.; Stage, Brian R.; Preston, Adam; Wagers, Shannon; Shacat, Joseph; Newell, Silvia

    2005-02-01

    We present data on major ions, nutrients and trace metals in an Antarctic stream. The Onyx River is located in Wright Valley (77-32 S; 161-34 E), one of a group of ancient river and glacier-carved landforms that comprise the McMurdo Dry Valleys of Antarctica. The river is more than 30 km long and is the largest of the glacial meltwater streams that characterize this relatively ice-free region near the Ross Sea. The complete absence of rainfall in the region and the usually small contributions of glacially derived tributaries to the main channel make this a comparatively simple system for geochemical investigation. Moreover, the lack of human impacts, past or present, provides an increasingly rare window onto a pristine aquatic system. For all major ions and silica, we observe increasing concentrations with distance from Lake Brownworth down to the recording weir near Lake Vanda. Chemical weathering rates are unexpectedly high and may be related to the rapid dissolution of ancient carbonate deposits and to the severe physical weathering associated with the harsh Antarctic winter. Of the nutrients, nitrate and dissolved reactive phosphate appear to have quite different sources. Nitrate is enriched in waters near the Lower Wright Glacier and may ultimately be derived from stratospheric sources; while phosphate is likely to be the product of chemical weathering of valley rocks and soils. We confirm the work of earlier investigations regarding the importance of the Boulder Pavement as a nutrient sink. Dissolved Mn, Fe, Ni, Cu, and Cd are present at nanomolar levels and, in all cases, the concentrations of these metals are lower than in average world river water. We hypothesize that metal uptake and exchange with particulate phases along the course of the river may serve as a buffer for the dissolved load. Concurrent study of these three solute classes points out significant differences in the mechanisms and sites of their removal from the Onyx River.

  6. Cranial Nerve Dysfunction Associated with Cavernous Dural Arteriovenous Fistulas After Transvenous Embolization with Onyx

    SciTech Connect

    Li, Chuanhui; Wang, Yang; Li, Youxiang; Jiang, Chuhan; Wu, Zhongxue; Yang, Xinjian

    2015-10-15

    PurposeCranial nerve dysfunction (CND) is not uncommon in patients with cavernous dural arteriovenous fistulas (cDAVFs), and may represent an initial manifestation or a complication after endovascular treatment. This study evaluated the outcome of CND associated with cDAVFs after transvenous embolization (TVE) using Onyx.Materials and MethodsForty-one patients with cDAVFs were treated with TVE in our department between April 2009 and October 2013. For each patient, clinical and radiologic records were retrospectively reviewed and evaluated, with an emphasis placed on evaluating the outcomes of the pre-existing cDAVF-induced CND and the TVE-induced CND.ResultsOf the 41 cases, 25 had a history of preoperative CND. Postoperatively, gradual remission to complete recovery (CR) within 8 months was observed in 17 of these cases, transient aggravation in 7, and significant improvement to be better than preoperative function but no CR in 1. All aggravation of CND occurred immediately or within 1 day after TVE and resolved completely within 5 months. Nine patients developed new CND after TVE. New CND occurred during the perioperative period in 8 cases, but all cases resolved completely within 15 days–6 months. Delayed CND was observed in 3 cases with a time lag of 3–25 months after TVE. Two of these completely resolved within 20 days–1 month and the remaining case significantly improved.ConclusionBoth the pre-existing cDAVF-induced CND and the TVE-induced new or aggravated CND completely resolved in almost all cases after embolization with Onyx.

  7. Transcranial direct middle meningeal artery puncture for the onyx embolization of dural arteriovenous fistula involving the superior sagittal sinus.

    PubMed

    Oh, Jae-Sang; Yoon, Seok-Mann; Shim, Jai-Joon; Bae, Hack-Gun

    2015-01-01

    A 66-year-old woman presented with intermittent paraparesis and generalized tonic-clonic seizure. Cerebral angiography demonstrated dural arteriovenous fistula (AVF) involving superior sagittal sinus (SSS), which was associated with SSS occlusion on the posterior one third. The dural AVF was fed by bilateral middle meningeal arteries (MMAs), superficial temporal arteries (STAs) and occipital arteries with marked retrograde cortical venous reflux. Transfemoral arterial Onyx embolization was performed through right MMA and STA, but it was not successful, which resulted in partial obliteration of dural AVF because of tortuous MMA preventing the microcatheter from reaching the fistula closely enough. Second procedure was performed through left MMA accessed by direct MMA puncture following small decortications of cranium overlying the MMA using diamond drill one week later. Microcatheter could be located far distally to the fistula through 5 F sheath placed into the MMA and complete obliteration of dural AVF was achieved using 3.9 cc of Onyx.

  8. Transarterial coil-augmented Onyx embolization for brain arteriovenous malformation. Technique and experience in 22 consecutive patients.

    PubMed

    Gao, Xu; Liang, Guobiao; Li, Zhiqing; Wang, Xiaogang; Yu, Chunyong; Cao, Peng; Chen, Jun; Li, Jingyuan

    2014-01-01

    Onyx has been widely adopted for the treatment of arteriovenous malformations (AVMs). However, its control demands operators accumulate a considerable learning curve. We describe our initial experience using a novel injection method for the embolization of AVMs. We retrospectively reviewed the data of all 22 patients with brain AVMs (12 men, 10 women; age range, 12-68 years; mean age, 43.2 years) treated by the transarterial coil-augmented Onyx injection technique. The size of the AVMs ranged from 25 mm to 70 mm (average 35.6 mm). The technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcome were evaluated. In every case, endovascular treatment (EVT) was completed. A total of 31 sessions were performed, with a mean injection volume of 6.1 mL (range, 1.5-16.0 mL). An average of 96.7% (range 85%-100%) estimated size reduction was achieved, and 18 AVMs could be completely excluded by EVT alone. The results remained stable on follow-up angiograms. A procedural complication occurred in one patient, with permanent mild neurologic deficit. Our preliminary series demonstrated that the coil-augmented Onyx injection technique is a valuable adjunct achieving excellent nidal penetration and improving the safety of the procedure.

  9. Protein based Block Copolymers

    PubMed Central

    Rabotyagova, Olena S.; Cebe, Peggy; Kaplan, David L.

    2011-01-01

    Advances in genetic engineering have led to the synthesis of protein-based block copolymers with control of chemistry and molecular weight, resulting in unique physical and biological properties. The benefits from incorporating peptide blocks into copolymer designs arise from the fundamental properties of proteins to adopt ordered conformations and to undergo self-assembly, providing control over structure formation at various length scales when compared to conventional block copolymers. This review covers the synthesis, structure, assembly, properties, and applications of protein-based block copolymers. PMID:21235251

  10. Geochemistry of the Onyx River (Wright Valley, Antarctica) and its role in the chemical evolution of Lake Vanda

    NASA Astrophysics Data System (ADS)

    Green, William J.; Canfield, Donald E.

    1984-12-01

    The Onyx River (Wright Valley, Antarctica) is a dilute meltwater stream originating in the vicinity of the Wright Lower Glacier. It acquires a significant fraction of its salt content when glacial meltwaters contact Wright Valley soils at Lake Brownworth and the concentrations of all ions increase with distance along the 28-km channel down to Lake Vanda. Average millimolar concentrations of major ions at the Vanda weir during the 1980-1981 flow season were: Ca = 0.119; Mg = 0.061; Na = 0.212; K = 0.033; Q = 0.212; SO4 = 0.045; HCO3 = 0.295; and SiO2 = 0.049. Based on the flow measurements of Chinn (1982), this amounts to an annual flux (in moles) to Lake Vanda of: Ca = 0.238 × 10 6; Mg = 0.122 × 10 6; Na = 0.424 × 10 6; K = 0.066 × 10 6; Cl = 0.424 × 10 6; SO4 = 0.09 × 10 6; HCO3 = 0.59 × 10 6; SiO2 = 0.098 × 10 6. In spite of the large salt input from this source, equilibrium evaporation of Onyx River water would have resulted in early calcite deposition and in the formation of a Na-Mg-Cl-HCO 3 brine rather than in the Ca-Na-Mg-Cl waters observed in Lake Vanda. The river alone could not have produced a brine having the qualitative geochemical features of the lower saline waters of Lake Vanda. It is proposed that the Vanda brine is instead the result of past ( > 1200 yrs BP) mixing events between Onyx River inflows and calcium chloride-rich deep groundwaters derived from the Don Juan Basin. The mixing model presented here shows that the Onyx River is the major contributor of K, HCO 3, SO 4, and (possibly) Mg found in the lake and a significant contributor (approximately one half) of the observed Na. Calcium and Cl, on the other hand, came largely from deep groundwater sources in the Don Juan Basin. All concentrations except Mg are well predicted by this model. The chemical composition of the geologically recent upper lake is explained in terms of ionic diffusion from the pre-formed brine, coupled with Onyx River inflow. Ionic ratios calculated from this

  11. Fabrication of high-performance flexible alkaline batteries by implementing multiwalled carbon nanotubes and copolymer separator.

    PubMed

    Wang, Zhiqian; Wu, Zheqiong; Bramnik, Natalia; Mitra, Somenath

    2014-02-12

    A flexible alkaline battery with multiwalled carbon nanotube (MWCNT) enhanced composite electrodes and polyvinyl alcohol (PVA)-poly (acrylic acid) (PAA) copolymer separator has been developed. Purified MWCNTs appear to be the most effective conductive additive, while the flexible copolymer separator not only enhances flexibility but also serves as electrolyte storage. PMID:24510667

  12. Advancements in real-time IR/EO scene generation utilizing the Silicon Graphics Onyx2

    NASA Astrophysics Data System (ADS)

    Simmons, Onda D.; Jacobs, Stephen E.; Makar, Robert J.; Stanley, Frank J.; Joyner, Thomas W.; Theim, Keem B.

    2000-07-01

    This paper describes advances in the development of IR/EO scene generation to support the Infrared Sensor Stimulator system (IRSS) which will be used for installed system testing of avionics electronic combat systems. The IRSS will provide a high frame rate, real-time, reactive, hardware-in-the-loop test capability for the stimulation of current and future infrared and ultraviolet based sensor systems. Scene generation in the IRSS is provided by an enhanced version of the Real-time (IR/EO Scene Simulator (RISS) which was previously developed by Comptek Amherst Systems. RISS utilizes the symmetric multiprocessing environment of the Silicon GraphicsR Onyx2TM to support the generation of IR/EO scenes in real-time. It is a generic scene generation system which can be programmed to accurately stimulate a wide variety of sensors. Significant advancements have been made in IRSS capabilities in the past year. This paper will discuss the addition of new simulation techniques which have been added to the system to better support the high resolution, geospecific testing requirements of a new generation of imaging sensors. IRSS now better supports the use of high resolution databases which contain material maps at photo realistic precision. Other developments which will be discussed include extensive improvements to the database and scenario development tools, advancements in the support for multiple synchronized scene generation channels, and new support for sea and ship models.

  13. Optoelectronics using block copolymers.

    SciTech Connect

    Botiz, I.; Darling, S. B.; Center for Nanoscale Materials

    2010-05-01

    Block copolymers, either as semiconductors themselves or as structure directors, are emerging as a promising class of materials for understanding and controlling processes associated with both photovoltaic energy conversion and light emitting devices.

  14. Antimicrobial Graft Copolymer Gels.

    PubMed

    Harvey, Amanda C; Madsen, Jeppe; Douglas, C W Ian; MacNeil, Sheila; Armes, Steven P

    2016-08-01

    In view of the growing worldwide rise in microbial resistance, there is considerable interest in designing new antimicrobial copolymers. The aim of the current study was to investigate the relationship between antimicrobial activity and copolymer composition/architecture to gain a better understanding of their mechanism of action. Specifically, the antibacterial activity of several copolymers based on 2-(methacryloyloxy)ethyl phosphorylcholine [MPC] and 2-hydroxypropyl methacrylate (HPMA) toward Staphylococcus aureus was examined. Both block and graft copolymers were synthesized using either atom transfer radical polymerization or reversible addition-fragmentation chain transfer polymerization and characterized via (1)H NMR, gel permeation chromatography, rheology, and surface tensiometry. Antimicrobial activity was assessed using a range of well-known assays, including direct contact, live/dead staining, and the release of lactate dehydrogenase (LDH), while transmission electron microscopy was used to study the morphology of the bacteria before and after the addition of various copolymers. As expected, PMPC homopolymer was biocompatible but possessed no discernible antimicrobial activity. PMPC-based graft copolymers comprising PHPMA side chains (i.e. PMPC-g-PHPMA) significantly reduced both bacterial growth and viability. In contrast, a PMPC-PHPMA diblock copolymer comprising a PMPC stabilizer block and a hydrophobic core-forming PHPMA block did not exhibit any antimicrobial activity, although it did form a biocompatible worm gel. Surface tensiometry studies and LDH release assays suggest that the PMPC-g-PHPMA graft copolymer exhibits surfactant-like activity. Thus, the observed antimicrobial activity is likely to be the result of the weakly hydrophobic PHPMA chains penetrating (and hence rupturing) the bacterial membrane. PMID:27409712

  15. Formation of Anisotropic Block Copolymer Gels

    NASA Astrophysics Data System (ADS)

    Liaw, Chya Yan; Shull, Kenneth; Henderson, Kevin; Joester, Derk

    2011-03-01

    Anisotropic, fibrillar gels are important in a variety of processes. Biomineralization is one example, where the mineralization process often occurs within a matrix of collagen or chitin fibers that trap the mineral precursors and direct the mineralization process. We wish to replicate this type of behavior within block copolymer gels. Particularly, we are interested in employing gels composed of cylindrical micelles, which are anisotropic and closely mimic biological fibers. Micelle geometry is controlled in our system by manipulating the ratio of molecular weights of the two blocks and by controlling the detailed thermal processing history of the copolymer solutions. Small-Angle X-ray Scattering and Dynamic Light Scattering are used to determine the temperature dependence of the gel formation process. Initial experiments are based on a thermally-reversible alcohol-soluble system, that can be subsequently converted to a water soluble system by hydrolysis of a poly(t-butyl methacrylate) block to a poly (methacrylic acid) block. MRSEC.

  16. Alcoholism and Alcohol Abuse

    MedlinePlus

    ... This means that their drinking causes distress and harm. It includes alcoholism and alcohol abuse. Alcoholism, or ... brain, and other organs. Drinking during pregnancy can harm your baby. Alcohol also increases the risk of ...

  17. Block coordination copolymers

    DOEpatents

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

    2012-11-13

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  18. Block coordination copolymers

    DOEpatents

    Koh, Kyoung Moo; Wong-Foy, Antek G.; Matzger, Adam J.; Benin, Annabelle I.; Willis, Richard R.

    2012-12-04

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  19. Block coordination copolymers

    DOEpatents

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

    2014-11-11

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  20. Ultraviolet absorbing copolymers

    DOEpatents

    Gupta, Amitava; Yavrouian, Andre H.

    1982-01-01

    Photostable and weather stable absorping copolymers have been prepared from acrylic esters such as methyl methacrylate containing 0.1 to 5% of an 2-hydroxy-allyl benzophenone, preferably the 4,4' dimethoxy derivative thereof. The pendant benzophenone chromophores protect the acrylic backbone and when photoexcited do not degrade the ester side chain, nor abstract hydrogen from the backbone.

  1. Onyx embolization of dural arteriovenous fistulas of the cavernous sinus through the superior pharyngeal branch of the ascending pharyngeal artery

    PubMed Central

    Pero, Guglielmo; Quilici, Luca; Piano, Mariangela; Valvassori, Luca; Boccardi, Edoardo

    2014-01-01

    We report three cases of dural arteriovenous fistula (DAVF) of the cavernous sinus treated by Onyx injection through the superior pharyngeal branch of the ascending pharyngeal artery. The treatment of choice of DAVFs of the cavernous sinus is endovascular, and it is preferentially done via transvenous occlusion of the cavernous sinus. The cavernous sinus can be reached through either the inferior petrosal sinus or the superior ophthalmic vein. When these venous routes are occluded, the first attempt is to pass through the occluded inferior petrosal sinus, but sometimes this attempt can fail. In some cases there are small transosseous feeders to the fistula arising from the superior pharyngeal branch of the ascending pharyngeal artery. When all of the more conventional approaches are unattainable, this route can be attempted. In our experience, it allowed safe and rapid occlusion of the fistula. PMID:24759156

  2. Double-lumen balloon for Onyx® embolization via extracranial arteries in transverse sigmoid dural arteriovenous fistulas: initial experience.

    PubMed

    Clarençon, Frédéric; Di Maria, Federico; Gabrieli, Joseph; Carpentier, Alexandre; Pistochi, Silvia; Bartolini, Bruno; Zeghal, Chiheb; Chiras, Jacques; Sourour, Nader-Antoine

    2016-10-01

    Transverse-sigmoid dural arteriovenous fistulas (TS DAVFs) can be challenging to treat by endovascular means. Indeed, a total cure of the fistula can only be achieved when complete occlusion of the fistulous point(s) is obtained by penetration of the embolic agent. However, in some cases, especially for transosseous branches from extracranial arteries like the occipital artery (OcA) or the superficial temporal artery (STA), such penetration is usually poor, leading to major proximal reflux and incomplete fistula obliteration. We present three cases of embolization in two patients with TS DAVF through the OcA and/or the STA with Onyx® using a double-lumen balloon (Microvention, Tustin, CA, USA). This technique allows the penetration of the embolic agent in the transosseous branches by forming a counter-pressure with the inflated balloon. This technique may be useful to achieve complete occlusion of TS DAVFs by endovascular means.

  3. Double-lumen balloon for Onyx® embolization via extracranial arteries in transverse sigmoid dural arteriovenous fistulas: initial experience.

    PubMed

    Clarençon, Frédéric; Di Maria, Federico; Gabrieli, Joseph; Carpentier, Alexandre; Pistochi, Silvia; Bartolini, Bruno; Zeghal, Chiheb; Chiras, Jacques; Sourour, Nader-Antoine

    2016-10-01

    Transverse-sigmoid dural arteriovenous fistulas (TS DAVFs) can be challenging to treat by endovascular means. Indeed, a total cure of the fistula can only be achieved when complete occlusion of the fistulous point(s) is obtained by penetration of the embolic agent. However, in some cases, especially for transosseous branches from extracranial arteries like the occipital artery (OcA) or the superficial temporal artery (STA), such penetration is usually poor, leading to major proximal reflux and incomplete fistula obliteration. We present three cases of embolization in two patients with TS DAVF through the OcA and/or the STA with Onyx® using a double-lumen balloon (Microvention, Tustin, CA, USA). This technique allows the penetration of the embolic agent in the transosseous branches by forming a counter-pressure with the inflated balloon. This technique may be useful to achieve complete occlusion of TS DAVFs by endovascular means. PMID:27522356

  4. Onyx embolization of an intraosseous pseudoaneurysm of the middle meningeal artery in a patient with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome.

    PubMed

    Settecase, Fabio; Nicholson, Andrew D; Amans, Matthew R; Higashida, Randall T; Halbach, Van V; Cooke, Daniel L; Dowd, Christopher F; Hetts, Steven W

    2016-03-01

    A 13-year-old boy with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome presented with an enlarging "lump" on his right forehead. A head CT scan revealed a polyostotic fibrous dysplasia involving the entire skull. A 3.4-cm right frontal osseous cavity and an overlying right forehead subcutaneous soft-tissue mass were seen, measuring 5.2 cm in diameter and 1.6 cm thick. Ultrasound of the cavity and overlying mass showed swirling of blood and an arterialized waveform. MRI revealed an en plaque meningioma underlying the cavity. An intraosseous pseudoaneurysm fed by 3 distal anterior division branches of the right middle meningeal artery (MMA) with contrast extravasation was found on angiography. Two MMA feeders were embolized with Onyx, with anterograde filling of the intraosseous cavity with Onyx. A small pocket of residual intracavity contrast filling postembolization from a smaller third MMA feeder eventually thrombosed and the forehead lump regressed.

  5. Onyx embolization of an intraosseous pseudoaneurysm of the middle meningeal artery in a patient with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome.

    PubMed

    Settecase, Fabio; Nicholson, Andrew D; Amans, Matthew R; Higashida, Randall T; Halbach, Van V; Cooke, Daniel L; Dowd, Christopher F; Hetts, Steven W

    2016-03-01

    A 13-year-old boy with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome presented with an enlarging "lump" on his right forehead. A head CT scan revealed a polyostotic fibrous dysplasia involving the entire skull. A 3.4-cm right frontal osseous cavity and an overlying right forehead subcutaneous soft-tissue mass were seen, measuring 5.2 cm in diameter and 1.6 cm thick. Ultrasound of the cavity and overlying mass showed swirling of blood and an arterialized waveform. MRI revealed an en plaque meningioma underlying the cavity. An intraosseous pseudoaneurysm fed by 3 distal anterior division branches of the right middle meningeal artery (MMA) with contrast extravasation was found on angiography. Two MMA feeders were embolized with Onyx, with anterograde filling of the intraosseous cavity with Onyx. A small pocket of residual intracavity contrast filling postembolization from a smaller third MMA feeder eventually thrombosed and the forehead lump regressed. PMID:26588455

  6. Sequence-regulated copolymers via tandem catalysis of living radical polymerization and in situ transesterification.

    PubMed

    Nakatani, Kazuhiro; Ogura, Yusuke; Koda, Yuta; Terashima, Takaya; Sawamoto, Mitsuo

    2012-03-01

    Sequence regulation of monomers is undoubtedly a challenging issue as an ultimate goal in polymer science. To efficiently produce sequence-controlled copolymers, we herein developed the versatile tandem catalysis, which concurrently and/or sequentially involved ruthenium-catalyzed living radical polymerization and in situ transesterification of methacrylates (monomers: RMA) with metal alkoxides (catalysts) and alcohols (ROH). Typically, gradient copolymers were directly obtained from the synchronization of the two reactions: the instantaneous monomer composition in feed gradually changed via the transesterification of R(1)MA into R(2)MA in the presence of R(2)OH during living polymerization to give R(1)MA/R(2)MA gradient copolymers. The gradient sequence of monomers along a chain was catalytically controlled by the reaction conditions such as temperature, concentration and/or species of catalysts, alcohols, and monomers. The sequence regulation of multimonomer units was also successfully achieved in one-pot by monomer-selective transesterification in concurrent tandem catalysis and iterative tandem catalysis, providing random-gradient copolymers and gradient-block counterparts, respectively. In contrast, sequential tandem catalysis via the variable initiation of either polymerization or in situ transesterification led to random or block copolymers. Due to the versatile adaptability of common and commercially available reagents (monomers, alcohols, catalysts), this tandem catalysis is one of the most efficient, convenient, and powerful tools to design tailor-made sequence-regulated copolymers.

  7. Successful Embolization of a Renal Artery Pseudoaneurysm with Arteriovenous Fistula and Extravasations Using Onyx After Partial Nephrectomy for Renal Cell Carcinoma

    SciTech Connect

    Zelenak, Kamil; Sopilko, Igor; Svihra, Jan; Kliment, Jan

    2009-01-15

    Partial nephrectomy can be associated with vascular complications. Computed tomography (CT) with CT angiography is ideal for noninvasive imaging of this process. The treatment of choice is selective embolization. Successful transcatheter embolization of right renal subsegmental artery pseudoaneurysm with arteriovenous fistula and extravasations using Onyx was performed in a 66-year-old woman with macrohematuria 12 days after partial nephrectomy for renal cell carcinoma.

  8. Application of Onyx for Renal Arteriovenous Malformation With First Case Report of a Renal Hyperdense Striation Sign: A CARE-Compliant Article.

    PubMed

    Juan, Yu-Hsiang; Lin, Yu-Ching; Sheng, Ting-Wen; Cheung, Yun-Chung; Ng, Shu-Hang; Yu, Chin-Wei; Wong, Ho-Fai

    2015-09-01

    Onyx is an emerging treatment modality for visceral vascular malformations, especially in cases in which delicate nidal penetration of the arteriovenous malformation (AVM) is desired. A computed tomography (CT) image presentation of hyperdense striations along the renal medulla secondary to the tantalum powder has not been previously reported. A 65-year-old woman presented to our institution with intermittent gross hematuria and left flank pain for 10 days. Both CT and conventional angiographies confirmed cirsoid-type renal AVM, which was successfully treated with Onyx. Follow-up CT after treatment revealed presence of hyperdense striations along the renal medulla, which resolved during later image follow-up. Despite its frequent usage in neural intervention, the application of Onyx in visceral AVM is gradually gaining interest, especially in cases in which delicate nidal penetration of the AVM is desired. Renal hyperdense striation sign should be recognized to avoid confusion with embolizer migration, and further studies in patients with renal function impairment may be helpful in understanding its influence of renal function. PMID:26426661

  9. Endovascular Treatment of Two High-Flow Brain Arteriovenous Fistulas with a Combination of Detachable Coils and Onyx in an Infant: Case Report and Review of Literature.

    PubMed

    Wang, Qihong; Quan, Zhe; Li, ZhiQiang

    2015-01-01

    Congenital brain arteriovenous fistulas (BAVFs) are rare neurovascular lesions of the brain, and few cases have been reported of their treatment with a combination of detachable coils and Onyx, especially in infants. Here, we present a case of 2 high-flow BAVFs occurring in a 12-month-old boy. Standard techniques of digital subtraction angiography were used, and dimethyl sulfoxide-compatible microcatheters were delivered and entered into a distal feeding artery as closely as possible to the fistulas. Then, a combination of detachable coils and Onyx was used. After the treatment of the 2 high-flow BAVFs, a complete percutaneous embolization of the fistulas was obtained. The fistulas remained closed, as ascertained by follow-up angiograms. No new neurological deficit related to the procedure was detected, and the infant was asymptomatic and in good health 4 years after the surgery. Our case shows that the endovascular treatment of high-flow BAVFs with a combination of detachable coils and Onyx in an infant is safe and effective.

  10. Vascular Steal Syndrome, Optic Neuropathy, and Foreign Body Granuloma Reaction to Onyx-18 Embolization for Congenital Orbito-Facial Vascular Malformation.

    PubMed

    Liu, Catherine Y; Yonkers, Marc A; Liu, Tiffany S; Minckler, Don S; Tao, Jeremiah P

    2016-04-01

    A 34-year-old patient presented with a right orbito-facial mass since childhood, consistent with a congenital arteriovenous (AV) malformation. Prior to presentation, she had multiple incomplete surgical resections and embolizations with N-butyl acetyl acrylate and Onyx-18. The patient reported gradual, progressive vision loss shortly after Onyx-18 embolization. Five months after embolization, she presented with decreased vision, disfigurement and mechanical ptosis relating to a large subcutaneous mass affecting the medial right upper eyelid and forehead. Significant exam findings included a visual acuity of 20/400 (20/60 prior to embolization), an afferent pupillary defect, and optic disc pallor. MRI and angiography revealed a persistent AV malformation with feeders from the ophthalmic artery and an absent choroidal flush to the right eye. Pathology from surgical resection showed a significant foreign body giant cell reaction to the embolization material adjacent to the vessels. We suggest that an incomplete embolization with Onyx-18 may have caused vascular steal syndrome from the ophthalmic artery.

  11. Application of Onyx for Renal Arteriovenous Malformation With First Case Report of a Renal Hyperdense Striation Sign: A CARE-Compliant Article.

    PubMed

    Juan, Yu-Hsiang; Lin, Yu-Ching; Sheng, Ting-Wen; Cheung, Yun-Chung; Ng, Shu-Hang; Yu, Chin-Wei; Wong, Ho-Fai

    2015-09-01

    Onyx is an emerging treatment modality for visceral vascular malformations, especially in cases in which delicate nidal penetration of the arteriovenous malformation (AVM) is desired. A computed tomography (CT) image presentation of hyperdense striations along the renal medulla secondary to the tantalum powder has not been previously reported. A 65-year-old woman presented to our institution with intermittent gross hematuria and left flank pain for 10 days. Both CT and conventional angiographies confirmed cirsoid-type renal AVM, which was successfully treated with Onyx. Follow-up CT after treatment revealed presence of hyperdense striations along the renal medulla, which resolved during later image follow-up. Despite its frequent usage in neural intervention, the application of Onyx in visceral AVM is gradually gaining interest, especially in cases in which delicate nidal penetration of the AVM is desired. Renal hyperdense striation sign should be recognized to avoid confusion with embolizer migration, and further studies in patients with renal function impairment may be helpful in understanding its influence of renal function.

  12. Endovascular Treatment of Two High-Flow Brain Arteriovenous Fistulas with a Combination of Detachable Coils and Onyx in an Infant: Case Report and Review of Literature.

    PubMed

    Wang, Qihong; Quan, Zhe; Li, ZhiQiang

    2015-01-01

    Congenital brain arteriovenous fistulas (BAVFs) are rare neurovascular lesions of the brain, and few cases have been reported of their treatment with a combination of detachable coils and Onyx, especially in infants. Here, we present a case of 2 high-flow BAVFs occurring in a 12-month-old boy. Standard techniques of digital subtraction angiography were used, and dimethyl sulfoxide-compatible microcatheters were delivered and entered into a distal feeding artery as closely as possible to the fistulas. Then, a combination of detachable coils and Onyx was used. After the treatment of the 2 high-flow BAVFs, a complete percutaneous embolization of the fistulas was obtained. The fistulas remained closed, as ascertained by follow-up angiograms. No new neurological deficit related to the procedure was detected, and the infant was asymptomatic and in good health 4 years after the surgery. Our case shows that the endovascular treatment of high-flow BAVFs with a combination of detachable coils and Onyx in an infant is safe and effective. PMID:26183946

  13. Vascular Steal Syndrome, Optic Neuropathy, and Foreign Body Granuloma Reaction to Onyx-18 Embolization for Congenital Orbito-Facial Vascular Malformation.

    PubMed

    Liu, Catherine Y; Yonkers, Marc A; Liu, Tiffany S; Minckler, Don S; Tao, Jeremiah P

    2016-04-01

    A 34-year-old patient presented with a right orbito-facial mass since childhood, consistent with a congenital arteriovenous (AV) malformation. Prior to presentation, she had multiple incomplete surgical resections and embolizations with N-butyl acetyl acrylate and Onyx-18. The patient reported gradual, progressive vision loss shortly after Onyx-18 embolization. Five months after embolization, she presented with decreased vision, disfigurement and mechanical ptosis relating to a large subcutaneous mass affecting the medial right upper eyelid and forehead. Significant exam findings included a visual acuity of 20/400 (20/60 prior to embolization), an afferent pupillary defect, and optic disc pallor. MRI and angiography revealed a persistent AV malformation with feeders from the ophthalmic artery and an absent choroidal flush to the right eye. Pathology from surgical resection showed a significant foreign body giant cell reaction to the embolization material adjacent to the vessels. We suggest that an incomplete embolization with Onyx-18 may have caused vascular steal syndrome from the ophthalmic artery. PMID:27239463

  14. Vascular Steal Syndrome, Optic Neuropathy, and Foreign Body Granuloma Reaction to Onyx-18 Embolization for Congenital Orbito-Facial Vascular Malformation

    PubMed Central

    Liu, Catherine Y.; Yonkers, Marc A.; Liu, Tiffany S.; Minckler, Don S.; Tao, Jeremiah P.

    2016-01-01

    A 34-year-old patient presented with a right orbito-facial mass since childhood, consistent with a congenital arteriovenous (AV) malformation. Prior to presentation, she had multiple incomplete surgical resections and embolizations with N-butyl acetyl acrylate and Onyx-18. The patient reported gradual, progressive vision loss shortly after Onyx-18 embolization. Five months after embolization, she presented with decreased vision, disfigurement and mechanical ptosis relating to a large subcutaneous mass affecting the medial right upper eyelid and forehead. Significant exam findings included a visual acuity of 20/400 (20/60 prior to embolization), an afferent pupillary defect, and optic disc pallor. MRI and angiography revealed a persistent AV malformation with feeders from the ophthalmic artery and an absent choroidal flush to the right eye. Pathology from surgical resection showed a significant foreign body giant cell reaction to the embolization material adjacent to the vessels. We suggest that an incomplete embolization with Onyx-18 may have caused vascular steal syndrome from the ophthalmic artery. PMID:27239463

  15. Block copolymer battery separator

    DOEpatents

    Wong, David; Balsara, Nitash Pervez

    2016-04-26

    The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

  16. Imide/arylene ether copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Hergenrother, Paul M. (Inventor); Bass, Robert G. (Inventor)

    1992-01-01

    Imide/arylene ether block copolymers are prepared by reacting anhydride terminated poly(amic acids) with amine terminated poly(arylene ethers) in polar aprotic solvents and by chemically or thermally cyclodehydrating the resulting intermediate poly(amic acids). The resulting block copolymers have one glass transition temperature or two, depending upon the particular structure and/or the compatibility of the block units. Most of these block copolymers form tough, solvent resistant films with high tensile properties.

  17. Roll-on perfume compositions containing polyoxybutylene-polyoxyethylene copolymers

    SciTech Connect

    Schmolka, I.R.

    1987-05-26

    This patent describes a liquid roll-on composition containing, in weight percent based upon the total composition weight, from 5 percent to 15 percent of a perfume oil, from 25 percent to 40 percent of a volatile alcohol, from 10 percent to 60 percent water, and from 10 percent to 30 percent of a nonionic polyether surfactant. The improvement comprises employing as the nonionic polyether surfactant a cogeneric polyoxybutylene-polyoxyethylene block copolymer.

  18. Interactions in random copolymers

    NASA Astrophysics Data System (ADS)

    Marinov, Toma; Luettmer-Strathmann, Jutta

    2002-04-01

    The description of thermodynamic properties of copolymers in terms of simple lattice models requires a value for the effective interaction strength between chain segments, in addition to parameters that can be derived from the properties of the corresponding homopolymers. If the monomers are chemically similar, Berthelot's geometric-mean combining rule provides a good first approximation for interactions between unlike segments. In earlier work on blends of polyolefins [1], we found that the small-scale architecture of the chains leads to corrections to the geometric-mean approximation that are important for the prediction of phase diagrams. In this work, we focus on the additional effects due to sequencing of the monomeric units. In order to estimate the effective interaction for random copolymers, the small-scale simulation approach developed in [1] is extended to allow for random sequencing of the monomeric units. The approach is applied here to random copolymers of ethylene and 1-butene. [1] J. Luettmer-Strathmann and J.E.G. Lipson. Phys. Rev. E 59, 2039 (1999) and Macromolecules 32, 1093 (1999).

  19. Block copolymer investigations

    NASA Astrophysics Data System (ADS)

    Yufa, Nataliya A.

    The research presented in this thesis deals with various aspects of block copolymers on the nanoscale: their behavior at a range of temperatures, their use as scaffolds, or for creation of chemically striped surfaces, as well as the behavior of metals on block copolymers under the influence of UV light, and the healing behavior of copolymers. Invented around the time of World War II, copolymers have been used for decades due to their macroscopic properties, such as their ability to be molded without vulcanization, and the fact that, unlike rubber, they can be recycled. In recent years, block copolymers (BCPs) have been used for lithography, as scaffolds for nano-objects, to create a magnetic hard drive, as well as in photonic and other applications. In this work we used primarily atomic force microscopy (AFM) and transmission electron microscopy (TEM), described in Chapter II, to conduct our studies. In Chapter III we demonstrate a new and general method for positioning nanoparticles within nanoscale grooves. This technique is suitable for nanodots, nanocrystals, as well as DNA. We use AFM and TEM to demonstrate selective decoration. In Chapters IV and V we use AFM and TEM to study the structure of polymer surfaces coated with metals and self-assembled monolayers. We describe how the surfaces were created, exhibit their structure on the nanoscale, and prove that their macroscopic wetting properties have been altered compared to the original polymer structures. Finally, Chapters VI and VII report out in-situ AFM studies of BCP at high temperatures, made possible only recently with the invention of air-tight high-temperature AFM imaging cells. We locate the transition between disordered films and cylinders during initial ordering. Fluctuations of existing domains leading to domain coarsening are also described, and are shown to be consistent with reptation and curvature minimization. Chapter VII deals with the healing of PS-b-PMMA following AFM-tip lithography or

  20. Alcoholism, Alcohol, and Drugs

    ERIC Educational Resources Information Center

    Rubin, Emanuel; Lieber, Charles S.

    1971-01-01

    Describes research on synergistic effects of alcohol and other drugs, particularly barbiturates. Proposes biochemical mechanisms to explain alcoholics' tolerance of other drugs when sober, and increased sensitivity when drunk. (AL)

  1. Polyether/Polyester Graft Copolymers

    NASA Technical Reports Server (NTRS)

    Bell, Vernon L., Jr.; Wakelyn, N.; Stoakley, D. M.; Proctor, K. M.

    1986-01-01

    Higher solvent resistance achieved along with lower melting temperature. New technique provides method of preparing copolymers with polypivalolactone segments grafted onto poly (2,6-dimethyl-phenylene oxide) backbone. Process makes strong materials with improved solvent resistance and crystalline, thermally-reversible crosslinks. Resulting graft copolymers easier to fabricate into useful articles, including thin films, sheets, fibers, foams, laminates, and moldings.

  2. Facile synthesis and characterization of novel biodegradable amphiphilic block copolymers bearing pendant hydroxyl groups.

    PubMed

    Hu, Gaicen; Fan, Xiaoshan; Xu, Bingcan; Zhang, Delong; Hu, Zhiguo

    2014-10-01

    Novel amphiphilic block copolymers bearing pendant hydroxyl groups polylactide-b-poly(3,3-bis(Hydroxymethyl-triazolylmethyl) oxetane)-b-polylactide (PLA-b-PHMTYO-b-PLA) were synthesized via a facile and efficient method. First, the block copolymer intermediates polylactide-b-poly(3,3-Diazidomethyloxetane)-b-polylactide (PLA-b-PBAMO-b-PLA) were synthesized through ring-opening polymerization of lactide using PBAMO as a macroinitiator. Following "Click" reaction of PLA-b-PBAMO-b-PLA with propargyl alcohol provided the targeted amphiphilic block copolymers PLA-b-PHMTYO-b-PLA with pendant hydroxyl groups. The composition and structure of prepared copolymers were characterized by (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy, Fourier transform infrared (FT-IR) and gel permeation chromatography (GPC). The self-assembly behavior of the copolymers in water was investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and static light scattering (SLS). The results showed that the novel copolymers PLA-b-PHMTYO-b-PLA self-assembled into spherical micelles with diameters ranging from 100 nm to 200 nm in aqueous solution. These copolymers also exhibited low critical micellar concentrations (CMC: 6.9 × 10(-4)mg/mL and 3.9 × 10(-5)mg/mL, respectively). In addition, the in vitro cytotoxicity of these copolymers was determined in the presence of L929 cells. The results showed that the block copolymers PLA-b-PHMTYO-b-PLA exhibited better biocompatibility. Therefore, these well-defined copolymers are expected to find some applications in drug delivery or tissue engineering. PMID:25175206

  3. Facile synthesis and characterization of novel biodegradable amphiphilic block copolymers bearing pendant hydroxyl groups.

    PubMed

    Hu, Gaicen; Fan, Xiaoshan; Xu, Bingcan; Zhang, Delong; Hu, Zhiguo

    2014-10-01

    Novel amphiphilic block copolymers bearing pendant hydroxyl groups polylactide-b-poly(3,3-bis(Hydroxymethyl-triazolylmethyl) oxetane)-b-polylactide (PLA-b-PHMTYO-b-PLA) were synthesized via a facile and efficient method. First, the block copolymer intermediates polylactide-b-poly(3,3-Diazidomethyloxetane)-b-polylactide (PLA-b-PBAMO-b-PLA) were synthesized through ring-opening polymerization of lactide using PBAMO as a macroinitiator. Following "Click" reaction of PLA-b-PBAMO-b-PLA with propargyl alcohol provided the targeted amphiphilic block copolymers PLA-b-PHMTYO-b-PLA with pendant hydroxyl groups. The composition and structure of prepared copolymers were characterized by (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy, Fourier transform infrared (FT-IR) and gel permeation chromatography (GPC). The self-assembly behavior of the copolymers in water was investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and static light scattering (SLS). The results showed that the novel copolymers PLA-b-PHMTYO-b-PLA self-assembled into spherical micelles with diameters ranging from 100 nm to 200 nm in aqueous solution. These copolymers also exhibited low critical micellar concentrations (CMC: 6.9 × 10(-4)mg/mL and 3.9 × 10(-5)mg/mL, respectively). In addition, the in vitro cytotoxicity of these copolymers was determined in the presence of L929 cells. The results showed that the block copolymers PLA-b-PHMTYO-b-PLA exhibited better biocompatibility. Therefore, these well-defined copolymers are expected to find some applications in drug delivery or tissue engineering.

  4. Influence of Architecture on the Behavior of Microphase Separated Block Copolymers

    NASA Astrophysics Data System (ADS)

    Speetjens, Frank W., II

    chemistry and physics of two other block copolymer systems are explored: (1) the self-assembly, thin film template fabrication, and post fabrication-template modification of reactive poly(styrene-b-vinyl dimethylazalactone) block copolymers, and (2) the synthesis and rheological characteristics of amphiphilic poly(vinyl alcohol)-based ABA triblock copolymer hydrogels.

  5. Anti-plasticizing effect of amorphous indomethacin induced by specific intermolecular interactions with PVA copolymer.

    PubMed

    Ueda, Hiroshi; Aikawa, Shohei; Kashima, Yousuke; Kikuchi, Junko; Ida, Yasuo; Tanino, Tadatsugu; Kadota, Kazunori; Tozuka, Yuichi

    2014-09-01

    The mechanism of how poly(vinyl alcohol-co-acrylic acid-co-methyl methacrylate) (PVA copolymer) stabilizes an amorphous drug was investigated. Solid dispersions of PVA copolymer, poly(vinyl pyrrolidone) (PVP), and poly(vinyl pyrrolidone-co-vinyl acetate) (PVPVA) with indomethacin (IMC) were prepared. The glass transition temperature (Tg)-proportion profiles were evaluated by differential scanning calorimetry (DSC). General Tg profiles decreasing with the IMC ratio were observed for IMC-PVP and IMC-PVPVA samples. An interesting antiplasticizing effect of IMC on PVA copolymer was observed; Tg increased up to 20% IMC ratio. Further addition of IMC caused moderate reduction with positive deviation from theoretical values. Specific hydrophilic and hydrophobic interactions between IMC and PVA copolymer were revealed by infrared spectra. The indole amide of IMC played an important role in hydrogen bonding with PVA copolymer, but not with PVP and PVPVA. X-ray diffraction findings and the endotherm on DSC profiles suggested that PVA copolymer could form a semicrystalline structure and a possibility of correlation of the crystallographic nature with its low hygroscopicity was suggested. PVA copolymer was able to prevent crystallization of amorphous IMC through both low hygroscopicity and the formation of a specific intermolecular interaction compared with that with PVP and PVPVA.

  6. Alcohol Alert

    MedlinePlus

    ... Us You are here Home » Alcohol Alert Alcohol Alert The NIAAA Alcohol Alert is a quarterly bulletin that disseminates important research ... text. To order single copies of select Alcohol Alerts, see ordering Information . To view publications in PDF ...

  7. Alcoholism - resources

    MedlinePlus

    Resources - alcoholism ... The following organizations are good resources for information on alcoholism : Alcoholics Anonymous -- www.aa.org Al-Anon/Alateen -- www.al-anon.org/home National Institute on Alcohol ...

  8. Alcoholic neuropathy

    MedlinePlus

    Neuropathy - alcoholic; Alcoholic polyneuropathy ... The exact cause of alcoholic neuropathy is unknown. It likely includes both a direct poisoning of the nerve by the alcohol and the effect of poor nutrition ...

  9. Alcohol Facts

    MedlinePlus

    ... raquo Alcohol Facts Alcohol Facts Listen Drinks like beer, malt liquor, wine, and hard liquor contain alcohol. Alcohol is the ingredient that gets you drunk. Hard liquor—such as whiskey, rum, or gin—has more ...

  10. Formation and Characterization of Anisotropic Block Copolymer Gels

    NASA Astrophysics Data System (ADS)

    Liaw, Chya Yan; Joester, Derk; Burghardt, Wesley; Shull, Kenneth

    2012-02-01

    Cylindrical micelles formed from block copolymer solutions closely mimic biological fibers that are presumed to guide mineral formation during biosynthesis of hard tissues like bone. The goal of our work is to use acrylic block copolymers as oriented templates for studying mineral formation reactions in model systems where the structure of the underlying template is well characterized and reproducible. Self-consistent mean field theory is first applied to investigate the thermodynamically stable micellar morphologies as a function of temperature and block copolymer composition. Small-angle x-ray scattering, optical birefringence and shear rheometry are used to study the morphology development during thermal processing. Initial experiments are based on a thermally-reversible alcohol-soluble system that can be converted to an aqueous gel by hydrolysis of a poly(t-butyl methacrylate) block to a poly(methacrylic acid) block. Aligned cylindrical domains are formed in the alcohol-based system when shear is applied in an appropriate temperature regime, which is below the critical micelle temperature but above the temperature at which the relaxation time of the gels becomes too large. Processing strategies for producing the desired cylindrical morphologies are being developed that account for both thermodynamic and kinetic effects.

  11. Effectiveness of bifenthrin (Onyx) and carbaryl (Sevin SL) for protecting individual, high-value conifers from bark beetle attack (Coleoptera: Curculionidae: Scolytinae) in the Western United States.

    PubMed

    Fettig, Christopher J; Allen, Kurt K; Borys, Robert R; Christopherson, John; Dabney, Christopher P; Eager, Thomas J; Gibson, Kenneth E; Hebertson, Elizabeth G; Long, Daniel F; Munson, A Steven; Shea, Patrick J; Smith, Sheri L; Haverty, Michael I

    2006-10-01

    High-value trees, such as those located in residential, recreational, or administrative sites, are particularly susceptible to bark beetle (Coleoptera: Curculionidae: Scolytinae) attack as a result of increased amounts of stress associated with drought, soil compaction, mechanical injury, or vandalism. Tree losses in these unique environments generally have a substantial impact. The value of these individual trees, cost of removal, and loss of esthetics may justify protection until the main thrust of a bark beetle infestation subsides. This situation emphasizes the need for ensuring that effective insecticides are available for individual tree protection. In this study, we assess the efficacy of bifenthrin (Onyx) and carbaryl (Sevin SL) for protecting: ponderosa pine, Pinus ponderosa Dougl. ex. Laws., from western pine beetle, Dendroctonus brevicomis LeConte, in California; mountain pine beetle, Dendroctonus ponderosae Hopkins in South Dakota; and Ips spp. in Arizona; lodgepole pine, Pinus contorta Dougl. ex Loud., from D. ponderosae in Montana; pinyon, Pinus edulis Engelm. in Colorado and Pinus monophylla Torr. and Frem. in Nevada from pinyon ips, Ips confusus (LeConte); and Engelmann spruce, Picea engelmannii Parry ex. Engelm. from spruce beetle, Dendroctonus rufipennis (Kirby) in Utah. Few trees were attacked by Ips spp. in Arizona and that study was discontinued. Sevin SL (2.0%) was effective for protecting P. ponderosa, P. contorta, and P. monophylla for two field seasons. Estimates of efficacy could not be made during the second field season in P. edulis and P. engelmannii due to insufficient mortality in untreated, baited control trees. Two field seasons of efficacy was demonstrated in P. ponderosa/D. brevicomis and P. monophylla for 0.06% Onyx. We conclude that Onyx is an effective individual tree protection tool, but repeated annual applications may be required in some systems if multiyear control is desired.

  12. Transarterial embolization of a hepatic arteriovenous malformation in an infant using Onyx: a case report and review of the differential diagnosis imaging findings.

    PubMed

    Bolus, Christopher; Yamada, Ricardo; Alshora, Sama; Hannegan, Christopher; Anderson, Bret

    2014-08-01

    Hepatic arteriovenous malformations are rare congenital lesions associated with significant morbidity and mortality, most commonly from high output cardiac failure. Efficient diagnosis and treatment demands an interdisciplinary approach, and the interventional radiologist plays a pivotal role in both. Imaging is important for diagnostic accuracy and treatment planning, and transcatheter embolization has become an established primary therapy. We report the clinical and imaging findings of a rare hepatic arteriovenous malformation in an infant presenting with high-output cardiac failure and pulmonary artery hypertension that was successfully treated by transarterial embolization using Onyx.

  13. Transarterial Embolization of a Hepatic Arteriovenous Malformation in an Infant Using Onyx: A Case Report and Review of the Differential Diagnosis Imaging Findings

    PubMed Central

    Bolus, Christopher; Yamada, Ricardo; Alshora, Sama; Hannegan, Christopher; Anderson, Bret

    2014-01-01

    Hepatic arteriovenous malformations are rare congenital lesions associated with significant morbidity and mortality, most commonly from high output cardiac failure. Efficient diagnosis and treatment demands an interdisciplinary approach, and the interventional radiologist plays a pivotal role in both. Imaging is important for diagnostic accuracy and treatment planning, and transcatheter embolization has become an established primary therapy. We report the clinical and imaging findings of a rare hepatic arteriovenous malformation in an infant presenting with high-output cardiac failure and pulmonary artery hypertension that was successfully treated by transarterial embolization using Onyx. PMID:25426243

  14. Phthalimide Copolymer Solar Cells

    NASA Astrophysics Data System (ADS)

    Xin, Hao; Guo, Xugang; Ren, Guoqiang; Kim, Felix; Watson, Mark; Jenekhe, Samson

    2010-03-01

    Photovoltaic properties of bulk heterojunction solar cells based on phthalimide donor-acceptor copolymers have been investigated. Due to the strong π-π stacking of the polymers, the state-of-the-art thermal annealing approach resulted in micro-scale phase separation and thus negligible photocurrent. To achieve ideal bicontinuous morphology, different strategies including quickly film drying and mixed solvent for film processing have been explored. In these films, nano-sale phase separation was achieved and a power conversion efficiency of 3.0% was obtained. Absorption and space-charge limited current mobility measurements reveal similar light harvesting and hole mobilities in all the films, indicating that the morphology is the dominant factor determining the photovoltaic performance. Our results demonstrate that for highly crystalline and/or low-solubility polymers, finding a way to prevent polymer aggregation and large scale phase separation is critical to realizing high performance solar cells.

  15. Hyperviscous diblock copolymer vesicles

    NASA Astrophysics Data System (ADS)

    Dimova, R.; Seifert, U.; Pouligny, B.; Förster, S.; Döbereiner, H.-G.

    2002-03-01

    Giant vesicles prepared from the diblock copolymer polybutadien-b-polyethyleneoxide (PB-PEO) exhibit a shear surface viscosity, which is about 500 times higher than those found in common phospholipid bilayers. Our result constitutes the first direct measurement of the shear surface viscosity of such polymersomes. At the same time, we measure bending and stretching elastic constants, which fall in the range of values typical for lipid membranes. Pulling out a tether from an immobilized polymersome and following its relaxation back to the vesicle body provides an estimate of the viscous coupling between the two monolayers composing the polymer membrane. The detected intermonolayer friction is about an order of magnitude higher than the characteristic one for phospholipid membranes. Polymersomes are tough vesicles with a high lysis tension. This, together with their robust rheological properties, makes them interesting candidates for a number of technological applications.

  16. Alcohol Alert: Genetics of Alcoholism

    MedlinePlus

    ... and Reports » Alcohol Alert » Alcohol Alert Number 84 Alcohol Alert Number 84 Print Version The Genetics of ... immune defense system. Genes Encoding Enzymes Involved in Alcohol Breakdown Some of the first genes linked to ...

  17. Skin delivery by block copolymer nanoparticles (block copolymer micelles).

    PubMed

    Laredj-Bourezg, Faiza; Bolzinger, Marie-Alexandrine; Pelletier, Jocelyne; Valour, Jean-Pierre; Rovère, Marie-Rose; Smatti, Batoule; Chevalier, Yves

    2015-12-30

    Block copolymer nanoparticles often referred to as "block copolymer micelles" have been assessed as carriers for skin delivery of hydrophobic drugs. Such carriers are based on organic biocompatible and biodegradable materials loaded with hydrophobic drugs: poly(lactide)-block-poly(ethylene glycol) copolymer (PLA-b-PEG) nanoparticles that have a solid hydrophobic core made of glassy poly(d,l-lactide), and poly(caprolactone)-block-poly(ethylene glycol) copolymer (PCL-b-PEG) nanoparticles having a liquid core of polycaprolactone. In vitro skin absorption of all-trans retinol showed a large accumulation of retinol in stratum corneum from both block copolymer nanoparticles, higher by a factor 20 than Polysorbate 80 surfactant micelles and by a factor 80 than oil solution. Additionally, skin absorption from PLA-b-PEG nanoparticles was higher by one order of magnitude than PCL-b-PEG, although their sizes (65nm) and external surface (water-swollen PEG layer) were identical as revealed by detailed structural characterizations. Fluorescence microscopy of histological skin sections provided a non-destructive picture of the storage of Nile Red inside stratum corneum, epidermis and dermis. Though particle cores had a different physical states (solid or liquid as measured by (1)H NMR), the ability of nanoparticles for solubilization of the drug assessed from their Hildebrand solubility parameters appeared the parameter of best relevance regarding skin absorption.

  18. Copolymer Crystallization: Approaching Equilibrium

    NASA Astrophysics Data System (ADS)

    Crist, Buckley; Finerman, Terry

    2002-03-01

    Random ethylene-butene copolymers of uniform chemical composition and degree of polymerization are crystallized by evaporation of thin films (1 μ m - 5 μ m) from solution. Macroscopic films ( 100 μm) formed by sequential layer deposition are characterized by density, calorimetry and X-ray techniques. Most notable is the density, which in some cases implies a crystalline fraction nearly 90% of the equilibrium value calculated from Flory theory. Melting temperature of these solution deposited layers is increased by as much as 8 ^oC over Tm for the same polymer crystallized from the melt. Small-angle X-ray scattering indicates that the amorphous layer thickness is strongly reduced by this layered crystallization process. X-ray diffraction shows a pronounced orientation of chain axes and lamellar normals parallel to the normal of the macroscopic film. It is clear that solvent enhances chain mobility, permitting proper sequences to aggregate and crystallize in a manner that is never achieved in the melt.

  19. Copolymers For Capillary Gel Electrophoresis

    DOEpatents

    Liu, Changsheng; Li, Qingbo

    2005-08-09

    This invention relates to an electrophoresis separation medium having a gel matrix of at least one random, linear copolymer comprising a primary comonomer and at least one secondary comonomer, wherein the comonomers are randomly distributed along the copolymer chain. The primary comonomer is an acrylamide or an acrylamide derivative that provides the primary physical, chemical, and sieving properties of the gel matrix. The at least one secondary comonomer imparts an inherent physical, chemical, or sieving property to the copolymer chain. The primary and secondary comonomers are present in a ratio sufficient to induce desired properties that optimize electrophoresis performance. The invention also relates to a method of separating a mixture of biological molecules using this gel matrix, a method of preparing the novel electrophoresis separation medium, and a capillary tube filled with the electrophoresis separation medium.

  20. Myths about drinking alcohol

    MedlinePlus

    ... to. I spend a lot of time getting alcohol, drinking alcohol, or recovering from the effects of alcohol. ... Institute on Alcohol Abuse and Alcoholism. Overview of Alcohol Consumption. www.niaaa.nih.gov/alcohol-health/overview-alcohol- ...

  1. Crystalline imide/arylene ether copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Hergenrother, Paul M. (Inventor); Bass, Robert G. (Inventor)

    1995-01-01

    Crystalline imide/arylene ether block copolymers are prepared by reacting anhydride terminated poly(amic acids) with amine terminated poly)arylene ethers) in polar aprotic solvents and chemically or thermally cyclodehydrating the resulting intermediate poly(amic acids). The block copolymers of the invention have one glass transition temperature or two, depending on the particular structure and/or the compatibility of the block units. Most of these crystalline block copolymers for tough, solvent resistant films with high tensile properties. While all of the copolymers produced by the present invention are crystalline, testing reveals that copolymers with longer imide blocks or higher imide content have increased crystallinity.

  2. Polyether-polyester graft copolymer

    NASA Technical Reports Server (NTRS)

    Bell, Vernon L. (Inventor)

    1987-01-01

    Described is a polyether graft polymer having improved solvent resistance and crystalline thermally reversible crosslinks. The copolymer is prepared by a novel process of anionic copolymerization. These polymers exhibit good solvent resistance and are well suited for aircraft parts. Previous aromatic polyethers, also known as polyphenylene oxides, have certain deficiencies which detract from their usefulness. These commercial polymers are often soluble in common solvents including the halocarbon and aromatic hydrocarbon types of paint thinners and removers. This limitation prevents the use of these polyethers in structural articles requiring frequent painting. In addition, the most popular commercially available polyether is a very high melting plastic. This makes it considerably more difficult to fabricate finished parts from this material. These problems are solved by providing an aromatic polyether graft copolymer with improved solvent resistance and crystalline thermally reversible crosslinks. The graft copolymer is formed by converting the carboxyl groups of a carboxylated polyphenylene oxide polymer to ionic carbonyl groups in a suitable solvent, reacting pivalolactone with the dissolved polymer, and adding acid to the solution to produce the graft copolymer.

  3. Alcohol and Alcoholism.

    ERIC Educational Resources Information Center

    National Inst. of Mental Health (DHEW), Chevy Chase, MD. National Clearinghouse for Mental Health Information.

    This concise survey presents some of the highlights of modern research on drinking and alcoholism, as based on technical articles published in the scientific literature and the views expressed by leading authorities in the field. Contents include discussions about: (1) the nature and scope of the problem; (2) the chemical composition of alcoholic…

  4. Transarterial Onyx embolization of jugular foramen dural arteriovenous fistula with spinal venous drainage manifesting as myelopathy-a case report and review of the literature.

    PubMed

    Jin, Hengwei; Lv, Xianli; Li, Youxiang

    2016-10-01

    We report a rare case of jugular foramen dural arteriovenous fistula (DAVF) with spinal venous drainage. A 48-year-old woman suffered from progressive weakness of lower extremities and incontinence of urine and feces for 14 days. Magnetic resonance imaging (MRI) revealed a tortuous posterior medullary vein at C2-T2 and ischemic signal at C2-C4 of the spinal cord. Brain MRI revealed an abnormal high signal near the left jugular foramen. Digital subtraction angiography of the spinal vascular was negative, while brain angiography showed a left jugular foramen DAVF with spinal perimedullary venous drainage. The patient recovered completely soon after endovascular embolization with Onyx-18. Diagnosis of a DAVF presenting with myelopathy is challenging. Early diagnosis and treatment are essential for a favorable outcome.

  5. Impacts of Repeat Unit Structure and Copolymer Architecture on Thermal and Solution Properties in Homopolymers, Copolymers, and Copolymer Blends

    NASA Astrophysics Data System (ADS)

    Marrou, Stephen Raye

    Gradient copolymers are a relatively new type of copolymer architecture in which the distribution of comonomers gradually varies over the length of the copolymer chain, resulting in a number of unusual properties derived from the arrangement of repeat units. For example, nanophase-segregated gradient copolymers exhibit extremely broad glass transition temperatures (Tgs) resulting from the wide range of compositions present in the nanostructure. This dissertation presents a number of studies on how repeat unit structure and copolymer architecture dictate bulk and solution properties, specifically taking inspiration from the gradient copolymer architecture and comparing the response from this compositionally heterogeneous material to other more conventional materials. The glass transition behavior of a range of common homopolymers was studied to determine the effects of subunit structure on Tg breadth, observing a significant increase in T g breadth with increasing side chain length in methacrylate-based homopolymers and random copolymers. Additionally, increasing the composition distribution of copolymers, either by blending individual random copolymers of different overall composition or synthesizing random copolymers to high conversion, resulted in significant increases to Tg breadth. Plasticization of homopolymers and random copolymers with low molecular weight additives also served to increase the Tg breadth; the most dramatic effect was observed in the selective plasticization of a styrene/4-vinylpyridine gradient copolymer with increases in T g breadth to values above 100 °C. In addition, the effects of repeat unit structure and copolymer architecture on other polymer properties besides Tg were also investigated. The intrinsic fluorescence of styrene units in styrene-containing copolymers was studied, noting the impact of repeat unit structure and copolymer architecture on the resulting fluorescence spectra in solution. The impact of repeat unit structure on

  6. Functionalized block copolymers as adhesion promoters

    SciTech Connect

    Kent, M.S.; Saunders, R.

    1995-03-01

    The goal of this work is to develop novel functionalized block copolymers to promote adhesion at inorganic substrate/polymer interfaces. We envision several potential advantages of functionalized block copolymers over small molecule coupling agents. Greater control over the structure of the interphase region should result through careful design of the backbone of the copolymer. The number of chains per area, the degree of entanglement between the copolymer and the polymer matrix, the number of sites per chain able to attach to the substrate, and the hydrophobicity of the interphase region can all be strongly affected by the choice of block lengths and the monomer sequence. In addition, entanglement between the copolymer and the polymer matrix, if achieved, should contribute significantly to adhesive strength. Our program involves four key elements: the synthesis of suitable functionalized block copolymers, characterization of the conformation of the copolymers at the interface by neutron reflectivity and atomic force microscopy, characterization of the degree of bonding by spectroscopy, and measurement of the mechanical properties of the interface. In this paper we discuss block copolymers designed as adhesion promoters for the copper/epoxy interface. We have synthesized a diblock with one block containing imidazole groups to bond to copper and a second block containing secondary amines to react with the epoxy matrix. We have also prepared a triblock copolymer containing a hydrophobic middle block. Below we describe the synthesis of the block copolymers by living, ring-opening metathesis polymerization (ROMP) and the first characterization data obtained by neutron reflectivity.

  7. Alcohol use disorder

    MedlinePlus

    ... Alcohol abuse; Problem drinking; Drinking problem; Alcohol addiction; Alcoholism - alcohol use; Substance use - alcohol ... The National Institute on Alcohol Abuse and Alcoholism ... 1 drink per day Men should not drink more than 2 drinks per day

  8. Discovering Complex Ordered Phases of Block Copolymers

    NASA Astrophysics Data System (ADS)

    Shi, An-Chang

    2012-02-01

    Block copolymers with their rich phase behavior and ordering transitions have become a paradigm for the study of structured soft materials. Understanding the structures and phase transitions in block copolymers has been one of the most active research areas in polymer science in the past two decades. One of the achievements is the self-consistent field theory (SCFT), which provides a powerful framework for the study of ordered phase of block copolymers. I will present a generic strategy to discover complex ordered phases of block copolymers within the SCFT framework. Specifically, a combination of real-space and reciprocal-space techniques is used to explore possible ordered phases in multiblock copolymer melts. These candidate phases can then be used to construct phase diagrams. Application of this strategy to linear and star ABC triblock copolymers has led to the discovery of a rich array of ordered phases.

  9. Bioinspired catecholic copolymers for antifouling surface coatings.

    PubMed

    Cho, Joon Hee; Shanmuganathan, Kadhiravan; Ellison, Christopher J

    2013-05-01

    We report here a synthetic approach to prepare poly(methyl methacrylate)-polydopamine diblock (PMMA-PDA) and triblock (PDA-PMMA-PDA) copolymers combining mussel-inspired catecholic oxidative chemistry and atom transfer radical polymerization (ATRP). These copolymers display very good solubility in a range of organic solvents and also a broad band photo absorbance that increases with increasing PDA content in the copolymer. Spin-cast thin films of the copolymer were stable in water and showed a sharp reduction (by up to 50%) in protein adsorption compared to those of neat PMMA. Also the peak decomposition temperature of the copolymers was up to 43°C higher than neat PMMA. The enhanced solvent processability, thermal stability and low protein adsorption characteristics of this copolymer makes it attractive for variety of applications including antifouling coatings on large surfaces such as ship hulls, buoys, and wave energy converters.

  10. Mixed interactions in random copolymers

    NASA Astrophysics Data System (ADS)

    Marinov, Toma; Luettmer-Strathmann, Jutta

    2002-03-01

    The description of thermodynamic properties of copolymers in terms of simple lattice models requires a value for the mixed interaction strength (ɛ_12) between unlike chain segments, in addition to parameters that can be derived from the properties of the corresponding homopolymers. If the monomers are chemically similar, Berthelot's geometric-mean combining rule provides a good first approximation for ɛ_12. In earlier work on blends of polyolefins [1], we found that the small-scale architecture of the chains leads to corrections to the geometric-mean approximation that are important for the prediction of phase diagrams. In this work, we focus on the additional effects due to sequencing of the monomeric units. In order to estimate the mixed interaction ɛ_12 for random copolymers, the small-scale simulation approach developed in [1] is extended to allow for random sequencing of the monomeric units. The approach is applied here to random copolymers of ethylene and 1-butene. [1] J. Luettmer-Strathmann and J.E.G. Lipson. Phys. Rev. E 59, 2039 (1999) and Macromolecules 32, 1093 (1999).

  11. Phase Behavior of Symmetric Sulfonated Block Copolymers

    SciTech Connect

    Park, Moon Jeong; Balsara, Nitash P.

    2008-08-21

    Phase behavior of poly(styrenesulfonate-methylbutylene) (PSS-PMB) block copolymers was studied by varying molecular weight, sulfonation level, and temperature. Molecular weights of the copolymers range from 2.9 to 117 kg/mol. Ordered lamellar, gyroid, hexagonally perforated lamellae, and hexagonally packed cylinder phases were observed in spite of the fact that the copolymers are nearly symmetric with PSS volume fractions between 0.45 and 0.50. The wide variety of morphologies seen in our copolymers is inconsistent with current theories on block copolymer phase behavior such as self-consistent field theory. Low molecular weight PSS-PMB copolymers (<6.2 kg/mol) show order-order and order-disorder phase transitions as a function of temperature. In contrast, the phase behavior of high molecular weight PSS-PMB copolymers (>7.7 kg/mol) is independent of temperature. Due to the large value of Flory-Huggins interaction parameter, x, between the sulfonated and non-sulfonated blocks, PSS-PMB copolymers with PSS and PMB molecular weights of 1.8 and 1.4 kg/mol, respectively, show the presence of an ordered gyroid phase with a 2.5 nm diameter PSS network. A variety of methods are used to estimate x between PSS and PMB chains as a function of sulfonation level. Some aspects of the observed phase behavior of PSS-PMB copolymers can be rationalized using x.

  12. Copolymers of fluorinated polydienes and sulfonated polystyrene

    DOEpatents

    Mays, Jimmy W.; Gido, Samuel P.; Huang, Tianzi; Hong, Kunlun

    2009-11-17

    Copolymers of fluorinated polydienes and sulfonated polystyrene and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization.

  13. Self-assembly of Random Copolymers

    PubMed Central

    Li, Longyu; Raghupathi, Kishore; Song, Cunfeng; Prasad, Priyaa; Thayumanavan, S.

    2014-01-01

    Self-assembly of random copolymers has attracted considerable attention recently. In this feature article, we highlight the use of random copolymers to prepare nanostructures with different morphologies and to prepare nanomaterials that are responsive to single or multiple stimuli. The synthesis of single-chain nanoparticles and their potential applications from random copolymers are also discussed in some detail. We aim to draw more attention to these easily accessible copolymers, which are likely to play an important role in translational polymer research. PMID:25036552

  14. Enhancement of deoxyribozyme activity by cationic copolymers.

    PubMed

    Gao, Jueyuan; Shimada, Naohiko; Maruyama, Atsushi

    2015-02-01

    Deoxyribozymes, or DNAzymes, are DNA molecules with enzymatic activity. DNAzymes with ribonuclease activity have various potential applications in biomedical and bioanalytical fields; however, most constructs have limited turnover despite optimization of reaction conditions and DNAzyme structures. A cationic comb-type copolymer accelerates DNA hybridization and strand exchange rates, and we hypothesized that the copolymer would enhance deoxyribozyme activity by promoting turnover. The copolymer did not change DNAzyme activity under single-turnover conditions, suggesting that the copolymer affects neither the folding structure of DNAzyme nor the association of a divalent cation, a catalytic cofactor, to DNAzyme. The copolymer enhanced activity of the evaluated DNAzyme over a wide temperature range under multiple-turnover conditions. The copolymer increased the DNAzyme kcat/KM by fifty-fold at 50 °C, the optimal temperature for the DNAzyme in the absence of the copolymer. The acceleration effect was most significant when the reaction temperature was slightly higher than the melting temperature of the enzyme/substrate complex; acceleration of two orders of magnitude was observed. We concluded that the copolymer accelerated the turnover step without influencing the chemical cleavage step. In contrast to the copolymer, a cationic surfactant, CTAB, strongly inhibited the DNAzyme activity under either single- or multiple-turnover conditions. PMID:26218121

  15. Occlusion of M1 segment after superficial temporal artery-middle cerebral artery bypass in a giant M1 aneurysm with Onyx-34 injected via a double-lumen balloon under balloon inflation.

    PubMed

    Clarençon, Frédéric; Nouet, Aurelien; Redondo, Aimée; Di Maria, Federico; Iosif, Christina; Le Jean, Lise; Chiras, Jacques; Sourour, Nader

    2014-05-01

    A 29-year-old patient attended our institution for recurrent strokes related to a giant partially thrombosed M1 aneurysm. Superficial temporal artery-middle cerebral artery (STA-MCA) bypass and subsequent occlusion of both the aneurysm and the dysplastic M1 segment were planned. However, owing to the shortness of the non-dysplastic segment of M1 and the risk of occlusion of the lenticulostriate arteries, the use of a double-lumen balloon was considered for coiling and subsequent injection of Onyx. STA-MCA bypass was performed using a regular technique. Endovascular occlusion of both the aneurysm and the parent artery was subsequently performed by means of coils and Onyx-34 that was injected via the Ascent balloon under balloon inflation. No complications were recorded and no stroke was observed on control MRI. The injection of Onyx-34 through a double-lumen balloon under balloon inflation is a quick and safe technique for precise occlusion of a parent artery.

  16. Dimensionally Stable Ether-Containing Polyimide Copolymers

    NASA Technical Reports Server (NTRS)

    Fay, Catharine C. (Inventor); St.Clair, Anne K. (Inventor)

    1999-01-01

    Novel polyimide copolymers containing ether linkages were prepared by the reaction of an equimolar amount of dianhydride and a combination of diamines. The polyimide copolymers described herein possess the unique features of low moisture uptake, dimensional stability, good mechanical properties, and moderate glass transition temperatures. These materials have potential application as encapsulants and interlayer dielectrics.

  17. Imide/arylene ether block copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Hergenrother, P. M.; Bass, R. G.

    1991-01-01

    Two series of imide/arylene either block copolymers were prepared using an arylene ether block and either an amorphous or semi-crystalline imide block. The resulting copolymers were characterized and selected physical and mechanical properties were determined. These results, as well as comparisons to the homopolymer properties, are discussed.

  18. Thermochemical characteristics of chitosan-polylactide copolymers

    NASA Astrophysics Data System (ADS)

    Goruynova, P. E.; Larina, V. N.; Smirnova, N. N.; Tsverova, N. E.; Smirnova, L. A.

    2016-05-01

    The energies of combustion of chitosan and its block-copolymers with different polylactide contents are determined in a static bomb calorimeter. Standard enthalpies of combustion and formation are calculated for these substances. The dependences of the thermochemical characteristics on block-copolymer composition are determined and discussed.

  19. Overview of Alcohol Consumption

    MedlinePlus

    ... Search Alcohol & Your Health Overview of Alcohol Consumption Alcohol's Effects on the Body Alcohol Use Disorder Fetal Alcohol ... other questions about alcohol. Here’s what we know: Alcohol’s effects vary from person to person, depending on a ...

  20. Alcohol and pregnancy

    MedlinePlus

    Drinking alcohol during pregnancy; Fetal alcohol syndrome - pregnancy; FAS - fetal alcohol syndrome ... When a pregnant woman drinks alcohol, the alcohol travels through her blood and into the baby's blood, tissues, and organs. Alcohol breaks down much more slowly in ...

  1. Processible Polyaniline Copolymers and Complexes.

    NASA Astrophysics Data System (ADS)

    Liao, Yun-Hsin

    1995-01-01

    Polyaniline (PANI) is an intractable polymer due to the difficulty of melt processing or dissolving it in common solvents. The purpose of the present investigation was to prepare a new class of conducting polyanilines with better solubility both in base and dope forms by (1) adding external salt to break aggregated chains, (2) introducing ring substituted units onto the backbone without disturbing the coplanar structure, and (3) complexing with polymeric dopants to form a soluble polymer complex. Aggregation of PANI chains in dilute solution was investigated in N-methyl-2-pyrrolidinone (NMP) by light scattering, gel permeation chromatography, and viscosity measurements. The aggregation of chains resulted in a negative second virial coefficient in light scattering measurement, a bimodal molecular weight distribution in gel permeation chromatography, and concave reduced viscosity curves. The aggregates can be broken by adding external salt, which resulting in a higher reduced viscosity. The driving force for aggregation is assumed to be a combination of hydrogen bonding between the imine and amine groups, and the rigidity of backbone. The aggregation was modeled to occur via side-on packing of PANI chains. The ring substituted PANI copolymers, poly(aniline -co-phenetidine) were synthesized by chemical oxidation copolymerization using ammonium persulfate as an oxidant. The degree of copolymerization declined with an increasing feed of o-phenetidine in the reaction mixture. The o-phenetidine had a higher reactivity than aniline in copolymerization resulting in a higher content of o-phenetidine in copolymers. The resulting copolymers can be readily dissolved in NMP up to 20% (w/w), and other common solvents, and solutions possess a longer gelation time. The highly soluble copolymer with 20 mole % o-phenetidine in the backbone has same order of conductivity as the unsubstituted PANI after it is doped by HCl. Complexation of PANI and polymeric dopant, poly

  2. Pattern transfer using block copolymers.

    PubMed

    Gu, Xiaodan; Gunkel, Ilja; Russell, Thomas P

    2013-10-13

    To meet the increasing demand for patterning smaller feature sizes, a lithography technique is required with the ability to pattern sub-20 nm features. While top-down photolithography is approaching its limit in the continued drive to meet Moore's law, the use of directed self-assembly (DSA) of block copolymers (BCPs) offers a promising route to meet this challenge in achieving nanometre feature sizes. Recent developments in BCP lithography and in the DSA of BCPs are reviewed. While tremendous advances have been made in this field, there are still hurdles that need to be overcome to realize the full potential of BCPs and their actual use.

  3. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false n-Alkylglutarimide/acrylic copolymers. 177.1060... Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic...) Identity. For the purpose of this section, n-alkylglutarimide/acrylic copolymers are copolymers obtained...

  4. Rapid self-assembly of block copolymers to photonic crystals

    DOEpatents

    Xia, Yan; Sveinbjornsson, Benjamin R; Grubbs, Robert H; Weitekamp, Raymond; Miyake, Garret M; Atwater, Harry A; Piunova, Victoria; Daeffler, Christopher Scot; Hong, Sung Woo; Gu, Weiyin; Russell, Thomas P.

    2016-07-05

    The invention provides a class of copolymers having useful properties, including brush block copolymers, wedge-type block copolymers and hybrid wedge and polymer block copolymers. In an embodiment, for example, block copolymers of the invention incorporate chemically different blocks comprising polymer size chain groups and/or wedge groups that significantly inhibit chain entanglement, thereby enhancing molecular self-assembly processes for generating a range of supramolecular structures, such as periodic nanostructures and microstructures. The present invention also provides useful methods of making and using copolymers, including block copolymers.

  5. Block Copolymer Membranes for Biofuel Purification

    NASA Astrophysics Data System (ADS)

    Evren Ozcam, Ali; Balsara, Nitash

    2012-02-01

    Purification of biofuels such as ethanol is a matter of considerable concern as they are produced in complex multicomponent fermentation broths. Our objective is to design pervaporation membranes for concentrating ethanol from dilute aqueous mixtures. Polystyrene-b-polydimethylsiloxane-b-polystyrene block copolymers were synthesized by anionic polymerization. The polydimethylsiloxane domains provide ethanol-transporting pathways, while the polystyrene domains provide structural integrity for the membrane. The morphology of the membranes is governed by the composition of the block copolymer while the size of the domains is governed by the molecular weight of the block copolymer. Pervaporation data as a function of these two parameters will be presented.

  6. Injectible bodily prosthetics employing methacrylic copolymer gels

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.

    2007-02-27

    The present invention provides novel block copolymers as structural supplements for injectible bodily prosthetics employed in medical or cosmetic procedures. The invention also includes the use of such block copolymers as nucleus pulposus replacement materials for the treatment of degenerative disc disorders and spinal injuries. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol) methyl ether polymer.

  7. Curable polyphosphazene copolymers and terpolymers

    NASA Technical Reports Server (NTRS)

    Reynard, Kennard A. (Inventor); Rose, Selwyn H. (Inventor)

    1976-01-01

    Copolymers and terpolymers comprising randomly repeating units represented by the general formulae ##EQU1## wherein the R' radicals contain OH functionality and R being at least one member of the group of monovalent radicals selected from alkyl, substituted alkyl, aryl, substituted aryl and arylalkyl, and R' is represented by ##EQU2## wherein Q represents either --(CH.sub.2).sub. n or --C.sub.6 H.sub.4 X(CH.sub.2).sub. m, the --X(CH.sub.2).sub. m group being either meta or para and n is an integer from 1 to 6, m is an integer from 1 to 3, X is O or CH.sub.2, and R is H or a lower alkyl radical with up to four carbon atoms (methyl, ethyl, etc.). The ratio of R to R' is between 99.5 to 0.5 and 65 to 35.

  8. Alcohol during Pregnancy

    MedlinePlus

    ... Home > Pregnancy > Is it safe? > Alcohol during pregnancy Alcohol during pregnancy E-mail to a friend Please ... and fetal alcohol spectrum disorders. How does drinking alcohol during pregnancy affect your baby's health? Drinking alcohol ...

  9. Alcohol Energy Drinks

    MedlinePlus

    ... Home / About Addiction / Alcohol / Alcohol Energy Drinks Alcohol Energy Drinks Read 17728 times font size decrease font size increase font size Print Email Alcohol energy drinks (AEDs) or Caffeinated alcoholic beverages (CABs) are ...

  10. Electrostatic control of block copolymer morphology

    NASA Astrophysics Data System (ADS)

    Sing, Charles E.; Zwanikken, Jos W.; Olvera de La Cruz, Monica

    2014-07-01

    Energy storage is at present one of the foremost issues society faces. However, material challenges now serve as bottlenecks in technological progress. Lithium-ion batteries are the current gold standard to meet energy storage needs; however, they are limited owing to the inherent instability of liquid electrolytes. Block copolymers can self-assemble into nanostructures that simultaneously facilitate ion transport and provide mechanical stability. The ions themselves have a profound, yet previously unpredictable, effect on how these nanostructures assemble and thus the efficiency of ion transport. Here we demonstrate that varying the charge of a block copolymer is a powerful mechanism to predictably tune nanostructures. In particular, we demonstrate that highly asymmetric charge cohesion effects can induce the formation of nanostructures that are inaccessible to conventional uncharged block copolymers, including percolated phases desired for ion transport. This vastly expands the design space for block copolymer materials and is informative for the versatile design of battery electrolyte materials.

  11. Arbitrary lattice symmetries via block copolymer nanomeshes

    PubMed Central

    Majewski, Pawel W.; Rahman, Atikur; Black, Charles T.; Yager, Kevin G.

    2015-01-01

    Self-assembly of block copolymers is a powerful motif for spontaneously forming well-defined nanostructures over macroscopic areas. Yet, the inherent energy minimization criteria of self-assembly give rise to a limited library of structures; diblock copolymers naturally form spheres on a cubic lattice, hexagonally packed cylinders and alternating lamellae. Here, we demonstrate multicomponent nanomeshes with any desired lattice symmetry. We exploit photothermal annealing to rapidly order and align block copolymer phases over macroscopic areas, combined with conversion of the self-assembled organic phase into inorganic replicas. Repeated photothermal processing independently aligns successive layers, providing full control of the size, symmetry and composition of the nanoscale unit cell. We construct a variety of symmetries, most of which are not natively formed by block copolymers, including squares, rhombuses, rectangles and triangles. In fact, we demonstrate all possible two-dimensional Bravais lattices. Finally, we elucidate the influence of nanostructure on the electrical and optical properties of nanomeshes. PMID:26100566

  12. Morphologies in Sulfonated Styrenic Pentablock Copolymer Membranes

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hong; Bramson, Matt; Winey, Karen I.

    2010-03-01

    Membranes of pentablock and triblock copolymers consisting of poly(tert-butyl styrene) (TBS), hydrogenated polyisoprene (HI), and partially sulfonated poly(styrene-ran-styrene sulfonate) (SS) were studied using small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The TBS-HI-SS-HI-TBS pentablock and TBS-HI-SS triblock copolymer membranes exhibit anisotropic microphase separated morphologies. Because the pentablock and triblock copolymers can be expected to have complex morphologies, thermal annealing was conducted to promote well-defined morphologies. The annealed membranes exhibit stronger peaks and more high order reflections in SAXS patterns, as well as better defined microstructures in the TEM. Electron microcopy studies with various staining protocols are underway to establish the morphology of the pentablock copolymer membranes including the size and shape of the three microdomains (TBS, HI and SS). We gratefully acknowledge Kraton Polymers, Inc. for materials.

  13. Block copolymer structures in nano-pores

    NASA Astrophysics Data System (ADS)

    Pinna, Marco; Guo, Xiaohu; Zvelindovsky, Andrei

    2010-03-01

    We present results of coarse-grained computer modelling of block copolymer systems in cylindrical and spherical nanopores on Cell Dynamics Simulation. We study both cylindrical and spherical pores and systematically investigate structures formed by lamellar, cylinders and spherical block copolymer systems for various pore radii and affinity of block copolymer blocks to the pore walls. The obtained structures include: standing lamellae and cylinders, ``onions,'' cylinder ``knitting balls,'' ``golf-ball,'' layered spherical, ``virus''-like and mixed morphologies with T-junctions and U-type defects [1]. Kinetics of the structure formation and the differences with planar films are discussed. Our simulations suggest that novel porous nano-containers can be formed by confining block copolymers in pores of different geometries [1,2]. [4pt] [1] M. Pinna, X. Guo, A.V. Zvelindovsky, Polymer 49, 2797 (2008).[0pt] [2] M. Pinna, X. Guo, A.V. Zvelindovsky, J. Chem. Phys. 131, 214902 (2009).

  14. 21 CFR 173.65 - Divinylbenzene copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... Divinylbenzene copolymer may be used for the removal of organic substances from aqueous foods under the following... are available from the Center for Food Safety and Applied Nutrition (HFS-200), Food and...

  15. 21 CFR 173.65 - Divinylbenzene copolymer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... Divinylbenzene copolymer may be used for the removal of organic substances from aqueous foods under the following... are available from the Center for Food Safety and Applied Nutrition (HFS-200), Food and...

  16. 21 CFR 173.65 - Divinylbenzene copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Divinylbenzene copolymer may be used for the removal of organic substances from aqueous foods under the following... are available from the Center for Food Safety and Applied Nutrition (HFS-200), Food and...

  17. Phase behaviors of cyclic diblock copolymers.

    PubMed

    Zhang, Guojie; Fan, Zhongyong; Yang, Yuliang; Qiu, Feng

    2011-11-01

    A spectral method of self-consistent field theory has been applied to AB cyclic block copolymers. Phase behaviors of cyclic diblock copolymers, such as order-disorder transition, order-order transition, and domain spacing size, have been studied, showing good consistency with previous experimental and theoretical results. Compared to linear diblocks, cyclic diblocks are harder to phase separate due to the topological constraint of the ring structure. A direct disorder-to-cylinder transition window is observed in the phase diagram, which is significantly different from the mean field phase diagram of linear diblock copolymers. The domain spacing size ratio between cyclic and linear diblock copolymers is typically close to 0.707, indicating in segregation that the cyclic polymer can be considered to be made up of linear diblocks with half of the original chain length. PMID:22070321

  18. Responsive Copolymers for Enhanced Petroleum Recovery

    SciTech Connect

    McCormick, C.; Hester, R.

    2001-02-27

    The objectives of this work was to: synthesize responsive copolymer systems; characterize molecular structure and solution behavior; measure rheological properties of aqueous fluids in fixed geometry flow profiles; and to tailor final polymer compositions for in situ rheology control under simulated conditions. This report focuses on the synthesis and characterization of novel stimuli responsive copolymers, the investigation of dilute polymer solutions in extensional flow and the design of a rheometer capable of measuring very dilute aqueous polymer solutions at low torque.

  19. Method for making block siloxane copolymers

    DOEpatents

    Butler, N.L.; Jessop, E.S.; Kolb, J.R.

    1981-02-25

    A method for synthesizing block polysiloxane copolymers is disclosed. Diorganoscyclosiloxanes and an end-blocking compound are interacted in the presence of a ring opening polymerization catalyst, producing a blocked prepolymer. The prepolymer is then interacted with a silanediol, resulting in condensation polymerization of the prepolymers. A second end-blocking compound is subsequently introduced to end-cap the polymers and copolymers formed from the condensation polymerization.

  20. Method for making block siloxane copolymers

    DOEpatents

    Butler, Nora; Jessop, Edward S.; Kolb, John R.

    1982-01-01

    A method for synthesizing block polysiloxane copolymers. Diorganoscyclosiloxanes and an end-blocking compound are interacted in the presence of a ring opening polymerization catalyst, producing a blocked prepolymer. The prepolymer is then interacted with a silanediol, resulting in condensation polymerization of the prepolymers. A second end-blocking compound is subsequently introduced to end-cap the polymers and copolymers formed from the condensation polymerization.

  1. Alcohol conversion

    DOEpatents

    Wachs, Israel E.; Cai, Yeping

    2002-01-01

    Preparing an aldehyde from an alcohol by contacting the alcohol in the presence of oxygen with a catalyst prepared by contacting an intimate mixture containing metal oxide support particles and particles of a catalytically active metal oxide from Groups VA, VIA, or VIIA, with a gaseous stream containing an alcohol to cause metal oxide from the discrete catalytically active metal oxide particles to migrate to the metal oxide support particles and to form a monolayer of catalytically active metal oxide on said metal oxide support particles.

  2. Alcoholic ketoacidosis

    MedlinePlus

    Tests may include: Arterial blood gases (measure the acid/base balance and oxygen level in blood) Blood alcohol ... PA: Elsevier Saunders; 2013:chap 161. Seifter JL. Acid-Base disorders. In: Goldman L, Schafer AI, eds. Goldman's ...

  3. Alcohol withdrawal

    MedlinePlus

    ... Seeing or feeling things that aren't there (hallucinations) Seizures Severe confusion ... alcohol withdrawal. You will be watched closely for hallucinations and other signs of delirium tremens. Treatment may ...

  4. Polyhydroxyalkanoate copolymers from forest biomass.

    PubMed

    Keenan, Thomas M; Nakas, James P; Tanenbaum, Stuart W

    2006-07-01

    The potential for the use of woody biomass in poly-beta-hydroxyalkanoate (PHA) biosynthesis is reviewed. Based on previously cited work indicating incorporation of xylose or levulinic acid (LA) into PHAs by several bacterial strains, we have initiated a study for exploring bioconversion of forest resources to technically relevant copolymers. Initially, PHA was synthesized in shake-flask cultures of Burkholderia cepacia grown on 2.2% (w/v) xylose, periodically amended with varying concentrations of levulinic acid [0.07-0.67% (w/v)]. Yields of poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) [P(3HB-co-3HV)] from 1.3 to 4.2 g/l were obtained and could be modulated to contain from 1.0 to 61 mol% 3-hydroxyvalerate (3HV), as determined by 1H and 13C NMR analyses. No evidence for either the 3HB or 4HV monomers was found. Characterization of these P(3HB-co-3HV) samples, which ranged in molecular mass (viscometric, Mv) from 511-919 kDa, by differential scanning calorimetry and thermogravimetric analyses (TGA) provided data which were in agreement for previously reported P(3HB-co-3HV) copolymers. For these samples, it was noted that melting temperature (Tm) and glass transition temperature (Tg) decreased as a function of 3HVcontent, with Tm demonstrating a pseudoeutectic profile as a function of mol% 3HV content. In order to extend these findings to the use of hemicellulosic process streams as an inexpensive carbon source, a detoxification procedure involving sequential overliming and activated charcoal treatments was developed. Two such detoxified process hydrolysates (NREL CF: aspen and CESF: maple) were each fermented with appropriate LA supplementation. For the NREL CF hydrolysate-based cultures amended with 0.25-0.5% LA, P(3HB-co-3HV) yields, PHA contents (PHA as percent of dry biomass), and mol% 3HV compositions of 2.0 g/l, 40% (w/w), and 16-52 mol% were obtained, respectively. Similarly, the CESF hydrolysate-based shake-flask cultures yielded 1.6 g/l PHA, 39% (w

  5. Initiator Effects in Reactive Extrusion of Starch Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch with water-soluble polymers such as polyacrylamide have potential applications including hydrogels, superabsorbents, and thickening agents. Reactive extrusion is a rapid, continuous method for production of starch graft copolymers with high reaction and grafting efficienc...

  6. Hydrogen-bonded aggregates in precise acid copolymers

    SciTech Connect

    Lueth, Christopher A.; Bolintineanu, Dan S.; Stevens, Mark J. Frischknecht, Amalie L.

    2014-02-07

    We perform atomistic molecular dynamics simulations of melts of four precise acid copolymers, two poly(ethylene-co-acrylic acid) (PEAA) copolymers, and two poly(ethylene-co-sulfonic acid) (PESA) copolymers. The acid groups are spaced by either 9 or 21 carbons along the polymer backbones. Hydrogen bonding causes the acid groups to form aggregates. These aggregates give rise to a low wavevector peak in the structure factors, in agreement with X-ray scattering data for the PEAA materials. The structure factors for the PESA copolymers are very similar to those for the PEAA copolymers, indicating a similar distance between aggregates which depends on the spacer length but not on the nature of the acid group. The PEAA copolymers are found to form more dimers and other small aggregates than do the PESA copolymers, while the PESA copolymers have both more free acid groups and more large aggregates.

  7. Deciding to quit drinking alcohol

    MedlinePlus

    ... Alcohol abuse - quitting drinking; Quitting drinking; Quitting alcohol; Alcoholism - deciding to quit ... pubmed/23698791 . National Institute on Alcohol Abuse and Alcoholism. Alcohol and health. www.niaaa.nih.gov/alcohol- ...

  8. Chain exchange in block copolymer micelles

    NASA Astrophysics Data System (ADS)

    Lu, Jie; Bates, Frank; Lodge, Timothy

    2014-03-01

    Block copolymer micelles are aggregates formed by self-assembly of amphiphilic copolymers dispersed in a selective solvent, driven by unfavorable interactions between the solvent and the core-forming block. Due to the relatively long chains being subject to additional thermodynamic and dynamic constraints (e.g., entanglements, crystallinity, vitrification), block copolymer micelles exhibit significantly slower equilibration kinetics than small molecule surfactants. As a result, details of the mechanism(s) of equilibration in block copolymer micelles remain unclear. This present works focuses on the chain exchange kinetics of poly(styrene-b-ethylenepropylene) block copolymers in squalane (C30H62) using time-resolved small angle neutron scattering (TR-SANS). A mixture of h-squalane and d-squalane is chosen so that it contrast matches a mixed 50/50 h/d polystyrene micelle core. When the temperature is appropriate and isotopically labeled chains undergo mixing, the mean core contrast with respect to the solvent decreases, and the scattering intensity is therefore reduced. This strategy allows direct probing of chain exchange rate from the time dependent scattering intensity I(q, t).

  9. Thermoreversible copolymer gels for extracellular matrix.

    PubMed

    Vernon, B; Kim, S W; Bae, Y H

    2000-07-01

    To improve the properties of a reversible synthetic extracellular matrix based on a thermally reversible polymer, copolymers of N-isopropylacrylamide and acrylic acid were prepared in benzene with varying contents of acrylic acid (0 to 3%) and the thermal properties were evaluated. The poly(N-isopropylacrylamide) and copolymers made with acrylic acid had molecular weights from 0.8 to 1.7 x10(6) D. Differential scanning calorimetry (DSC) showed the high-molecular-weight acrylic acid copolymers had similar onset temperatures to the homopolymers, but the peak width was considerably increased with increasing acrylic acid content. DSC and cloud point measurements showed that polymers with 0 to 3% acrylic acid exhibit a lower critical solution temperature (LCST) transition between 30 degrees and 37 degrees C. In swelling studies, the homopolymer showed significant syneresis at temperatures above 31 degrees C. Copolymers with 1 and 1.5% showed syneresis beginning at 32 degrees and 37 degrees C, respectively. At 37 degrees C the copolymers with 1.5-3% acrylic acid showed little or no syneresis. Due to the high water content and a transition near physiologic conditions (below 37 degrees C), the polymers with 1.5-2.0% acrylic acid exhibited properties that would be useful in the development of a refillable synthetic extracellular matrix. Such a matrix could be applied to several cell types, including islets of Langerhans, for a biohybrid artificial pancreas.

  10. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile copolymers and resins. 181.32...-Sanctioned Food Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and resins listed in this section, containing less than 30 percent acrylonitrile and complying with...

  11. pH-sensitive methacrylic copolymers and the production thereof

    SciTech Connect

    Mallapragada, Surya K.; Anderson, Brian C.; Bloom, Paul D.; Sheares Ashby, Valerie V.

    2006-02-14

    The present invention provides novel multi-functional methacrylic copolymers that exhibit cationic pH-sensitive behavior as well as good water solubility under acidic conditions. The copolymers are constructed from tertiary amine methacrylates and poly(ethylene glycol) containing methacrylates. The copolymers are useful as gene vectors, pharmaceutical carriers, and in protein separation applications.

  12. pH-sensitive methacrylic copolymers and the production thereof

    SciTech Connect

    Mallapragada, Surya K.; Anderson, Brian C.; Bloom, Paul D.; Sheares Ashby, Valerie V.

    2007-01-09

    The present invention provides novel multi-functional methacrylic copolymers that exhibit cationic pH-sensitive behavior as well as good water solubility under acidic conditions. The copolymers are constructed from tertiary amine methacrylates and poly(ethylene glycol) containing methacrylates. The copolymers are useful as gene vectors, pharmaceutical carriers, and in protein separation applications.

  13. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile copolymers and resins. 181.32 Section... Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and resins listed in... of the vinyl chloride resin) resin—for use only in contact with oleomargarine. (iv)...

  14. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  15. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  16. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be...

  17. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may... produced by the polymerization of methacrylic acid and divinylbenzene. The divinylbenzene functions as...

  18. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be...

  19. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be...

  20. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  1. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylonitrile copolymers and resins....

  2. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acrylonitrile copolymers and resins....

  3. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  4. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  5. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false n-Alkylglutarimide/acrylic copolymers. 177.1060... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic copolymers identified in this section may be safely used as...

  6. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  7. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  8. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true n-Alkylglutarimide/acrylic copolymers. 177.1060... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic copolymers identified in this section may be safely used as...

  9. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false n-Alkylglutarimide/acrylic copolymers. 177.1060... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic copolymers identified in this section may be safely used as...

  10. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be...

  11. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  12. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false n-Alkylglutarimide/acrylic copolymers. 177.1060... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic copolymers identified in this section may be safely used as...

  13. Nanoscale Ionic Aggregate Morphology in Zwitterionic Copolymers

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hong; Huyck, Rebecca; Salas-de La Cruz, David; Long, Timothy E.; Winey, Karen I.

    2009-03-01

    The morphology of two different zwitterionic copolymers, poly(sulfobetaine methacrylate-ran-butyl acrylate), and poly(sulfobetaine methacrylamide-ran-butyl acrylate) are investigated as a function of the mol % content of SBMA (7 and 9 mol %) and SBMAm (6, 10 and 13 mol %), respectively. In both copolymers, X-ray scattering results show a new structure in the material arising from ionic aggregates. The sizes of the ionic aggregates are obtained through the scattering model. The sizes of the ionic aggregates increase as the ion content increases. The application of scanning transmission electron microscopy to the study of ionomer morphology has enabled direct, model-independent visualization of the ionic aggregates. The correlation between X-ray scattering results and the real space imaging for morphology of these zwitterionic copolymers will be presented.

  14. Optical properties of coumarins containing copolymers

    NASA Astrophysics Data System (ADS)

    Skowronski, L.; Krupka, O.; Smokal, V.; Grabowski, A.; Naparty, M.; Derkowska-Zielinska, B.

    2015-09-01

    We investigate the optical properties such as absorption coefficient, refractive index, real and imaginary parts of dielectric function and energy band gap of coumarin-containing copolymers thin films by means of spectroscopic ellipsometry (SE) combined with transmittance measurements (T) and atomic force microscopy (AFM). We found that the optical properties of coumarin-containing copolymers strongly depend from length of alkyl spacer as well as the type of substitution in coumarin moiety. In our case the refractive index as well as the energy band gap of coumarin-containing copolymer decrease with increase the length of alkyl spacer. Additionally, the lengthening of the alkyl spacer brings the bathochromic shifts of the absorption spectra towards longer wavelengths.

  15. Rod-Coil Block Polyimide Copolymers

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B. (Inventor); Kinder, James D. (Inventor)

    2005-01-01

    This invention is a series of rod-coil block polyimide copolymers that are easy to fabricate into mechanically resilient films with acceptable ionic or protonic conductivity at a variety of temperatures. The copolymers consist of short-rigid polyimide rod segments alternating with polyether coil segments. The rods and coil segments can be linear, branched or mixtures of linear and branched segments. The highly incompatible rods and coil segments phase separate, providing nanoscale channels for ion conduction. The polyimide segments provide dimensional and mechanical stability and can be functionalized in a number of ways to provide specialized functions for a given application. These rod-coil black polyimide copolymers are particularly useful in the preparation of ion conductive membranes for use in the manufacture of fuel cells and lithium based polymer batteries.

  16. Fetal alcohol syndrome

    MedlinePlus

    Alcohol in pregnancy; Alcohol-related birth defects; Fetal alcohol effects; FAS ... varies. Almost none of these babies have normal brain development. Infants and children with fetal alcohol syndrome have many different problems, which can be ...

  17. Fetal Alcohol Spectrum Disorders

    MedlinePlus

    ... alcohol can cause a group of conditions called fetal alcohol spectrum disorders (FASDs). Effects can include physical and behavioral problems such ... alcohol syndrome is the most serious type of FASD. People with fetal alcohol syndrome have facial abnormalities, ...

  18. Morphologies of poly(cyclohexadiene) diblock copolymers

    SciTech Connect

    Kumar, Rajeev; Mays, Jimmy; Sides, Scott; Goswami, Monojoy; Sumpter, Bobby G; Hong, Kunlun; Avgeropoulos, Apostolos; Russell, Thomas P; Gido, Samuel; Tsoukatos, Thodoris; Beyer, Fredrick

    2012-01-01

    Concerted experimental and theoretical investigations have been carried out to understand the micro-phase separation in diblock copolymer melts containing poly (1,3-cyclohexadiene), PCHD, as one of the constituents. In particular, we have studied diblock copolymer melts containing polystyrene (PS), polybutadiene (PB), and polyisoprene (PI) as the second block. We have systematically varied the ratio of 1,2- /1,4-microstructures of poly (1,3-cyclohexadiene) to tune the conformational asymmetry between the two blocks and characterized the effects of these changes on the morphologies using transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). Our experimental investigations reveal that the melts of PCHD-b-PB, PCHD-b-PS and PCHD-b-PI containing nearly equal fractions of each component and high percentage of 1,4-microstructures in the PCHD block form cylindrical rather than lamellar morphologies as expected in symmetric diblock copolymers. In contrast, the morphologies of PCHD-b-PB, PCHD-b-PS and PCHD-b-PI containing PCHD block with higher 1,2-microstructure are found to be disordered at 110 C. The change in the morphological behavior is in good agreement with our numerical calculations using the random phase approximation and self-consistent field theory for conformationally asymmetric diblock copolymer melts. Also, the effects of composition fluctuations are studied by extending the Brazovskii-Leibler-Fredrickson-Helfand (J. Chem. Phys. 87, 697 (1987)) theory to conformationally asymmetric diblock copolymer melts. These results allow the understanding of the underlying self-assembly process that highlights the importance of the conformational asymmetry in tuning the morphologies in block copolymers.

  19. Dynamics of Block Copolymer Nanocomposites

    SciTech Connect

    Mochrie, Simon G. J.

    2014-09-09

    A detailed study of the dynamics of cadmium sulfide nanoparticles suspended in polystyrene homopolymer matrices was carried out using X-ray photon correlation spectroscopy for temperatures between 120 and 180 °C. For low molecular weight polystyrene homopolymers, the observed dynamics show a crossover from diffusive to hyper-diffusive behavior with decreasing temperatures. For higher molecular weight polystyrene, the nanoparticle dynamics appear hyper-diffusive at all temperatures studied. The relaxation time and characteristic velocity determined from the measured hyper-diffusive dynamics reveal that the activation energy and underlying forces determined are on the order of 2.14 × 10-19 J and 87 pN, respectively. We also carried out a detailed X-ray scattering study of the static and dynamic behavior of a styrene– isoprene diblock copolymer melt with a styrene volume fraction of 0.3468. At 115 and 120 °C, we observe splitting of the principal Bragg peak, which we attribute to phase coexistence of hexagonal cylindrical and cubic double- gyroid structure. In the disordered phase, above 130 °C, we have characterized the dynamics of composition fluctuations via X-ray photon correlation spectroscopy. Near the peak of the static structure factor, these fluctuations show stretched-exponential relaxations, characterized by a stretching exponent of about 0.36 for a range of temperatures immediately above the MST. The corresponding characteristic relaxation times vary exponentially with temperature, changing by a factor of 2 for each 2 °C change in temperature. At low wavevectors, the measured relaxations are diffusive with relaxation times that change by a factor of 2 for each 8 °C change in temperature.

  20. Co-polymer films for sensors

    NASA Technical Reports Server (NTRS)

    Ryan, Margaret A. (Inventor); Homer, Margie L. (Inventor); Yen, Shiao-Pin S. (Inventor); Kisor, Adam (Inventor); Jewell, April D. (Inventor); Shevade, Abhijit V. (Inventor); Manatt, Kenneth S. (Inventor); Taylor, Charles (Inventor); Blanco, Mario (Inventor); Goddard, William A. (Inventor)

    2010-01-01

    Embodiments include a sensor comprising a co-polymer, the co-polymer comprising a first monomer and a second monomer. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is polystyrene and the second monomer is poly-2-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium benzylamine chloride. Other embodiments are described and claimed.

  1. Co-polymer Films for Sensors

    NASA Technical Reports Server (NTRS)

    Ryan, Margaret A. (Inventor); Homer, Margie L. (Inventor); Yen, Shiao-Pin S. (Inventor); Kisor, Adam (Inventor); Jewell, April D. (Inventor); Shevade, Abhijit V. (Inventor); Manatt, Kenneth S. (Inventor); Taylor, Charles (Inventor); Blanco, Mario (Inventor); Goddard, William A. (Inventor)

    2012-01-01

    Embodiments include a sensor comprising a co-polymer, the co-polymer comprising a first monomer and a second monomer. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is polystyrene and the second monomer is poly-2-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium benzylamine chloride. Other embodiments are described and claimed.

  2. Allyl alcohol

    Integrated Risk Information System (IRIS)

    Allyl alcohol ; CASRN 107 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  3. Propargyl alcohol

    Integrated Risk Information System (IRIS)

    Propargyl alcohol ; CASRN 107 - 19 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  4. Isobutyl alcohol

    Integrated Risk Information System (IRIS)

    Isobutyl alcohol ; CASRN 78 - 83 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  5. Alcohol project

    SciTech Connect

    Not Available

    1980-12-01

    The Great Western Sugar Company has announced plans for the construction of a $300 million plant for the production of fuel grade alcohol from corn. The plant at Reserve, Lousiana, will also produce high fructose corn syrup and animal feed by-products and will employ an additional 200 people.

  6. Osmotic Pressure Measurements of the Order Disorder Transition in Acrylic Triblock Copolymer Gels

    NASA Astrophysics Data System (ADS)

    Bras, Rafael E.; Shull, Kenneth R.

    2006-03-01

    Semi-dilute solutions of PMMA-PnBA-PMMA triblock co-polymers in alcohols are excellent binder materials for a novel ceramics processing method, thermo-reversible gel casting. Processing methods based on this technology offer a low cost alternative to traditional slip and gel casting techniques. The rapid transition of these gels from freely flowing liquids to elastic solids has been attributed to the aggregation of the PMMA endblocks to form small spherical domains. We have recently begun to examine the order disorder transition of the PMMA endblocks with vapor pressure osmometry. This technique measures osmotic pressure by monitoring the equilibrium temperature of a solution droplet relative to the temperature of a pure solvent droplet. Measurements of solutions consisting of 15 vol % acrylic triblock copolymer in butanol show a significant drop in osmotic pressure between 80 and 85 C. This result indicates that the relaxation times of the ordered gels can be quite low, so that the order-disorder transition of the triblock copolymer occurs at temperatures higher than the rheologically determined gelation temperature of about 65 C.

  7. Alcoholism and Minority Populations.

    ERIC Educational Resources Information Center

    Watts, Thomas D.; Wright, Roosevelt, Jr.

    1991-01-01

    Briefly discusses some aspects of the role of the state and the position of minorities in respect to alcoholism policies and services. Includes case study of a Black alcoholic. Refers readers to studies on Black alcoholism, Native American alcoholism, Hispanic alcoholism, and Asian-American alcoholism. (Author/NB)

  8. Polyvinyl alcohol membranes as alkaline battery separators

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Gonzalez-Sanabria, O.; Manzo, M. A.

    1982-01-01

    Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed.

  9. Synthesis of amphiphilic diblock copolymer for surface modification of Ethylene-Norbornene Copolymers

    NASA Astrophysics Data System (ADS)

    Levinsen, Simon; Svendsen, Winnie Edith; Horsewell, Andy; Almdal, Kristoffer

    2014-03-01

    The aim of this work is to produce polymer modifiers in order to develop hydrophilic polymeric surfaces for use in microfluidics. The use of hydrophilic polymers in microfluidics will have many advantages e.g. preventing protein absorbance. Here we present an amphiphilic diblock copolymer consisting of a bulk material compatible block and a hydrophilic block. To utilize the possibility of incorporating diblock copolymers into ethylene-norbornene copolymers, we have in this work developed a model poly(ethylene-1-butene) polymer compatible with the commercial available ethylene-norbornene copolymer TOPAS. Through matching of the radius of gyration for the model polymer and TOPAS the miscibility was achieved. The poly(ethylene-1-butene) polymer was synthesized from a hydrogenated anionic polymerized polybutadiene polymer. As hydrophilic block poly(ethylene oxide) was subsequently added also with anionic polymerization. Recent miscibility results between the model polymer and TOPAS will be presented, as well ongoing efforts to study the hydrophilic surface.

  10. Molecular Interaction Control in Diblock Copolymer Blends and Multiblock Copolymers with Opposite Phase Behaviors

    NASA Astrophysics Data System (ADS)

    Cho, Junhan

    2014-03-01

    Here we show how to control molecular interactions via mixing AB and AC diblock copolymers, where one copolymer exhibits upper order-disorder transition and the other does lower disorder-order transition. Linear ABC triblock copolymers possessing both barotropic and baroplastic pairs are also taken into account. A recently developed random-phase approximation (RPA) theory and the self-consistent field theory (SCFT) for general compressible mixtures are used to analyze stability criteria and morphologies for the given systems. It is demonstrated that the copolymer systems can yield a variety of phase behaviors in their temperature and pressure dependence upon proper mixing conditions and compositions, which is caused by the delicate force fields generated in the systems. We acknowledge the financial support from National Research Foundation of Korea and Center for Photofunctional Energy Materials.

  11. Mixing thermodynamics of block-random copolymers

    NASA Astrophysics Data System (ADS)

    Beckingham, Bryan Scott

    Random copolymerization of A and B monomers represents a versatile method to tune interaction strengths between polymers, as ArB random copolymers will exhibit a smaller effective Flory interaction parameter chi; (or interaction energy density X) upon mixing with A or B homopolymers than upon mixing A and B homopolymers with each other, and the ArB composition can be tuned continuously. Thus, the incorporation of a random copolymer block into the classical block copolymer architecture to yield "block-random" copolymers introduces an additional tuning mechanism for the control of structure-property relationships, as the interblock interactions and physical properties can be tuned continuously through the random block's composition. However, typical living or controlled polymerizations produce compositional gradients along the "random" block, which can in turn influence the phase behavior. This dissertation demonstrates a method by which narrow-distribution copolymers of styrene and isoprene of any desired composition, with no measurable down-chain gradient, are synthesized. This synthetic method is then utilized to incorporate random copolymers of styrene and isoprene as blocks into block-random copolymers in order to examine the resulting interblock mixing thermodynamics. A series of well-defined near-symmetric block and block-random copolymers (S-I, Bd-S, I-SrI, S-SrI and Bd-S rI diblocks, where S is polystyrene, I is polyisoprene and Bd is polybutadiene), with varying molecular weight and random-block composition are synthesized and the mixing thermodynamics---via comparison of their interaction energy densities, X---of their hydrogenated derivatives is examined through measurement of the order-disorder transition (ODT) temperature. Hydrogenated derivatives of I-SrI and S-SrI block-random copolymers, both wherein the styrene aromaticity is retained and derivatives wherein the styrene units are saturated to vinylcyclohexane (VCH), are found to hew closely to the

  12. Fluctuation Effects on Phase Behavior of Gradient Copolymer Systems

    NASA Astrophysics Data System (ADS)

    Pandav, Gunja; Ganesan, Venkat

    2013-03-01

    We consider the effect of sequence polydispersity on fluctuation induced shift in order-disorder transition (ODT) temperature for symmetric systems of gradient copolymers. Using single chain in mean field simulations, a systematic change in scaling prediction for shift in ODT with Ginzburg parameter is reported. We demonstrate that gradient strength and overall blockiness of sequences has a significant impact on shift in ODT temperature. The weak gradient copolymers having high compositional polydispersity mimic random copolymers whereas, strong gradient copolymers possess inherent blockiness and are close to diblock copolymers. The blockiness parameter has a minimal impact on shift in ODT in strong gradient copolymers. Also, ternary blends of homopolymer/gradient copolymer are investigated to capture effect of compositional polydispersity on phase diagram and formation of microemulsion structures.

  13. Block copolymer compatibilization of cocontinuous polymer blends.

    SciTech Connect

    Galloway, Jeffrey A.; Macosko, Christopher W.; Bell, Joel R.; Jeon, Hyun K.

    2004-12-01

    The effect of block copolymers on the cocontinuous morphology of 50/50 (w/w) polystyrene (PS)/high density polyethylene (HDPE) blends was investigated using symmetric polystyrene-polyethylene block copolymers (PS-PE) with molecular weights varying from 6 to 200 kg/mol. The coarsening rate during annealing was compared to the Doi-Ohta theory. An intermediate molecular weight PS-PE, 40 kg/mol, showed remarkable results in reducing the phase size and stabilizing the blend morphology during annealing. Mixing small amounts of 6, 100 or 200 kg/mol PS-PE in the blend did not reduce the phase size significantly, but did decrease the coarsening rate during annealing. In stabilizing the morphology, 6 kg/mol PS-PE was inferior to 100 and 200 kg/mol. The existence of an optimal molecular weight block copolymer is due to a balance between the ability of the block copolymer to reach the interface and its relative stabilization effect at the interface.

  14. Microphase separation of block copolymer thin films.

    PubMed

    Zhang, Jilin; Yu, Xinhong; Yang, Ping; Peng, Juan; Luo, Chunxia; Huang, Weihuan; Han, Yanchun

    2010-04-01

    Today, high-ordered micro- and nano-patterned surfaces are widely used in many areas, such as in the preparation of super-thin dielectric films, photonic crystals, antireflective films, super-non-wetting surfaces, bio-compatible surfaces and microelectric devices. Considering the critical fabrication conditions and the irreducible high cost of the photolithography technique in patterning nano-scale structures (<100 nm), the development of other micro- and nano-patterning techniques that can be used to fabricate long-range ordered features - especially nanoscale arrays - is a promising subject in surface science. In contrast to the traditional photolithography patterning technique, block copolymers can spontaneously phase separate into arrays of periodic patterns with length-scales of 10-50 nm, which provides an efficient pathway to pattern nanoscale features. Today, preparing long-range ordered arrays by block copolymer microphase separation is one of the most promising techniques for the fabrication of nanoscale arrays, not only being a simple process but also having a lower cost than traditional methods. In this feature article, we first summarize the many techniques developed to induce ordering in the microphase separation of the block copolymer thin films. Then, evolution, order-order transitions and reversible switching microdomains are considered, since they are very important in the ordered engineering of microphase separation of the block copolymer thin films. Finally, the outlook of this research area will be given.

  15. 21 CFR 173.65 - Divinylbenzene copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... with food only of Types I, II, and VI-B (excluding carbonated beverages) described in table 1 of... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Divinylbenzene copolymer. 173.65 Section 173.65 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  16. Copolymer sealant compositions and method for making

    NASA Technical Reports Server (NTRS)

    Singh, Navjot (Inventor); Leman, John Thomas (Inventor); Whitney, John M. (Inventor); Krabbenhoft, Herman Otto (Inventor)

    2004-01-01

    Condensation curable poly(fluoroorgano)siloxane-poly(silarylene)siloxane block copolymer compositions having a glass transition temperature not exceeding about -54.degree. C. and excellent solvent resistance have been found useful as sealants. Polyalkoxysilylorgano compounds, such as 1,4-bis[trimethoxysilyl(ethyl)]benzene have been found to be effective as cross-linkers.

  17. Copolymer sealant compositions and method for making

    NASA Technical Reports Server (NTRS)

    Singh, Navjot (Inventor); Leman, John Thomas (Inventor); Whitney, John M. (Inventor); Krabbenhoft, Herman Otto (Inventor)

    2003-01-01

    Condensation curable poly(fluoroorgano)siloxane-poly(silarylene)siloxane block copolymer compositions having a glass transition temperature not exceeding about -54.degree. C. and excellent solvent resistance have been found useful as sealants. Polyalkoxysilylorgano compounds, such as 1,4-bis[trimethoxysilyl(ethyl)]benzene have been found to be effective as cross-linkers.

  18. Copolymer sealant compositions and method for making

    NASA Technical Reports Server (NTRS)

    Singh, Navjot (Inventor); Leman, John Thomas (Inventor); Whitney, John M. (Inventor); Krabbenhoft, Herman Otto (Inventor)

    2002-01-01

    Condensation curable poly(fluoroorgano)siloxane-poly(silarylene)siloxane block copolymer compositions having a glass transition temperature not exceeding about -54.degree. C. and excellent solvent resistance have been found useful as sealants. Polyalkoxysilylorgano compounds, such as 1,4-bis[trimethoxysilyl(ethyl)]benzene have been found to be effective as cross-linkers.

  19. Phase Transitions in Thin Block Copolymer Films

    SciTech Connect

    Kramer, Edward J.

    2010-10-08

    David Turnbull's experiments and theoretical insights paved the way for much of our modern understanding of phase transitions in materials. In recognition of his contributions, this lecture will concentrate on phase transitions in a material system not considered by Turnbull, thin diblock copolymer films. Well-ordered block copolymer films are attracting increasing interest as we attempt to extend photolithography to smaller dimensions. In the case of diblock copolymer spheres, an ordered monolayer is hexagonal, but the ordered bulk is body-centered cubic (bcc). There is no hexagonal plane in the bcc structure, so a phase transition must occur as n, the number of layers of spheres in the film, increases. How this phase transition occurs with n and how it can be manipulated is the subject of the first part of my presentation. In the second part of the talk, I show that monolayers of diblock copolymer spheres and cylinders undergo order-to-disorder transitions that differ greatly from those of the bulk. These ordered 2D monolayers are susceptible to phonon-generated disorder as well as to thermal generation of defects, such as dislocations, which, while they are line defects in 3D, are point defects in 2D. The results are compared to the theories of melting of 2D crystals (spheres) and of 2D smectic liquid crystals (cylinders), a comparison that will allow us to understand most, but not all, of the features of these order-disorder transitions that occur as the temperature is increased.

  20. Interstellar Alcohols

    NASA Technical Reports Server (NTRS)

    Charnley, S. B.; Kress, M. E.; Tielens, A. G. G. M.; Millar, T. J.

    1995-01-01

    We have investigated the gas-phase chemistry in dense cores where ice mantles containing ethanol and other alcohols have been evaporated. Model calculations show that methanol, ethanol, propanol, and butanol drive a chemistry leading to the formation of several large ethers and esters. Of these molecules, methyl ethyl ether (CH3OC2H5) and diethyl ether (C2H5)2O attain the highest abundances and should be present in detectable quantities within cores rich in ethanol and methanol. Gas-phase reactions act to destroy evaporated ethanol and a low observed abundance of gas-phase C,H,OH does not rule out a high solid-phase abundance. Grain surface formation mechanisms and other possible gas-phase reactions driven by alcohols are discussed, as are observing strategies for the detection of these large interstellar molecules.

  1. Alcohol use and safe drinking

    MedlinePlus

    ... RISKS OF ALCOHOL Alcohol increases the risk of: Alcoholism Falls, drownings, and other accidents Head, neck, stomach, ... pubmed/23698791 . National Institute on Alcohol Abuse and Alcoholism. Alcohol and your health. www.niaaa.nih.gov/ ...

  2. Complexation-tailored morphology of asymmetric block copolymer membranes.

    PubMed

    Madhavan, Poornima; Peinemann, Klaus-Viktor; Nunes, Suzana P

    2013-08-14

    Hydrogen-bond formation between polystyrene-b-poly (4-vinylpyridine) (PS-b-P4VP) block copolymer (BCP) and -OH/-COOH functionalized organic molecules was used to tune morphology of asymmetric nanoporous membranes prepared by simultaneous self-assembly and nonsolvent induced phase separation. The morphologies were characterized by field emmision scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Hydrogen bonds were confirmed by infrared (IR), and the results were correlated to rheology characterization. The OH-functionalized organic molecules direct the morphology into hexagonal order. COOH-functionalized molecules led to both lamellar and hexagonal structures. Micelle formation in solutions and their sizes were determined using dynamic light scattering (DLS) measurements and water fluxes of 600-3200 L/m(2)·h·bar were obtained. The pore size of the plain BCP membrane was smaller than with additives. The following series of additives led to pores with hexagonal order with increasing pore size: terephthalic acid (COOH-bifunctionalized) < rutin (OH-multifunctionalized) < 9-anthracenemethanol (OH-monofunctionalized) < 3,5-dihydroxybenzyl alcohol (OH-trifunctionalized).

  3. [Alcohol and alcoholism: attitudes of nursing students].

    PubMed

    Vargas, Divane; Bittencourt, Marina Nolli

    2013-01-01

    This is a descriptive exploratory study that aimed to verify nursing students' attitudes facing to the alcoholic drinks, alcoholism and alcoholics, according to their position in face of an attitudes scale items. For data collection, it was used the Scale of Attitudes to alcohol, alcoholism and alcoholic, applied to 144 nursing students. The results showed a tendency to negative attitudes of these students in face of alcoholism, alcoholic person and alcoholic drinks, since most participants were placed in category indifferent or disagree with the positive items, agreeing with negative scale items. We conclude that this trend of negative attitudes is connected to insufficient attention given to the subject during the nurses' education, being verified the need for greater importance to be given to this problem.

  4. Phase behavior of model ABC triblock copolymers

    NASA Astrophysics Data System (ADS)

    Chatterjee, Joon

    The phase behavior of poly(isoprene-b-styrene- b-ethylene oxide) (ISO), a model ABC triblock copolymer has been studied. This class of materials exhibit self-assembly, forming a large array of ordered morphologies at length scales of 5-100 nm. The formation of stable three-dimensionally continuous network morphologies is of special interest in this study. Since these nanostructures considerably impact the material properties, fundamental knowledge for designing ABC systems have high technological importance for realizing applications in the areas of nanofabrication, nanoporous media, separation membranes, drug delivery and high surface area catalysts. A comprehensive framework was developed to describe the phase behavior of the ISO triblock copolymers at weak to intermediate segregation strengths spanning a wide range of composition. Phases were characterized through a combination of characterization techniques, including small angle x-ray scattering, dynamic mechanical spectroscopy, transmission electron microscopy, and birefringence measurements. Combined with previous investigations on ISO, six different stable ordered state symmetries have been identified: lamellae (LAM), Fddd orthorhombic network (O70), double gyroid (Q230), alternating gyroid (Q214), hexagonal (HEX), and body-centered cubic (BCC). The phase map was found to be somewhat asymmetric around the fI = fO isopleth. This work provides a guide for theoretical studies and gives insight into the intricate effects of various parameters on the self-assembly of ABC triblock copolymers. Experimental SAXS data evaluated with a simple scattering intensity model show that local mixing varies continuously across the phase map between states of two- and three-domain segregation. Strategies of blending homopolymers with ISO triblock copolymer were employed for studying the swelling properties of a lamellar state. Results demonstrate that lamellar domains swell or shrink depending upon the type of homopolymer that

  5. Solvent enhanced block copolymer ordering in thin films

    NASA Astrophysics Data System (ADS)

    Misner, Matthew J.

    Diblock copolymer self-assembly of materials is emerging as a key element in the fabrication of functional nanostructured materials. By solvent casting or solvent annealing block copolymer thin films, we have demonstrated methods to produce diblock copolymer films with highly oriented, close-packed arrays of nanoscopic cylindrical domains with a high degree of long-range lateral order with few defects. The solvent imparts a high degree of mobility in the microphase-separated copolymer that enables a rapid removal of defects and a high degree of lateral order. Though the use of a selective cosolvent during solvent casting, it was found that the microdomain size and spacing could be increased, leading to a size-tunable system. Additionally, the presence of water also led to the ability to control the microdomain orientation during solvent annealing. Ionic complexation within cylinder-forming PS- b-EO block copolymer thin films was also investigated, where added salts bind PEO block as the minor component. Small amounts of added salts, on the order a few ions per chain, show large effects on the ordering of the copolymer films during solvent annealing. By using gold or cobalt salts, well-organized patterns of nanoparticles can be generated in the copolymer microdomains. Topographically and chemically patterned surfaces were used as a route to sectorizing and controlling the lattice orientation of copolymer films. Topographically patterned surfaces allow well-defined boundaries to confine the copolymer microdomains on a surface and effectively direct the ordering and grain orientation of the copolymer microdomains. Chemically patterned surfaces provide a route to direct the block copolymer ordering on completely flat surface, which may have advantages in applications where adding additional topography may be undesirable. To generate nanoporous templates from PS-b-PEO bases materials several routs were followed. The first route was through the addition and selective

  6. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification... adhesive is a device composed of polyvinylmethylether maleic anhydride, acid copolymer,...

  7. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC)...

  8. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC)...

  9. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC)...

  10. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC)...

  11. Mechanism of Molecular Exchange in Copolymer Micelles

    NASA Astrophysics Data System (ADS)

    Choi, Soo-Hyung; Lodge, Timothy; Bates, Frank

    2010-03-01

    Compared to thermodynamic structure, much less has been known about the kinetics of block copolymer micelles which should underlay the attainment of thermodynamic equilibrium. In this presentation, molecular exchange between spherical micelles formed by isotopically labeled diblock copolymers was investigated using time-resolved small-angle neutron scattering. Two pairs of structurally matched poly(styrene-b-ethylene-alt-propylene) (PS-PEP) were synthesized and dispersed in isotopic mixture of squalane, highly selective to PEP block. Each pair includes polymers with fully deuterated (dPS-PEP) and a normal (hPS-PEP) PS blocks. Temperature dependence of the micelle exchange rate R(t) is consistent with melt dynamics for the core polymer. Furthermore, R(t) is significantly sensitive to the core block length N due to the thermodynamic penalty associated with ejecting a core block into the solvent. This hypersensitivity, combined with modest polydispersity in N, leads to an approximately logarithmic decay in R(t).

  12. Multigraft Copolymer Superelastomers: Synthesis Morphology, and Properties

    SciTech Connect

    Uhrig, David; Schlegel, Ralf; Weidisch, Roland; Mays, Jimmy

    2011-01-01

    The synthesis of well-defined multigraft copolymers having a polydiene backbone with polystyrene side chains is briefly reviewed, with particular focus on controlling branch point spacing and branch point functionality. Use of living anionic polymerization and chlorosilane linking chemistry has led to the synthesis of series of materials having regularly spaced trifunctional (comb), tetrafunctional (centipede), and hexafunctional (barbwire) branch points. The morphologies of these materials were characterized by transmission electron microscopy and small-angle X-ray scattering, and it was found that the morphologies were controlled by the local architectural asymmetry associated with each branch point. Mechanical properties studies revealed that such multigraft copolymers represent a new class of thermoplastic elastomers (TPEs) with superior elongation at break and low residual strains as compared to conventional TPEs.

  13. Block copolymers for opto-electronics

    NASA Astrophysics Data System (ADS)

    Sun, Sam-Shajing; Fan, Zhen; Wang, Yiqing; Taft, Charles; Haliburton, James H.; Maaref, Shahin; Ledbetter, Abram J.; Bonner, Carl E.

    2004-05-01

    A D(donor)-B(bridge)-A(acceptor)-B(bridge)-type block copolymer system has been developed and preliminarily examined for potential opto-electronic photovoltaic functions. The unique feature of the device includes a primary DBAB-type block copolymer backbone, where D and A are conjugated donor and acceptor polymer blocks, and B is a non-conjugated and flexible chain, a π orbital stacked and conjugated chain self-assembled and ordered "secondary structure", and a donor/acceptor asymmetric layers sandwiched D/A columnar "tertiary structure". This structure is expected to improve photovoltaic power conversion efficiency significantly in comparison to most existing organic or polymeric donor/acceptor binary photovoltaic systems due to the reduction of "exciton loss", the "carrier loss", as well as the "photon loss" via three-dimensional space and energy level optimizations. Preliminary experimental results revealed better morphology and opto-electronic properties of DBAB vs. D/A blends.

  14. Toughness in block copolymer modified epoxies

    NASA Astrophysics Data System (ADS)

    Declet-Perez, Carmelo

    One of the major shortcomings preventing the widespread use of epoxy resins in engineering applications is the inherent brittleness of these materials. The incorporation of small amounts of amphiphilic block copolymers into the formulation is one of the most promising strategies to toughen epoxies. These molecules are known to form nanostructures in the epoxy resin that can be preserved upon curing. This strategy is very attractive since significant enhancements in toughness can be obtained without detrimental effects on other properties of the matrix. Despite many examples of successful implementation, an in-depth understanding of the factors that lead to toughness in block copolymer modified epoxies is still elusive. The goal of this dissertation is to understand, first, the deformation mechanisms leading to toughness and, second, how different formulation parameters affect these processes. In this work we used two types of block copolymer modifiers, which produced nanostructures with different physical properties. These block copolymers self-assembled into well-dispersed spherical micelles with either rubbery or glassy cores in various epoxy formulations. Both of these modifiers toughened different epoxy formulations, although to different extents. The rubbery core micelles consistently outperformed the glassy core micelles by roughly a factor of two. While the toughening afforded by the rubbery core micelles was consistent with the current understanding of toughening, the results from the glassy core micelles could not be explained with the same reasoning. In order to understand the deformation mechanisms leading to different levels of toughness, we performed small-angle x-ray scattering experiments while simultaneously deforming our material. This combination of techniques, referred to as in-situ SAXS, allowed us to monitor changes in the structure of the block copolymer micelles as a result of the applied load. With this technique, we showed that the rubbery

  15. Rapid ordering of block copolymer thin films

    NASA Astrophysics Data System (ADS)

    Majewski, Pawel W.; Yager, Kevin G.

    2016-10-01

    Block-copolymers self-assemble into diverse morphologies, where nanoscale order can be finely tuned via block architecture and processing conditions. However, the ultimate usage of these materials in real-world applications may be hampered by the extremely long thermal annealing times—hours or days—required to achieve good order. Here, we provide an overview of the fundamentals of block-copolymer self-assembly kinetics, and review the techniques that have been demonstrated to influence, and enhance, these ordering kinetics. We discuss the inherent tradeoffs between oven annealing, solvent annealing, microwave annealing, zone annealing, and other directed self-assembly methods; including an assessment of spatial and temporal characteristics. We also review both real-space and reciprocal-space analysis techniques for quantifying order in these systems.

  16. Phase Behavior of Gradient Copolymer Solution

    NASA Astrophysics Data System (ADS)

    Pandav, Gunja; Gallow, Keith; Loo, Yueh-Lin; Ganesan, Venkat

    2012-02-01

    We study the behavior of amphiphilic linear gradient copolymer chains under poor solvent conditions. Using Bond Fluctuation model and parallel tempering algorithm, we explore qualitative behavior of this class of polymers with varying gradient strength; which is the largest difference in the instantaneous composition along the polymer chain. Under poor solvent conditions, the chains collapse to form micelles. We find a linear dependence of hydrophilic to hydrophobic transition temperature on gradient strength. Systematic analysis of these clusters reveals a strong dependence of micelle properties on gradient strength. Also, we discuss our results with reference to recent experiments on synthesis and cloud point depression in gradient copolymers confirming gradient strength as key parameter in tuning micelle properties.

  17. Behind the Label "Alcoholic."

    ERIC Educational Resources Information Center

    Wright, Deborah M.

    1989-01-01

    Relates individual's personal story of her childhood influenced by her parent's alcoholism, her own alcoholism as a young adult, and her experiences with counseling. Asks others not to reject her because of the label "alcoholic." (ABL)

  18. Breath alcohol test

    MedlinePlus

    Alcohol test - breath ... There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual. One ...

  19. On the birefringence of multilayered symmetric diblock copolymer films

    SciTech Connect

    Kim, J.; Chin, I.; Smith, B.A.; Russell, T.P. ); Mays, J.W. . Dept. of Chemistry)

    1993-09-27

    The chain extension at lamellar interfaces was studied in thin films of symmetric diblock copolymers on gold substrates. The first copolymer consisted of blocks of polystyrene (PS) and poly(2-vinylpyridine) (P2VP), denoted P(S-b-2VP). The second was a diblock copolymer of PS and poly(methyl methacrylate) (PMMA), denoted P(S-b-MMA), on a gold substrate. Using attenuated total reflectance spectroscopy, the refractive indices parallel, n[sub [parallel

  20. Reversible geling co-polymer and method of making

    DOEpatents

    Gutowska, Anna

    2005-12-27

    The present invention is a thereapeutic agent carrier having a thermally reversible gel or geling copolymer that is a linear random copolymer of an [meth-]acrylamide derivative and a hydrophilic comonomer, wherein the linear random copolymer is in the form of a plurality of linear chains having a plurality of molecular weights greater than or equal to a minimum geling molecular weight cutoff and a therapeutic agent.

  1. Gyroid nickel nanostructures from diblock copolymer supramolecules.

    PubMed

    Vukovic, Ivana; Punzhin, Sergey; Voet, Vincent S D; Vukovic, Zorica; de Hosson, Jeff Th M; ten Brinke, Gerrit; Loos, Katja

    2014-01-01

    Nanoporous metal foams possess a unique combination of properties - they are catalytically active, thermally and electrically conductive, and furthermore, have high porosity, high surface-to-volume and strength-to-weight ratio. Unfortunately, common approaches for preparation of metallic nanostructures render materials with highly disordered architecture, which might have an adverse effect on their mechanical properties. Block copolymers have the ability to self-assemble into ordered nanostructures and can be applied as templates for the preparation of well-ordered metal nanofoams. Here we describe the application of a block copolymer-based supramolecular complex - polystyrene-block-poly(4-vinylpyridine)(pentadecylphenol) PS-b-P4VP(PDP) - as a precursor for well-ordered nickel nanofoam. The supramolecular complexes exhibit a phase behavior similar to conventional block copolymers and can self-assemble into the bicontinuous gyroid morphology with two PS networks placed in a P4VP(PDP) matrix. PDP can be dissolved in ethanol leading to the formation of a porous structure that can be backfilled with metal. Using electroless plating technique, nickel can be inserted into the template's channels. Finally, the remaining polymer can be removed via pyrolysis from the polymer/inorganic nanohybrid resulting in nanoporous nickel foam with inverse gyroid morphology. PMID:24797367

  2. Crystallization in Ordered Polydisperse Polyolefin Diblock Copolymers

    SciTech Connect

    Li, Sheng; Register, Richard A.; Landes, Brian G.; Hustad, Phillip D.; Weinhold, Jeffrey D.

    2010-12-07

    The morphologies of polydisperse ethylene-octene diblock copolymers, synthesized via a novel coordinative chain transfer polymerization process, are examined using two-dimensional synchrotron small-angle and wide-angle X-ray scattering on flow-aligned specimens. The diblock copolymers comprise one amorphous block with high 1-octene content and one semicrystalline block with relatively low 1-octene content, and each block ideally exhibits the most-probable distribution. Near-symmetric diblocks with a sufficiently large octene differential between the amorphous and semicrystalline blocks show well-ordered lamellar domain structures with long periods exceeding 100 nm. Orientation of these domain structures persists through multiple melting/recrystallization cycles, reflecting a robust structure which self-assembles in the melt. The domain spacings are nearly 3-fold larger than those in near-monodisperse polyethylene block copolymers of similar molecular weights. Although the well-ordered lamellar domain structure established in the melt is preserved in the solid state, the crystallites are isotropic in orientation. These materials display crystallization kinetics consistent with a spreading growth habit, indicating that the lamellae do not confine or template the growing crystals. The exceptionally large domain spacings and isotropic crystal growth are attributed to interblock mixing resulting from the large polydispersity; short hard blocks dissolved in the soft-block-rich domains swell the domain spacing in the melt and allow hard block crystallization to proceed across the lamellar domain interfaces.

  3. Regulating block copolymer phases via selective homopolymers

    SciTech Connect

    Yang, Shuang E-mail: eqchen@pku.edu.cn; Lei, Zhen; Hu, Nan; Chen, Er-Qiang E-mail: eqchen@pku.edu.cn; Shi, An-Chang

    2015-03-28

    The phase behavior of strongly segregated AB diblock copolymer and selective C homopolymer blends is examined theoretically using a combination of strong stretching theory (SST) and self-consistent field theory (SCFT). The C-homopolymer is immiscible with the B-blocks but strongly attractive with the A-blocks. The effect of homopolymer content on the order-order phase transitions is analyzed. It is observed that, for AB diblock copolymers with majority A-blocks, the addition of the C-homopolymers results in lamellar to cylindrical to spherical phase transitions because of the A/C complexation. For diblock copolymers with minor A-blocks, adding C-homopolymers leads to transitions from spherical or cylindrical morphology with A-rich core to lamellae to inverted cylindrical and spherical morphologies with B-rich core. The results from analytical SST and numerical SCFT are in good agreement within most regions of the phase diagram. But the deviation becomes more obvious when the composition of A-blocks is too small and the content of added C-homopolymers is large enough, where the SCFT predicts a narrow co-existence region between different ordered phases. Furthermore, it is found that the phase behavior of the system is insensitive to the molecular weight of C-homopolymer.

  4. Cavitation in block copolymer modified epoxy

    NASA Astrophysics Data System (ADS)

    Declet-Perez, Carmelo; Francis, Lorraine; Bates, Frank

    2013-03-01

    Today, brittleness in epoxy networks limits most commercial applications. Significant toughness can be imparted by adding small amounts of micelle forming block copolymers (BCP) without compromising critical properties such as high use temperature and modulus. Curing the network locks in the self-assembled BCP micellar structures formed in the monomer resin providing control of the resulting morphology. Despite significant research over the last decade, a complete description of the parameters influencing toughness in block copolymer modified epoxies is still lacking. In this presentation we compare the ultimate mechanical behavior of epoxies modified with spherical micelle forming BCP's containing rubbery and glassy cores using real-time in-situ small-angle X-ray scattering (SAXS) performed during tensile deformation. Striking differences in the 2D SAXS patterns were documented for epoxies modified with rubbery (PEP) versus glassy (PS) micelle cores. Rubbery cores dilate by 100% in volume upon specimen yielding, while the glassy micelle cores deform at approximately constant volume. These results provide direct evidence of a cavitation mediated mechanism for toughness in block copolymer modified epoxies. We further interpret characteristic butterfly features in the 2D SAXS patterns in terms of epoxy network deformation. Support was provided by the NSF sponsored MRSEC at the University of Minnesota

  5. Sulfonated Polymerized Ionic Liquid Block Copolymers.

    PubMed

    Meek, Kelly M; Elabd, Yossef A

    2016-07-01

    The successful synthesis of a new diblock copolymer, referred to as sulfonated polymerized ionic liquid (PIL) block copolymer, poly(SS-Li-b-AEBIm-TFSI), is reported, which contains both sulfonated blocks (sulfonated styrene: SS) and PIL blocks (1-[(2-acryloyloxy)ethyl]-3-butylimidazolium: AEBIm) with both mobile cations (lithium: Li(+) ) and mobile anions (bis(trifluoromethylsulfonyl)imide: TFSI(-) ). Synthesis consists of polymerization via reversible addition-fragmentation chain transfer, followed by post-functionalization reactions to covalently attach the imidazolium cations and sulfonic acid anions to their respective blocks, followed by ion exchange metathesis resulting in mobile Li(+) cations and mobile TFSI(-) anions. Solid-state films containing 1 m Li-TFSI salt dissolved in ionic liquid result in an ion conductivity of >1.5 mS cm(-1) at 70 °C, where small-angle X-ray scattering data indicate a weakly ordered microphase-separated morphology. These results demonstrate a new ion-conducting block copolymer containing both mobile cations and mobile anions. PMID:27125600

  6. Block and Graft Copolymers of Polyhydroxyalkanoates

    NASA Astrophysics Data System (ADS)

    Marchessault, Robert H.; Ravenelle, François; Kawada, Jumpei

    2004-03-01

    Polyhydroxyalkanoates (PHAs) were modified for diblock copolymer and graft polymer by catalyzed transesterification in the melt and by chemical synthesis to extend the side chains of the PHAs, and the polymers were studied by transmission electron microscopy (TEM) X-ray diffraction, thermal analysis and nuclear magnetic resonance (NMR). Catalyzed transesterification in the melt is used to produce diblock copolymers of poly[3-hydroxybutyrate] (PHB) and monomethoxy poly[ethylene glycol] (mPEG) in a one-step process. The resulting diblock copolymers are amphiphilic and self-assemble into sterically stabilized colloidal suspensions of PHB crystalline lamellae. Graft polymer was synthesized in a two-step chemical synthesis from biosynthesized poly[3-hydroxyoctanoate-co-3-hydroxyundecenoate] (PHOU) containing ca. 25 mol chains. 11-mercaptoundecanoic acid reacts with the side chain alkenes of PHOU by the radical addition creating thioether linkage with terminal carboxyl functionalities. The latter groups were subsequently transformed into the amide or ester linkage by tridecylamine or octadecanol, respectively, producing new graft polymers. The polymers have different physical properties than poly[3-hydroxyoctanoate] (PHO) which is the main component of the PHOU, such as non-stickiness and higher thermal stability. The combination of biosynthesis and chemical synthesis produces a hybrid thermoplastic elastomer with partial biodegradability.

  7. Regulating block copolymer phases via selective homopolymers.

    PubMed

    Yang, Shuang; Lei, Zhen; Hu, Nan; Chen, Er-Qiang; Shi, An-Chang

    2015-03-28

    The phase behavior of strongly segregated AB diblock copolymer and selective C homopolymer blends is examined theoretically using a combination of strong stretching theory (SST) and self-consistent field theory (SCFT). The C-homopolymer is immiscible with the B-blocks but strongly attractive with the A-blocks. The effect of homopolymer content on the order-order phase transitions is analyzed. It is observed that, for AB diblock copolymers with majority A-blocks, the addition of the C-homopolymers results in lamellar to cylindrical to spherical phase transitions because of the A/C complexation. For diblock copolymers with minor A-blocks, adding C-homopolymers leads to transitions from spherical or cylindrical morphology with A-rich core to lamellae to inverted cylindrical and spherical morphologies with B-rich core. The results from analytical SST and numerical SCFT are in good agreement within most regions of the phase diagram. But the deviation becomes more obvious when the composition of A-blocks is too small and the content of added C-homopolymers is large enough, where the SCFT predicts a narrow co-existence region between different ordered phases. Furthermore, it is found that the phase behavior of the system is insensitive to the molecular weight of C-homopolymer. PMID:25833605

  8. Sulfur copolymers for infrared optical imaging

    NASA Astrophysics Data System (ADS)

    Namnabat, S.; Gabriel, J. J.; Pyun, J.; Norwood, R. A.; Dereniak, E. L.; van der Laan, J.

    2014-06-01

    The development of organic polymers with low infrared absorption has been investigated as a possible alternative to inorganic metal oxide, semiconductor, or chalcogenide-based materials for a variety of optical devices and components, such as lenses, goggles, thermal imaging cameras and optical fibers. In principle, organic-based polymers are attractive for these applications because of their low weight, ease of processing, mechanical toughness, and facile chemical variation using commercially available precursors. Herein we report on the optical characterization of a new class of sulfur copolymers that are readily moldable, transparent above 500 nm, possess high refractive index (n > 1.8) and take advantage of the low infrared absorption of S-S bonds for potential use in the mid-infrared at 3-5 microns. These materials are largely made from elemental sulfur by an inverse vulcanization process; in the current study we focus on the properties of a chemically stable, branched copolymer of poly(sulfur-random-1,3-diisopropenylbenzene) (poly(S-r- DIB). Copolymers with elemental sulfur content ranging from 50% to 80% by weight were studied by UV-VIS spectroscopy, FTIR, and prism coupling for refractive index measurement. Clear correlation between material composition and the optical properties was established, confirming that the high polarizability of the sulfur atom leads to high refractive index while also maintaining low optical loss in the infrared.

  9. Gyroid Nickel Nanostructures from Diblock Copolymer Supramolecules

    PubMed Central

    Vukovic, Ivana; Punzhin, Sergey; Voet, Vincent S. D.; Vukovic, Zorica; de Hosson, Jeff Th. M.; ten Brinke, Gerrit; Loos, Katja

    2014-01-01

    Nanoporous metal foams possess a unique combination of properties - they are catalytically active, thermally and electrically conductive, and furthermore, have high porosity, high surface-to-volume and strength-to-weight ratio. Unfortunately, common approaches for preparation of metallic nanostructures render materials with highly disordered architecture, which might have an adverse effect on their mechanical properties. Block copolymers have the ability to self-assemble into ordered nanostructures and can be applied as templates for the preparation of well-ordered metal nanofoams. Here we describe the application of a block copolymer-based supramolecular complex - polystyrene-block-poly(4-vinylpyridine)(pentadecylphenol) PS-b-P4VP(PDP) - as a precursor for well-ordered nickel nanofoam. The supramolecular complexes exhibit a phase behavior similar to conventional block copolymers and can self-assemble into the bicontinuous gyroid morphology with two PS networks placed in a P4VP(PDP) matrix. PDP can be dissolved in ethanol leading to the formation of a porous structure that can be backfilled with metal. Using electroless plating technique, nickel can be inserted into the template's channels. Finally, the remaining polymer can be removed via pyrolysis from the polymer/inorganic nanohybrid resulting in nanoporous nickel foam with inverse gyroid morphology. PMID:24797367

  10. Engineering topochemical polymerizations using block copolymer templates.

    PubMed

    Zhu, Liangliang; Tran, Helen; Beyer, Frederick L; Walck, Scott D; Li, Xin; Agren, Hans; Killops, Kato L; Campos, Luis M

    2014-09-24

    With the aim to achieve rapid and efficient topochemical polymerizations in the solid state, via solution-based processing of thin films, we report the integration of a diphenyldiacetylene monomer and a poly(styrene-b-acrylic acid) block copolymer template for the generation of supramolecular architectural photopolymerizable materials. This strategy takes advantage of non-covalent interactions to template a topochemical photopolymerization that yields a polydiphenyldiacetylene (PDPDA) derivative. In thin films, it was found that hierarchical self-assembly of the diacetylene monomers by microphase segregation of the block copolymer template enhances the topochemical photopolymerization, which is complete within a 20 s exposure to UV light. Moreover, UV-active cross-linkable groups were incorporated within the block copolymer template to create micropatterns of PDPDA by photolithography, in the same step as the polymerization reaction. The materials design and processing may find potential uses in the microfabrication of sensors and other important areas that benefit from solution-based processing of flexible conjugated materials. PMID:25208609

  11. Comparing Fluid and Elastic Block Copolymer Shells

    NASA Astrophysics Data System (ADS)

    Rozairo, Damith; Croll, Andrew B.

    2014-03-01

    Emulsions can be stabilized with the addition of an amphiphilic diblock copolymer, resulting in droplets surrounded and protected by a polymer monolayer. Such droplets show considerable promise as advanced cargo carriers in pharmaceuticals or cosmetics due to their strength and responsiveness. Diblock copolymer interfaces remain mostly fluid and may not be able to attain the mechanical performance desired by industry. To strengthen block copolymer emulsion droplets we have developed a novel method for creating thin elastic shells using polystyrene-b-poly(acrylic acid)-b-polystyrene (PS-PAA-PS). Characterization of the fluid filled elastic shells is difficult with traditional means which lead us to develop a new and general method of mechanical measurement. Specifically, we use laser scanning confocal microscopy to achieve a high resolution measure of the deformation of soft spheres under the influence of gravity. To prove the resilience of the technique we examine both a polystyrene-b-poly(ethylene oxide) (PS-PEO) stabilized emulsion and the PS-PAA-PS emulsion. The mechanical measurement allows the physics of the polymer at the interface to be examined, which will ultimately lead to the rational development of these technologies.

  12. Structure and Properties of Block Copolymers of Polystyrene and Polybutadiene

    NASA Astrophysics Data System (ADS)

    Askadskii, Andrei A.; Andryushchenko, T. A.; Zubov, P. I.

    1984-08-01

    Recent studies of the structure and properties of block copolymers of polystyrene and polybutadiene are reviewed, with special emphasis on the effect of the structure and of the formation conditions for the samples on the interrelated physico-mechanical properties. Problems associated with the macro- and micro-layering of block copolymer solutions are examined in detail. Work on the analysis of block copolymer structures from measurements of sorption characteristics is reviewed in the light of an assumed relaxation mechanism for the sorption and swelling processes. The prospects of controlling the structure and properties of block copolymers are shown to be good. The bibliography contains 190 references.

  13. Synthetic Cell Elements from Block Copolymers. Dynamic Aspects

    NASA Astrophysics Data System (ADS)

    Discher, Dennis

    2003-03-01

    Amphiphilic block copolymers can self-assemble in water into various stable morphologies which resemble key cell structures, notably filaments and membranes. Filamentous worms of copolymer, microns-long, will be introduced, and related dynamics of copolymer vesicle polymersomes will be detailed. Fluorescence visualization of single worms stretched under flow demonstrates their stability as well as a means to control flexibility. Polymersome membranes have been more thoroughly studied, especially copolymer molecular weight effects. We summarize results suggestive of a transition from Rouse-like behavior to entangled chains. Viewed together, the results ask the question: what physics are needed next to mimic cell activities such as crawling?

  14. Health risks of alcohol use

    MedlinePlus

    Alcoholism - risks; Alcohol abuse - risks; Alcohol dependence - risks; Risky drinking ... Beer, wine, and liquor all contain alcohol. If you are drinking any of these, you are using alcohol. Your drinking patterns may vary, depending on who you are with ...

  15. Nurses' Attitudes towards Alcoholics.

    ERIC Educational Resources Information Center

    Speer, Rita D.

    Nurses' attitudes toward the alcoholic can have a profound impact on the person suffering from alcoholism. These attitudes can affect the alcoholic's care and even whether the alcoholic chooses to recover. This study investigated attitudes of approximately 68 nurses employed in hospitals, 49 nurses in treatment facilities, 58 nursing students, and…

  16. Internet Alcohol Marketing and Underage Alcohol Use

    PubMed Central

    McClure, Auden C.; Tanski, Susanne E.; Li, Zhigang; Jackson, Kristina; Morgenstern, Matthis; Li, Zhongze; Sargent, James D.

    2016-01-01

    BACKGROUND AND OBJECTIVE Internet alcohol marketing is not well studied despite its prevalence and potential accessibility and attractiveness to youth. The objective was to examine longitudinal associations between self-reported engagement with Internet alcohol marketing and alcohol use transitions in youth. METHODS A US sample of 2012 youths aged 15 to 20 was surveyed in 2011. An Internet alcohol marketing receptivity score was developed, based on number of positive responses to seeing alcohol advertising on the Internet, visiting alcohol brand Web sites, being an online alcohol brand fan, and cued recall of alcohol brand home page images. We assessed the association between baseline marketing receptivity and both ever drinking and binge drinking (≥6 drinks per occasion) at 1-year follow-up with multiple logistic regression, controlling for baseline drinking status, Internet use, sociodemographics, personality characteristics, and peer or parent drinking. RESULTS At baseline, ever-drinking and binge-drinking prevalence was 55% and 27%, respectively. Many (59%) reported seeing Internet alcohol advertising, but few reported going to an alcohol Web site (6%) or being an online fan (3%). Higher Internet use, sensation seeking, having family or peers who drank, and past alcohol use were associated with Internet alcohol marketing receptivity, and a score of 1 or 2 was independently associated with greater adjusted odds of initiating binge drinking (odds ratio 1.77; 95% confidence interval, 1.13–2.78 and odds ratio 2.15; 95% confidence interval, 1.06–4.37 respectively) but not with initiation of ever drinking. CONCLUSIONS Although high levels of engagement with Internet alcohol marketing were uncommon, most underage youths reported seeing it, and we found a prospective association between receptivity to this type of alcohol marketing and future problem drinking, making additional research and ongoing surveillance important. PMID:26738886

  17. 40 CFR 721.4700 - Metalated alkylphenol copolymer (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Metalated alkylphenol copolymer (generic name). 721.4700 Section 721.4700 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4700 Metalated alkylphenol copolymer (generic name). (a)...

  18. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from the American Society for... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethylene-carbon monoxide copolymers. 177.1312... Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon...

  19. Imide/arylene ether copolymers with pendent trifluoromethyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J.; Havens, Stephen J.

    1992-01-01

    A series of imide/arylene ether block copolymers were prepared using an arylene ether block containing a hexafluoroisopropylidene group and an imide block containing a hexafluoroisopropylidene and a trifluoromethyl group in the polymer backbone. The copolymers were characterized and mechanical properties were determined and compared to the homopolymers.

  20. Piezoelectric Properties of Non-Polar Block Copolymers

    SciTech Connect

    Pester, Christian; Ruppel, Markus A; Schoberth, Heiko; Schmidt, K.; Liedel, Clemens; Van Rijn, Patrick; Littrell, Ken; Schindler, Kerstin; Hiltl, Stephanie; Czubak, Thomas; Mays, Jimmy; Urban, Volker S; Boker, Alexander

    2011-01-01

    Piezoelectric properties in non-polar block copolymers are a novelty in the field of electroactive polymers. The piezoelectric susceptibility of poly(styrene-b-isoprene) block copolymer lamellae is found to be up to an order of magnitude higher when compared to classic piezoelectric materials. The electroactive response increases with temperature and is found to be strongest in the disordered phase.

  1. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... percent by weight unless it is blended with polyethylene or with one or more olefin copolymers complying with § 177.1520 or with a mixture of polyethylene and one or more olefin copolymers, in such... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification....

  2. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... percent by weight unless it is blended with polyethylene or with one or more olefin copolymers complying with § 177.1520 or with a mixture of polyethylene and one or more olefin copolymers, in such... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification....

  3. Morphological studies on block copolymer modified PA 6 blends

    NASA Astrophysics Data System (ADS)

    Poindl, M.; Bonten, C.

    2014-05-01

    Recent studies show that compounding polyamide 6 (PA 6) with a PA 6 polyether block copolymers made by reaction injection molding (RIM) or continuous anionic polymerization in a reactive extrusion process (REX) result in blends with high impact strength and high stiffness compared to conventional rubber blends. In this paper, different high impact PA 6 blends were prepared using a twin screw extruder. The different impact modifiers were an ethylene propylene copolymer, a PA PA 6 polyether block copolymer made by reaction injection molding and one made by reactive extrusion. To ensure good particle matrix bonding, the ethylene propylene copolymer was grafted with maleic anhydride (EPR-g-MA). Due to the molecular structure of the two block copolymers, a coupling agent was not necessary. The block copolymers are semi-crystalline and partially cross-linked in contrast to commonly used amorphous rubbers which are usually uncured. The combination of different analysis methods like atomic force microscopy (AFM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) gave a detailed view in the structure of the blends. Due to the partial cross-linking, the particles of the block copolymers in the blends are not spherical like the ones of ethylene propylene copolymer. The differences in molecular structure, miscibility and grafting of the impact modifiers result in different mechanical properties and different blend morphologies.

  4. Morphological studies on block copolymer modified PA 6 blends

    SciTech Connect

    Poindl, M. E-mail: christian.bonten@ikt.uni-stuttgart.de; Bonten, C. E-mail: christian.bonten@ikt.uni-stuttgart.de

    2014-05-15

    Recent studies show that compounding polyamide 6 (PA 6) with a PA 6 polyether block copolymers made by reaction injection molding (RIM) or continuous anionic polymerization in a reactive extrusion process (REX) result in blends with high impact strength and high stiffness compared to conventional rubber blends. In this paper, different high impact PA 6 blends were prepared using a twin screw extruder. The different impact modifiers were an ethylene propylene copolymer, a PA PA 6 polyether block copolymer made by reaction injection molding and one made by reactive extrusion. To ensure good particle matrix bonding, the ethylene propylene copolymer was grafted with maleic anhydride (EPR-g-MA). Due to the molecular structure of the two block copolymers, a coupling agent was not necessary. The block copolymers are semi-crystalline and partially cross-linked in contrast to commonly used amorphous rubbers which are usually uncured. The combination of different analysis methods like atomic force microscopy (AFM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) gave a detailed view in the structure of the blends. Due to the partial cross-linking, the particles of the block copolymers in the blends are not spherical like the ones of ethylene propylene copolymer. The differences in molecular structure, miscibility and grafting of the impact modifiers result in different mechanical properties and different blend morphologies.

  5. Phase Behavior of All-Hydrocarbon ``Diblock-Random'' Copolymers

    NASA Astrophysics Data System (ADS)

    Beckingham, Bryan; Register, Richard

    2013-03-01

    ``Block-random'' copolymers (AxB1-x) -(AyB1-y) , where each of the two blocks is a random copolymer of monomers A and B, present a convenient and useful variation on the typical block copolymer architecture, as the interblock interactions and physical properties can be tuned continuously through the random block's composition. The ability to tune the effective interaction parameter between the blocks continuously, allows for the order-disorder transition temperature (TODT) to be tuned independently of molecular weight using only two monomers. This flexibility makes block-random copolymers a versatile platform for the exploration of polymer phase behavior and structure-property relationships. Here, we present the phase behavior of hydrogenated derivatives of various lamellae-forming diblock-random copolymers where one block is a styrene/isoprene (S rI) random copolymer. Using small-angle x-ray scattering, we investigate a series of isoprene hydrogenated hI-S rhI with varying styrene content, determine order-disorder transition temperatures and compare the observed phase behavior to that of more typical S-hI block copolymers via mean-field theory. Additionally, diblock-random copolymers, 50 wt. % styrene in the S rI block, are synthesized with polyisoprene, polybutadiene or polystyrene blocks and we examine the phase behavior of both their hydrogenated derivatives, prepared with catalysts which either leave the S units intact or saturate them to vinylcyclohexane.

  6. 40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... phosphate (generic). 721.10213 Section 721.10213 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10213 Polyether polyester copolymer phosphate (generic). (a) Chemical... as polyether polyester copolymer phosphate (PMN P-09-253) is subject to reporting under this...

  7. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethylene-acrylic acid copolymers. 177.1310 Section... Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid... for use in contact with food subject to the provisions of this section. (a) The ethylene-acrylic...

  8. Alcohol and bone.

    PubMed

    Mikosch, Peter

    2014-01-01

    Alcohol is widely consumed across the world in different cultural and social settings. Types of alcohol consumption differ between (a) light, only occasional consumption, (b) heavy chronic alcohol consumption, and (c) binge drinking as seen as a new pattern of alcohol consumption among teenagers and young adults. Heavy alcohol consumption is detrimental to many organs and tissues, including bones. Osteoporosis is regularly mentioned as a secondary consequence of alcoholism, and chronic alcohol abuse is established as an independent risk factor for osteoporosis. The review will present the different mechanisms and effects of alcohol intake on bone mass, bone metabolism, and bone strength, including alcoholism-related "life-style factors" such as malnutrition, lack of exercise, and hormonal changes as additional causative factors, which also contribute to the development of osteoporosis due to alcohol abuse. PMID:24477631

  9. [Alcohol and arrhythmias].

    PubMed

    Pfeiffer, D; Jurisch, D; Neef, M; Hagendorff, A

    2016-09-01

    The effects of alcohol on induction of arrhythmias is dose-dependent, independent of preexisting cardiovascular diseases or heart failure and can affect otherwise healthy subjects. While the probability of atrial fibrillation increases with the alcohol dosage, events of sudden cardiac death are less frequent with low and moderate consumption but occur more often in heavy drinkers with alcoholic cardiomyopathy. Men are first affected at higher dosages of alcohol but women can suffer from arrhythmias at lower dosages. Thromboembolisms and ischemic stroke can occur less often at lower dosages of alcohol; however, hemorrhagic stroke and subarachnoid hemorrhage are increased with higher alcohol dosages. Recognizable protective mechanisms of alcohol with respect to cardiovascular diseases only occur with lower amounts of alcohol of less than 10 g per day. Underlying mechanisms explain these controversial effects. Specific therapeutic options for alcohol-related arrhythmias apart from abstinence from alcohol consumption are not known. PMID:27582366

  10. Light-emitting block copolymers composition, process and use

    DOEpatents

    Ferraris, John P.; Gutierrez, Jose J.

    2006-11-14

    Generally, and in one form, the present invention is a composition of light-emitting block copolymer. In another form, the present invention is a process producing a light-emitting block copolymers that intends polymerizing a first di(halo-methyl) aromatic monomer compound in the presence of an anionic initiator and a base to form a polymer and contacting a second di(halo-methyl) aromatic monomer compound with the polymer to form a homopolymer or block copolymer wherein the block copolymer is a diblock, triblock, or star polymer. In yet another form, the present invention is an electroluminescent device comprising a light-emitting block copolymer, wherein the electroluminescent device is to be used in the manufacturing of optical and electrical devices.

  11. Preparation and Morphology of ABn Mictoarm Block Copolymers

    NASA Astrophysics Data System (ADS)

    Takano, Atsushi; Watanabe, Momoka; Asai, Yusuke; Suzuki, Jiro; Matsushita, Yushu

    A series of ABn mictoarm block copolymers (bottle brush copolymers) consisting of polystyrene (S) as a backbone and polyisoprenes (I) as grafts were precisely synthesized by an anionic polymerization, and their microphase-separated structures were investigated by transmission electron microscopy (TEM) and small-angle X-ray scattering(SAXS). A copolymer with composition of φS =0.57 and number of grafts(n) of 10 shows characteristic cylindrical structure, where microdomains of S reveals hexagonal cross section with non-constant mean curvature interface. While a sample with composition of φS =0.37 and number of grafts(n) of 40 shows spherical structure with rather large S isolated domains and characteristic domain packing manner was found. Furthermore composition dependence of microphase-separated structures for SIn mictoarm block copolymers were investigated and compared to SI diblock copolymer system.

  12. Block Copolymer Templates for Optical Materials and Devices

    NASA Astrophysics Data System (ADS)

    Urbas, Augustine; Martin, Maldovan; Carter, W. C.; Thomas, E. L.; Fasolka, Michael; Fraser, Cassandra

    2002-03-01

    Block copolymers can act as super-lattices for creating novel optical structures. We have fabricated block copolymer photonic crystals from one, two and three dimensionally periodic systems and have enhanced their dielectric properties towards creating complete 3D band gaps. By using carefully selected blends of linear and star block copolymers, we are able to create hierarchical blends which exhibit precise molecular positioning of fluorescent molecules. We are exploring these unique patterning capabilities of block copolymer systems for the formation of ordered arrays of optically active components within a photonic crystal. Precise location of both fluorescent and nonlinear components within block copolymer photonic crystals affords new opportunities for creating low threshold, upconverting and array lasers as well as optical modulators and other photonic devices.

  13. Electric field induced selective disordering in lamellar block copolymers.

    PubMed

    Ruppel, Markus; Pester, Christian W; Langner, Karol M; Sevink, Geert J A; Schoberth, Heiko G; Schmidt, Kristin; Urban, Volker S; Mays, Jimmy W; Böker, Alexander

    2013-05-28

    External electric fields align nanostructured block copolymers by either rotation of grains or nucleation and growth depending on how strongly the chemically distinct block copolymer components are segregated. In close vicinity to the order-disorder transition, theory and simulations suggest a third mechanism: selective disordering. We present a time-resolved small-angle X-ray scattering study that demonstrates how an electric field can indeed selectively disintegrate ill-aligned lamellae in a lyotropic block copolymer solution, while lamellae with interfaces oriented parallel to the applied field prevail. The present study adds an additional mechanism to the experimentally corroborated suite of mechanistic pathways, by which nanostructured block copolymers can align with an electric field. Our results further unveil the benefit of electric field assisted annealing for mitigating orientational disorder and topological defects in block copolymer mesophases, both in close vicinity to the order-disorder transition and well below it. PMID:23573901

  14. First-principles investigation of PVDF and its copolymers

    NASA Astrophysics Data System (ADS)

    Ranjan, V.; Yu, Liping; Buongiorno Nardelli, Marco; Bernholc, J.

    2009-03-01

    Recently, PVDF and its copolymers have generated significant interest due to their electroactive properties [1] and potential for ultra-high energy-storage applications [2]. In this talk, we present the results of first-principles calculations of stable phases and dielectric properties of different copolymers and terpolymers of PVDF at varying concentrations. Our results show that at very high concentrations of Chloro-trifluoroethylene (CTFE), PVDF/CTFE displays sharp transitions between non-polar (α) and polar (β) phases. On the contrary, the same transitions in copolymers with trifluoroethylene (TrFE) and tetrafluoroethylene (TeFE) are not sharp and happen at lower concentrations. We discuss the interplay of copolymer admixture on the dielectric properties of PVDF and discuss the suitability of copolymers for energy storage and electroactive applications. [1] S. G. Lu et al., App. Phys. Lett. 93, 042905 (2008). [2] V. Ranjan et al., Phys. Rev. Lett. 99, 047801 (2007).

  15. Well-defined organic nanotubes from multicomponent bottlebrush copolymers.

    PubMed

    Huang, Kun; Rzayev, Javid

    2009-05-20

    Bottlebrush copolymers are comblike macromolecules with densely grafted polymeric branches that adopt a cylindrical shape in solutions. We demonstrate a new method for the preparation of organic nanotubes by single molecule templating of core-shell bottlebrush copolymers. Multicomponent bottlebrush copolymers with well-defined structural parameters are synthesized by a combination of different living polymerization methods. Tubular structures can be prepared by cross-linking the shell layer and selectively etching out the core. The shape and size of original bottlebrush macromolecules are preserved during these transformations, which leads to the formation of well-defined organic nanotubes. The length and diameter of nanotubes are dictated by the length of the backbones and branches of the polymeric precursors, respectively. Water-soluble nanotubes with a hydrophobic interior can be prepared from bottlebrush copolymers with triblock copolymer branches. Herein, we outline molecular design strategies to fabricate nanotubes with controlled lengths, open pores, and different solubility characteristics.

  16. Alcohol fuels

    SciTech Connect

    Not Available

    1990-07-01

    Ethanol is an alcohol made from grain that can be blended with gasoline to extend petroleum supplies and to increase gasoline octane levels. Congressional proposals to encourage greater use of alternative fuels could increase the demand for ethanol. This report evaluates the growth potential of the ethanol industry to meet future demand increases and the impacts increased production would have on American agriculture and the federal budget. It is found that ethanol production could double or triple in the next eight years, and that American farmers could provide the corn for this production increase. While corn growers would benefit, other agricultural segments would not; soybean producers, for example could suffer for increased corn oil production (an ethanol byproduct) and cattle ranchers would be faced with higher feed costs because of higher corn prices. Poultry farmers might benefit from lower priced feed. Overall, net farm cash income should increase, and consumers would see slightly higher food prices. Federal budget impacts would include a reduction in federal farm program outlays by an annual average of between $930 million (for double current production of ethanol) to $1.421 billion (for triple production) during the eight-year growth period. However, due to an partial tax exemption for ethanol blended fuels, federal fuel tax revenues could decrease by between $442 million and $813 million.

  17. Active surfaces engineered by immobilizing protein-polymer nanoreactors for selectively detecting sugar alcohols.

    PubMed

    Zhang, Xiaoyan; Lomora, Mihai; Einfalt, Tomaz; Meier, Wolfgang; Klein, Noreen; Schneider, Dirk; Palivan, Cornelia G

    2016-05-01

    We introduce active surfaces generated by immobilizing protein-polymer nanoreactors on a solid support for sensitive sugar alcohols detection. First, such selective nanoreactors were engineered in solution by simultaneous encapsulation of specific enzymes in copolymer polymersomes, and insertion of membrane proteins for selective conduct of sugar alcohols. Despite the artificial surroundings, and the thickness of the copolymer membrane, functionality of reconstituted Escherichia coli glycerol facilitator (GlpF) was preserved, and allowed selective diffusion of sugar alcohols to the inner cavity of the polymersome, where encapsulated ribitol dehydrogenase (RDH) enzymes served as biosensing entities. Ribitol, selected as a model sugar alcohol, was detected quantitatively by the RDH-nanoreactors with GlpF-mediated permeability in a concentration range of 1.5-9 mM. To obtain "active surfaces" for detecting sugar alcohols, the nanoreactors optimized in solution were then immobilized on a solid support: aldehyde groups exposed at the compartment external surface reacted via an aldehyde-amino reaction with glass surfaces chemically modified with amino groups. The nanoreactors preserved their architecture and activity after immobilization on the glass surface, and represent active biosensing surfaces for selective detection of sugar alcohols, with high sensitivity.

  18. Fluctuation Dynamics of Block Copolymer Vesicles

    SciTech Connect

    Falus, P.; Borthwick, M.A.; Mochrie, S.G.J.

    2010-07-13

    X-ray photon correlation spectroscopy was used to characterize the wave-vector- and temperature-dependent dynamics of spontaneous thermal fluctuations in a vesicle (L4) phase that occurs in a blend of a symmetric poly(styrene-ethylene/butylene-styrene) triblock copolymer with a polystyrene homopolymer. Measurements of the intermediate scattering function reveal stretched-exponential behavior versus time, with a stretching exponent slightly larger than 2/3. The corresponding relaxation rates show an approximate q{sup 3} dependence versus wave vector. Overall, the experimental measurements are well described by theories that treat the dynamics of independent membrane plaquettes.

  19. Small domain-size multiblock copolymer electrolytes

    DOEpatents

    Pistorino, Jonathan; Eitouni, Hany Basam

    2016-09-20

    New block polymer electrolytes have been developed which have higher conductivities than previously reported for other block copolymer electrolytes. The new materials are constructed of multiple blocks (>5) of relatively low domain size. The small domain size provides greater protection against formation of dendrites during cycling against lithium in an electrochemical cell, while the large total molecular weight insures poor long range alignment, which leads to higher conductivity. In addition to higher conductivity, these materials can be more easily synthesized because of reduced requirements on the purity level of the reagents.

  20. Multi-block copolymers in thin films.

    NASA Astrophysics Data System (ADS)

    Maniadis, Panagiotis; Kober, Edward; Lookman, Turab

    2008-03-01

    We study the behavior of an ABn multi-block copolymer confined to a thin film, using self consistent field theory (SCFT) methods. Due to the breaking of symmetry in the direction of confinement, the propagators do not obey the usual diffusion equation. We derive the diffusion equation which correctly describes the confined polymer system and find that it differs from the original in an area which is approximately 3 times the Kuhn length of the polymer, close to the surface of the film. We use the modified diffusion equation to study the structure of the confined polymer.

  1. Fabrication of nanoporous block copolymer films using highly selective solvents and non-solvent extraction

    NASA Astrophysics Data System (ADS)

    Ye, Changhuai; Vogt, Bryan

    Nanoporous polymeric films with high porosity are necessary for some applications, such as anti-reflective coating. A simple and relatively environmental benign method is developed to fabricate nanoporous block copolymer thin film with tunable porosity up to 69% based on selective solvent swelling of the majority phase and subsequent rapid extraction with a miscible non-solvent (water). Poly(butylnorbornene)-block-poly(hydroxyhexafluoroisopropyl norbornene) (BuHFA) is used to generate these porous thin films due to its high Tg (>300 °C) and the selectivity of primary alcohols towards HFA. The porosity of these nanoporous films is highly dependent on the solvent quality for HFA. The modulus of the as-prepared nanoporous BuHFA thin films with the porosity from 0% to 69% was investigated by surface wrinkling and a scaling law of modulus versus density was obtained. These nanoporous thin films act as anti-reflective coatings and an increase in transmittance from approximately 92% to 99.1% (average for the full range of visible light) was obtained for double-side coated glass slides. This methodology is simple and highly tunable; extension to other block copolymer systems is likely possible if sufficient solubility contrast between segments exists.

  2. Long-Range Ordering of Block Copolymers on Well-Controlled Patterned Substrates

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Eun; Kim, Nam-Kyun; Park, Jina; Lee, Donghyun

    2015-03-01

    In this study, we achieved long-range ordering of block copolymers (BCPs) by combining solvent-annealing process and well-controlled patterned substrates. Nano-lines of poly(tetrafluoro ethylene) (PTFE) were firstly fabricated in large area as a PTFE bar was rubbed on Si substrates at 340 °C. The amplitude and pitch distance of PTFE nanolines were around 17 nm and 150 nm, respectively. Then, asymmetric polystyrene-block-poly(2-vinylpyridine) copolymers (PS- b-P2VP) were subsequently spin-coated on the patterned substrates after a thin layer of poly(vinyl alcohol) (PVA) was prepared on the PTFE patterned substrates to enhance the wettability of BCP thin films. As BCP thin films were solvent-annealed in vapor of organic solvents, highly ordered BCP nanostructures oriented either parallel or perpendicular to the surface were generated in large area. In addition, the nanopatterns were successfully transferred to the underlying PVA layer or Si substrate by dry etching. Thus, the resulting nanopatterns were utilized as templates to synthesize inorganic nanofeatures. The ordering behavior of BCP thin films on the patterned substrates was characterized by using AFM, SEM and GI-SAXS.

  3. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene-methyl acrylate copolymer resins. 177...-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as... prescribed conditions: (a) For the purpose of this section, the ethylene-methyl acrylate copolymer...

  4. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-methyl acrylate copolymer resins. 177.1340... copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as articles or components of...) For the purpose of this section, the ethylene-methyl acrylate copolymer resins consist of...

  5. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethylene-methyl acrylate copolymer resins. 177... Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl... section, the ethylene-methyl acrylate copolymer resins consist of basic copolymers produced by...

  6. Alcoholic hepatitis.

    PubMed

    Damgaard Sandahl, Thomas

    2014-10-01

    Alcoholic hepatitis (AH) is an acute inflammatory syndrome causing significant morbidity and mortality. The prognosis is strongly dependent on disease severity, as assessed by clinical scoring systems. Reliable epidemiological data as well as knowledge of the clinical course of AH are essential for planning and resource allocation within the health care system. Likewise, individual evaluation of risk is desirable in the clinical handling of patients with AH as it can guide treatment, improve patient information, and serve as strata in clinical trials. The present PhD thesis is based on three studies using a cohort of nearly 2000 patients diagnosed with AH in Denmark from 1999 to 2008 as a cohort, in a population-based study design. The aims of this thesis were as follows. (1) To describe the incidence and short- and long-term mortality, of AH in Denmark (Study I). (2) To validate and compare the ability of the currently available prognostic scores to predict mortality in AH (Study II). (3) To investigate the short- and long-term causes of death of patients with AH (Study III). During the study decade, the annual incidence rate in the Danish population rose from 37 to 46 per 106 for men and from 24 to 34 per 106 for women. Both short- and long-term mortality rose for men and women, and the increase in short-term mortality was attributable to increasing patient age and prevalence of cirrhosis. Our evaluation of the most commonly used prognostic scores for predicting the mortality of patients with AH showed that all scores performed similarly, with Area under the Receiver Operator Characteristics curves giving values between 0.74 and 0.78 for 28-day mortality assessed on admission. Our study on causes of death showed that in the short-term (< 84 days after diagnosis), patients with AH were likely to die from liver-related events and infections. In the long-term (≥ 84 days after diagnosis), those who developed cirrhosis mainly died from liver-related causes, and

  7. Alcoholism and alcohol drinking habits predicted from alcohol dehydrogenase genes.

    PubMed

    Tolstrup, Janne Schurmann; Nordestgaard, Børge Grønne; Rasmussen, Søren; Tybjaerg-Hansen, Anne; Grønbaek, Morten

    2008-06-01

    Alcohol drinking habits and alcoholism are partly genetically determined. Alcohol is degraded primarily by alcohol dehydrogenase (ADH) wherein genetic variation that affects the rate of alcohol degradation is found in ADH1B and ADH1C. It is biologically plausible that these variations may be associated with alcohol drinking habits and alcoholism. By genotyping 9080 white men and women from the general population, we found that men and women with ADH1B slow vs fast alcohol degradation drank more alcohol and had a higher risk of everyday drinking, heavy drinking, excessive drinking and of alcoholism. For example, the weekly alcohol intake was 9.8 drinks (95% confidence interval (CI): 9.1-11) among men with the ADH1B.1/1 genotype compared to 7.5 drinks (95% CI: 6.4-8.7) among men with the ADH1B.1/2 genotype, and the odds ratio (OR) for heavy drinking was 3.1 (95% CI: 1.7-5.7) among men with the ADH1B.1/1 genotype compared to men with the ADH1B.1/2 genotype. Furthermore, individuals with ADH1C slow vs fast alcohol degradation had a higher risk of heavy and excessive drinking. For example, the OR for heavy drinking was 1.4 (95% CI: 1.1-1.8) among men with the ADH1C.1/2 genotype and 1.4 (95% CI: 1.0-1.9) among men with the ADH1B.2/2 genotype, compared with men with the ADH1C.1/1 genotype. Results for ADH1B and ADH1C genotypes among men and women were similar. Finally, because slow ADH1B alcohol degradation is found in more than 90% of the white population compared to less than 10% of East Asians, the population attributable risk of heavy drinking and alcoholism by ADH1B.1/1 genotype was 67 and 62% among the white population compared with 9 and 24% among the East Asian population.

  8. Perillyl Alcohol (Monoterpene Alcohol), Limonene.

    PubMed

    Shojaei, Shahla; Kiumarsi, Amir; Moghadam, Adel Rezaei; Alizadeh, Javad; Marzban, Hassan; Ghavami, Saeid

    2014-01-01

    Natural products have a long history of use in traditional medicines and their activities against different diseases have been the focus of many basic and clinical researches in past few decades. The essential oils, volatile liquid containing aroma compound from plants, are known as active ingredients in the herbal medicine. Perillyl alcohol (POH) is usually available through dietary sources and is being explored for its cancer chemoprevention, tumor growth suppression, and regression. Citrus peels are the waste product of juice manufacturing industries and have been considered as a critical problem for environmental green ecology policies for years. One of the most well-known approaches to overcome this problem is transformation of these monoterpene by the use of specific strains of bacteria or yeasts. Limonene (1-methyl-4-isopropyl-cyclohexene) is a monoterpene, as other monoterpenes consists of two isoprene units, that comprises more than 90% of citrus essential oil and it exists in many fruits and vegetables. Although, the anticancer activity of d-limonene has identified nearly two decades ago, it has recently attracted much more attention in translational medicine. In this chapter, we will overview the anticancer effects of POH and d-limonene. Later, we will address the pharmacokinetics of these compounds, highlight the signaling pathways which are targeted by these proteins, review the clinical trials which have been done for these compounds in different cancer models, and finally discuss the future directions of the research in this field that might be more applicable in future cancer therapy strategies.

  9. Perillyl Alcohol (Monoterpene Alcohol), Limonene.

    PubMed

    Shojaei, Shahla; Kiumarsi, Amir; Moghadam, Adel Rezaei; Alizadeh, Javad; Marzban, Hassan; Ghavami, Saeid

    2014-01-01

    Natural products have a long history of use in traditional medicines and their activities against different diseases have been the focus of many basic and clinical researches in past few decades. The essential oils, volatile liquid containing aroma compound from plants, are known as active ingredients in the herbal medicine. Perillyl alcohol (POH) is usually available through dietary sources and is being explored for its cancer chemoprevention, tumor growth suppression, and regression. Citrus peels are the waste product of juice manufacturing industries and have been considered as a critical problem for environmental green ecology policies for years. One of the most well-known approaches to overcome this problem is transformation of these monoterpene by the use of specific strains of bacteria or yeasts. Limonene (1-methyl-4-isopropyl-cyclohexene) is a monoterpene, as other monoterpenes consists of two isoprene units, that comprises more than 90% of citrus essential oil and it exists in many fruits and vegetables. Although, the anticancer activity of d-limonene has identified nearly two decades ago, it has recently attracted much more attention in translational medicine. In this chapter, we will overview the anticancer effects of POH and d-limonene. Later, we will address the pharmacokinetics of these compounds, highlight the signaling pathways which are targeted by these proteins, review the clinical trials which have been done for these compounds in different cancer models, and finally discuss the future directions of the research in this field that might be more applicable in future cancer therapy strategies. PMID:27102697

  10. Star-shaped PHB-PLA block copolymers: immortal polymerization with dinuclear indium catalysts.

    PubMed

    Yu, I; Ebrahimi, T; Hatzikiriakos, S G; Mehrkhodavandi, P

    2015-08-28

    The first example of a one-component precursor to star-shaped polyesters, and its utilization in the synthesis of previously unknown star-shaped poly(hydroxybutyrate)-poly(lactic acid) block copolymers, is reported. A series of such mono- and bis-benzyl alkoxy-bridged complexes were synthesized, fully characterized, and their solvent dependent solution structures and reactivity were examined. These complexes were highly active catalysts for the controlled polymerization of β-butyrolactone to form poly(hydroxybutyrate) at room temperature. Solution studies indicate that a mononuclear propagating species formed in THF and that the dimer-monomer equilibrium affects the rates of BBL polymerization. In the presence of linear and branched alcohols, these complexes catalyze well-controlled immortal polymerization and copolymerization of β-butyrolactone and lactide.

  11. Substantially isotactic, linear, alternating copolymers of carbon monoxide and an olefin

    DOEpatents

    Sen, A.; Jiang, Z.

    1996-05-28

    The compound, [Pd(Me-DUPHOS)(MeCN){sub 2}](BF{sub 4}){sub 2}, [Me-DUPHOS: 1,2-bis(2,5-dimethylphospholano)benzene] is an effective catalyst for the highly enantioselective, alternating copolymerization of olefins, such as aliphatic {alpha}-olefins, with carbon monoxide to form optically active, isotactic polymers which can serve as excellent starting materials for the synthesis of other classes of chiral polymers. For example, the complete reduction of a propylene-carbon monoxide copolymer resulted in the formation of a novel, optically active poly(1,4-alcohol). Also, the previously described catalyst is a catalyst for the novel alternating isomerization cooligomerization of 2-butene with carbon monoxide to form optically active, isotactic poly(1,5-ketone).

  12. Substantially isotactic, linear, alternating copolymers of carbon monoxide and an olefin

    DOEpatents

    Sen, Ayusman; Jiang, Zhaozhong

    1996-01-01

    The compound, [Pd(Me-DUPHOS)(MeCN).sub.2 ](BF.sub.4).sub.2, [Me-DUPHOS: 1,2-bis(2,5-dimethylphospholano)benzene] is an effective catalyst for the highly enantioselective, alternating copolymerization of olefins, such as aliphatic .alpha.-olefins, with carbon monoxide to form optically active, isotactic polymers which can serve as excellent starting materials for the synthesis of other classes of chiral polymers. For example, the complete reduction of a propylene-carbon monoxide copolymer resulted in the formation of a novel, optically active poly(1,4-alcohol). Also, the previously described catalyst is a catalyst for the novel alternating isomerization cooligomerization of 2-butene with carbon monoxide to form optically active, isotactic poly(1,5-ketone)

  13. Structure-property relationships in ABA copolymer gels with A homopolymer additions

    NASA Astrophysics Data System (ADS)

    Seitz, Michelle; Rottsolk, Rebecca; Page, Kirt; Shull, Kenneth

    2009-03-01

    ABA acrylic triblock copolymers with poly(methyl methacrylate) endblocks and poly(butyl acrylate) midblocks transition from free flowing liquids to elastic solids with decreasing temperature in alcohol solvents. Homopolymer PMMA chains can be solubilized in the micelle cores if they are shorter than the endblocks. Indentation and compression tests were used to determine gel's modulus and large strain behavior. Gels with volume fractions of PMMA less than ˜0.2 are highly elastic and have moduli dictated by stretching of bridging midblocks. At higher PMMA contents, gels exhibit greater permanent deformation and moduli over an order of magnitude larger than would be expected from rubber elasticity alone. Small angle X-ray and neutron scattering and mean field simulations were used to correlate changes in gel structure and micelle morphology with the addition of homopolymer.

  14. Correlated disorder in random block copolymers

    NASA Astrophysics Data System (ADS)

    Westfahl, Harry, Jr.; Schmalian, Jörg

    2005-07-01

    We study the effect of a random Flory-Huggins parameter in a symmetric diblock copolymer melt which is expected to occur in a copolymer where one block is near its structural glass transition. In the clean limit the microphase segregation between the two blocks causes a weak, fluctuation induced first order transition to a lamellar state. Using a renormalization group approach combined with the replica trick to treat the quenched disorder, we show that beyond a critical disorder strength, which depends on the length of the polymer chain, the character of the transition is changed. The system becomes dominated by strong randomness and a glassy rather than an ordered lamellar state occurs. A renormalization of the effective disorder distribution leads to nonlocal disorder correlations that reflect strong compositional fluctuation on the scale of the radius of gyration of the polymer chains. The reason for this behavior is shown to be the chain length dependent role of critical fluctuations, which are less important for shorter chains and become increasingly more relevant as the polymer length increases and the clean first order transition becomes weaker.

  15. Anomalous Micellization of Pluronic Block Copolymers

    NASA Astrophysics Data System (ADS)

    Leonardi, Amanda; Ryu, Chang Y.

    2014-03-01

    Poly(ethylene oxide) - poly(propylene oxide) - poly(ethylene oxide) (PEO-PPO-PEO) block copolymers, commercially known as Pluronics, are a unique family of amphiphilic triblock polymers, which self-assemble into micelles in aqueous solution. These copolymers have shown promise in therapeutic, biomedical, cosmetic, and nanotech applications. As-received samples of Pluronics contain low molecular weight impurities (introduced during the manufacturing and processing), that are ignored in most applications. It has been observed, however, that in semi-dilute aqueous solutions, at concentrations above 1 wt%, the temperature dependent micellization behavior of the Pluronics is altered. Anomalous behavior includes a shift of the critical micellization temperature and formation of large aggregates at intermediate temperatures before stable sized micelles form. We attribute this behavior to the low molecular weight impurities that are inherent to the Pluronics which interfere with the micellization process. Through the use of Dynamic Light Scattering and HPLC, we compared the anomalous behavior of different Pluronics of different impurity levels to their purified counterparts.

  16. Chain exchange in triblock copolymer micelles

    NASA Astrophysics Data System (ADS)

    Lu, Jie; Lodge, Timothy; Bates, Frank

    2015-03-01

    Block polymer micelles offer a host of technological applications including drug delivery, viscosity modification, toughening of plastics, and colloidal stabilization. Molecular exchange between micelles directly influences the stability, structure and access to an equilibrium state in such systems and this property recently has been shown to be extraordinarily sensitive to the core block molecular weight in diblock copolymers. The dependence of micelle chain exchange dynamics on molecular architecture has not been reported. The present work conclusively addresses this issue using time-resolved small-angle neutron scattering (TR-SANS) applied to complimentary S-EP-S and EP-S-EP triblock copolymers dissolved in squalane, a selective solvent for the EP blocks, where S and EP refer to poly(styrene) and poly(ethylenepropylene), respectively. Following the overall SANS intensity as a function of time from judiciously deuterium labelled polymer and solvent mixtures directly probes the rate of molecular exchange. Remarkably, the two triblocks display exchange rates that differ by approximately ten orders of magnitude, even though the solvophobic S blocks are of comparable size. This discovery is considered in the context of a model that successfully explains S-EP diblock exchange dynamics.

  17. Neurologic effects of alcoholism.

    PubMed Central

    Diamond, I; Messing, R O

    1994-01-01

    Alcoholism, a worldwide disorder, is the cause of a variety of neurologic disorders. In this article we discuss the cellular pathophysiology of ethanol addition and abuse as well as evidence supporting and refuting the role of inheritance in alcoholism. A genetic marker for alcoholism has not been identified, but neurophysiologic studies may be promising. Some neurologic disorders related to longterm alcoholism are due predominantly to inadequate nutrition (the thiamine deficiency that causes Wernicke's encephalopathy), but others appear to involve the neurotoxicity of ethanol on brain (alcohol withdrawal syndrome and dementia) and peripheral nerves (alcoholic neuropathy and myopathy). Images PMID:7975567

  18. Effects of Blockiness on the phase behavior of random copolymers

    NASA Astrophysics Data System (ADS)

    Vanderwoude, Gordon; Shi, An-Chang

    Theoretical study of random block copolymers remains a challenging topic due in part to the sheer enormity of their phase space. In this study we use the self-consistent field theory to investigate the phase behaviour of linear (AB)n-type and (AB)n-C-type multiblock copolymers with randomly distributed A and B blocks. In particular, we examine the effect of ``blockiness'' of the random copolymers on the formation of ordered phases. The blockiness can be quantified by the average length of individual A or B blocks, which can be taken as a measure of the heterogeneity of the random copolymers. We observed that the critical value of the χ parameter, at which the order-disorder transition occurs, decreases with increasing blockiness in the (AB)n copolymers. We also observed that the phase behaviour of the (AB)n-C copolymers depends strongly on the blockiness of the random chain. In particular, the blockiness governs whether or not the A/B blocks can phase separate within the A/B domains, thus dictating whether the (AB)n-C behaves as A/B-C diblock copolymers or as ABC terpolymers. The theoretical phase diagrams will be compared with available experiments.

  19. Manipulating Ordering Transitions in Interfacially Modified Block Copolymers

    SciTech Connect

    Singh, N.; Tureau, M; Epps, T

    2009-01-01

    We report a synthetic strategy that allows us to manipulate the interfacial region between blocks and control ordering transitions in poly(isoprene-b-styrene) [P(I-S)] block copolymers. This interfacial modification is accomplished by combining a semi-batch feed with anionic polymerization techniques. Using this approach, we are able to control the segmental composition and molecular interactions in our phase-separated block copolymers, independent of molecular weight and block constituents. A library of copolymers is prepared with various interfacial modifications to examine the effect of interfacial composition on copolymer self-assembly. The morphological characteristics of the self-assembled structures are investigated using small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and dynamic mechanical analysis (DMA). Normal and inverse tapered block copolymers, containing approximately 15-35 vol% tapered material, show a measurable decrease in the order-disorder transition temperature (TODT) relative to the corresponding non-tapered diblock copolymers, with the inverse tapered materials showing the greatest deviation in TODT. Additionally, TODT was inversely related to the volume fraction of the tapered region in both normal and inverse tapered copolymer materials.

  20. Tribological Behavior of Aqueous Copolymer Lubricant in Mixed Lubrication Regime.

    PubMed

    Ta, Thi D; Tieu, A Kiet; Zhu, Hongtao; Zhu, Qiang; Kosasih, Prabouno B; Zhang, Jie; Deng, Guanyu

    2016-03-01

    Although a number of experiments have been attempted to investigate the lubrication of aqueous copolymer lubricant, which is applied widely in metalworking operations, a comprehensive theoretical investigation at atomistic level is still lacking. This study addresses the influence of loading pressure and copolymer concentration on the structural properties and tribological performance of aqueous copolymer solution of poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide) (PPO-PEO-PPO) at mixed lubrication using a molecular dynamic (MD) simulation. An effective interfacial potential, which has been derived from density functional theory (DFT) calculations, was employed for the interactions between the fluid's molecules and iron surface. The simulation results have indicated that the triblock copolymer is physisorption on iron surface. Under confinement by iron surfaces, the copolymer molecules form lamellar structure in aqueous solution and behave differently from its bulk state. The lubrication performance of aqueous copolymer lubricant increases with concentration, but the friction reduction is insignificant at high loading pressure. Additionally, the plastic deformation of asperity is dependent on both copolymer concentration and loading pressure, and the wear behavior shows a linear dependence of friction force on the number of transferred atoms between contacting asperities. PMID:26828119

  1. Microemulsions of ABA Amphiphilic Block Copolymers and Surfactants

    NASA Astrophysics Data System (ADS)

    Braun-Shmueli, Liora; Netanel, Ortal; Regev, Oren; Gottlieb, Moshe

    2001-03-01

    The system composed of oil (decane), water and an ABA amphiphilic block copolymer is capable of exhibiting an extremely rich phase and rheological behavior. In this paper we describe the rheological properties of a synthetic amphiphilic block copolymer dissolved in a water-in-oil microemulsion with and without the stabilizing effect of small molecular weight surfactant molecules. The block copolymer is an ABA type copolymer composed of poly(oxyethylene) (PEO) as the hydrophilic A block and poly(dimethyl siloxane) (PDMS) as the hydrophobic center B block. The resulting copolymer is insoluble in water and hardly soluble in decane (good solvent for the PDMS). In the presence of water in oil microemulsion stabilized by the small molecular weight surfactant AOT a one-phase region is maintained when the copolymer is added. Yet, peculiar rheological behavior is observed. For constant water-microemulsion concentration (φ) addition of polymer increases the system viscosity as expected. Yet, the lower φ the higher the viscosity and at high φ the effect of polymer addition is quite low. Furthermore, the insoluble block copolymer in oil turns into a gel-like one phase system upon addition of small amounts of either water or water and surfactant solution. Experiments show that a maximum in elasticity or viscosity is attained at a droplet concentration equivalent to about 80 polymer chains per drop. Small angle x-ray and neutron scattering experiments were carried out to elucidate the system morphology.

  2. Using Tapered Block Copolymers to Create Conducting Nanomaterials

    NASA Astrophysics Data System (ADS)

    Epps, Thomas, III

    2014-03-01

    Soft materials, such as polymers, colloids, surfactants, and liquid crystals, are a technologically important class of matter employed in a variety of applications. One sub-class of soft material, block copolymers, provides the opportunity to design materials with attractive chemical and mechanical properties based on the ability to assemble into periodic structures with nanoscale domain spacings. Several applications for block copolymers currently under investigation in my group include battery and fuel cell membranes, analytical separations membranes, nano-tool templates, precursors to electronic arrays, and drug delivery vehicles. One area of recent progress in the group focuses on the behavior of conventional block copolymer and tapered block copolymer systems for lithium battery membrane applications. We find that we can tune poly(styrene- b-ethylene oxide) diblock copolymer nanostructures by adjusting the lithium counterion and lithium salt concentration, as well as the taper volume fraction and composition. Additionally, we can estimate the effective interaction parameters (χeff) for the salt-doped copolymers to determine the overall influence of tapering on the energetics of copolymer assembly. These tapered materials allow us to design nanostructured membrane systems with increased conductivity and improved mechanical properties in ion transport devices. We gratefully acknowledge AFOSR-PECASE (FA9550-09-1-0706) and NSF-CAREER (DMR-0645586) for financial support.

  3. Nanopatterning of recombinant proteins and viruses using block copolymer templates

    NASA Astrophysics Data System (ADS)

    Cresce, Arthur Von Wald

    The study of interfaces is important in understanding biological interactions, including cellular signaling and virus infection. This thesis is an original effort to examine the interaction between a block copolymer and both a protein and a virus. Block copolymers intrinsically form nanometer-scale structures over large areas without expensive processing, making them ideal for the synthesis of the nanopatterned surfaces used in this study. The geometry of these nanostructures can be easily tuned for different applications by altering the block ratio and composition of the block copolymer. Block copolymers can be used for controlled uptake of metal ions, where one block selectively binds metal ions while the other does not. 5-norbornene-2,3-dicarboxylic acid is synthesized through ring-opening metathesis polymerization. It formed spherical domains with spheres approximately 30 nm in diameter, and these spheres were then subsequently loaded with nickel ion. This norbornene block copolymer was tested for its ability to bind histidine-tagged green fluorescent protein (hisGFP), and it was found that the nickel-loaded copolymer was able to retain hisGFP through chelation between the histidine tag and the metal-containing portions of the copolymer surface. Poly(styrene-b-4-vinylpyridine) (PS/P4VP) was also loaded with nickel, forming a cylindrical microstructure. The binding of Tobacco mosaic virus and Tobacco necrosis virus was tested through Tween 20 detergent washes. Electron microscopy allowed for observation of both block copolymer nanostructures and virus particles. Results showed that Tween washes could not remove bound Tobacco mosaic virus from the surface of PS/P4VP. It was also seen that the size and tunability of block copolymers and the lack of processing needed to attain different structures makes them attractive for many applications, including microfluidic devices, surfaces to influence cellular signaling and growth, and as a nanopatterning surface for

  4. Fetal Alcohol Spectrum Disorders.

    PubMed

    Williams, Janet F; Smith, Vincent C

    2015-11-01

    Prenatal exposure to alcohol can damage the developing fetus and is the leading preventable cause of birth defects and intellectual and neurodevelopmental disabilities. In 1973, fetal alcohol syndrome was first described as a specific cluster of birth defects resulting from alcohol exposure in utero. Subsequently, research unequivocally revealed that prenatal alcohol exposure causes a broad range of adverse developmental effects. Fetal alcohol spectrum disorder (FASD) is the general term that encompasses the range of adverse effects associated with prenatal alcohol exposure. The diagnostic criteria for fetal alcohol syndrome are specific, and comprehensive efforts are ongoing to establish definitive criteria for diagnosing the other FASDs. A large and growing body of research has led to evidence-based FASD education of professionals and the public, broader prevention initiatives, and recommended treatment approaches based on the following premises:▪ Alcohol-related birth defects and developmental disabilities are completely preventable when pregnant women abstain from alcohol use.▪ Neurocognitive and behavioral problems resulting from prenatal alcohol exposure are lifelong.▪ Early recognition, diagnosis, and therapy for any condition along the FASD continuum can result in improved outcomes.▪ During pregnancy:◦no amount of alcohol intake should be considered safe;◦there is no safe trimester to drink alcohol;◦all forms of alcohol, such as beer, wine, and liquor, pose similar risk; and◦binge drinking poses dose-related risk to the developing fetus.

  5. Fetal Alcohol Spectrum Disorders.

    PubMed

    Williams, Janet F; Smith, Vincent C

    2015-11-01

    Prenatal exposure to alcohol can damage the developing fetus and is the leading preventable cause of birth defects and intellectual and neurodevelopmental disabilities. In 1973, fetal alcohol syndrome was first described as a specific cluster of birth defects resulting from alcohol exposure in utero. Subsequently, research unequivocally revealed that prenatal alcohol exposure causes a broad range of adverse developmental effects. Fetal alcohol spectrum disorder (FASD) is the general term that encompasses the range of adverse effects associated with prenatal alcohol exposure. The diagnostic criteria for fetal alcohol syndrome are specific, and comprehensive efforts are ongoing to establish definitive criteria for diagnosing the other FASDs. A large and growing body of research has led to evidence-based FASD education of professionals and the public, broader prevention initiatives, and recommended treatment approaches based on the following premises:▪ Alcohol-related birth defects and developmental disabilities are completely preventable when pregnant women abstain from alcohol use.▪ Neurocognitive and behavioral problems resulting from prenatal alcohol exposure are lifelong.▪ Early recognition, diagnosis, and therapy for any condition along the FASD continuum can result in improved outcomes.▪ During pregnancy:◦no amount of alcohol intake should be considered safe;◦there is no safe trimester to drink alcohol;◦all forms of alcohol, such as beer, wine, and liquor, pose similar risk; and◦binge drinking poses dose-related risk to the developing fetus. PMID:26482673

  6. Effect of water uptake on morphology of polymerized ionic liquid block copolymers and random copolymers

    NASA Astrophysics Data System (ADS)

    Wang, Tsen-Shan; Ye, Yuesheng; Elabd, Yossef; Winey, Karen

    2012-02-01

    Dynamic studies of polymer morphology probe how the physical properties of polymerized ionic liquids are affected by the environment, such as temperature or moisture. For a series of poly(methyl methacrylate-b-1-[2-(methacryloyloxy)ethyl]-3-Butylimidazolium X^-) block and random copolymers with hydrophilic counterions (X^- = Br^-, HCO3^-, OH^-), the introduction of water vapor to the system can swell the ionic liquid block, causing enlarged hydrophilic domains and swollen channels for ion conduction. This expected expansion of ionic liquid domains in humid environments can be used to intelligently design these copolymers for use in technological applications. The effect of water vapor exposure in these imidazolium-based acrylate polymers is studied by small-angle X-ray scattering. These morphology results will be discussed alongside complementary studies of water uptake and ion conductivity.

  7. Electrically conductive doped block copolymer of polyacetylene and polyisoprene

    DOEpatents

    Aldissi, Mahmoud

    1985-01-01

    An electrically conductive block copolymer of polyisoprene and polyacetyl and a method of making the same are disclosed. The polymer is prepared by first polymerizing isoprene with n-butyllithium in a toluene solution to form an active isoprenyllithium polymer. The active polymer is reacted with an equimolar amount of titanium butoxide and subsequently exposed to gaseous acetylene. A block copolymer of polyisoprene and polyacetylene is formed. The copolymer is soluble in common solvents and may be doped with I.sub.2 to give it an electrical conductivity in the metallic regime.

  8. Polysaccharide based Copolymers as Supramolecular Systems in Biomedical Applications.

    PubMed

    Célia Monteiro de Paula, Regina; Andrade Feitosa, Judith Pessoa; Beserra Paula, Haroldo César

    2015-01-01

    Polysaccharides are natural polymers, obtained from a large variety of sources ranging from fungi to more complex organisms such as birds and whales. Their use for pharmaceutical and biomedical applications has been the subject of numerous researches by the world´s academia. Polysaccharide chemical/physical modifications leading to graft copolymers are discussed in this review, focusing on those nanosystems that are potential candidates for drug delivery applications. Therefore, this review focuses on the biomedical application of polysaccharide based copolymers, particularly as nanocarriers. Copolymer of polysaccharides such as alginate, cellulose, chitosan, dextran, guar, hyaluronic acid, pullulan and starch as drug delivery nanocarriers will be discussed. PMID:26424388

  9. Neutron reflectivity studies of composite nanoparticle - copolymer thin films

    NASA Astrophysics Data System (ADS)

    Lauter-Pasyuk, V.; Lauter, H. J.; Ausserre, D.; Gallot, Y.; Cabuil, V.; Hamdoun, B.; Kornilov, E. I.

    1998-06-01

    Neutron reflection was used for the investigation of a new class of copolymers - composite materials, consisting of symmetric polystyrene-polybuthylmethacrylate (PS-PBMA) diblock copolymer with incorporated nanoparticles γ-Fe 2O 3 of a few nanometers in diameter. The presence of the nanoparticles induces an elastic distortion of the copolymer matrix. From the experiments we obtained information about the lamellar order of the polymer matrix, the distribution of the nanoparticles in the film and the distortion of the interfaces caused by the nanoparticles.

  10. Photocrosslinkable copolymers for non-linear optical applications

    SciTech Connect

    Kawatsuki, N.; Pakbaz, K.; Schmidt, H.W.

    1993-12-31

    New photocrosslinkable copolymers have been synthesized and applied as non-linear optical materials. The copolymers are based on methyl methacrylate, a photo-excitable benzophenone monomer, a non-linear optical active 4`-[(2-hydroxyethyl)ethylamino]-4-nitro-azobenzene (disperse red 1) side chain monomer and a crosslinkable 2-butenyl monomer. These copolymers can be crosslinked by UV light at 366 nm in the poled state and show a stable alignment of NLO chromophore by monitoring the adsorption spectra. The crosslinked and poled film did not change its alignment after storing 4 weeks at room temperature.

  11. Patchy micelles based on coassembly of block copolymer chains and block copolymer brushes on silica particles.

    PubMed

    Zhu, Shuzhe; Li, Zhan-Wei; Zhao, Hanying

    2015-04-14

    Patchy particles are a type of colloidal particles with one or more well-defined patches on the surfaces. The patchy particles with multiple compositions and functionalities have found wide applications from the fundamental studies to practical uses. In this research patchy micelles with thiol groups in the patches were prepared based on coassembly of free block copolymer chains and block copolymer brushes on silica particles. Thiol-terminated and cyanoisopropyl-capped polystyrene-block-poly(N-isopropylacrylamide) block copolymers (PS-b-PNIPAM-SH and PS-b-PNIPAM-CIP) were synthesized by reversible addition-fragmentation chain transfer polymerization and chemical modifications. Pyridyl disulfide-functionalized silica particles (SiO2-SS-Py) were prepared by four-step surface chemical reactions. PS-b-PNIPAM brushes on silica particles were prepared by thiol-disulfide exchange reaction between PS-b-PNIPAM-SH and SiO2-SS-Py. Surface micelles on silica particles were prepared by coassembly of PS-b-PNIPAM-CIP and block copolymer brushes. Upon cleavage of the surface micelles from silica particles, patchy micelles with thiol groups in the patches were obtained. Dynamic light scattering, transmission electron microscopy, and zeta-potential measurements demonstrate the preparation of patchy micelles. Gold nanoparticles can be anchored onto the patchy micelles through S-Au bonds, and asymmetric hybrid structures are formed. The thiol groups can be oxidized to disulfides, which results in directional assembly of the patchy micelles. The self-assembly behavior of the patchy micelles was studied experimentally and by computer simulation. PMID:25811763

  12. Alcohol Use and Older Adults

    MedlinePlus

    ... version of this page please turn Javascript on. Alcohol Use and Older Adults Alcohol and Aging Adults of any age can have ... Escape (Esc) button on your keyboard.) What Is Alcohol? Alcohol, also known as ethanol, is a chemical ...

  13. Alcohol and Cancer Risk

    MedlinePlus

    ... Overview Cancer Prevention Overview–for health professionals Research Alcohol and Cancer Risk On This Page What is ... in the risk of colorectal cancer. Research on alcohol consumption and other cancers: Numerous studies have examined ...

  14. Alcohol and Migraine

    MedlinePlus

    ... on Pinterest Follow us on Instagram DONATE TODAY Alcohol and Migraine Abuse, Maltreatment, and PTSD and Their ... to Migraine Altitude, Acute Mountain Sickness and Headache Alcohol and Migraine Anxiety and Depression Caffeine and Migraine ...

  15. Benzyl Alcohol Topical

    MedlinePlus

    Benzyl alcohol lotion is used to treat head lice (small insects that attach themselves to the skin) in adults ... children less than 6 months of age. Benzyl alcohol is in a class of medications called pediculicides. ...

  16. Translational Studies of Alcoholism

    PubMed Central

    Zahr, Natalie M.; Sullivan, Edith V.

    2008-01-01

    Human studies are necessary to identify and classify the brain systems predisposing individuals to develop alcohol use disorders and those modified by alcohol, while animal models of alcoholism are essential for a mechanistic understanding of how chronic voluntary alcohol consumption becomes compulsive, how brain systems become damaged, and how damage resolves. Our current knowledge of the neuroscience of alcohol dependence has evolved from the interchange of information gathered from both human alcoholics and animal models of alcoholism. Together, studies in humans and animal models have provided support for the involvement of specific brain structures over the course of alcohol addiction, including the prefrontal cortex, basal ganglia, cerebellum, amygdala, hippocampus, and the hypothalamic–pituitary–adrenal axis. PMID:20041042

  17. [Neurologic sequelae of alcohol].

    PubMed

    Ladurner, G; Griebnitz, E

    1986-10-10

    The consequences of alcoholism on the peripheral and central nervous system are discussed. Polyneuropathy is present in 30% of the alcoholics, whilst cranial nerve involvement is found in 5-25%. Alcoholic myopathy is only very rarely seen. Wernicke's encephalopathy is found at post mortem investigation in 1.8% of alcoholics, but is rarely clinically diagnosed. The Marchiafava-Bignamy syndrome and central pontine myelinolysis are rarely seen; alcoholic amblyopia which is seen in 0.5% of the hospitalised alcoholics is more frequent, but still a rare finding. Cerebral seizures are common in chronic alcoholics with an incidence varying from 5 to 37% according to the type of drinking habit and have, thus, to be categorised. Brain atrophy is a common finding and correlates with the duration and extent of the alcoholism. PMID:3788182

  18. Alcohol and Cancer

    MedlinePlus

    ... developing some kinds of cancer. The way alcohol causes cancer isn’t completely understood. In fact, there might ... For example, it could be that alcohol itself causes cancer by increasing hormone levels, or it may be ...

  19. Alcohol Calorie Calculator

    MedlinePlus

    ... Alcohol Calorie Calculator Find out the number of beer and hard alcohol calories you are consuming. Simply ... calories) Average Drinks Per Week Monthly Subtotal Calories Beer Regular 12 149 Regular Beer Light 12 110 ...

  20. National Institute on Alcohol Abuse and Alcoholism

    MedlinePlus

    ... TODAY: “Neurodevelopment and Alcohol: From Cell Adhesion to Cell Phones" Dr. Michael Charness, 11/3 @3 , Masur t. ... lecture: “Neurodevelopment and Alcohol: From Cell Adhesion to Cell Phones" Dr. Michael Charness, 11/3 @3 pm, Masur ...

  1. Alcohol and motorcycle fatalities.

    PubMed Central

    Baker, S P; Fisher, R S

    1977-01-01

    A series of 99 fatal motorcycle crashes in Maryland was studied retrospectively, using police and medical examiner records. Blood alcohol concentrations were determined for 62 motorcycle drivers; measurable amounts of alcohol were found in two-thirds (41), and one-half (31) had illegally high concentrations of 100 mg/100 ml or more. The police report mentioned alcohol in only 9 instances. High blood alcohol concentrations were found most commonly among drivers age 20-34. PMID:842762

  2. The Alcoholism Questionnaire.

    ERIC Educational Resources Information Center

    Ferneau, E.; Mueller, S.

    The alcoholism questionnaire used to survey college student attitudes on the subject is provided. It is identical to the drug-abuse questionnaire except for word changes appropriate to the subject matter. The questionnaire consists of 40 statements about alcoholics and alcoholism, with 7 possible responses: (1) completely disagree; (2) mostly…

  3. Youths' Perceptions of Alcoholism.

    ERIC Educational Resources Information Center

    Lorch, Barbara (Day); Hughes, Robert H.

    1986-01-01

    Only a third of students in this study accepted the medical model of alcoholism. Those who had the least knowledge of, and experience with, alcohol were the most likely to consider alcoholism as an illness. The source of information on drugs most conducive to acceptance of the medical model was parents. (Author/ABB)

  4. Alcohol and Minority Youth.

    ERIC Educational Resources Information Center

    Wright, Roosevelt, Jr.; Watts, Thomas D.

    1991-01-01

    Maintains that minority youth who use (or abuse) alcohol in American society deal with using alcohol, being minority, and being young, three dimensions viewed by society with mixed, sometimes hostile and/or fearful reactions. Suggests that examining alcoholism among minority youth involves coming to grips with poverty, education, income, and life…

  5. Television: Alcohol's Vast Adland.

    ERIC Educational Resources Information Center

    2002

    Concern about how much television alcohol advertising reaches underage youth and how the advertising influences their attitudes and decisions about alcohol use has been widespread for many years. Lacking in the policy debate has been solid, reliable information about the extent of youth exposure to television alcohol advertising. To address this…

  6. Alcohol on Campus.

    ERIC Educational Resources Information Center

    ACU-I Bulletin, 1984

    1984-01-01

    Alcohol use on campus and strategies colleges are using to educate students about alcohol are considered in two articles. In "When Alternatives Aren't," Ruth Bradford Burnham and Stephen J. Nelson explore the role alcoholic beverages play in young people's social lives and some of the implications for planning social events. They offer a balanced…

  7. Biological Vulnerability to Alcoholism.

    ERIC Educational Resources Information Center

    Schuckit, Marc A.

    1987-01-01

    Reviews the role of biological factors in the risk for alcoholism. Notes the importance of the definition of primary alcoholism and highlights data indicating that this disorder is genetically influenced. In studies of men at high risk for the future development of alcoholism, vulnerability shows up in reactions to ethanol brain wave amplitude and…

  8. Adult Children of Alcoholics.

    ERIC Educational Resources Information Center

    Goodman, Ronald W.

    1987-01-01

    Presents analysis of adult children of alcoholics, their experience and adjustment in relation to the severity and type of alcoholism, age considerations and perceptions as a child, and existence and nature of significant others. Discusses alcoholics' and others' family issues, focusing on roles taken, and personality characteristics. Emphasizes…

  9. Alcoholism and Lesbians

    ERIC Educational Resources Information Center

    Gedro, Julie

    2014-01-01

    This chapter explores the issues involved in the relationship between lesbianism and alcoholism. It examines the constellation of health and related problems created by alcoholism, and it critically interrogates the societal factors that contribute to the disproportionately high rates of alcoholism among lesbians by exploring the antecedents and…

  10. Alcoholism's Hidden Curriculum.

    ERIC Educational Resources Information Center

    Gress, James R.

    1988-01-01

    Discusses children of alcoholics as victims of fetal alcohol syndrome, family violence, retarded social development, and severe emotional scars. These children bring family roles to school that allow survival in the alcoholic home but are dysfunctional outside it. Educators can take certain steps to address these students' problems. Includes six…

  11. Women and Alcohol

    MedlinePlus

    ... alcohol, which is found in: »» 12 ounces of beer with 5 percent alcohol content »» 5 ounces of wine with 12 percent alcohol content »» 1.5 ounces ... reflect customary serving sizes. A large cup of beer, an overpoured glass of wine, or a single ...

  12. [Emulsification experiments with dimethylsiloxane/phenylmethylsiloxane copolymer].

    PubMed

    Ikeda, T; Nakamura, K; Sakagami, K; Iwahashi, H; Sugimoto, K; Matsuda, T; Tano, Y

    1997-02-01

    We compared the emulsification tendency of dimethylsiloxane/phenylmethylsiloxane copolymer (DPC; 5%-phenylated, specific gravity 0.984) with that of silicone oil (dimethylsiloxane; SO, specific gravity 0.966) and fluorosilicone oil (methyl-3,3,3-trifluoropropylsiloxane; FSO, specific gravity 1.256), which are clinically used as an intraocular tamponade. After SO, DPC and FSO were placed in a glass container with an equal amount of albumin solution (1 mg/ml) or gamma-globulin solution (1 mg/ml), and shaken SO and DPC, with their specific gravities being closer to water, showed less emulsification than FSO. Following vitrectomy, DPC was injected into the rabbit vitreous cavity, but did not seem to show any severe histological damage. Highly-phenylated DPC, which is slightly heavier than water, may be useful to treat inferior retinal detachment in place of FSO.

  13. Equilibrium and Kinetics of Block Copolymers Micelles

    NASA Astrophysics Data System (ADS)

    Mysona, Joshua; Morse, David

    Both equilibrium properties of micelles, such as the critical micelle concentration (CMC), and dynamical properties such as the micelle lifetime are difficult to study in simulations because of the slow dynamics of the processes by which micelles are created and destroyed. We first discuss a method of precisely identifying the CMC in a simple model of block copolymer micelles in a homopolymer matrix, which makes use of thermodynamic integration to compute the free energy of formation. We then examine the free energy barriers to competing mechanisms for creating and destroying micelles, which could occur predominantly either by a step-wise process involving insertion and extraction of single molecules or by fission and fusion of entire micelles.

  14. Concentration Dependent Structure of Block Copolymer Solutions

    NASA Astrophysics Data System (ADS)

    Choi, Soohyung; Bates, Frank S.; Lodge, Timothy P.

    2015-03-01

    Addition of solvent molecules into block copolymer can induce additional interactions between the solvent and both blocks, and therefore expands the range of accessible self-assembled morphologies. In particular, the distribution of solvent molecules plays a key role in determining the microstructure and its characteristic domain spacing. In this study, concentration dependent structures formed by poly(styrene-b-ethylene-alt-propylene) (PS-PEP) solution in squalane are investigated using small-angle X-ray scattering. This reveals that squalane is essentially completely segregated into the PEP domains. In addition, the conformation of the PS block changes from stretched to nearly fully relaxed (i.e., Gaussian conformation) as amounts of squalane increases. NRF

  15. Cationic vinyl pyridine copolymers and products thereof

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor)

    1978-01-01

    Quaternized, cross-linked, insoluble copolymers of unsubstituted and substituted vinyl pyridines and a dihalo organic compound are spontaneously formed at ambient temperature on mixing the two monomers in bulk, in solution or in suspension. The amount of cross-linking may be varied according to the composition and reaction conditions. The polymer product exhibits ion exchange capacity and undergoes a reversible color change from black at a pH above 7 to yellow at a pH below 7. The polymer may be formed in the presence of preformed polymers, substrates such as porous or impervious particles or films to deposit an ion exchange film in situ or on the surface of the substrate. The coated or resin impregnated substrate may be utilized for separation of anionic species from aqueous solution.

  16. Log-rolling block copolymers cylinders

    NASA Astrophysics Data System (ADS)

    Kim, So Youn; Kim, Ye Chan; Kim, Dong Hyup; Kwon, Na Kyung; Register, Richard A.

    Shear has been the most effective method to create long range order of micro- or nano- structures in soft materials. When shear is applied, soft particles or polymers tend to align along the shear direction to minimize the viscous dissipation, thus transverse (so-called ``log-rolling'') alignment is unfavored. In this study, for the first time we report the transverse alignment of cylinder-forming block copolymers. Poly(styrene-b-methyl methacrylate), PS-PMMA, can form a metastable hemicylinder structure when confined in a thin film, and this hemicylinder structure can align either along the shear direction, or transverse to the shear direction (``log-rolling''), depending on the shearing temperature. This unusual ``log-rolling'' behavior is explained by the different chain mobility of the two blocks in PS-PMMA; the rigidity of core cylinder is the critical parameter determining the direction of shear alignment.

  17. Alcohol and the elderly.

    PubMed

    Dufour, M C; Archer, L; Gordis, E

    1992-02-01

    Moderate drinking for the elderly of both genders is no more than one drink per day, where a drink is defined as 12 oz of beer, 5 oz of wine, or 1.5 oz of spirits. Age does not affect the rate of absorption or elimination of alcohol. Lean body mass decreases and adipose tissue increases with age, however, resulting in a corresponding decrease in the volume of total body water. With a smaller volume of distribution, an alcohol dose identical to that administered to a younger individual of the same size and gender will produce a higher blood alcohol concentration in the elderly. Low-dose alcohol stimulates appetite and promoters regular bowel function. In the well-nourished nonalcoholic elderly, the negative impact of alcohol consumption on nutrition is minimal. Alcohol consumption improves mood by increasing feelings of happiness and freedom from care while lessening inhibitions, stress, tension, and depression. Although in the laboratory low-dose alcohol improves certain types of cognitive function in young men, in other types of task performance, alcohol induces impairment, which worsens with age. The effects of alcohol on sleep are primarily detrimental, worsening both insomnia and breathing disturbances during sleep. Although the role of alcohol consumption in mortality from heart disease has not been investigated in the elderly, moderate drinking appears safe. Under some circumstances low-dose alcohol may produce analgesia whereas in others it may worsen pain. The elderly use a significant proportion of both prescription and over-the-counter medication, a large variety of which interact with alcohol. Alcoholic beverage consumption may exacerbate cognitive impairment and dementias of other etiology. Although some studies suggest that moderate use of alcohol by institutionalized senior citizens appears to produce benefits including improved socialization, separation of the effects of the social situation from those specifically attributable to alcohol remains to

  18. Characterisation of poly(vinyl alcohol) by liquid chromatography techniques

    SciTech Connect

    Meehan, E.; Warner, F.P.; Patterson, M.

    1995-12-01

    The molecular weight distribution of poly (vinyl alcohol) can be measured by aqueous size exclusion chromatography methods but the choice of eluent is critical in eliminating non size exclusion behavior. Aqueous size exclusion experiments have been carried out using a number of eluents including standard electrolytes and surfactants. The most favorable molecular size separation was obtained using 0.25% w/v sodium lauryl sulphate as eluent. Compositional distributions in copolymer systems can be assessed using high performance liquid chromatography employing a reverse phase separation mechanism. For poly (vinyl alcohol) gradient elution with water/tetrahydrofuran was found to produce a separation according to composition. Fast gradient elution (>10% tetrahydrofuran/minute) suggested abroad distribution of composition which was verified using a column packed with non-porous beads. Slower gradient elution (<1% tetrahydrofuran/minute) suggested that this was not due to a gradual composition change but rather discrete fractions of similarly hydrophobic material.

  19. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    NASA Astrophysics Data System (ADS)

    Şolpan, Dilek; Güven, Olgun

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by γ-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tüdös (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively.

  20. Multicompartmental Microcapsules from Star Copolymer Micelles

    SciTech Connect

    Choi, Ikjun; Malak, Sidney T.; Xu, Weinan; Heller, William T.; Tsitsilianis, Constantinos; Tsukruk, Vladimir V.

    2013-02-26

    We present the layer-by-layer (LbL) assembly of amphiphilic heteroarm pH-sensitive star-shaped polystyrene-poly(2-pyridine) (PSnP2VPn) block copolymers to fabricate porous and multicompartmental microcapsules. Pyridine-containing star molecules forming a hydrophobic core/hydrophilic corona unimolecular micelle in acidic solution (pH 3) were alternately deposited with oppositely charged linear sulfonated polystyrene (PSS), yielding microcapsules with LbL shells containing hydrophobic micelles. The surface morphology and internal nanopore structure of the hollow microcapsules were comparatively investigated for shells formed from star polymers with a different numbers of arms (9 versus 22) and varied shell thickness (5, 8, and 11 bilayers). The successful integration of star unimers into the LbL shells was demonstrated by probing their buildup, surface segregation behavior, and porosity. The larger arm star copolymer (22 arms) with stretched conformation showed a higher increment in shell thickness due to the effective ionic complexation whereas a compact, uniform grainy morphology was observed regardless of the number of deposition cycles and arm numbers. Small-angle neutron scattering (SANS) revealed that microcapsules with hydrophobic domains showed different fractal properties depending upon the number of bilayers with a surface fractal morphology observed for the thinnest shells and a mass fractal morphology for the completed shells formed with the larger number of bilayers. Moreover, SANS provides support for the presence of relatively large pores (about 25 nm across) for the thinnest shells as suggested from permeability experiments. The formation of robust microcapsules with nanoporous shells composed of a hydrophilic polyelectrolyte with a densely packed hydrophobic core based on star amphiphiles represents an intriguing and novel case of compartmentalized microcapsules with an ability to simultaneously store different hydrophilic, charged, and hydrophobic

  1. Counit Inclusion in Hydrogenated Polynorbornene Copolymer Crystals

    NASA Astrophysics Data System (ADS)

    Burns, Adam; Showak, Michael; Stella, Andrew; Register, Richard

    2014-03-01

    Crystallization in poly(A-co-B) random copolymers, where homopolymer A is crystalline but B is not, is dictated by the degree to which crystals of A can include B units. Typically, B units are strongly excluded from the A crystals, drastically reducing the degree of crystallinity wc and crystal thickness tc even at modest comonomer contents. However, in some cases, B units can be incorporated into the crystals as defects, significantly diminishing the counits' impact on wc and tc. The extent and consequences of counit inclusion have been investigated in hydrogenated polynorbornene (hPN) with alkylnorbornene counits, synthesized by living ring-opening metathesis polymerization followed by hydrogenation. In the case of 5-hexylnorbornene (HxN) counits, a steep decline in wc and tc with counit content is found, indicative of strong exclusion. In contrast, when the counits are 5-methylnorbornene (MeN), extensive inclusion of MeN units into the crystals is observed. hP(N-co-MeN) copolymers maintain appreciable crystallinity above 30 mol% MeN, and the dependence of the melting point Tm on tc tracks that of the hPN homopolymer. Four times as much MeN as HxN (molar basis) is required to produce a comparable drop in wc. Therefore, copolymerization with MeN can be used to tune Tm without drastically reducing wc. Additionally, hPN exhibits a polymorphic transition to a rotationally disordered (RD) crystal at temperature Tcc

  2. Insensitive explosive composition of halogenated copolymer and triaminotrinitrobenzene

    DOEpatents

    Benziger, Theodore M.

    1976-01-01

    A highly insensitive and heat resistant plastic-bonded explosive containing 90 wt % triaminotrinitrobenzene and 10 wt % of a fully saturated copolymer of chlorotrifluoroethylene and vinylidene fluoride is readily manufactured by the slurry process.

  3. Surface Characterization of Aliphatic Polyester -g- Phosphorylcholine Copolymers

    NASA Astrophysics Data System (ADS)

    Zhang, Xiongfei; Emrick, Todd; Hsu, Shaw L.

    2007-03-01

    In order to control biodegradation behavior of a class of polyesters, hydrophilic functional groups were grafted onto the main chains. Phosphorylcholine (PC) molecules with azide attached at the end were synthesized. Due to their excellent biocompatibility and hydrophilicity, they have been covalently coupled to biodegradable aliphatic polyesters via a ``click'' cycloaddition reaction to produce amphiphilic graft copolymers. A series of copolymers were prepared by varying the molar incorporation of PC groups. Surface properties of the copolymers were examined to further explore their applications in drug delivery systems. Grazing angle reflection infrared spectroscopy was employed to determine segmental orientation at the film surface. XPS was used to verify surface composition. A water adsorption experiment was carried out to determine the water permeation rate. The improvement in hydrophilicity was confirmed by a water contact experiment. Results indicate that the graft copolymers were promising in drug delivery systems.

  4. 21 CFR 173.60 - Dimethylamine-epichlorohydrin copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... solution of the copolymer has a minimum viscosity of 175 centipoises at 25 °C as determined by LVT-series... analytical method entitled “The Determination of Epichlorohydrin and 1,3-Dichloro-2-Propanol in...

  5. 21 CFR 173.60 - Dimethylamine-epichlorohydrin copolymer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... weight percent on a dry basis. (2) A 50-percent-by-weight aqueous solution of the copolymer has a minimum... epichlorohydrin and 1,3-dichloro-2-propanol content is determined by an analytical method entitled...

  6. Self-Consistent Field Theory of ABn Miktoarm Copolymer Melts

    NASA Astrophysics Data System (ADS)

    Grason, Gregory; Kamien, Randall

    2004-03-01

    Using self-consistent field theory (SCFT) techniques we investigate the phase behavior of AB_n, miktoarm copolymer melts. In particular, we examine how the molecularasymmetry stabilizes morpholgies with highly curved interfaces. While strong-segregation theory tends to overestimate this effect for asymmetric molecules, the SCFT results are in strong agreement with experiments on PI-PS miktoarm copolymer melts. In addition, we report the stability of a new cubic phase of one-component block copolymer melts, with Pm bar3 n symmetry. This phase, the A15 phase of spherical micelles, is stable in melts of ABn copolymers for n ≥ 2. We interpret the relative stability of the sphere phases in terms of well-studied, geometric moments of the candidate sphere lattices.

  7. Microdomain contraction in microphase-separated multiblock copolymers

    SciTech Connect

    Smith, S.D. ); Spontak, R.J. ); Satkowski, M.M.; Ashraf, A. ); Lin, J.S. )

    1993-06-01

    Linear multiblock copolymers, like their diblock analogs, undergo microphase separation and order into periodic morphologies when the blocks are sufficiently incompatible. To explore the conformations of such materials, four symmetric poly(styrene-[ital b]-isoprene)[sub [ital n

  8. Crystalline Morphology of Propylene 1-Octene Random Copolymers

    NASA Astrophysics Data System (ADS)

    Jeon, Keesu; Alamo, Rufina G.

    2008-03-01

    The morphology of isotactic propylene 1-octene random copolymers has been studied by AFM, DSC, WAXS, and FTIR in an octene range of 10-20 mol %. Different morphologies were observed below and above 15 mol %. The morphological components in the higher counit copolymers are not of the lamellae-type, thicker than lamellae observed below 15 mol %, connected and isotropic in their orientation. Their global morphology is developed via nucleation and growth (NG) of spherulitic aggregates. The evolution of heat of fusion with time is also sigmoidal shape, typical of NG-type crystallization mechanism. WAXS diffractograms for the higher counit copolymers are devoid of crystalline reflections, except for small and broad peaks suggesting mesomorphic-like structures, which by FTIR show small contents of the 840 cm-1, 12 and higher units regularity bands, and hence formed of short helical sequences. The PO morphology is additionally compared with copolymers with ethylene, 1-butene and 1-hexene counits at matched contents.

  9. Synthesis of non-polar/hydrogen bonding block copolymers

    NASA Astrophysics Data System (ADS)

    Montgomery, Steven J.

    Methods for the synthesis of novel block copolymers consisting of a non-polar segment and a hydrogen bonding segment were developed using a combination of living polymerization techniques. A series of well defined block copolymers was synthesized consisting of polybutadiene-block-poly(t-butyldimethylsilyloxystyrene), polybutadiene-block-poly(p-acetoxystyrene) and polybutadiene-block-poly(methyl methacrylate). The block copolymers containing t-butyldimethylsilyloxystyrene and p-acetoxystyrene may be deprotected to yield polybutadiene-block-poly(4-hydroxystyrene). Specifically, non-polar/hydrogen bonding (NP/HB) block copolymers were synthesized via two routes. The first consisted of anionic polymerization. The second involved a mechanistic transformation technique comprised of anionic and atom transfer radical polymerization techniques. The mechanistic transformation route was determined to be the superior method with regard to the molecular weight of the polymers produced, the abundance of compatible monomers, and the facile nature of the reaction technique.

  10. Thermal analytical study of polyamide copolymer/Surlyn Ionomers Blends

    SciTech Connect

    Qin, C.; Ding, Y.P.

    1993-12-31

    Thermal analytical technique was used as a screening method to study polyamide(Nylon)/ethylene-co-methacrylic acid copolymer-based ionomer(Surlyn)blends. The retardation of crystallization process from molten state of Nylon-12 by the existence of the ionomer was observed, but the crystallization of Nylon-12 can not be thwarted even at high concentration of ionomers. Zinc ionomers shows stronger effect than sodium ionomers. A Nylon copolymer, polyamide-6,6-co-polyamide-6,10, was used to blend with different ionomers and the crystallization process from molten state of Nylon copolymer could be thwarted at high concentration of zinc ionomer even at very cooling rate. Interesting cold crystallization behavior of polyamide copolymer was observed during second DSC heating cycle in the temperature range of the melting process of ionomer.

  11. Melt structure and self-nucleation of ethylene copolymers

    NASA Astrophysics Data System (ADS)

    Alamo, Rufina G.

    A strong memory effect of crystallization has been observed in melts of random ethylene copolymers well above the equilibrium melting temperature. These studies have been carried out by DSC, x-ray, TEM and optical microscopy on a large number of model, narrow, and broad copolymers with different comonomer types and contents. Melt memory is correlated with self-seeds that increase the crystallization rate of ethylene copolymers. The seeds are associated with molten ethylene sequences from the initial crystals that remain in close proximity and lower the nucleation barrier. Diffusion of all sequences to a randomized melt state is a slow process, restricted by topological chain constraints (loops, knots, and other entanglements) that build in the intercrystalline region during crystallization. Self-seeds dissolve above a critical melt temperature that demarcates homogeneity of the copolymer melt. There is a critical threshold level of crystallinity to observe the effect of melt memory on crystallization rate, thus supporting the correlation between melt memory and the change in melt structure during copolymer crystallization. Unlike binary blends, commercial ethylene-1-alkene copolymers with a range in inter-chain comonomer composition between 1 and about 15 mol % display an inversion of the crystallization rate in a range of melt temperatures where narrow copolymers show a continuous acceleration of the rate. With decreasing the initial melt temperature, broadly distributed copolymers show enhanced crystallization followed by a decrease of crystallization rate. The inversion demarcates the onset of liquid-liquid phase separation (LLPS) and a reduction of self-nuclei due to the strong thermodynamic drive for molecular segregation inside the binodal. The strong effect of melt memory on crystallization rate can be used to identify liquid-liquid phase separation in broadly distributed copolymers, and offers strategies to control the state of copolymer melts in ways of

  12. Photooxidative degradation of clear ultraviolet absorbing acrylic copolymer surfaces

    NASA Technical Reports Server (NTRS)

    Gupta, A.; Liang, R. H.; Vogl, O.; Pradellok, W.; Huston, A. L.; Scott, G. W.

    1983-01-01

    Photodegradation of copolymer of methyl methacrylate and 2(2'-hydroxy 5'vinyl-phenyl) 2H-benzotriazole has been investigated in order to determine the changes in the chemical composition of the surface of the copolymer on photooxidation. An electronic energy transfer mechanism has been postulated in order to interpret the observed photochemical changes in the polymer. Preliminary examination of the photophysical properties of the chromophore provides support for such a mechanism.

  13. Pyrrole copolymers with enhanced ion diffusion rates for lithium batteries

    SciTech Connect

    Calvert, P.; Gardlund, Z.; Huntoon, T.; Hall, H.K.; Padias, A.

    1998-07-01

    Copolymers of pyrrole with a polyether-substituted pyrrole were tested as cathodes for lithium batteries. The charge and discharge characteristics showed that anion transport was much faster in the copolymer than in polypyrrole. As a result these electrodes store and release much more charge at higher current densities but are similar to polypyrrole at low currents. Pulse and relaxation measurements of the ion diffusion showed that this difference was due to a ten-fold increase in the anion diffusion coefficient.

  14. Microphase Ordering in Melts of Randomly Grafted Copolymers

    SciTech Connect

    Qi, S.; Chakraborty, A.K.; Wang, H.; Lefebvre, A.A.; Balsara, N.P.; Shakhnovich, E.I.; Xenidou, M.; Hadjichristidis, N.

    1999-04-01

    Using optical birefringence, small-angle neutron scattering, and field-theoretic methods, we study the effects of frustrating quenched randomness and connectivity on microphase ordering in copolymer melts. Our results show that randomly grafted copolymers are good model systems to examine these effects, and we find that these materials exhibit behavior different from that observed heretofore for other types of molten polymers. {copyright} {ital 1999} {ital The American Physical Society}

  15. Block copolymer adhesion promoters via ring-opening metathesis polymerization

    DOEpatents

    Kent, Michael S.; Saunders, Randall

    1997-01-01

    Coupling agents based on functionalized block copolymers for bonding thermoset polymers to solid materials. These are polymers which possess at least two types of functional groups, one which is able to attach to and react with solid surfaces, and another which can react with a thermoset resin, which are incorporated as pendant groups in monomers distributed in blocks (typically two) along the backbone of the chain. The block copolymers in this invention are synthesized by living ring-opening metathesis polymerization.

  16. Combining Biomimetic Block Copolymer Worms with an Ice-Inhibiting Polymer for the Solvent-Free Cryopreservation of Red Blood Cells.

    PubMed

    Mitchell, Daniel E; Lovett, Joseph R; Armes, Steven P; Gibson, Matthew I

    2016-02-18

    The first fully synthetic polymer-based approach for red-blood-cell cryopreservation without the need for any (toxic) organic solvents is reported. Highly hydroxylated block copolymer worms are shown to be a suitable replacement for hydroxyethyl starch as a extracellular matrix for red blood cells. When used alone, the worms are not a particularly effective preservative. However, when combined with poly(vinyl alcohol), a known ice-recrystallization inhibitor, a remarkable additive cryopreservative effect is observed that matches the performance of hydroxyethyl starch. Moreover, these block copolymer worms enable post-thaw gelation by simply warming to 20 °C. This approach offers a new solution for both the storage and transport of red blood cells and also a convenient matrix for subsequent 3D cell cultures.

  17. Radical-cured block copolymer-modified thermosets

    SciTech Connect

    Redline, Erica M.; Francis, Lorraine F.; Bates, Frank S.

    2013-01-10

    Poly(ethylene-alt-propylene)-b-poly(ethylene oxide) (PEP-PEO) diblock copolymers were synthesized and added at 4 wt % to 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (BisGMA), a monomer that cures using free radical chemistry. In separate experiments, poly(ethylene glycol) dimethacrylate (PEGDMA) was combined as a secondary monomer with BisGMA and the monomers were loaded with 4 wt % PEP-PEO. The diblock copolymers self-assembled into well-dispersed spherical micelles with PEP cores and PEO coronas. No appreciable change in the final extent of cure of the thermosets was caused by the addition of diblock copolymer, except in the case of BisGMA, where the addition of the block copolymer increased extent of cure by 12%. Furthermore, the extent of cure was increased by 29% and 37% with the addition of 25 and 50 wt % PEGDMA, respectively. Elastic modulus and fracture resistance were also determined, and the values indicate that the addition of block copolymers does not significantly toughen the thermoset materials. This finding is surprising when compared with the large increase in fracture resistance seen in block copolymer-modified epoxies, and an explanation is proposed.

  18. Oligoaniline-containing supramolecular block copolymer nanodielectric materials.

    PubMed

    Hardy, Christopher G; Islam, Md Sayful; Gonzalez-Delozier, Dioni; Ploehn, Harry J; Tang, Chuanbing

    2012-05-14

    We report a new generation of nanodielectric energy storage materials based on supramolecular block copolymers. In our approach, highly polarizable, conducting nanodomains are embedded within an insulating matrix through block copolymer microphase separation. An applied electric field leads to electronic polarization of the conducting domains. The high interfacial area of microphase-separated domains amplifies the polarization, leading to high dielectric permittivity. Specifically, reversible addition fragmentation transfer (RAFT) polymerization was used to prepare block copolymers with poly(methyl acrylate) (PMA) as the insulating segment and a strongly acidic dopant moiety, poly-(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA), as the basis for the conducting segment. The PAMPSA block was complexed with an oligoaniline trimer to form a dopant-conjugated moiety complex that is electronically conductive after oxidation. For the undoped neat block copolymers, the increase of the PMA block length leads to a transition in dielectric properties from ionic conductor to dielectric capacitor with polarization resulting from migration of protons within the isolated PAMPSA domains. The oligoaniline-doped copolymers show remarkably different dielectric properties. At frequencies above 200 kHz, they exhibit characteristics of dielectric capacitors with much higher permittivity and lower dielectric loss than the corresponding undoped copolymers. PMID:22331602

  19. Theory for the aggregation of proteins and copolymers

    SciTech Connect

    Fields, G.B.; Alonso, D.O.V.; Stigter, D.; Dill, K.A.

    1992-05-14

    We develop mean-field lattice statistical mechanics theory for the equilibrium between denatured and aggregated states of proteins and other random copolymers of hydrophobic and polar monomers in aqueous solution. We suppose that the aggregated state is a mixture of amorphous polymer plus solvent and that the driving forces are the hydrophobic interaction, which favors aggregation, and conformational and translational entropies, which favor disaggregation. The theory predicts that the phase diagram for thermal aggregation is an asymmetric closed loop, and for denaturants (guanidinium hydrochloride of urea) it is asymmetric with an upper consolute point. The theory predicts that a copolymer in a poor solvent will expand with increasing polymer concentration because of {open_quotes}screening{close_quotes} of the solvent interactions by the other chains; the chain ultimately reaches a theta-like state in the absence of solvent. The screening concentration depends strongly on the copolymer composition. We find two striking features of these copolymer phase diagrams. First, they are extraordinarily sensitive to the copolymer composition; a change of one amino acid can substantially change the aggregation behavior. Second, relative to homopolymers, copolymers should be stable against aggregation at concentrations that are higher by many orders of magnitude. 43 refs., 13 figs.

  20. Nanopatterning of Viruses and Proteins Using Microphase Separated Block Copolymers

    NASA Astrophysics Data System (ADS)

    Cresce, Arthur; Lewandowski, Angela; Bentley, William; Kofinas, Peter

    2006-03-01

    Diblock copolymers containing nickel ions have been prepared that are capable of selectively adsorbing histidine-tagged green fluorescent protein (hisGFP), and also binding tobacco mosaic virus (TMV). A block copolymer of norbornene and norbornene dicarboxylic acid was synthesized using ring-opening metathesis polymerization. A 400/50 block ratio achieved a spherical microphase-separated morphology with roughly 20 nm diameter dicarboxylic acid spheres. The spherical phase was exposed to nickel ions in solution, templating the formation of nickel nanoparticles. This process gave a nickel-loaded diblock copolymer film whose surface was used to chelate hisGFP. Fluorescence spectroscopy and TEM confirmed the presence of the protein on the polymer surface. A sulfonated triblock copolymer was loaded with nickel ions using a similar solution-doping procedure. The morphology of this copolymer was lamellar, and its sulfonated block was loaded with nickel ions. TEM studies revealed the presence of the virus on the surface of the copolymer and showed that the bond between the TMV and the polymer surface can withstand severe detergent washes.

  1. MALDI-ToF Analysis of Model Copolymer Blends

    NASA Astrophysics Data System (ADS)

    Pan, David; Arnould, Mark

    2008-03-01

    MALDI-ToF mass spectrometry was used to determine the composition of a low MW styrene (S) / n-butyl acrylate (nBA) copolymer. Bernoullian chain statistics were used to predict the copolymer distribution and confirm that MALDI-ToF detects the correct composition. The copolymer was blended with a low MW polystyrene homopolymer having the same end group as the copolymer at several levels to determine if MALDI-ToF could be used to calculate the amount of homopolymer by subtracting homopolymer peak areas. It is found that, while MALDI-ToF can be used to monitor the amount of homopolymer blended into the copolymer, the observed increase is always greater than the actual amount added, e.g. up to 13% error. This could be due to the fact that the homopolymer ionizes more efficiently than the low MW copolymer. A model to improve the accuracy of the calculated amount of homopolymer in the blend is discussed.

  2. Block Copolymer Bottlebrushes: New Routes to Ever Smaller Microdomain Sizes

    NASA Astrophysics Data System (ADS)

    Mahanthappa, Mahesh; Speetjens, Frank

    Block copolymer self-assembly presents exciting opportunities for the development of nanotemplates for advanced lithography applications, wherein the microdomain sizes (~10-100 nm) are governed by the total copolymer degree of polymerization, N. However, this methodology is limited in its smallest achievable length scale, since AB diblock copolymers self-assemble only above a critical N that depends on the magnitude of the effective segmental interaction parameter χAB. Numerous recent reports have focused on developing ``high χAB'' AB diblocks that self-assemble at low values of N. In this talk we explore the ability of non-linear polymer architectures to induce block copolymer ordering at reduced length scales. Thus, we describe the melt and thin-film self-assembly behavior of block copolymer bottlebrushes derived from linking the block junctions of low molecular weight AB diblocks. We quantitatively demonstrate that increasing the bottlebrush backbone degree of polymerization (Nbackbone) results in a larger reduction in the critical copolymer arm degree of polymerization (Narm) required for self-assembly, thus reducing the length scales at which these materials self-assemble.

  3. Thin film assembly of spider silk-like block copolymers.

    PubMed

    Krishnaji, Sreevidhya T; Huang, Wenwen; Rabotyagova, Olena; Kharlampieva, Eugenia; Choi, Ikjun; Tsukruk, Vladimir V; Naik, Rajesh; Cebe, Peggy; Kaplan, David L

    2011-02-01

    We report the self-assembly of monolayers of spider silk-like block copolymers. Langmuir isotherms were obtained for a series of bioengineered variants of the spider silks, and stable monolayers were generated. Langmuir-Blodgett films were prepared by transferring the monolayers onto silica substrates and were subsequently analyzed by atomic force microscopy (AFM). Static contact angle measurements were performed to characterize interactions across the interface (thin film, water, air), and molecular modeling was used to predict 3D conformation of spider silk-like block copolymers. The influence of molecular architecture and volume fraction of the proteins on the self-assembly process was assessed. At high surface pressure, spider silk-like block copolymers with minimal hydrophobic block (f(A) = 12%) formed oblate structures, whereas block copolymer with a 6-fold larger hydrophobic domain (f(A) = 46%) formed prolate structures. The varied morphologies obtained with increased hydrophobicity offer new options for biomaterials for coatings and related options. The design and use of bioengineered protein block copolymers assembled at air-water interfaces provides a promising approach to compare 2D microstructures and molecular architectures of these amphiphiles, leading to more rationale designs for a range of nanoengineered biomaterial needs as well as providing a basis of comparison to more traditional synthetic block copolymer systems. PMID:21207952

  4. Complex nanostructured materials from segmented copolymers prepared by ATRP.

    PubMed

    Kowalewski, T; McCullough, R D; Matyjaszewski, K

    2003-01-01

    The development of new controlled/living radical polymerization processes, such as Atom Transfer Radical Polymerization (ATRP) and other techniques such as nitroxide mediated polymerization and degenerative transfer processes, including RAFT, opened the way to the use of radical polymerization for the synthesis of well-defined, complex functional nanostructures. The development of such nanostructures is primarily dependent on self-assembly of well-defined segmented copolymers. This article describes the fundamentals of ATRP, relevant to the synthesis of such systems. The self-assembly of block copolymers prepared by ATRP is illustrated by three examples. In the first, block copolymers of poly(butyl acrylate) with polyacrylonitrile phase separate, leading to spherical, cylindrical or lamellar morphologies, depending on the block copolymer composition. At a higher temperature, polyacrylonitrile block converts to nanostructured carbon clusters, whereas poly(butyl acrylate) block serves as a sacrificial block, aiding the development of designed nanostructures. In the second example, conductive nanoribbons of poly(n-hexylthiophene) surrounded by a matrix of organic polymers are formed from block copolymers prepared by ATRP. The third example describes an inorganic-organic hybrid system consisting of hard nanocolloidal silica particles (approximately 20 nm) grafted by ATRP with well-defined polystyrene-poly(benzyl acrylate) block copolymer chains (approximately 1000 chains per particle). Silica cores in this system are surrounded by a rigid polystyrene inner shell and softer polyacrylate outer shell. PMID:15011074

  5. Antimicrobial activity of poly(acrylic acid) block copolymers.

    PubMed

    Gratzl, Günther; Paulik, Christian; Hild, Sabine; Guggenbichler, Josef P; Lackner, Maximilian

    2014-05-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid-base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure.

  6. Oligoaniline-containing supramolecular block copolymer nanodielectric materials.

    PubMed

    Hardy, Christopher G; Islam, Md Sayful; Gonzalez-Delozier, Dioni; Ploehn, Harry J; Tang, Chuanbing

    2012-05-14

    We report a new generation of nanodielectric energy storage materials based on supramolecular block copolymers. In our approach, highly polarizable, conducting nanodomains are embedded within an insulating matrix through block copolymer microphase separation. An applied electric field leads to electronic polarization of the conducting domains. The high interfacial area of microphase-separated domains amplifies the polarization, leading to high dielectric permittivity. Specifically, reversible addition fragmentation transfer (RAFT) polymerization was used to prepare block copolymers with poly(methyl acrylate) (PMA) as the insulating segment and a strongly acidic dopant moiety, poly-(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA), as the basis for the conducting segment. The PAMPSA block was complexed with an oligoaniline trimer to form a dopant-conjugated moiety complex that is electronically conductive after oxidation. For the undoped neat block copolymers, the increase of the PMA block length leads to a transition in dielectric properties from ionic conductor to dielectric capacitor with polarization resulting from migration of protons within the isolated PAMPSA domains. The oligoaniline-doped copolymers show remarkably different dielectric properties. At frequencies above 200 kHz, they exhibit characteristics of dielectric capacitors with much higher permittivity and lower dielectric loss than the corresponding undoped copolymers.

  7. Synthesis, characterization and electrical properties of Fe3O4/poly(vinyl alcohol-co-acrylic acid) nanocomposites

    NASA Astrophysics Data System (ADS)

    P, Jayakrishnan; Ramesan, M. T.

    2014-10-01

    This work focused on the synthesis of magnetite (Fe3O4)/poly(vinyl alcohol-co-acrylic acid) nanocomposite by in situ polymerization. The composite were characterized by FT-IR spectroscopy, XRD, SEM, TGA, AC and DC conductivity measurements. The spectroscopic studies revealed the molecular interaction between the polymer and nanocomposites. SEM, XRD indicated the uniform dispersion of nanoparticle inside the molecular chain of copolymer. TGA studies indicated the excellent thermal stability of copolymer nanocomposites. AC and DC conductivity of nanocomposites were higher than that of the copolymer and conductivity values were significantly increased with increase in concentration of metal oxide nanoparticles. These properties suggest that the polymer composite can be used as multifunctional material for nanoelectronics.

  8. Alcohol and the Intestine.

    PubMed

    Patel, Sheena; Behara, Rama; Swanson, Garth R; Forsyth, Christopher B; Voigt, Robin M; Keshavarzian, Ali

    2015-01-01

    Alcohol abuse is a significant contributor to the global burden of disease and can lead to tissue damage and organ dysfunction in a subset of alcoholics. However, a subset of alcoholics without any of these predisposing factors can develop alcohol-mediated organ injury. The gastrointestinal tract (GI) could be an important source of inflammation in alcohol-mediated organ damage. The purpose of review was to evaluate mechanisms of alcohol-induced endotoxemia (including dysbiosis and gut leakiness), and highlight the predisposing factors for alcohol-induced dysbiosis and gut leakiness to endotoxins. Barriers, including immunologic, physical, and biochemical can regulate the passage of toxins into the portal and systemic circulation. In addition, a host of environmental interactions including those influenced by circadian rhythms can impact alcohol-induced organ pathology. There appears to be a role for therapeutic measures to mitigate alcohol-induced organ damage by normalizing intestinal dysbiosis and/or improving intestinal barrier integrity. Ultimately, the inflammatory process that drives progression into organ damage from alcohol appears to be multifactorial. Understanding the role of the intestine in the pathogenesis of alcoholic liver disease can pose further avenues for pathogenic and treatment approaches.

  9. Alcohol and the Intestine

    PubMed Central

    Patel, Sheena; Behara, Rama; Swanson, Garth R.; Forsyth, Christopher B.; Voigt, Robin M.; Keshavarzian, Ali

    2015-01-01

    Alcohol abuse is a significant contributor to the global burden of disease and can lead to tissue damage and organ dysfunction in a subset of alcoholics. However, a subset of alcoholics without any of these predisposing factors can develop alcohol-mediated organ injury. The gastrointestinal tract (GI) could be an important source of inflammation in alcohol-mediated organ damage. The purpose of review was to evaluate mechanisms of alcohol-induced endotoxemia (including dysbiosis and gut leakiness), and highlight the predisposing factors for alcohol-induced dysbiosis and gut leakiness to endotoxins. Barriers, including immunologic, physical, and biochemical can regulate the passage of toxins into the portal and systemic circulation. In addition, a host of environmental interactions including those influenced by circadian rhythms can impact alcohol-induced organ pathology. There appears to be a role for therapeutic measures to mitigate alcohol-induced organ damage by normalizing intestinal dysbiosis and/or improving intestinal barrier integrity. Ultimately, the inflammatory process that drives progression into organ damage from alcohol appears to be multifactorial. Understanding the role of the intestine in the pathogenesis of alcoholic liver disease can pose further avenues for pathogenic and treatment approaches. PMID:26501334

  10. Alcohol and the Intestine.

    PubMed

    Patel, Sheena; Behara, Rama; Swanson, Garth R; Forsyth, Christopher B; Voigt, Robin M; Keshavarzian, Ali

    2015-01-01

    Alcohol abuse is a significant contributor to the global burden of disease and can lead to tissue damage and organ dysfunction in a subset of alcoholics. However, a subset of alcoholics without any of these predisposing factors can develop alcohol-mediated organ injury. The gastrointestinal tract (GI) could be an important source of inflammation in alcohol-mediated organ damage. The purpose of review was to evaluate mechanisms of alcohol-induced endotoxemia (including dysbiosis and gut leakiness), and highlight the predisposing factors for alcohol-induced dysbiosis and gut leakiness to endotoxins. Barriers, including immunologic, physical, and biochemical can regulate the passage of toxins into the portal and systemic circulation. In addition, a host of environmental interactions including those influenced by circadian rhythms can impact alcohol-induced organ pathology. There appears to be a role for therapeutic measures to mitigate alcohol-induced organ damage by normalizing intestinal dysbiosis and/or improving intestinal barrier integrity. Ultimately, the inflammatory process that drives progression into organ damage from alcohol appears to be multifactorial. Understanding the role of the intestine in the pathogenesis of alcoholic liver disease can pose further avenues for pathogenic and treatment approaches. PMID:26501334

  11. Genetics and alcoholism.

    PubMed

    Edenberg, Howard J; Foroud, Tatiana

    2013-08-01

    Alcohol is widely consumed; however, excessive use creates serious physical, psychological and social problems and contributes to the pathogenesis of many diseases. Alcohol use disorders (that is, alcohol dependence and alcohol abuse) are maladaptive patterns of excessive drinking that lead to serious problems. Abundant evidence indicates that alcohol dependence (alcoholism) is a complex genetic disease, with variations in a large number of genes affecting a person's risk of alcoholism. Some of these genes have been identified, including two genes involved in the metabolism of alcohol (ADH1B and ALDH2) that have the strongest known affects on the risk of alcoholism. Studies continue to reveal other genes in which variants affect the risk of alcoholism or related traits, including GABRA2, CHRM2, KCNJ6 and AUTS2. As more variants are analysed and studies are combined for meta-analysis to achieve increased sample sizes, an improved picture of the many genes and pathways that affect the risk of alcoholism will be possible.

  12. Alcoholic and non-alcoholic steatohepatitis

    PubMed Central

    Neuman, Manuela G.; French, Samuel W.; French, Barbara A.; Seitz, Helmut K.; Cohen, Lawrence B.; Mueller, Sebastian; Osna, Natalia A.; Kharbanda, Kusum K.; Seth, Devanshi; Bautista, Abraham; Thompson, Kyle J.; McKillop, Iain H.; Kirpich, Irina A.; McClain, Craig J.; Bataller, Ramon; Nanau, Radu M.; Voiculescu, Mihai; Opris, Mihai; Shen, Hong; Tillman, Brittany; Li, Jun; Liu, Hui; Thomas, Paul G.; Ganesan, Murali; Malnick, Steve

    2015-01-01

    This paper is based upon the “Charles Lieber Satellite Symposia” organized by Manuela G. Neuman at the Research Society on Alcoholism (RSA) Annual Meetings, 2013 and 2014. The present review includes pre-clinical, translational and clinical research that characterize alcoholic liver disease (ALD) and non-alcoholic steatohepatitis (NASH). In addition, a literature search in the discussed area was performed. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD. The liver biopsy can confirm the etiology of NASH or alcoholic steatohepatitis (ASH) and assess structural alterations of cells, their organelles, as well as inflammatory activity. Three histological stages of ALD are simple steatosis, ASH, and chronic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes such as cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Alcohol mediated hepatocarcinogenesis, immune response to alcohol in ASH, as well as the role of other risk factors such as its comorbidities with chronic viral hepatitis in the presence or absence of human deficiency virus are discussed. Dysregulation of hepatic methylation, as result of ethanol exposure, in hepatocytes transfected with hepatitis C virus (HCV), illustrates an impaired interferon signaling. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota are suggested. The clinical aspects of NASH, as part of metabolic syndrome in the aging population, are offered. The integrative symposia investigate different aspects of alcohol-induced liver damage and possible

  13. Alcohol disrupts sleep homeostasis.

    PubMed

    Thakkar, Mahesh M; Sharma, Rishi; Sahota, Pradeep

    2015-06-01

    Alcohol is a potent somnogen and one of the most commonly used "over the counter" sleep aids. In healthy non-alcoholics, acute alcohol decreases sleep latency, consolidates and increases the quality (delta power) and quantity of NREM sleep during the first half of the night. However, sleep is disrupted during the second half. Alcoholics, both during drinking periods and during abstinences, suffer from a multitude of sleep disruptions manifested by profound insomnia, excessive daytime sleepiness, and altered sleep architecture. Furthermore, subjective and objective indicators of sleep disturbances are predictors of relapse. Finally, within the USA, it is estimated that societal costs of alcohol-related sleep disorders exceeds $18 billion. Thus, although alcohol-associated sleep problems have significant economic and clinical consequences, very little is known about how and where alcohol acts to affect sleep. In this review, we have described our attempts to unravel the mechanism of alcohol-induced sleep disruptions. We have conducted a series of experiments using two different species, rats and mice, as animal models. We performed microdialysis, immunohistochemical, pharmacological, sleep deprivation and lesion studies which suggest that the sleep-promoting effects of alcohol may be mediated via alcohol's action on the mediators of sleep homeostasis: adenosine (AD) and the wake-promoting cholinergic neurons of the basal forebrain (BF). Alcohol, via its action on AD uptake, increases extracellular AD resulting in the inhibition of BF wake-promoting neurons. Since binge alcohol consumption is a highly prevalent pattern of alcohol consumption and disrupts sleep, we examined the effects of binge drinking on sleep-wakefulness. Our results suggest that disrupted sleep homeostasis may be the primary cause of sleep disruption observed following binge drinking. Finally, we have also shown that sleep disruptions observed during acute withdrawal, are caused due to impaired

  14. Method of forming oriented block copolymer line patterns, block copolymer line patterns formed thereby, and their use to form patterned articles

    SciTech Connect

    Russell, Thomas P.; Hong, Sung Woo; Lee, Doug Hyun; Park, Soojin; Xu, Ting

    2015-10-13

    A block copolymer film having a line pattern with a high degree of long-range order is formed by a method that includes forming a block copolymer film on a substrate surface with parallel facets, and annealing the block copolymer film to form an annealed block copolymer film having linear microdomains parallel to the substrate surface and orthogonal to the parallel facets of the substrate. The line-patterned block copolymer films are useful for the fabrication of magnetic storage media, polarizing devices, and arrays of nanowires.

  15. Real-time monitoring of the penetration of amphiphilic acrylate copolymer in leather using a fluorescent copolymer as tracer.

    PubMed

    Du, Jin-Xia; Shi, Lu; Peng, Bi-Yu

    2015-12-01

    A fluorescent tracer, poly (acrylic-co-stearyl acrylate-co-3-acryloyl fluorescein) [poly (AA-co-SA-co-Ac-Flu)], used for real-time monitoring the penetration of amphiphilic acrylate copolymer, poly (acrylic-co-stearyl acrylate) [poly (AA-co-SA)], in leather was synthesized by radical polymerization of acrylic, stearyl acrylate and fluorescent monomer, 3-acryloyl fluorescein (Ac-Flu). The structure, molecular weight, introduced fluorescent group content and fluorescent characteristics of the fluorescent tracer and target copolymer, amphiphilic acrylate copolymer, were also characterized. The results show that the tracer presents the similar structural characteristics to the target and enough fluorescence intensity with 1.68 wt % of the fluorescent monomer introduced amount. The vertical section of the leather treated with the target copolymer mixing with 7% of the tracer exhibits evident fluorescence, and the change of fluorescence intensity along with the vertical section with treating time increasing can reflect the penetration depth of the target copolymer. The introduction of the fluorescent group in polymer structure through copolymerization with a limited amount of fluorescent monomer, Ac-Flu, is an effective way to make a tracer to monitor the penetration of the target in leather, which provides a new thought for the penetration research of syntans such as vinyl copolymer materials in leather manufacture.

  16. Shape memory rubber bands & supramolecular ionic copolymers

    NASA Astrophysics Data System (ADS)

    Brostowitz, Nicole

    subject covered in this dissertation is supra-molecular ionic copolymers. Supramolecular interactions are non-covalent; e.g. hydrogen bonding, ionic interactions, van der Waals forces. Supramolecular interactions in polymers can be used to tailor the thermo-mechanical properties by controlling bond association and dissociation. Recent research has focused on hydrogen bonded systems due to established synthesis mechanisms. Reversibility of the supramolecular interactions can be triggered by environmental changes. Ionic interactions would provide greater bond strength and more control over operating conditions. Research has been limited on ionic copolymers due to complicated synthesis methods needed to include functionalization. Low molecular weight polymers were synthesized by atom transfer radical polymerization with post polymerization conversion to phosphonium end-groups. Both polystyrene and poly(methyl acrylate) were investigated with similar reaction conditions. Chromatography measured the molecular weight and indicated a low polydispersity consistent with controlled reactions. Copolymers were formed by interfacial mixing of the cationic polymers with multifunctional, anionic oligomers. Oligomers containing sulfonate groups were used to create linear or three-dimensional polymer networks. NMR and rheology was used to characterize the presence and effect of ionic groups when compared to the neat polymer.

  17. Nanopatterned barium titanate on block copolymers

    NASA Astrophysics Data System (ADS)

    Lee, Tu

    This dissertation describes the synthesis, the characterization and the modeling of a triblock copolymer of polystyrene(PS)-polybutadiene(PB)-polystyrene(PS) monolayer thin film patterned with nanometer sized cubic BaTiO3 crystals, with a focus on the influence of length scales and the hierarchical structure on the ferroelectric properties of BaTiO3. BaTiO3, a dielectric and a ferroelectric, is used extensively in multilayer capacitors, thermistors and electrooptic devices. Its ferroelectric properties are known to be size dependent in the nanometer scale. To gain further insight into the fundamental characteristics of BaTiO3 in the nanometer scale, BaTiO3 is crystallized, for the first time, in a confined environment hosted by a PS-PB-PS triblock copolymer monolayer thin film with nanodomains of tunable geometry and size. The engineering of the PS-PB-PS triblock copolymer monolayer thin film includes fractionation, elimination of interfacial interaction, control of film thickness and minimization of pinholes. The resulting monolayer contains cylindrical PS nanodomains embedded in a PB matrix. The film thickness, the diameter of the PS domain and the domain center-to-domain center distance are 31 nm, 15 nm and 31 nm respectively. Cubic BaTiO3 nanoparticles having a narrow size distribution of 10 nm are formed and located predominantly within the PB matrices by three steps: epoxidation-hydroxylation, barium titanation and vapor-phase hydrothermal process. The volume fraction of BaTiO3 phase is 0.0113. The effective dielectric constant of the BaTiO3/PS-PB-PS composite monolayer is 5.5 +/- 2.5. With the assistance of dielectric mixing rules, the dielectric constant of the cubic BaTiO3 phase is determined to be 160. The relative low dielectric constant of the BaTiO3 phase is usually explained by the critical size above which BaTiO3 particles are tetragonal and ferroelectric and below which particles are cubic and non-ferroelectric. But, the inconsistency of the

  18. [Alcohol and crime].

    PubMed

    Lévay, Boglárka

    2006-01-01

    The role alcohol abuse plays in criminality has been a matter of primary concern for scholars for decades, as indicated by numerous studies and research projects. Most of these studies focus on determining the presence of a relationship between criminal behaviour and alcohol use, and whether criminal inclinations increase with the consumption of alcohol. Research shows that alcohol use indeed increases the risk of criminal behaviour, and that there is an especially strong and consistent correlation between alcohol abuse and violent crimes. However, researchers still disagree on the exact extent to which alcohol use effects criminality, and on the mechanisms causing alcohol to induce violent behaviour. A significant proportion of studies have focused in recent years on aggressive behaviour as a result of drinking alcohol. One of the most important means of measurement is the study of violent behaviour in places where alcohol is on sale. Studying the forms and frequency of violence in pubs and near off-licence stores greatly enables experts to understand the general context of the problem. This is the reason for the increasing interest in the topic throughout the past few decades. The present study focuses mainly on the literature published in English and German in leading journals of criminology since 1980, as well as on the most recent and fundamental publications on the topic, with special regard to results concerning drinking habits, and the relationship between drinking alcohol and violent or criminal behaviour, respectively.

  19. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    NASA Astrophysics Data System (ADS)

    Hoarfrost, Megan Lane

    Incorporating an ionic liquid into one block copolymer microphase provides a platform for combining the outstanding electrochemical properties of ionic liquids with a number of favorable attributes provided by block copolymers. In particular, block copolymers thermodynamically self-assemble into well-ordered nanostructures, which can be engineered to provide a durable mechanical scaffold and template the ionic liquid into continuous ion-conducting nanochannels. Understanding how the addition of an ionic liquid affects the thermodynamic self-assembly of block copolymers, and how the confinement of ionic liquids to block copolymer nanodomains affects their ion-conducting properties is essential for predictable structure-property control. The lyotropic phase behavior of block copolymer/ionic liquid mixtures is shown to be reminiscent of mixtures of block copolymers with selective molecular solvents. A variety of ordered microstructures corresponding to lamellae, hexagonally close-packed cylinders, body-centered cubic, and face-centered cubic oriented micelles are observed in a model system composed of mixtures of imidazolium bis(trifluoromethylsulfonyl)imide ([Im][TFSI]) and poly(styrene- b-2-vinyl pyridine) (PS-b-P2VP). In contrast to block copolymer/molecular solvent mixtures, the interfacial area occupied by each PS-b-P2VP chain decreases upon the addition of [Im][TFSI], indicating a considerable increase in the effective segregation strength of the PS-b-P2VP copolymer with ionic liquid addition. The relationship between membrane structure and ionic conductivity is illuminated through the development of scaling relationships that describe the ionic conductivity of block copolymer/ionic liquid mixtures as a function of membrane composition and temperature. It is shown that the dominant variable influencing conductivity is the overall volume fraction of ionic liquid in the mixture, which means there

  20. Alcohol Expectancies in Young Adult Sons of Alcoholics and Controls.

    ERIC Educational Resources Information Center

    Brown, Sandra A.; And Others

    Adolescent offspring of alcoholics have been found to have higher alcohol reinforcement expectancies than do teenagers from nonalcoholic families. In particular, those with a positive family history of alcoholism expect more cognitive and motor enhancement with alcohol consumption. This study examined the alcohol expectancies of 58 matched pairs…

  1. Exposure to Televised Alcohol Ads and Subsequent Adolescent Alcohol Use

    ERIC Educational Resources Information Center

    Stacy, Alan W.; Zogg, Jennifer B.; Unger, Jennifer B.; Dent, Clyde W.

    2004-01-01

    Objective : To assess the impact of televised alcohol commercials on adolescents' alcohol use. Methods : Adolescents completed questionnaires about alcohol commercials and alcohol use in a prospective study. Results : A one standard deviation increase in viewing television programs containing alcohol commercials in seventh grade was associated…

  2. Theory of the Miscibility of Fullerenes in Random Copolymer Melts

    SciTech Connect

    Dadmun, Mark D; Sumpter, Bobby G; Schweizer, Kenneth; Banerjee, Debapriya

    2013-01-01

    We combine polymer integral equation theory and computational chemistry methods to study the interfacial structure, effective interactions, miscibility and spatial dispersion mechanism of fullerenes dissolved in specific random AB copolymer melts characterized by strong non-covalent electron donor-acceptor interactions with the nanofiller. A statistical mechanical basis is developed for designing random copolymers to optimize fullerene dispersion at intermediate copolymer compositions. Pair correlation calculations reveal a strong sensitivity of interfacial packing near the fullerene to copolymer composition and adsorption energy mismatch. The potential of mean force between fullerenes displays rich trends, often non-monotonic with copolymer composition, reflecting a non-additive competition between direct filler attractions and polymer-mediated bridging and steric stabilization. The spinodal phase diagrams are in qualitative agreement with recent solubility limit experimental observations on three systems, and testable predictions are made for other random copolymers. The distinctive non-monotonic variation of miscibility with copolymer composition is found to be primarily a consequence of composition-dependent, spatially short-range attractions between the A and B monomers with the fullerene. A remarkably rich, polymer-specific temperature dependence of the spinodal diagram is predicted which reflects the thermal sensitivity of spatial correlations which can result in fullerene miscibility either increasing or decreasing with cooling. The calculations are contrasted with a simpler effective homopolymer model and the random structure Flory-Huggins model. The former appears to be qualitatively reasonable but can incur large quantitative errors since it misses preferential packing of monomers near nanoparticles, while the latter appears to fail qualitatively due to its neglect of all spatial correlations.

  3. New adhesive systems based on functionalized block copolymers

    SciTech Connect

    Kent, M.; Saunders, R.; Hurst, M.; Small, J.; Emerson, J.; Zamora, D.

    1997-05-01

    The goal of this work was to evaluate chemically-functionalized block copolymers as adhesion promoters for metal/thermoset resin interfaces. Novel block copolymers were synthesized which contain pendant functional groups reactive toward copper and epoxy resins. In particular, imidazole and triazole functionalities that chelate with copper were incorporated onto one block, while secondary amines were incorporated onto the second block. These copolymers were found to self-assemble from solution onto copper surfaces to form monolayers. The structure of the adsorbed monolayers were studied in detail by neutron reflection and time-of-flight secondary ion mass spectrometry. The monolayer structure was found to vary markedly with the solution conditions and adsorption protocol. Appropriate conditions were found for which the two blocks form separate layers on the surface with the amine functionalized block exposed at the air surface. Adhesion testing of block copolymer-coated copper with epoxy resins was performed in both lap shear and peel modes. Modest enhancements in bond strengths were observed with the block copolymer applied to the native oxide. However, it was discovered that the native oxide is the weak link, and that by simply removing the native oxide, and then applying an epoxy resin before the native oxide can reform, excellent bond strength in the as-prepared state as well as excellent retention of bond strength after exposure to solder in ambient conditions are obtained. It is recommended that long term aging studies be performed with and without the block copolymer. In addition, the functionalized block copolymer method should be evaluated for another system that has inherently poor bonding, such as the nickel/silicone interface, and for systems involving metals and alloys which form oxides very rapidly, such as aluminum and stainless steel, where bonding strategies involve stabilizing the native oxide.

  4. Tianeptine and alcohol dependence.

    PubMed

    Favre, J D; Guelfi-Sozzi, C; Delalleau, B; Lôo, H

    1997-10-01

    Several arguments are in favour of the use of antidepressant drugs in alcohol-dependent patients, especially those acting on the serotoninergic system: (1) neurochemical data indicate the interaction between alcohol and 5-HT metabolism, (2) pharmacological studies show an improvement in the behaviour of alcoholized animals treated with antidepressants, (3) depression is a frequent disease in alcoholic patients. Tianeptine has been shown to be active in the treatment of depression in patients with history of alcohol abuse or dependence. In a first double-blind study performed versus amitryptiline, depression after withdrawal was improved by tianeptine, and biological abnormalities usually related to chronic alcohol intake tended to decrease. Similar results were found in an open study carried out on 277 alcoholic patients treated for 1 year. As these patients were depressed, no definite conclusion could be drawn from these results in respect of a specific action of tianeptine on alcohol dependence. Thus, a multicentre double-blind study has been performed which compared tianeptine (12.5 mg t.i.d) and placebo in 342 non-depressed patients fulfilling DSM-III-R criteria for Psychoactive Substance Dependence (alcohol). Other inclusion criteria were: daily alcohol intake higher than 80 g, minimum score of 3 on the Short-Mast Questionnaire, mean corpuscular volume above 98 fl and/or gamma Gt more than twice the upper limit of normal. The patients were treated for 9 months. The intention-to-treat population and the per protocol population were made up of 327 patients and 111 patients, respectively. The main efficacy criterion was the absence of alcoholic relapse (abstinence) defined by the patient's statements, the investigators clinical judgement and some biological parameters: alcohol blood levels, gamma Gt levels. Secondary criteria were the evolution of the alcohol consumption in the patients who relapsed, cumulative abstinence duration, a visual analogue scale for the

  5. [Alcohol and nutrition].

    PubMed

    Maillot, F; Farad, S; Lamisse, F

    2001-11-01

    Alcoholism and alcohol-associated organ injury is one of the major health problems worldwide. Alcohol may lead to an alteration in intermediary metabolism and the relation between alcohol intake and body weight is a paradox. The effect of alcohol intake on resting metabolic rate, assessed by indirect calorimetry, and lipid oxidation, is still controversial. Small quantities of ethanol seem to have no effect on body weight. Ingestion of moderate amounts may lead to an increase in body weight, via a lipid-oxidizing suppressive effect. Chronic intake of excessive amounts in alcoholics leads to a decrease in body weight, probably via increased lipid oxidation and energy expenditure. Chronic ethanol abuse alters lipid-soluble (vitamins A, D and E) and water-soluble (B-complex vitamins, vitamin C) vitamins status, and some trace elements status such as magnesium, selenium or zinc.

  6. Update on Alcoholic Hepatitis.

    PubMed

    Torok, Natalie J

    2015-11-02

    Alcoholic liver disease is one of the most prevalent liver diseases worldwide, and a major cause of morbidity and mortality. Alcoholic hepatitis is a severe form of liver injury in patients with alcohol abuse, can present as an acute on chronic liver failure associated with a rapid decline in liver synthetic function, and consequent increase in mortality. Despite therapy, about 30%-50% of patients with severe alcoholic hepatitis eventually die. The pathogenic pathways that lead to the development of alcoholic hepatitis are complex and involve oxidative stress, gut dysbiosis, and dysregulation of the innate and adaptive immune system with injury to the parenchymal cells and activation of hepatic stellate cells. As accepted treatment approaches are currently limited, a better understanding of the pathophysiology would be required to generate new approaches that improve outcomes. This review focuses on recent advances in the diagnosis, pathogenesis of alcoholic hepatitis and novel treatment strategies.

  7. Update on Alcoholic Hepatitis

    PubMed Central

    Torok, Natalie J.

    2015-01-01

    Alcoholic liver disease is one of the most prevalent liver diseases worldwide, and a major cause of morbidity and mortality. Alcoholic hepatitis is a severe form of liver injury in patients with alcohol abuse, can present as an acute on chronic liver failure associated with a rapid decline in liver synthetic function, and consequent increase in mortality. Despite therapy, about 30%–50% of patients with severe alcoholic hepatitis eventually die. The pathogenic pathways that lead to the development of alcoholic hepatitis are complex and involve oxidative stress, gut dysbiosis, and dysregulation of the innate and adaptive immune system with injury to the parenchymal cells and activation of hepatic stellate cells. As accepted treatment approaches are currently limited, a better understanding of the pathophysiology would be required to generate new approaches that improve outcomes. This review focuses on recent advances in the diagnosis, pathogenesis of alcoholic hepatitis and novel treatment strategies. PMID:26540078

  8. Alcoholic liver disease: Treatment

    PubMed Central

    Suk, Ki Tae; Kim, Moon Young; Baik, Soon Koo

    2014-01-01

    The excess consumption of alcohol is associated with alcoholic liver diseases (ALD). ALD is a major healthcare problem, personal and social burden, and significant reason for economic loss worldwide. The ALD spectrum includes alcoholic fatty liver, alcoholic hepatitis, cirrhosis, and the development of hepatocellular carcinoma. The diagnosis of ALD is based on a combination of clinical features, including a history of significant alcohol intake, evidence of liver disease, and laboratory findings. Abstinence is the most important treatment for ALD and the treatment plan varies according to the stage of the disease. Various treatments including abstinence, nutritional therapy, pharmacological therapy, psychotherapy, and surgery are currently available. For severe alcoholic hepatitis, corticosteroid or pentoxifylline are recommended based on the guidelines. In addition, new therapeutic targets are being under investigation. PMID:25278689

  9. [Biological markers of alcoholism].

    PubMed

    Marcos Martín, M; Pastor Encinas, I; Laso Guzmán, F J

    2005-09-01

    Diagnosis of alcoholism is very important, given its high prevalence and possibility of influencing the disease course. For this reason, the so-called biological markers of alcoholism are useful. These are analytic parameters that alter in the presence of excessive alcohol consumption. The two most relevant markers are the gamma-glutamyltranspeptidase and carbohydrate deficient transferrin. With this clinical comment, we aim to contribute to the knowledge of these tests and promote its use in the clinical practice. PMID:16194480

  10. Molecular Exchange in Ordered Diblock Copolymer Micelles

    NASA Astrophysics Data System (ADS)

    Choi, Soo-Hyung; Lodge, Timothy; Bates, Frank

    2011-03-01

    Previously, molecular exchange between spherical micelles in dilute solution (1 vol% polymer) was investigated using time-resolved small-angle neutron scattering (TR-SANS). As the concentration of spherical micelles formed by the diblock copolymers increases, the micelles begin to overlap and eventually pack onto body-centered cubic (BCC) lattice. In this study, concentrated, ordered micelles (15 vol% polymers) prepared by dispersing isotopically labeled poly(styrene- b -ethylene-alt-propylene) in an isotopic squalane mixture was investigated to understand the micellar concentration dependence of the molecular exchange. Perfectly random mixing of isotopically labeled micelles on the BCC lattice was confirmed by SANS patterns where the interparticle contribution vanishes, resulting in an intensity that directly relates to the exchange kinetics. The measured molecular exchange process for the concentrated, ordered system is qualitatively consistent with the previous observations, but the rate is more than an order of magnitude slower than that for the dilute, disordered system. Infineum(IPrime), MRSEC(NSF), NIST.

  11. Molecular Exchange Dynamics in Block Copolymer Micelles

    NASA Astrophysics Data System (ADS)

    Bates, Frank; Lu, Jie; Choi, Soohyung; Lodge, Timothy

    2012-02-01

    Poly(styrene-b-ethylene propylene) (PS-PEP) diblock copolymers were mixed with squalane (C30H62) at 1% by weight resulting in the formation of spherical micelles. The structure and dynamics of molecular exchange were characterized by synchrotron small-angle x-ray scattering (SAXS) and time resolved small-angle neutron scattering (TR-SANS), respectively, between 100 C and 160 C. TR-SANS measurements were performed with solutions initially containing deuterium labeled micelle cores and normal cores dispersed in a contrast matched squalane. Monitoring the reduction in scattering intensity as a function of time at various temperatures revealed molecular exchange dynamics highly sensitive to the core molecular weight and molecular weight distribution. Time-temperature superposition of data acquired at different temperatures produced a single master curve for all the mixtures. Experiments conducted with isotopically labeled micelle cores, each formed from two different but relatively mondisperse PS blocks, confirmed a simple dynamical model based on first order kinetics and core Rouse single chain relaxation. These findings demonstrate a dramatic transition to nonergodicity with increasing micelle core molecular weight and confirm the origins of the logarithmic exchange kinetics in such systems.

  12. Hot embossing of cyclic olefin copolymers

    NASA Astrophysics Data System (ADS)

    Leech, P. W.

    2009-05-01

    The hot embossing properties of cyclic olefin copolymer (COC) have been examined as a function of comonomer content. Six standard grades of COC with varying norbornene content (61-82 wt%) were used in these experiments in order to provide a range of glass transition temperatures, Tg. All grades of COC exhibited sharp increases in embossed depth over a critical range of temperature. The transition temperature in embossed depth increased linearly with norbornene content for both 35 and 70 µm deep structures. At temperatures above this transition, the dimensions of the embossed patterns were essentially independent of the COC grade, the applied pressure and duration of loading. Channels formed above the transition in a regime of viscous liquid flow were extremely smooth in morphology for all grades. The average surface roughness, Ra, measured at the base of the channels decreased sharply at the transition temperature, with a levelling off at higher temperatures. Grades of COC with a higher norbornene content exhibited extensive micro-cracking during embossing at temperatures close to the transition temperature.

  13. 40 CFR 721.7200 - Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... modified alkyl methacrylate copolymer. 721.7200 Section 721.7200 Protection of Environment ENVIRONMENTAL... alkyl methacrylate copolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as perfluoroalkyl aromatic carbamate modified...

  14. 40 CFR 721.7200 - Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... modified alkyl methacrylate copolymer. 721.7200 Section 721.7200 Protection of Environment ENVIRONMENTAL... alkyl methacrylate copolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as perfluoroalkyl aromatic carbamate modified...

  15. 40 CFR 721.7200 - Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... modified alkyl methacrylate copolymer. 721.7200 Section 721.7200 Protection of Environment ENVIRONMENTAL... alkyl methacrylate copolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as perfluoroalkyl aromatic carbamate modified...

  16. 40 CFR 721.7200 - Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... modified alkyl methacrylate copolymer. 721.7200 Section 721.7200 Protection of Environment ENVIRONMENTAL... alkyl methacrylate copolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as perfluoroalkyl aromatic carbamate modified...

  17. 40 CFR 721.7200 - Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... modified alkyl methacrylate copolymer. 721.7200 Section 721.7200 Protection of Environment ENVIRONMENTAL... alkyl methacrylate copolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as perfluoroalkyl aromatic carbamate modified...

  18. Monte Carlo simulations of the phase separation of a copolymer blend in a thin film.

    PubMed

    Wang, Zhexiao; Shao, Jing; Pan, Heng; Feng, Xiaoshuang; Chen, Peng; Xia, Ru; Wu, Xiangsong; Qian, Jiasheng

    2015-02-23

    Monte Carlo simulations were carried out to study the phase separation of a copolymer blend comprising an alternating copolymer and/or block copolymer in a thin film, and a phase diagram was constructed with a series of composed recipes. The effects of composition and segregation strength on phase separation were discussed in detail. The chain conformation of the block copolymer and alternating copolymer were investigated with changes of the segregation strength. Our simulations revealed that the segment distribution along the copolymer chain and the segregation strength between coarse-grained beads are two important parameters controlling phase separation and chain conformation in thin films of a copolymer blend. A well-controlled phase separation in the copolymer blend can be used to fabricate novel nanostructures. PMID:25504337

  19. Tobacco, Alcohol, Drugs, and Pregnancy

    MedlinePlus

    ... What are fetal alcohol spectrum disorders? • What is fetal alcohol syndrome? • What amounts of alcohol can cause FAS? • Is ... disabilities that can last a lifetime. What is fetal alcohol syndrome? Fetal alcohol syndrome (FAS) is the most severe ...

  20. Fetal Alcohol Syndrome "Chemical Genocide."

    ERIC Educational Resources Information Center

    Asetoyer, Charon

    In the Northern Plains of the United States, 100% of Indian reservations are affected by alcohol related problems. Approximately 90% of Native American adults are currently alcohol users or abusers or are recovering from alcohol abuse. Alcohol consumption has a devastating effect on the unborn. Fetal Alcohol Syndrome (FAS) is an irreversible birth…

  1. Affordability of alcohol and alcohol-related mortality in Belarus.

    PubMed

    Razvodovsky, Yury E

    2013-01-01

    Alcohol abuse has numerous adverse health and social consequences. The consumer response to changes in alcohol affordability is an important issue on alcohol policy debates. Studies from many countries have shown an inverse relationship between alcohol prices and alcohol consumption in the population. There are, however, suggestions that increasing the price of alcohol by rising taxes may have limited effect on alcohol-related problems, associated with long-term heavy drinking. The aim of the present study was to evaluate the relationship between alcohol affordability and alcohol-related mortality rates in post-Soviet Belarus. For this purpose trends in alcohol-related mortality rates (mortality from liver cirrhosis, pancreatitis, alcoholism and alcohol psychoses) and affordability of vodka between 1990 and 2010 were compared. The time series analysis revealed that 1% increase in vodka affordability is associated with an increase in liver cirrhosis mortality of 0,77%, an increase in pancreatitis mortality of 0.53%, an increase in mortality from alcoholism and alcohol psychoses of 0,70%. The major conclusion emerging from this study is that affordability of alcohol is one of the most important predictor of alcohol-related problems in a population. These findings provide additional evidence that decreasing in affordability of alcohol is an effective strategy for reducing alcohol consumption and alcohol-related harm.

  2. [Alcohol and criminal behavior].

    PubMed

    Arzt, G

    1990-05-01

    The topic 'alcohol and crime' has several aspects. This article shows how drug administration is based on a complex network of legal provisions and is enforced by criminal law sanctions. As to crimes influenced by alcohol, drunken driving is by far the most important and best researched field. Next, the article turns to the role of alcohol with regard to severe common crimes such as murder or child abuse. Finally, the issue of drunkenness as a defence is raised and the treatment of alcoholics as a criminal law sanction discussed.

  3. Alcohol disrupts sleep homeostasis

    PubMed Central

    Thakkar, Mahesh M.; Sharma, Rishi; Sahota, Pradeep

    2014-01-01

    Alcohol is a potent somnogen and one of the most commonly used “over the counter” sleep aids. In healthy non-alcoholics, acute alcohol decreases sleep latency, consolidates and increases the quality (delta power) and quantity of NREM sleep during the first half of the night. However, sleep is disrupted during the second half. Alcoholics, both during drinking periods and during abstinences, suffer from a multitude of sleep disruptions manifested by profound insomnia, excessive daytime sleepiness, and altered sleep architecture. Furthermore, subjective and objective indicators of sleep disturbances are predictors of relapse. Finally, within the USA, it is estimated that societal costs of alcohol-related sleep disorders exceeds $18 billion. Thus, although alcohol-associated sleep problems have significant economic and clinical consequences, very little is known about how and where alcohol acts to affect sleep. In this review, we have described our attempts to understand how and where alcohol acts to affect sleep. We have conducted a series of experiments using two different species, rats and mice, as animal models, and a combination of multi-disciplinary experimental methodologies to examine and understand anatomical and cellular substrates mediating the effects of acute and chronic alcohol exposure on sleep-wakefulness. The results of our studies suggest that the sleep-promoting effects of alcohol may be mediated via alcohol’s action on the mediators of sleep homeostasis: adenosine (AD) and the wake-promoting cholinergic neurons of the basal forebrain (BF). Alcohol, via its action on AD uptake, increases extracellular AD resulting in the inhibition of BF wake-promoting neurons. Lesions of the BF cholinergic neurons or blockade of AD A1 receptors results in attenuation of alcohol-induced sleep promotion, suggesting that AD and BF cholinergic neurons are critical for sleep-promoting effects of alcohol. Since binge alcohol consumption is a highly prevalent pattern

  4. Older Adults and Alcohol

    MedlinePlus

    ... Disorders Publications & Multimedia Brochures & Fact Sheets NIAAA Journal Alcohol Alert Bulletin Professional Education Materials Classroom Resources Presentations & Videocasts Video Bank Publicaciones ...

  5. Microwave alcohol fuel sensor

    SciTech Connect

    Kimura, K.; Endo, A.; Morozumi, H.; Shibata, T.

    1984-06-05

    A microwave alcohol fuel sensor comprises a microwave oscillator, a microwave receiver, and a microwave transmission circuit connected to the oscillator and the receiver. The microwave transmission circuit comprises a dielectric substrate and, a strip line mounted on the substrate so that microwaves leak from the substrate to an alcohol gasoline fuel, and the microwaves attenuate by alcohol dielectric loss, whereby output voltage from the receiver corresponds to alcohol content rate. The dielectric substrate is formed tubular so that a constant amount of the fuel is fed the sensor.

  6. A Solid-State NMR Investigation of MQ Silicone Copolymers.

    PubMed

    Vasil'ev, Sergey G; Volkov, Vitaly I; Tatarinova, Elena A; Muzafarov, Aziz M

    2013-01-01

    The structure of MQ copolymers of the general chemical formula [(CH3)3SiO0.5]m [SiO2]n was characterized by means of solid-state magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. The MQ copolymers are highly branched polycyclic compounds (densely cross-linked nanosized networks). MQ copolymers were prepared by hydrolytic polycondensation in active medium. (29)Si NMR spectra were obtained by single pulse excitation (or direct polarization, DP) and cross-polarization (CP) (29)Si{(1)H} techniques in concert with MAS. It was shown that material consist of monofunctional M (≡SiO Si (CH3)3) and two types of tetrafunctional Q units: Q(4) ((≡SiO)4 Si) and Q(3) ((≡SiO)3 SiOH). Spin-lattice relaxation times T 1 measurements of (29)Si nuclei and analysis of (29)Si{(1)H} variable contact time signal intensities allowed us to obtain quantitative data on the relative content of different sites in copolymers. These investigations indicate that MQ copolymers represent dense structure with core and shell. PMID:23914072

  7. Electrostatic Self-Assembly in Copolymers-Nanoparticles Systems

    NASA Astrophysics Data System (ADS)

    Berret, Jean-Francois

    2004-03-01

    We have investigated the phase behavior of neutral/polyelectrolyte block copolymers (also called double-hydrophilic block copolymers) with oppositely charged surfactants [1,2]. When the neutral part of the copolymer is long enough as compared to the charged block, in aqueous solutions the copolymers associate with the surfactant micelles so as to form colloidal complexes of typical sizes 100 nm. We call the mechanism of formation of the complexes electrostatic self-assembly. Using scattering experiments (neutron, x-ray, light) we have found that the colloids have a core-shell microstructure. The core is constituted by densely packed surfactant micelles connected by the polyelectrolyte chains. More recently, we have shown that neutral/polyelectrolyte copolymers also associate with a wide variety of oppositely charged species, such as multivalent counterions, globular proteins and solid nanoparticles. In this communication, we demonstrate the ability of charged diblocks to generate nanostructures of adjustable sizes and morphologies. [1] P. Hervé et al., Europhys. Lett. 58, 912 (2002). J.-F. Berret et al., Eur. Phys. J. E 9, 301 (2002). [2] J.-F. Berret et al., J. Phys. Chem. B 107, 8111 (2003)

  8. Relaxation processes in a lower disorder order transition diblock copolymer

    SciTech Connect

    Sanz, Alejandro; Ezquerra, Tiberio A.; Nogales, Aurora

    2015-02-14

    The dynamics of lower disorder-order temperature diblock copolymer leading to phase separation has been observed by X ray photon correlation spectroscopy. Two different modes have been characterized. A non-diffusive mode appears at temperatures below the disorder to order transition, which can be associated to compositional fluctuations, that becomes slower as the interaction parameter increases, in a similar way to the one observed for diblock copolymers exhibiting phase separation upon cooling. At temperatures above the disorder to order transition T{sub ODT}, the dynamics becomes diffusive, indicating that after phase separation in Lower Disorder-Order Transition (LDOT) diblock copolymers, the diffusion of chain segments across the interface is the governing dynamics. As the segregation is stronger, the diffusive process becomes slower. Both observed modes have been predicted by the theory describing upper order-disorder transition systems, assuming incompressibility. However, the present results indicate that the existence of these two modes is more universal as they are present also in compressible diblock copolymers exhibiting a lower disorder-order transition. No such a theory describing the dynamics in LDOT block copolymers is available, and these experimental results may offer some hints to understanding the dynamics in these systems. The dynamics has also been studied in the ordered state, and for the present system, the non-diffusive mode disappears and only a diffusive mode is observed. This mode is related to the transport of segment in the interphase, due to the weak segregation on this system.

  9. Regular and Irregular Mixing in Hydrocarbon Block Copolymers

    NASA Astrophysics Data System (ADS)

    Register, Richard; Beckingham, Bryan

    2014-03-01

    Since hydrocarbon polymers interact through relatively simple (dispersive) interactions, one might expect them to be described by simple models of mixing energetics, such as regular mixing. However, the pioneering work of Graessley on saturated hydrocarbon polymer blends showed that while regular mixing is obeyed in some cases, both positive and negative deviations (in the magnitude of the mixing enthalpy) from regular mixing are observed in other cases. Here, we describe the mixing energetics for two series of hydrocarbon polymers wherein the interaction strengths may be continuously tuned, and which can be readily incorporated into block copolymers. Random copolymers of styrene and medium-vinyl isoprene, in which either the isoprene or both the isoprene and styrene units have been saturated, obey regular mixing over the entire composition range and for both hydrogenated derivatives. Well-defined block copolymers with arbitrarily small interblock interaction strengths can be constructed from these units, permitting the interdomain spacing to be made arbitrarily large while holding the order-disorder transition temperature constant. However, block copolymers of hydrogenated polybutadiene with such random copolymers show very strong positive deviations from regular mixing when the styrene aromaticity is preserved, and sizable negative deviations when the styrene units are saturated to vinylcyclohexane. Both of these cases can be quantitatively described by a ternary mixing model.

  10. Relaxation processes in a lower disorder order transition diblock copolymer.

    PubMed

    Sanz, Alejandro; Ezquerra, Tiberio A; Hernández, Rebeca; Sprung, Michael; Nogales, Aurora

    2015-02-14

    The dynamics of lower disorder-order temperature diblock copolymer leading to phase separation has been observed by X ray photon correlation spectroscopy. Two different modes have been characterized. A non-diffusive mode appears at temperatures below the disorder to order transition, which can be associated to compositional fluctuations, that becomes slower as the interaction parameter increases, in a similar way to the one observed for diblock copolymers exhibiting phase separation upon cooling. At temperatures above the disorder to order transition TODT, the dynamics becomes diffusive, indicating that after phase separation in Lower Disorder-Order Transition (LDOT) diblock copolymers, the diffusion of chain segments across the interface is the governing dynamics. As the segregation is stronger, the diffusive process becomes slower. Both observed modes have been predicted by the theory describing upper order-disorder transition systems, assuming incompressibility. However, the present results indicate that the existence of these two modes is more universal as they are present also in compressible diblock copolymers exhibiting a lower disorder-order transition. No such a theory describing the dynamics in LDOT block copolymers is available, and these experimental results may offer some hints to understanding the dynamics in these systems. The dynamics has also been studied in the ordered state, and for the present system, the non-diffusive mode disappears and only a diffusive mode is observed. This mode is related to the transport of segment in the interphase, due to the weak segregation on this system. PMID:25681940

  11. Controlling block copolymer phase behavior using ionic surfactant

    NASA Astrophysics Data System (ADS)

    Ray, D.; Aswal, V. K.

    2016-05-01

    The phase behavior of poly(ethylene oxide)-poly(propylene oxide-poly(ethylene oxide) PEO-PPO-PEO triblock copolymer [P85 (EO26PO39EO26)] in presence of anionic surfactant sodium dodecyl sulfate (SDS) in aqueous solution as a function of temperature has been studied using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations (1 wt%) of block copolymer and surfactants. Each of the individual components (block copolymer and surfactant) and the nanoparticle-surfactant mixed system have been examined at varying temperature. The block copolymer P85 forms spherical micelles at room temperature whereas shows sphere-to-rod like micelle transition at higher temperatures. On the other hand, SDS surfactant forms ellipsoidal micelles over a wide temperature range. Interestingly, it is found that phase behavior of mixed micellar system (P85 + SDS) as a function of temperature is drastically different from that of P85, giving the control over the temperature-dependent phase behavior of block copolymers.

  12. Self-Assembled Antimicrobial and biocompatible copolymer films on Titanium

    PubMed Central

    Pfaffenroth, Cornelia; Winkel, Andreas; Dempwolf, Wibke; Gamble, Lara J.; Castner, David G.; Stiesch, Meike; Menzel, Henning

    2013-01-01

    Biofilm formation on biomedical devices such as dental implants can result in serious infections and finally in device failure. Polymer coatings which provide antimicrobial action to surfaces without compromising the compatibility with human tissue are of great interest. Copolymers of 4-vinyl-N-hexylpyridinium bromide and dimethyl(2-methacryloyloxyethyl) phosphonate are interesting candidates in this respect. These copolymers form ultrathin polycationic layers on titanium surfaces. As the copolymerization reaction is almost ideal statistical, copolymers with varying compositions can be synthesized and immobilized onto titanium surfaces for comprehensive screening concerning antimicrobial activity and biocompatibility. Copolymer films on titanium were characterized by contact angle measurements, ellipsometry and X-ray photoelectron spectroscopy. Antibacterial properties were assessed by investigation of adherence of S. mutans which represents a strain found in the human oral cavity. Biocompatibility was rated based on human gingival fibroblast adhesion, proliferation and cell morphology. Depending on polymer composition the coatings displayed a behavior ranging from biocompatibility equal to titanium but no antibacterial action to highly antimicrobial activity but poor biocompatibility. By balancing these two opposing effects by tailoring chemical composition, copolymer coatings were fabricated, which were able to inhibit the growth of S. mutans on the surface significantly but still show a sufficient attachment of gingival fibroblasts. PMID:21818855

  13. Prenatal alcohol consumption and knowledge about alcohol consumption and fetal alcohol syndrome in Korean women.

    PubMed

    Kim, Oksoo; Park, Kyungil

    2011-09-01

    The study investigated prenatal alcohol consumption and knowledge of alcohol risks and fetal alcohol syndrome among Korean women. The participants were 221 Korean women who attended the post-partum care centers in Seoul, Korea. The data included the participants' background characteristics, quantity-frequency typology, Student Alcohol Questionnaire, and a scale on the participants' knowledge of fetal alcohol syndrome. Alcohol was consumed during pregnancy by 12.7% of the participants. Of these, 60.7% drank alcohol with their spouse. A few participants reported that nurses identified their drinking habits and gave them information on alcohol consumption and fetal alcohol syndrome. Most of the participants did not have the opportunity for prenatal counseling about fetal alcohol syndrome. The knowledge level regarding alcohol risks and fetal alcohol syndrome among the participants was poor. Alcohol consumption before pregnancy was significantly related to prenatal alcohol consumption. Prenatal alcohol consumption was not related to knowledge about alcohol consumption and fetal alcohol syndrome. The assessment of alcohol consumption and counseling about alcohol are needed for pregnant women in order to prevent fetal alcohol syndrome.

  14. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  15. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  16. 40 CFR 721.10179 - Copolymers of phenol and aromatic hydocarbon (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Copolymers of phenol and aromatic... Specific Chemical Substances § 721.10179 Copolymers of phenol and aromatic hydocarbon (generic). (a... generically as copolymers of phenol and aromatic hydocarbon (PMNs P-04-346 and P-04-347) are subject...

  17. 40 CFR 721.10179 - Copolymers of phenol and aromatic hydocarbon (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copolymers of phenol and aromatic... Specific Chemical Substances § 721.10179 Copolymers of phenol and aromatic hydocarbon (generic). (a... generically as copolymers of phenol and aromatic hydocarbon (PMNs P-04-346 and P-04-347) are subject...

  18. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Copolymer of alkyl acrylate and... Significant New Uses for Specific Chemical Substances § 721.10101 Copolymer of alkyl acrylate and...) The chemical substance identified generically as copolymer of alkyl acrylate and...

  19. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Copolymer of alkyl acrylate and... Significant New Uses for Specific Chemical Substances § 721.10101 Copolymer of alkyl acrylate and...) The chemical substance identified generically as copolymer of alkyl acrylate and...

  20. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Copolymer of alkyl acrylate and... Significant New Uses for Specific Chemical Substances § 721.10101 Copolymer of alkyl acrylate and...) The chemical substance identified generically as copolymer of alkyl acrylate and...

  1. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copolymer of alkyl acrylate and... Significant New Uses for Specific Chemical Substances § 721.10101 Copolymer of alkyl acrylate and...) The chemical substance identified generically as copolymer of alkyl acrylate and...

  2. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nitrile rubber modified acrylonitrile-methyl... Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile... rubber modified acrylonitrile-methyl acrylate copolymers consist of basic copolymers produced by...

  3. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Nitrile rubber modified acrylonitrile-methyl... Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile... rubber modified acrylonitrile-methyl acrylate copolymers consist of basic copolymers produced by...

  4. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Nitrile rubber modified acrylonitrile-methyl... Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile... rubber modified acrylonitrile-methyl acrylate copolymers consist of basic copolymers produced by...

  5. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Nitrile rubber modified acrylonitrile-methyl... Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile... rubber modified acrylonitrile-methyl acrylate copolymers consist of basic copolymers produced by...

  6. Affinity-mediated capture and release of amphiphilic copolymers for controlling antimicrobial activity.

    PubMed

    Takahashi, Haruko; Akiyoshi, Kazunari; Kuroda, Kenichi

    2015-08-14

    Capture and release of amphiphilic copolymers by a nano-sized polysaccharide gel (nanogel) was controlled by altering the hydrophobic binding affinity between the copolymer chains and nanogel. The antimicrobial activity of captured copolymer chains was suppressed, and regained upon release from the nanogel. PMID:26154063

  7. 40 CFR 721.10419 - Tetrafluoroethylene chlorotrifluoroethylene copolymer (generic) (P-11-561).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... chlorotrifluoroethylene copolymer (generic) (P-11-561). 721.10419 Section 721.10419 Protection of Environment... chlorotrifluoroethylene copolymer (generic) (P-11-561). (a) Chemical substance and significant new uses subject to... copolymer (PMN P-11-561) is subject to reporting under this section for the significant new uses...

  8. 40 CFR 721.10419 - Tetrafluoroethylene chlorotrifluoroethylene copolymer (generic) (P-11-561).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... chlorotrifluoroethylene copolymer (generic) (P-11-561). 721.10419 Section 721.10419 Protection of Environment... chlorotrifluoroethylene copolymer (generic) (P-11-561). (a) Chemical substance and significant new uses subject to... copolymer (PMN P-11-561) is subject to reporting under this section for the significant new uses...

  9. 40 CFR 721.10419 - Tetrafluoroethylene chlorotrifluoroethylene copolymer (generic) (P-11-561).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... chlorotrifluoroethylene copolymer (generic) (P-11-561). 721.10419 Section 721.10419 Protection of Environment... chlorotrifluoroethylene copolymer (generic) (P-11-561). (a) Chemical substance and significant new uses subject to... copolymer (PMN P-11-561) is subject to reporting under this section for the significant new uses...

  10. 21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly-1-butene resins and butene/ethylene copolymers... resins and butene/ethylene copolymers. The poly-1-butene resins and butene/ethylene copolymers identified... with food subject to the provisions of this section. (a) Identity. Poly-1-butene resins are produced...

  11. 21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Poly-1-butene resins and butene/ethylene...-butene resins and butene/ethylene copolymers. The poly-1-butene resins and butene/ethylene copolymers... produced by the catalytic polymerization of 1-butene liquid monomer. Butene/ethylene copolymers...

  12. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethylene-methyl acrylate copolymer resins. 177... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used...

  13. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethylene-methyl acrylate copolymer resins. 177... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used...

  14. 21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Poly-1-butene resins and butene/ethylene...-butene resins and butene/ethylene copolymers. The poly-1-butene resins and butene/ethylene copolymers... produced by the catalytic polymerization of 1-butene liquid monomer. Butene/ethylene copolymers...

  15. 40 CFR 721.10179 - Copolymers of phenol and aromatic hydocarbon (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Copolymers of phenol and aromatic... Specific Chemical Substances § 721.10179 Copolymers of phenol and aromatic hydocarbon (generic). (a... generically as copolymers of phenol and aromatic hydocarbon (PMNs P-04-346 and P-04-347) are subject...

  16. 40 CFR 721.10179 - Copolymers of phenol and aromatic hydocarbon (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Copolymers of phenol and aromatic... Specific Chemical Substances § 721.10179 Copolymers of phenol and aromatic hydocarbon (generic). (a... generically as copolymers of phenol and aromatic hydocarbon (PMNs P-04-346 and P-04-347) are subject...

  17. 40 CFR 721.10179 - Copolymers of phenol and aromatic hydocarbon (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Copolymers of phenol and aromatic... Specific Chemical Substances § 721.10179 Copolymers of phenol and aromatic hydocarbon (generic). (a... generically as copolymers of phenol and aromatic hydocarbon (PMNs P-04-346 and P-04-347) are subject...

  18. Responsive copolymers for enhanced petroleum recovery. Quarterly technical progress report, March 22, 1994--June 21, 1994

    SciTech Connect

    McCormick, C.; Hester, R.

    1994-09-01

    In this report, the authors consider the synthesis of copolymers of interest in the enhanced recovery of petroleum. Acrylamide and N,N-dimethyl-N-dodecyl-N-(2-amidoethyl) ammonium bromide copolymers were synthesized and characterized by various instrumental methods. The rheological properties of this copolymer were investigated using a porous media elongation rheometer.

  19. Responsive copolymers for enhanced petroleum recovery. Quarterly technical progress report, March 22, 1993--June 22, 1993

    SciTech Connect

    McCormick, C.; Hester, R.

    1993-08-01

    The overall goal of this research is the development of advanced water-soluble copolymers for use in enhanced oil recovery which rely on reversible microheterogeneous associations for mobility control and reservoir conformance. Technical progress for the quarter is summarized for the following tasks: advanced copolymer syntheses; characterization of molecular structure of copolymers; and polymer solution rheology.

  20. Water-soluble graft copolymers of starch-acrylamide and uses therefor

    DOEpatents

    Butler, G.B.; Hogen-Esch, T.E.; Meister, J.J.; Pledger, H. Jr.

    1983-08-23

    Graft copolymers having starch as the central chain with grafted side chains of acrylamide or acrylamide-acrylic acid, and a process for preparation of such copolymers in the presence of Ce[sup +4] or other redox initiators are disclosed. These copolymers are employed in preparing highly viscous aqueous solutions that are particularly useful in oil recovery from subterranean wells. 2 figs.

  1. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  2. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  3. 40 CFR 721.10389 - Styrene, copolymer with acrylic acid, salt with alkoxylated alkenylamine (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Styrene, copolymer with acrylic acid... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10389 Styrene, copolymer with acrylic... subject to reporting. (1) The chemical substance identified generically as styrene, copolymer with...

  4. 40 CFR 721.10389 - Styrene, copolymer with acrylic acid, salt with alkoxylated alkenylamine (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Styrene, copolymer with acrylic acid... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10389 Styrene, copolymer with acrylic... subject to reporting. (1) The chemical substance identified generically as styrene, copolymer with...

  5. 40 CFR 721.10389 - Styrene, copolymer with acrylic acid, salt with alkoxylated alkenylamine (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Styrene, copolymer with acrylic acid... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10389 Styrene, copolymer with acrylic... subject to reporting. (1) The chemical substance identified generically as styrene, copolymer with...

  6. 40 CFR 721.338 - Salt of an acrylate copolymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Salt of an acrylate copolymer (generic... Substances § 721.338 Salt of an acrylate copolymer (generic). Link to an amendment published at 79 FR 34636... substances identified generically as salt of an acrylate copolymer (PMNs P-00-0333 and P-00-0334) are...

  7. Water-soluble graft copolymers of starch-acrylamide and uses therefor

    DOEpatents

    Butler, George B.; Hogen-Esch, Thieo E.; Meister, John J.; Pledger, Jr., Huey

    1983-08-23

    Graft copolymers having starch as the central chain with grafted side chains of acrylamide or acrylamide-acrylic acid, and a process for preparation of such copolymers in the presence of Ce.sup.+4 or other redox initiators. These copolymers are employed in preparing highly viscous aqueous solutions that are particularly useful in oil recovery from subterranean wells.

  8. Alcohol-Related Liver Disease

    MedlinePlus

    ... to run events. Please support us. Donate | Volunteer Alcohol-Related Liver Disease Discussion on Inspire Support Community ... Liver > Liver Disease Information > Alcohol-Related Liver Disease Alcohol-Related Liver Disease Explore this section to learn ...

  9. Structure of Block Copolymer Hydrogel Formed by Complex Coacervate Process

    NASA Astrophysics Data System (ADS)

    Choi, Soohyung; Ortony, Julia; Krogstad, Daniel; Spruell, Jason; Lynd, Nathaniel; Han, Songi; Kramer, Edward

    2012-02-01

    Complex coacervation occurs when oppositely charged polyelectrolytes associate in solution, forming dense micron-sized droplets. Hydrogels with coacervate block domains were formed by mixing two ABA and A'BA' triblock copolymer solutions in water where the A and A' blocks are oppositely charged. Small-angle neutron scattering (SANS) was used to investigate the structure of hydrogels formed by ABA triblock copolymers (A block: poly(allyl glycidyl ether) functionalized with guanidinium (A) or sulfonate (A'), B block: poly(ethylene oxide)). By using an appropriate fitting model, structural information such as coacervate core block radius and water volume fraction w can be extracted from SANS data. The results reveal that w in the coacervate core block was significantly higher than in conventional triblock copolymer hydrogels where microphase separation is driven by the hydrophobicity of the core-forming blocks.

  10. Self-assembly of ABA triblock copolymers under soft confinement

    NASA Astrophysics Data System (ADS)

    Sheng, Yuping; An, Jian; Zhu, Yutian

    2015-05-01

    Using Monte Carlo method, the self-assembly of ABA triblock copolymers under soft confinement is investigated in this study. The soft confinement is achieved by a poor solvent environment for the polymer, which makes the polymer aggregate into a droplet. Various effects, including the block length ratio, the solvent quality for the blocks B, and the incompatibility between blocks A and B, on the micellar structures induced by soft confinement are examined. By increasing the solvent quality of B blocks, the micellar structure transforms from stacked lamella to bud-like structure, and then to onion-like structure for A5B8A5 triblock copolymers, while the inner micellar structure changes from spherical phase to various cylindrical phase, such as inner single helix, double helixes, stacked rings and cage-like structures, for A7B4A7 triblock copolymers. Moreover, the formation pathways of some typical aggregates are examined to illustrate their growth mechanisms.

  11. Studies on N-vinylformamide cross-linked copolymers

    NASA Astrophysics Data System (ADS)

    Świder, Joanna; Tąta, Agnieszka; Sokołowska, Katarzyna; Witek, Ewa; Proniewicz, Edyta

    2015-12-01

    Copolymers of N-vinylformamide (NVF) cross-linked with three multifunctional monomers, including divinylbenzene (DVB), ethylene glycol dimethacrylate (EGDMA), and N,N‧-methylenebisacrylamide (MBA) were synthetized by a three-dimensional free radical polymerization in inverse suspension using 2,2‧-azobis(2-methylpropionamide) dihydrochloride (AIBA) as an initiator. Methyl silicon oil was used as the continuous phase during the polymerization processes. Fourier-transform adsorption infrared (FT-IR) spectra revealed the presence of silicone oil traces and suggested that silicone oil strongly interacted with the copolymers surface. Purification procedure allowed to completely remove the silicon oil traces from P(NVF-co-DVB) only. The morphology and the structure of the investigated copolymers were examined by optical microscopy, FT-IR, and FT-Raman (Fourier-transform Raman spectroscopy) methods.

  12. Performance behavior of modified cellulosic fabrics using polyurethane acrylate copolymer.

    PubMed

    Zuber, Mohammad; Shah, Sayyed Asim Ali; Jamil, Tahir; Asghar, Muhammad Irfan

    2014-06-01

    The surface of the cellulosic fabrics was modified using self-prepared emulsions of polyurethane acrylate copolymers (PUACs). PUACs were prepared by varying the molecular weight of polycaprolactone diol (PCL). The PCL was reacted with isophorone diisocyanate (IPDI) and chain was extended with 2-hydroxy ethyl acrylate (HEA) to form vinyl terminated polyurethane (VTPU) preploymer. The VTPU was further co-polymerized through free radical polymerization with butyl acrylate in different proportions. The FT-IR spectra of monomers, prepolymers and copolymers assured the formation of proposed PUACs structure. The various concentrations of prepared PUACs were applied onto the different fabric samples using dip-padding techniques. The results revealed that the application of polyurethane butyl acrylate copolymer showed a pronounced effect on the tear strength and pilling resistance of the treated fabrics.

  13. Structure-Property Relationships in Sulfonated Pentablock Copolymers

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hong; Willis, Carl; Winey, Karen I.

    2011-03-01

    Membranes of pentablock copolymers consisting of poly(tert-butyl styrene) (TBS), hydrogenated polyisoprene (HI), and partially sulfonated poly(styrene-ran-styrene sulfonate) (SS) were studied using small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The TBS-HI-SS-HI-TBS pentablock copolymer in solution forms spherical micelles with a core of SS and a corona of solvated HI and TBS. The spherical micelles in solution compact as the solvent evaporates and some of SS cores merge to form interconnected SS microdomains without substantially changing their shape. The number of connections increases with the volume fraction of the SS block, which increases with sulfonation level. The structure does not have long-range order, because strong ionic interactions prevent extensive rearrangement. The morphologies of the sulfonated pentablock copolymers will be correlated with their transport properties.

  14. Thermoresponsive behavior of chitosan-g-N-isopropylacrylamide copolymer solutions.

    PubMed

    Recillas, Maricarmen; Silva, Luisa L; Peniche, Carlos; Goycoolea, Francisco M; Rinaudo, Marguerite; Argüelles-Monal, Waldo M

    2009-06-01

    Chitosan-g-N-isopropylacrylamide (NIPAm) water-soluble copolymers were synthesized and characterized by FTIR and (1)H NMR spectroscopies combined with conductometric and potentiometric titrations. Their thermoresponsive, fully reversible, behavior in aqueous solutions was characterized by means of microcalorimetry and rheology. During heating of copolymer solutions there is a well-known endothermic effect, which coincides with a marked increase in G' and a moderate decrement in G'' due to the formation of a hydrophobic network at the expense of the net amount of sol fraction. It was also found that a straight dependence between the values of G' above the LCST and the enthalpies associated with the transition reflecting that the connectivity in the gel network is governed by the net number of formed enthalpic-hydrophobic driven-junctions. Both the LCST and the enthalpy change vary with the ionic strength of copolymer solutions, but no dependence was found with the neutralization of the polyelectrolyte chain.

  15. Hypoxia-Responsive Copolymer for siRNA Delivery.

    PubMed

    Perche, Federico; Biswas, Swati; Patel, Niravkumar R; Torchilin, Vladimir P

    2016-01-01

    A wide variety of nanomedicine has been designed for cancer therapy. Herein, we describe the synthesis and evaluation of a hypoxia-responsive copolymer for siRNA delivery (Perche et al., Angew Chem Int Ed Engl 53:3362-3366, 2014). The synthesis is achieved using established coupling chemistry and accessible purification procedures. A polyelectrolyte-lipid conjugate (polyethyleneimine 1.8 kDa-dioleyl-phosphatidylinositol, PEI-PE) and polyethylene glycol 2000 (PEG) were assembled via the hypoxia-sensitive azobenzene (Azo) unit to obtain the PEG-Azo-PEI-DOPE copolymer. This copolymer can condense siRNA and shows hypoxia-induced cellular internalization and reporter gene downregulation in vitro and tumor accumulation in vivo after parenteral administration (Perche et al., Angew Chem Int Ed Engl 53:3362-3366, 2014). We also detail procedures to evaluate hypoxia-targeted polymers both in monolayer cultures, cancer cell spheroids and in tumor xenografts murine models. PMID:26530922

  16. Defects in a Noncentrosymmetric Lemellar Block Copolymer Blend

    SciTech Connect

    Chen, Shujun; Gido, Samuel; Tsoukatos, Thodoris; Avgeropoulos, Apostolos; Hadjichristidis, Nikos; Hong, Kunlun; Mays, Jimmy

    2005-01-01

    Here we report results from a defect study on the noncentrosymmetric (NCS) lamellar blend of an ABCD tetrablock copolymer and an AD diblock copolymer. The block copolymers used were polystyrene-block-polybutadiene-block-polyisoprene-block-polycyclohexadiene and polystyrene-block-polycyclohexadiene. Coexisting tetrablock-rich mixed centrosymmetric (CS) and NCS lamellar morphologies were seen in TEM, as predicted by the mean-field theory. NCS grain boundary defects similar to those in CS lamellar systems were observed as well as new defects unique to NCS layered systems, such as chain polarity reversals and kink bands with dilation or compression of the layers. In addition to morphology observations, geometrical and energetic calculations were performed on several new NCS defects, which are in good agreement with experimental results.

  17. Phase Behavior and Significantly Enhanced Toughness in Polylactide Graft Copolymers

    NASA Astrophysics Data System (ADS)

    Robertson, Megan; Theryo, Grayce; Jing, Feng; Hillmyer, Marc

    2011-03-01

    Polylactide (PLA), a biodegradable polyester derived from plant sugars, is commercially available and used in a variety of applications ranging from serviceware to resorbable sutures. One limitation to diversifying the applications of the material is its inherent brittleness. Graft copolymers containing PLA arms and a rubbery aliphatic polymer backbone were synthesized by a combination of ring-opening metathesis and ring-opening transesterification polymerizations. The high degree of incompatibility between the arms and backbone resulted in microphase separation of the graft copolymer at increasingly low fractions of the backbone polymer, as evidenced by small-angle x-ray scattering. In graft copolymers with a rubbery content of only 5 wt percent, the tensile strain at break was observed to be as high as twenty times that of neat PLA. Studies are underway to provide insight into the critical polymer molecular parameters for enhanced toughness and the deformation mechanisms.

  18. Patterned silica films using microphase separation of a block copolymer

    NASA Astrophysics Data System (ADS)

    Kataoka, Sho; Takeuchi, Yasutaka; Endo, Akira

    2014-11-01

    Block copolymers exhibit various nanoscale ordered morphologies induced by microphase separation. Here, we present a method for providing two types of patterned silica films on Si wafer substrates simply by shifting the phase equilibrium of a block copolymer, polystyrene-block-poly(4-vinylpyridine) (PS-P4VP). In this method, siloxane is adsorbed onto poly(4-vinylpyridine) blocks of PS-P4VP whose structure varies with solvent polarity and is calcined to remove the block copolymer. Siloxane is in a dispersed phase with toluene as a solvent resulting in silica nanoparticle arrays, while siloxane is in a continuous phase with N, N-dimethylformamide (DMF) resulting in silica films with ordered mesopores. Since the pore size of silica films prepared in DMF is approximately 20 nm, the film has the ability to serve as a support for enzymes such as laccase.

  19. Liquid-crystalline ordering helps block copolymer self-assembly.

    PubMed

    Yu, Haifeng; Kobayashi, Takaomi; Yang, Huai

    2011-08-01

    Interaction between liquid-crystalline elastic deformation and microphase separation in liquid-crystalline block copolymers enables them to supramolecularly assemble into ordered nanostructures with high regularity. With the help of liquid-crystalline alignment, parallel and perpendicular patterning of nanostructures is fabricated with excellent reproducibility and mass production, which provides nanotemplates and nanofabrication processes for preparing varieties of nanomaterials. Furthermore, nanoscale microphase separation improves the optical performance of block-copolymer fi lms by eliminating the scattering of visible light, leading to advanced applications in optical devices and actuators. Recent progress in liquid-crystalline block copolymers, including their phase diagram, structure-property relationship, nanostructure control and nanotemplate applications, is reviewed. PMID:21910267

  20. Polarized Raman study of random copolymers of propylene with olefins

    NASA Astrophysics Data System (ADS)

    Gen, D. E.; Chernyshov, K. B.; Prokhorov, K. A.; Nikolaeva, G. Yu.; Sagitova, E. A.; Pashinin, P. P.; Kovalchuk, A. A.; Klyamkina, A. N.; Nedorezova, P. M.; Optov, V. A.; Shklyaruk, B. F.

    2010-06-01

    The polarized Raman spectroscopy is employed in the study of structural modifications in the films of isotactic polypropylene (PP) whose chain contains ethylene, 1-butene, 1-hexene, 1-octene, and 4-metyl-pentene-1, which represents an isomer of 1-hexene. It is demonstrated that the phase and conformational compositions of copolymer molecules depend on the comonomer content and the side-chain length of the second monomer. The content of the PP molecules in the helical conformation in the crystalline and amorphous phases of the copolymers monotonically decreases with increasing content of the second monomer. The decrease in the content of helical macromolecules in the crystalline phase is faster than the decrease in the amorphous phase. At a certain content of comonomers, the total content of the helical fragments decreases with increasing length of the side chain of the second monomer. The structures and Raman spectra of the copolymers of propylene with 1-hexene and 4-methyl-1-pentene are similar.