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Sample records for accelerates macrophage-mediated vascular

  1. Accelerated Vascular Aging as a Paradigm for Hypertensive Vascular Disease: Prevention and Therapy.

    Barton, Matthias; Husmann, Marc; Meyer, Matthias R

    2016-05-01

    Aging is considered the most important nonmodifiable risk factor for cardiovascular disease and death after age 28 years. Because of demographic changes the world population is expected to increase to 9 billion by the year 2050 and up to 12 billion by 2100, with several-fold increases among those 65 years of age and older. Healthy aging and prevention of aging-related diseases and associated health costs have become part of political agendas of governments around the world. Atherosclerotic vascular burden increases with age; accordingly, patients with progeria (premature aging) syndromes die from myocardial infarctions or stroke as teenagers or young adults. The incidence and prevalence of arterial hypertension also increases with age. Arterial hypertension-like diabetes and chronic renal failure-shares numerous pathologies and underlying mechanisms with the vascular aging process. In this article, we review how arterial hypertension resembles premature vascular aging, including the mechanisms by which arterial hypertension (as well as other risk factors such as diabetes mellitus, dyslipidemia, or chronic renal failure) accelerates the vascular aging process. We will also address the importance of cardiovascular risk factor control-including antihypertensive therapy-as a powerful intervention to interfere with premature vascular aging to reduce the age-associated prevalence of diseases such as myocardial infarction, heart failure, hypertensive nephropathy, and vascular dementia due to cerebrovascular disease. Finally, we will discuss the implementation of endothelial therapy, which aims at active patient participation to improve primary and secondary prevention of cardiovascular disease. PMID:27118295

  2. Engineered human vascularized constructs accelerate diabetic wound healing.

    Shen, Yu-I; Cho, Hongkwan; Papa, Arianne E; Burke, Jacqueline A; Chan, Xin Yi; Duh, Elia J; Gerecht, Sharon

    2016-09-01

    Stem cell-based therapy is emerging as a promising approach for chronic diabetic wounds, but strategies for optimizing both cellular differentiation and delivery remain as major obstacles. Here, we study bioengineered vascularized constructs as a therapeutic modality for diabetic wound healing. We developed a wound model in immunodeficient rodent and treated it with engineered vascularized constructs from endothelial progenitors or early vascular cells-derived from human induced pluripotent stem cells (hiPSCs) reprogrammed either from healthy donor or type-1 diabetic patient. We found that all vascularized constructs expedited wound closure and reperfusion, with endothelial progenitor constructs having the earliest maximum closure rate followed closely by healthy and diabetic hiPSC-derivative constructs. This was accompanied by rapid granulation layer formation and regression in all vascularized construct groups. Macrophage infiltration into the hydrogel matrix occurred during early stages of healing, seeming to facilitate rapid neovascularization of the wound that could then better persist in the vascularized constructs. Blood perfusion of the human vasculature could be detected after three days, indicating rapid integration with the host vasculature. Overall, we propose a potential therapeutic strategy using allograft or autologous vascularized constructs to treat type-1 diabetic wounds. This approach highlights the unprecedented prospects of designing patient-specific stem cell therapy. PMID:27328431

  3. Accelerating Vascularization in Polycaprolactone Scaffolds by Endothelial Progenitor Cells

    Singh, Shivani; Wu, Benjamin M.; Dunn, James C.Y.

    2011-01-01

    Vascularization is a major challenge in tissue engineering. The purpose of this study is to expedite the formation of blood vessels in porous polycaprolactone (PCL) scaffolds by the delivery of endothelial progenitor cells (EPCs). To establish a pro-angiogenic and pro-vasculogenic microenvironment, we employed EPCs seeded in PCL scaffold with surface-immobilized heparin and vascular endothelial growth factor (VEGF). EPCs seeded on scaffolds with VEGF exhibited phosphorylation of the receptor....

  4. Vascular health late after Kawasaki disease: implications for accelerated atherosclerosis

    Cheung, Yiu-Fai

    2014-01-01

    Kawasaki disease (KD), an acute vasculitis that primarily affects young children, is the most common acquired paediatric cardiovascular disease in developed countries. While sequelae of arterial inflammation in the acute phase of KD are well documented, its late effects on vascular health are increasingly unveiled. Late vascular dysfunction is characterized by structural alterations and functional impairment in term of arterial stiffening and endothelial dysfunction and shown to involve both ...

  5. Phosphate overload accelerates vascular aging in uremic patients

    Diego Brancaccio

    2006-05-01

    Full Text Available Vascular calcification is a very common event in patients affected by diabetes and chronic kidney disease (CKD. Recently, it has been well documented that abnormalities in mineral and bone metabolism in CKD patients are associated with increased morbidity and mortality. Elevated serum phosphate and calcium-phosphate product levels play an important role in the pathogenesis of vascular mineralization in uremic patients and also appear to be associated with increased cardiovascular mortality. Together with classical passive precipitation of calciumphosphate in soft tissues, during the last decade it has been demonstrated that inorganic phosphate may cause extraskeletal calcification directly through a real “ossification” of the tunica media in the vasculature of CKD patients. Therefore, control of phosphate retention is now an even more crucial target of treatment in patients affected by chronic kidney disease.

  6. Effect of gravitational acceleration, hypokinesia and hypodynamia on the structure of the intestinal vascular bed

    Nikitin, M. V.

    1980-01-01

    A series of experiments comparing single and combined effects of hypokinesia and gravitational acceleration on morphology of intestinal blood vessels are discussed. Results indicate that hypokinesia has a whole body nonspecific effect reflected even in an organ whose activity shows little or no change due to hypokinesia. In early hypokinetic stages blood redistribution caused anorexia, intestinal atonia, and secretory disruption. Destructive changes from further exposure include aneurisms, varicoses, extravascular movement of blood elements, and vascular wall muscle fiber degeneration. The effect of acceleration is greatest in the ventrodorsal direction. Changes due to acceleration then hypokinesia are like those due to hypokinesia alone; changes due to acceleration before and after hypokinesia are like those due to acceleration. Adaptation raises acceleration tolerance but the effects do not survive four-week hypokinesia.

  7. Adipose-derived Stromal Cells Overexpressing Vascular Endothelial Growth Factor Accelerate Mouse Excisional Wound Healing

    Nauta, Allison; Seidel, Catharina; Deveza, Lorenzo; Montoro, Daniel; Grova, Monica; Ko, Sae Hee; Hyun, Jeong; Geoffrey C Gurtner; Longaker, Michael T.; Yang, Fan

    2012-01-01

    Angiogenesis is essential to wound repair, and vascular endothelial growth factor (VEGF) is a potent factor to stimulate angiogenesis. Here, we examine the potential of VEGF-overexpressing adipose-derived stromal cells (ASCs) for accelerating wound healing using nonviral, biodegradable polymeric vectors. Mouse ASCs were transfected with DNA plasmid encoding VEGF or green fluorescent protein (GFP) using biodegradable poly (β-amino) esters (PBAE). Cells transfected using Lipofectamine 2000, a c...

  8. Oxygen dependence of human alveolar macrophage-mediated antibody-dependent cytotoxicity.

    Conkling, P.; Papermaster-Bender, G; Whitcomb, M; Sagone, A L

    1982-01-01

    We studied the metabolic characteristics of the human alveolar macrophage-mediated antibody-dependent cytotoxicity (ADCC) reaction, using an anti-D sensitized human erythrocyte target system. Metabolic experiments demonstrated a high resting rate of glucose metabolism in macrophages, but no oxidative metabolic burst was found to accompany the ADCC reaction. These findings were confirmed by oxygen consumption studies, showing a high resting rate of oxygen consumption by macrophages, but no cha...

  9. Interleukin-10 overexpression promotes Fas-ligand-dependent chronic macrophage-mediated demyelinating polyneuropathy.

    Dru S Dace

    Full Text Available BACKGROUND: Demyelinating polyneuropathy is a debilitating, poorly understood disease that can exist in acute (Guillain-Barré syndrome or chronic forms. Interleukin-10 (IL-10, although traditionally considered an anti-inflammatory cytokine, has also been implicated in promoting abnormal angiogenesis in the eye and in the pathobiology of autoimmune diseases such as lupus and encephalomyelitis. PRINCIPAL FINDINGS: Overexpression of IL-10 in a transgenic mouse model leads to macrophage-mediated demyelinating polyneuropathy. IL-10 upregulates ICAM-1 within neural tissues, promoting massive macrophage influx, inflammation-induced demyelination, and subsequent loss of neural tissue resulting in muscle weakness and paralysis. The primary insult is to perineural myelin followed by secondary axonal loss. Infiltrating macrophages within the peripheral nerves demonstrate a highly pro-inflammatory signature. Macrophages are central players in the pathophysiology, as in vivo depletion of macrophages using clodronate liposomes reverses the phenotype, including progressive nerve loss and paralysis. Macrophage-mediate demyelination is dependent on Fas-ligand (FasL-mediated Schwann cell death. SIGNIFICANCE: These findings mimic the human disease chronic idiopathic demyelinating polyneuropathy (CIDP and may also promote further understanding of the pathobiology of related conditions such as acute idiopathic demyelinating polyneuropathy (AIDP or Guillain-Barré syndrome.

  10. Improving hemocompatibility and accelerating endothelialization of vascular stents by a copper-titanium film.

    Liu, Hengquan; Pan, Changjiang; Zhou, Shijie; Li, Junfeng; Huang, Nan; Dong, Lihua

    2016-12-01

    Bio-inorganic films and drug-eluting coatings are usually used to improve the hemocompatibility and inhibit restenosis of vascular stent; however, above bio-performances couldn't combine together with single materials. In the present study, we reported a simple approach to fabricate a metal film with the aim of imparting the stent with good blood compatibility and accelerating endothelialization. The films with various ratios of Cu and Ti were prepared through the physical vapor deposition. Phase structure and element composition were investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The releasing volume of copper ion in Cu/Ti film was determined by immersing test. The hemolysis ratio, platelet adhesion and clotting time were applied to evaluate the hemocompatibility. The proliferative behaviors of endothelial cells and smooth muscle cells under certain copper concentration were investigated in vitro and in vivo. Results indicated that copper-titanium films exhibited good hemocompatibility in vitro; however, the increase of Cu/Ti ratio could lead to increasing hemolysis ratio. Endothelial cells displayed more proliferative than smooth muscle cells when the copper concentration was <7.5μg/ml, however both cells tended to apoptosis to some degree when the copper concentration was increased. The complete endothelialization of the film with low copper in vivo was observed at the 2nd week, indicating that the copper-titanium film with the lower copper concentration could promote endothelialization. Therefore, the inorganic copper-titanium film could be potential biomaterials to improve blood compatibility and accelerating endothelialization of vascular stents. PMID:27612815

  11. Apoptotic CD8 T-lymphocytes disable macrophage-mediated immunity to Trypanosoma cruzi infection.

    Cabral-Piccin, M P; Guillermo, L V C; Vellozo, N S; Filardy, A A; Pereira-Marques, S T; Rigoni, T S; Pereira-Manfro, W F; DosReis, G A; Lopes, M F

    2016-01-01

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. CD8 T-lymphocytes help to control infection, but apoptosis of CD8 T cells disrupts immunity and efferocytosis can enhance parasite infection within macrophages. Here, we investigate how apoptosis of activated CD8 T cells affects M1 and M2 macrophage phenotypes. First, we found that CD8 T-lymphocytes and inflammatory monocytes/macrophages infiltrate peritoneum during acute T. cruzi infection. We show that treatment with anti-Fas ligand (FasL) prevents lymphocyte apoptosis, upregulates type-1 responses to parasite antigens, and reduces infection in macrophages cocultured with activated CD8 T cells. Anti-FasL skews mixed M1/M2 macrophage profiles into polarized M1 phenotype, both in vitro and following injection in infected mice. Moreover, inhibition of T-cell apoptosis induces a broad reprogramming of cytokine responses and improves macrophage-mediated immunity to T. cruzi. The results indicate that disposal of apoptotic CD8 T cells increases M2-macrophage differentiation and contributes to parasite persistence. PMID:27195678

  12. Platelets accelerate gastric ulcer healing through presentation of vascular endothelial growth factor

    Wallace, John L; Dicay, Michael; McKnight, Webb; Dudar, Genevieve K

    2006-01-01

    Platelets contain an array of growth factors that can modulate healing processes, including both pro- (e.g., vascular endothelial growth factor (VEGF)) and antiangiogenic (e.g., endostatin) factors. Previous studies have shown that circulating platelets contribute significantly to gastric ulcer healing, acting as a delivery system for these growth factors to the site of injury. In this study, we examined the effects of orally administered human platelets on the healing of gastric ulcers in ra...

  13. MFAP4 Promotes Vascular Smooth Muscle Migration, Proliferation and Accelerates Neointima Formation

    Schlosser, Anders; Pilecki, Bartosz; Hemstra, Line E; Kejling, Karin; Kristmannsdottir, Gudlaug B; Wulf-Johansson, Helle; Moeller, Jesper B; Füchtbauer, Ernst-Martin; Nielsen, Ole; Kirketerp-Møller, Katrine; Dubey, Lalit K; Hansen, Pernille B L; Stubbe, Jane; Wrede, Christoph; Hegermann, Jan; Ochs, Matthias; Rathkolb, Birgit; Schrewe, Anja; Bekeredjian, Raffi; Wolf, Eckhard; Gailus-Durner, Valérie; Fuchs, Helmut; de Angelis, Martin Hrabě; Lindholt, Jes S; Holmskov, Uffe; Sorensen, Grith L

    2016-01-01

    inhibitors of focal adhesion kinase and downstream kinases. In addition, we showed that MFAP4 promotes monocyte chemotaxis in integrin αVβ3-dependent manner. CONCLUSIONS: MFAP4 regulates integrin αVβ3-induced VSMC proliferation and migration, as well as monocyte chemotaxis, and accelerates neointimal...

  14. Accelerated ischemic vascular retinopathy after intravitreally injected bevacizumab for central retinal vein occlusion in elderly patients

    Isola V

    2013-03-01

    Full Text Available Vincenzo Isola,1 Alfredo Pece,1,2 Claudio Massironi,1 Simone Reposi,1 Fabio Dimastrogiovanni11Department of Ophthalmology, Melegnano Hospital, 2Fondazione Retina 3000, Milano, ItalyBackground: Ischemic changes in the retinal circulation are an uncommon but severe adverse vascular reaction to intravitreal bevacizumab (Avastin®, Genentech, San Francisco, CA, USA/Roche, Basel, Switzerland for central retinal vein occlusion (CRVO. In the two cases reported here, ischemic changes in the retina vasculature following intravitreal bevacizumab for CRVO were observed with the aim of describing the clinical and angiographic features of these changes.Methods: Two elderly patients with recent-onset CRVO received one off-label intravitreal injection of bevacizumab 0.05 mL/1.25 mg.Results: In Case 1, the patient's pre-treatment visual acuity was 20/400. At 3 weeks post injection, the patient could count fingers at a distance of 1 ft (30 cm and fluorescein angiography showed reduction in intraretinal hemorrhages and areas of retinal non-perfusion. However, at 6 weeks these were markedly increased compared with those seen in the photograph taken 3 weeks after treatment. In Case 2, the patient's pre-treatment visual acuity was 20/200. At 1 month post injection, vision had decreased to 20/400 and fluorescein angiography showed severe macular ischemia with a remarkable capillary dropout throughout the macula.Conclusion: Ischemic retinal injury may be an uncommon but severe adverse vascular reaction to intravitreal bevacizumab for CRVO. Although progression of retinal ischemia in CRVO could be observed shortly after intravitreal bevacizumab, whether this is a drug- or procedure-related effect or part of the natural history of the condition remains uncertain.Keywords: Avastin, ischemia, macular infarction, intraretinal hemorrhage, retinal non-perfusion

  15. Inhibition of the proliferation and acceleration of migration of vascular endothelial cells by increased cysteine-rich motor neuron 1

    Nakashima, Yukiko; Morimoto, Mayuka [Department of Immunobiology, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women' s University, 11-68 Koshien Kyuban-cho, Nishinomiya, Hyogo 663-8179 (Japan); Toda, Ken-ichi [Department of Dermatology, Kitano Hospital, The Tazuke Kofukai Nedical Institute, 2-4-20 Ohgimachi, Kita-ku, Osaka 530-8480 (Japan); Shinya, Tomohiro; Sato, Keizo [Department of Clinical Biochemistry, School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, Nobeoka, Miyazaki 882-8508 (Japan); Takahashi, Satoru, E-mail: imwalrus@mukogawa-u.ac.jp [Department of Immunobiology, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women' s University, 11-68 Koshien Kyuban-cho, Nishinomiya, Hyogo 663-8179 (Japan); Institute for Biosciences, Mukogawa Women' s University, 11-68 Koshien Kyuban-cho, Nishinomiya, Hyogo 663-8179 (Japan)

    2015-07-03

    Cysteine-rich motor neuron 1 (CRIM1) is upregulated only in extracellular matrix gels by angiogenic factors such as vascular endothelial growth factor (VEGF). It then plays a critical role in the tube formation of endothelial cells. In the present study, we investigated the effects of increased CRIM1 on other endothelial functions such as proliferation and migration. Knock down of CRIM1 had no effect on VEGF-induced proliferation or migration of human umbilical vein endothelial cells (HUVECs), indicating that basal CRIM1 is not involved in the proliferation or migration of endothelial cells. Stable CRIM1-overexpressing endothelial F-2 cells, termed CR1 and CR2, were constructed, because it was difficult to prepare monolayer HUVECs that expressed high levels of CRIM1. Proliferation was reduced and migration was accelerated in both CR1 and CR2 cells, compared with normal F-2 cells. Furthermore, the transient overexpression of CRIM1 resulted in decreased proliferation and increased migration of bovine aortic endothelial cells. In contrast, neither proliferation nor migration of COS-7 cells were changed by the overexpression of CRIM1. These results demonstrate that increased CRIM1 reduces the proliferation and accelerates the migration of endothelial cells. These CRIM1 effects might contribute to tube formation of endothelial cells. CRIM1 induced by angiogenic factors may serve as a regulator in endothelial cells to switch from proliferating cells to morphological differentiation. - Highlights: • CRIM1 was upregulated only in tubular endothelial cells, but not in monolayers. • Increased CRIM1 reduced the proliferation of endothelial cells. • Increased CRIM1 accelerated the migration of endothelial cells. • Increased CRIM1 had no effect on the proliferation or migration of COS-7 cells.

  16. Inhibition of the proliferation and acceleration of migration of vascular endothelial cells by increased cysteine-rich motor neuron 1

    Cysteine-rich motor neuron 1 (CRIM1) is upregulated only in extracellular matrix gels by angiogenic factors such as vascular endothelial growth factor (VEGF). It then plays a critical role in the tube formation of endothelial cells. In the present study, we investigated the effects of increased CRIM1 on other endothelial functions such as proliferation and migration. Knock down of CRIM1 had no effect on VEGF-induced proliferation or migration of human umbilical vein endothelial cells (HUVECs), indicating that basal CRIM1 is not involved in the proliferation or migration of endothelial cells. Stable CRIM1-overexpressing endothelial F-2 cells, termed CR1 and CR2, were constructed, because it was difficult to prepare monolayer HUVECs that expressed high levels of CRIM1. Proliferation was reduced and migration was accelerated in both CR1 and CR2 cells, compared with normal F-2 cells. Furthermore, the transient overexpression of CRIM1 resulted in decreased proliferation and increased migration of bovine aortic endothelial cells. In contrast, neither proliferation nor migration of COS-7 cells were changed by the overexpression of CRIM1. These results demonstrate that increased CRIM1 reduces the proliferation and accelerates the migration of endothelial cells. These CRIM1 effects might contribute to tube formation of endothelial cells. CRIM1 induced by angiogenic factors may serve as a regulator in endothelial cells to switch from proliferating cells to morphological differentiation. - Highlights: • CRIM1 was upregulated only in tubular endothelial cells, but not in monolayers. • Increased CRIM1 reduced the proliferation of endothelial cells. • Increased CRIM1 accelerated the migration of endothelial cells. • Increased CRIM1 had no effect on the proliferation or migration of COS-7 cells

  17. Interleukin-2 protects neonatal mice from lethal herpes simplex virus infection: a macrophage-mediated, gamma interferon-induced mechanism.

    Kohl, S; Loo, L S; Drath, D B; Cox, P

    1989-02-01

    Administration of human recombinant interleukin-2 (IL-2) protected neonatal mice from a lethal herpes simplex virus (HSV) infection. Protection was not associated with viral antibody production, enhanced natural killer cell cytotoxicity, or intrinsic resistance of macrophages to viral infection. Protection was associated with increased macrophage-mediated antiviral antibody-dependent cellular cytotoxicity (ADCC). Spleen cells from IL-2-treated neonatal mice and from neonatal mice that were treated in vitro with IL-2 transferred protection to neonatal mice. These cells, by adherence, silica, and asialo GM 1 antibody treatment, were shown to be macrophages. IL-2 treatment in vitro enhanced the neonatal macrophages' ADCC function and superoxide release. Similar protection was induced by gamma interferon (IFN-gamma)-treated spleen cells. Antibody to IFN-gamma ablated both IFN-gamma- and IL-2-induced protection by adherent spleen cells. Thus, IL-2-mediated protection against murine neonatal HSV infection was affected by stimulated macrophage activity, via helper T cell-produced IFN-gamma. PMID:2492588

  18. Immune modulation with sulfasalazine attenuates immunopathogenesis but enhances macrophage-mediated fungal clearance during Pneumocystis pneumonia.

    Jing Wang

    Full Text Available Although T cells are critical for host defense against respiratory fungal infections, they also contribute to the immunopathogenesis of Pneumocystis pneumonia (PcP. However, the precise downstream effector mechanisms by which T cells mediate these diverse processes are undefined. In the current study the effects of immune modulation with sulfasalazine were evaluated in a mouse model of PcP-related Immune Reconstitution Inflammatory Syndrome (PcP-IRIS. Recovery of T cell-mediated immunity in Pneumocystis-infected immunodeficient mice restored host defense, but also initiated the marked pulmonary inflammation and severe pulmonary function deficits characteristic of IRIS. Sulfasalazine produced a profound attenuation of IRIS, with the unexpected consequence of accelerated fungal clearance. To determine whether macrophage phagocytosis is an effector mechanism of T cell-mediated Pneumocystis clearance and whether sulfasalazine enhances clearance by altering alveolar macrophage phagocytic activity, a novel multispectral imaging flow cytometer-based method was developed to quantify the phagocytosis of Pneumocystis in vivo. Following immune reconstitution, alveolar macrophages from PcP-IRIS mice exhibited a dramatic increase in their ability to actively phagocytose Pneumocystis. Increased phagocytosis correlated temporally with fungal clearance, and required the presence of CD4(+ T cells. Sulfasalazine accelerated the onset of the CD4(+ T cell-dependent alveolar macrophage phagocytic response in PcP-IRIS mice, resulting in enhanced fungal clearance. Furthermore, sulfasalazine promoted a TH2-polarized cytokine environment in the lung, and sulfasalazine-enhanced phagocytosis of Pneumocystis was associated with an alternatively activated alveolar macrophage phenotype. These results provide evidence that macrophage phagocytosis is an important in vivo effector mechanism for T cell-mediated Pneumocystis clearance, and that macrophage phenotype can be altered

  19. Biostability and macrophage-mediated foreign body reaction of silicone-modified polyurethanes.

    Christenson, Elizabeth M; Dadsetan, Mahrokh; Hiltner, Anne

    2005-08-01

    biodegradation of the polyether or polycarbonate soft segments; however, the rate of chain scission of PEU-S and PCU-S seemed to be slower than the control polyurethanes. To verify this finding and to quantify the rate of chain scission in order to predict long-term biostability, an in vitro environment that simulated the microenvironment at the adherent cell-material interface was used to accelerate the biodegradation of the polyurethanes. Polyurethane films were treated in vitro for up to 36 days in 20% hydrogen peroxide/0.1M cobalt chloride solution at 37 degrees Celsius. Characterization with attenuated total reflectance-Fourier transform infrared and scanning electron microscopy showed soft segment and hard segment degradation consistent with the chemical changes observed after long-term in vivo treatment. The biostability ranking of these four materials based on rate of chain scission and surface pitting was as follows: PEU modification increased the biostability of the PEU and PCU elastomers while maintaining the thermoplastic elastomeric properties. PMID:16201029

  20. Accelerator

    The invention claims equipment for stabilizing the position of the front covers of the accelerator chamber in cyclic accelerators which significantly increases accelerator reliability. For stabilizing, it uses hydraulic cushions placed between the electromagnet pole pieces and the front chamber covers. The top and the bottom cushions are hydraulically connected. The cushions are disconnected and removed from the hydraulic line using valves. (J.P.)

  1. Calcification of human vascular smooth muscle cells: associations with osteoprotegerin expression and acceleration by high-dose insulin

    Olesen, Ping; Knudsen, Kirsten Quyen Nguyen; Wogensen, Lise;

    2007-01-01

    and measured the expression of the bone-related molecule osteoprotegerin (OPG). Human vascular smooth muscle cells (VSMCs) were grown from aorta from kidney donors. Induction of calcification was performed with beta-glycerophosphate. The influence of insulin (200 microU/ml or 1,000 microU/ml) on calcification...... not. Calcified cells expressed ALP and BSP activity in high levels. In conclusion, high concentration of insulin enhances in vitro-induced calcification in VSMCs. Altered OPG levels during the calcification raise the possibility that OPG may have a potent function in regulating the calcification...

  2. NF-κB/AP-1-Targeted Inhibition of Macrophage-Mediated Inflammatory Responses by Depigmenting Compound AP736 Derived from Natural 1,3-Diphenylpropane Skeleton

    Van Thai Ha

    2014-01-01

    Full Text Available AP736 was identified as an antimelanogenic drug that can be used for the prevention of melasma, freckles, and dark spots in skin by acting as a suppressor of melanin synthesis and tyrosinase expression. Since macrophage-mediated inflammatory responses are critical for skin health, here we investigated the potential anti-inflammatory activity of AP736. The effects of AP736 on various inflammatory events such as nitric oxide (NO/prostaglandin (PG E2 production, inflammatory gene expression, phagocytic uptake, and morphological changes were examined in RAW264.7 cells. AP736 was found to strongly inhibit the production of both NO and PGE2 in lipopolysaccharide- (LPS- treated RAW264.7 cells. In addition, AP736 strongly inhibited both LPS-induced morphological changes and FITC-dextran-induced phagocytic uptake. Furthermore, AP736 also downregulated the expression of multiple inflammatory genes, such as inducible NO synthase (iNOS, cyclooxygenase- (COX- 2, and interleukin- (IL- 1β in LPS-treated RAW264.7 cells. Transcription factor analysis, including upstream signalling events, revealed that both NF-κB and AP-1 were targeted by AP736 via inhibition of the IKK/IκBα and IRAK1/TAK1 pathways. Therefore, our results strongly suggest that AP736 is a potential anti-inflammatory drug due to its suppression of NF-κB-IKK/IκBα and AP-1-IRAK1/TAK1 signalling, which may make AP736 useful for the treatment of macrophage-mediated skin inflammation.

  3. Static pressure accelerates ox-LDL-induced cholesterol accumulation via SREBP-1-mediated caveolin-1 downregulation in cultured vascular smooth muscle cells

    Research highlights: → Vertical static pressure accelerates ox-LDL-induced cholesterol accumulation in cultured vascular smooth muscle cells. → Static pressure induces SREBP-1 activation. → Static pressure downregulates the expressions of caveolin-1 by activating SREBP-1. → Static pressure also downregulates the transcription of ABCA1 by activating SREBP-1. → Static pressure increases ox-LDL-induced cholesterol accumulation by SREBP-1-mediated caveolin-1 downregulation in vascular smooth muscle cells cultured in vitro. -- Abstract: Objective: To investigate the effect of static pressure on cholesterol accumulation in vascular smooth muscle cells (VSMCs) and its mechanism. Methods: Rat-derived VSMC cell line A10 treated with 50 mg/L ox-LDL and different static pressures (0, 60, 90, 120, 150, 180 mm Hg) in a custom-made pressure incubator for 48 h. Intracellular lipid droplets and lipid levels were assayed by oil red O staining and HPLC; The mRNA levels of caveolin-1 and ABCA1, the protein levels of caveolin-1 SREBP-1 and mature SREBP-1 were respectively detected by RT-PCR or western blot. ALLN, an inhibitor of SREBP metabolism, was used to elevate SREBP-1 protein level in VSMCs treated with static pressure. Results: Static pressures significantly not only increase intracellular lipid droplets in VSMCs, but also elevate cellular lipid content in a pressure-dependent manner. Intracellular free cholesterol (FC), cholesterol ester (CE), total cholesterol (TC) were respectively increased from 60.5 ± 2.8 mg/g, 31.8 ± 0.7 mg/g, 92.3 ± 2.1 mg/g at atmosphere pressure (ATM, 0 mm Hg) to 150.8 ± 9.4 mg/g, 235.9 ± 3.0 mg/g, 386.7 ± 6.4 mg/g at 180 mm Hg. At the same time, static pressures decrease the mRNA and protein levels of caveolin-1, and induce the activation and nuclear translocation of SREBP-1. ALLN increases the protein level of mature SREBP-1 and decreases caveolin-1 expression, so that cellular lipid levels were upregulated. Conclusion: Static

  4. Vascular Cures

    ... our CEO Board of Directors Scientific Advisory Board History of Vascular Cures Impact Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic ...

  5. Melanoma exosome induction of endothelial cell GM-CSF in pre-metastatic lymph nodes may result in different M1 and M2 macrophage mediated angiogenic processes.

    Hood, Joshua L

    2016-09-01

    Angiogenesis is a key process in the preparation of lymph nodes for melanoma metastasis. Granulocyte macrophage colony stimulating factor (GM-CSF) induces hypoxia inducible factor 1 alpha (HIF-1α) in M1 or HIF-2α in M2 polarized macrophages. HIF-1α promotes neoangiogenesis while HIF-2α facilitates morphogenic normalization of neovasculature. Melanoma exosomes induce GM-CSF expression by endothelial cells in vitro and HIF-1α expression in pre-metastatic lymph nodes in vivo. This suggest a relationship between melanoma exosome induced endothelial GM-CSF and macrophage mediated angiogenesis in lymph nodes. Theoretically, induction of endothelial cell derived GM-CSF by melanoma exosomes mediates different angiogenic functions in pre-metastatic lymph nodes depending on subcapsular sinus (SCS) macrophage polarity. To explore this hypothesis, experiments utilizing melanoma exosomes in a lymph node model are outlined. Despite their opposing immune functions, indirect melanoma exosome stimulation of M1 or M2 SCS macrophages via endothelial derived GM-CSF in lymph nodes may induce different although complementary pro-tumor angiogenic processes. PMID:27515216

  6. Acceleration of aneurysm healing by P(DLLA-co-TMC)-coated coils enabling the controlled release of vascular endothelial growth factor.

    Wang, Qiujing; Gao, Yuyuan; Sun, Xinlin; Ji, Bin; Cui, Xubo; Liu, Yaqi; Zheng, Tao; Chen, Chengwei; Jiang, Xiaodan; Zhu, Aiping; Quan, Daping

    2014-08-01

    Since the introduction of the detachable coil in endovascular treatment of intracranial aneurysms, the in-hospital mortality rate has been significantly decreased. Recurrence of the aneurysm remains the major drawback of using detachable coils. We prepared a bioactive coil coated with poly(d,l-lactide)-7co-(1,3-trimethylene carbonate) (P(DLLA-co-TMC)), a novel copolymer for controlling the release of vascular endothelial growth factor (VEGF). Platinum coils were prepared by successive coating with cationic P(DLLA-co-TMC) and anionic heparin. Then, recombinant human VEGF-165 (rhVEGF) was immobilized by affinity binding to heparin. The morphological characteristics and sustained in vitro release of rhVEGF were examined using scanning electron microscopy and enzyme-linked immunosorbent assay, respectively. The efficacy of these novel coils modified by P(DLLA-co-TMC)/rhVEGF was tested using a common carotid artery aneurysm model in rats. Experimental aneurysms were embolized with unmodified, P(DLLA-co-TMC)/heparin-coated or P(DLLA-co-TMC)/rhVEGF-coated platinum coils (n = 18). The coils were removed on days 15, 30 and 90 after insertion, and the histological and immunohistochemical analysis of factor VIII was performed to confirm the presence of endothelial cells in the organized area. In addition, the controlled in vivo release of VEGF was confirmed by Western blotting analysis. The release of VEGF tended to increase during the whole period and no burst release was observed. In the group treated with P(DLLA-co-TMC)/rhVEGF-coated platinum coils, clot organization and endothelial cell proliferation were accelerated. The immunohistochemistry study showed that the expression of factor VIII was found in the P(DLLA-co-TMC)/rhVEGF-coated coil group but not in the other two groups. Furthermore, Western blotting analysis confirmed that the major released VEGF in the aneurysm sac was from the P(DLLA-co-TMC)/VEGF-coated coil. P(DLLA-co-TMC)/rhVEGF-coated platinum coils can

  7. Acceleration of aneurysm healing by P(DLLA-co-TMC)-coated coils enabling the controlled release of vascular endothelial growth factor

    Since the introduction of the detachable coil in endovascular treatment of intracranial aneurysms, the in-hospital mortality rate has been significantly decreased. Recurrence of the aneurysm remains the major drawback of using detachable coils. We prepared a bioactive coil coated with poly(d,l-lactide)-7co-(1,3-trimethylene carbonate) (P(DLLA-co-TMC)), a novel copolymer for controlling the release of vascular endothelial growth factor (VEGF). Platinum coils were prepared by successive coating with cationic P(DLLA-co-TMC) and anionic heparin. Then, recombinant human VEGF-165 (rhVEGF) was immobilized by affinity binding to heparin. The morphological characteristics and sustained in vitro release of rhVEGF were examined using scanning electron microscopy and enzyme-linked immunosorbent assay, respectively. The efficacy of these novel coils modified by P(DLLA-co-TMC)/rhVEGF was tested using a common carotid artery aneurysm model in rats. Experimental aneurysms were embolized with unmodified, P(DLLA-co-TMC)/heparin-coated or P(DLLA-co-TMC)/rhVEGF-coated platinum coils (n = 18). The coils were removed on days 15, 30 and 90 after insertion, and the histological and immunohistochemical analysis of factor VIII was performed to confirm the presence of endothelial cells in the organized area. In addition, the controlled in vivo release of VEGF was confirmed by Western blotting analysis. The release of VEGF tended to increase during the whole period and no burst release was observed. In the group treated with P(DLLA-co-TMC)/rhVEGF-coated platinum coils, clot organization and endothelial cell proliferation were accelerated. The immunohistochemistry study showed that the expression of factor VIII was found in the P(DLLA-co-TMC)/rhVEGF-coated coil group but not in the other two groups. Furthermore, Western blotting analysis confirmed that the major released VEGF in the aneurysm sac was from the P(DLLA-co-TMC)/VEGF-coated coil. P(DLLA-co-TMC)/rhVEGF-coated platinum coils can

  8. Vascular MR

    This project investigates cardiac gated gradient echo pulses sequences for vascular MR imaging. These pulse sequences have been used to acquire and display MR projection angiograms. The authors have applied these methods in two distinct populations of patients for evaluation and comparison with standard angiography. Twenty patients with abdominal aortic aneurysms, and 35 patients with aortoiliac atherosclerotic disease or peripheral vascular disease were investigated using this method and the results are presented

  9. Vascular Dementia

    Maria Alekseyevna Cherdak; O. V. Uspenskaya

    2015-01-01

    Vascular dementia is one of the most common causes of dementia after Alzheimer's disease, causing around 15% of cases. However, unlike Alzheimer's disease, there are no licensed treatments for vascular dementia. Progress in the specialty has been difficult because of uncertainties over disease classification and diagnostic criteria, controversy over the exact nature of the relation between cerebrovascular pathology and cognitive impairment, and the paucity of identifiable tractable treatment ...

  10. 21-O-Angeloyltheasapogenol E3, a Novel Triterpenoid Saponin from the Seeds of Tea Plants, Inhibits Macrophage-Mediated Inflammatory Responses in a NF-κB-Dependent Manner

    Woo Seok Yang

    2014-01-01

    Full Text Available 21-O-Angeloyltheasapogenol E3 (ATS-E3 is a triterpenoid saponin recently isolated from the seeds of the tea tree Camellia sinensis (L. O. Kuntze. ATS-E3 has several beneficial properties including anti-inflammatory, antidiabetic, antiatherosclerotic, and anticancer effects. Unlike other phenolic compounds isolated from tea plants, there are no studies reporting the pharmacological action of ATS-E3. In this study, we therefore aimed to explore the cellular and molecular inhibitory activities of ATS-E3 in macrophage-mediated inflammatory responses. ATS-E3 remarkably diminished cellular responses of macrophages such as FITC-dextran-induced phagocytic uptake, sodium nitroprusside- (SNP- induced radical generation, and LPS-induced nitric oxide (NO production. Analysis of its molecular activity showed that this compound significantly suppressed the expression of inducible NO synthase (iNOS, nuclear translocation of nuclear factor- (NF- κB subunits (p50 and p65, phosphorylation of inhibitor of κB kinase (IKK, and the enzyme activity of AKT1. Taken together, the novel triterpenoid saponin compound ATS-E3 contributes to the beneficial effects of tea plants by exerting anti-inflammatory and antioxidative activities in an AKT/IKK/NF-κB-dependent manner.

  11. What Is Vascular Disease?

    ... our CEO Board of Directors Scientific Advisory Board History of Vascular Cures Impact Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic ...

  12. Diabetes and Vascular Disease

    ... our CEO Board of Directors Scientific Advisory Board History of Vascular Cures Impact Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic ...

  13. Cell-based strategies for vascular regeneration.

    Zou, Tongqiang; Fan, Jiabing; Fartash, Armita; Liu, Haifeng; Fan, Yubo

    2016-05-01

    Vascular regeneration is known to play an essential role in the repair of injured tissues mainly through accelerating the repair of vascular injury caused by vascular diseases, as well as the recovery of ischemic tissues. However, the clinical vascular regeneration is still challenging. Cell-based therapy is thought to be a promising strategy for vascular regeneration, since various cells have been identified to exert important influences on the process of vascular regeneration such as the enhanced endothelium formation on the surface of vascular grafts, and the induction of vessel-like network formation in the ischemic tissues. Here are a vast number of diverse cell-based strategies that have been extensively studied in vascular regeneration. These strategies can be further classified into three main categories, including cell transplantation, construction of tissue-engineered grafts, and surface modification of scaffolds. Cells used in these strategies mainly refer to terminally differentiated vascular cells, pluripotent stem cells, multipotent stem cells, and unipotent stem cells. The aim of this review is to summarize the reported research advances on the application of various cells for vascular regeneration, yielding insights into future clinical treatment for injured tissue/organ. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1297-1314, 2016. PMID:26864677

  14. Fetal origin of vascular aging

    Shailesh Pitale

    2011-01-01

    Full Text Available Aging is increasingly regarded as an independent risk factor for development of cardiovascular diseases such as atherosclerosis and hypertension and their complications (e.g. MI and Stroke. It is well known that vascular disease evolve over decades with progressive accumulation of cellular and extracellular materials and many inflammatory processes. Metabolic syndrome, obesity and diabetes are conventionally recognized as risk factors for development of coronary vascular disease (CVD. These conditions are known to accelerate ageing process in general and vascular ageing in particular. Adverse events during intrauterine life may programme organ growth and favour disease later in life, popularly known as, ′Barker′s Hypothesis′. The notion of fetal programming implies that during critical periods of prenatal growth, changes in the hormonal and nutritional milieu of the conceptus may alter the full expression of the fetal genome, leading to permanent effects on a range of physiological.

  15. Society for Vascular Medicine

    ... and find out! Patient Information Pages from Vascular Medicine August 2016 The Vascular Laboratory More info for ... Learn more. Trending Now: Hot Topics in Vascular Medicine Video Series Fibromuscular Dysplasia (FMD) with Drs. Jeffrey ...

  16. Molecular signal transduction in vascular cell apoptosis

    2001-01-01

    Apoptosis is a form of genetically programmed cell death, which plays a key role in regulation of cellularity in a variety of tissue and cell types including the cardiovascular tissues. Under both physiological and pathophysiological conditions, various biophysiological and biochemical factors, including mechanical forces, reactive oxygen and nitrogen species, cytokines, growth factors, oxidized lipoproteins, etc., may influence apoptosis of vascular cells. The Fas/Fas ligand/caspase death-signaling pathway, Bcl-2 protein family/mitochondria, the tumor suppressive gene p53, and the proto-oncogene c-myc may be activated in atherosclerotic lesions, and mediates vascular apoptosis during the development of atherosclerosis. Abnormal expression and dysfunction of these apoptosis-regulating genes may attenuate or accelerate vascular cell apoptosis and affect the integrity and stability of atherosclerotic plaques. Clarification of the molecular mechanism that regulates apoptosis may help design a new strategy for treatment of atherosclerosis and its major complication, the acute vascular syndromes.

  17. Heart and vascular services

    ... branch of medicine that focuses on the cardiovascular system. ... Circulatory system; Vascular system; Cardiovascular system ... to diagnose, monitor or treat diseases of the circulatory and vascular system include: Cardiac CT for calcium scoring Cardiac MRI ...

  18. Collagen vascular disease

    ... this page: //medlineplus.gov/ency/article/001223.htm Collagen vascular disease To use the sharing features on this page, ... were previously said to have "connective tissue" or "collagen vascular" disease. We now have names for many of many ...

  19. Can Accelerators Accelerate Learning?

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  20. How to Prevent Vascular Disease

    ... our CEO Board of Directors Scientific Advisory Board History of Vascular Cures Impact Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic ...

  1. Plasma accelerators

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  2. Linear Accelerators

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics.

  3. Strategic Plan for Lung Vascular Research

    Erzurum, Serpil; Rounds, Sharon I.; Stevens, Troy; Aldred, Micheala; Aliotta, Jason; Archer, Stephen L.; Asosingh, Kewal; Balaban, Robert; Bauer, Natalie; Bhattacharya, Jahar; Bogaard, Harm; Choudhary, Gaurav; Dorn, Gerald W.; Dweik, Raed; Fagan, Karen; Fallon, Michael; Finkel, Toren; Geraci, Mark; Gladwin, Mark T.; Hassoun, Paul M.; Humbert, Marc; Kaminski, Naftali; Kawut, Steven M.; Loscalzo, Joseph; McDonald, Donald; McMurtry, Ivan F.; Newman, John; Nicolls, Mark; Rabinovitch, Marlene; Shizuru, Judy; Oka, Masahiko; Polgar, Peter; Rodman, David; Schumacker, Paul; Stenmark, Kurt; Tuder, Rubin; Voelkel, Norbert; Sullivan, Eugene; Weinshilboum, Richard; Yoder, Mervin C.; Zhao, Yingming; Gail, Dorothy; Moore, Timothy M.

    2010-01-01

    The Division of Lung Diseases of the National Heart, Lung, and Blood Institute, with the Office of Rare Diseases Research, held a workshop to identify priority areas and strategic goals to enhance and accelerate research that will result in improved understanding of the lung vasculature, translational research needs, and ultimately the care of patients with pulmonary vascular diseases. Multidisciplinary experts with diverse experience in laboratory, translational, and clinical studies identified seven priority areas and discussed limitations in our current knowledge, technologies, and approaches. The focus for future research efforts include the following: (1) better characterizing vascular genotype–phenotype relationships and incorporating systems biology approaches when appropriate; (2) advancing our understanding of pulmonary vascular metabolic regulatory signaling in health and disease; (3) expanding our knowledge of the biologic relationships between the lung circulation and circulating elements, systemic vascular function, and right heart function and disease; (4) improving translational research for identifying disease-modifying therapies for the pulmonary hypertensive diseases; (5) establishing an appropriate and effective platform for advancing translational findings into clinical studies testing; and (6) developing the specific technologies and tools that will be enabling for these goals, such as question-guided imaging techniques and lung vascular investigator training programs. Recommendations from this workshop will be used within the Lung Vascular Biology and Disease Extramural Research Program for planning and strategic implementation purposes. PMID:20833821

  4. Imaging Pediatric Vascular Lesions.

    Nguyen, Tuyet A; Krakowski, Andrew C; Naheedy, John H; Kruk, Peter G; Friedlander, Sheila Fallon

    2015-12-01

    Vascular anomalies are commonly encountered in pediatric and dermatology practices. Most of these lesions are benign and easy to diagnose based on history and clinical exam alone. However, in some cases the diagnosis may not be clear. This may be of particular concern given that vascular anomalies may occasionally be associated with an underlying syndrome, congenital disease, or serious, life-threatening condition. Defining the type of vascular lesion early and correctly is particularly important to determine the optimal approach to management and treatment of each patient. The care of pediatric patients often requires collaboration from a multitude of specialties including pediatrics, dermatology, plastic surgery, radiology, ophthalmology, and neurology. Although early characterization of vascular lesions is important, consensus guidelines regarding the evaluation and imaging of vascular anomalies does not exist to date. Here, the authors provide an overview of pediatric vascular lesions, current classification systems for characterizing these lesions, the various imaging modalities available, and recommendations for appropriate imaging evaluation. PMID:26705446

  5. Imaging Pediatric Vascular Lesions

    Nguyen, Tuyet A.; Krakowski, Andrew C.; Naheedy, John H.; Kruk, Peter G.

    2015-01-01

    Vascular anomalies are commonly encountered in pediatric and dermatology practices. Most of these lesions are benign and easy to diagnose based on history and clinical exam alone. However, in some cases the diagnosis may not be clear. This may be of particular concern given that vascular anomalies may occasionally be associated with an underlying syndrome, congenital disease, or serious, life-threatening condition. Defining the type of vascular lesion early and correctly is particularly important to determine the optimal approach to management and treatment of each patient. The care of pediatric patients often requires collaboration from a multitude of specialties including pediatrics, dermatology, plastic surgery, radiology, ophthalmology, and neurology. Although early characterization of vascular lesions is important, consensus guidelines regarding the evaluation and imaging of vascular anomalies does not exist to date. Here, the authors provide an overview of pediatric vascular lesions, current classification systems for characterizing these lesions, the various imaging modalities available, and recommendations for appropriate imaging evaluation. PMID:26705446

  6. Vascularity in thyroid neoplasms

    Larsen, Karen Kjaer; Andersen, Niels Frost; Melsen, Flemming;

    2006-01-01

    The aim of the present study was to evaluate the reliability of four different methods (vascular grading, Chalkley count, microvessel density (MVD) and stereological estimation) for quantifying intratumoral microvascularity in thyroid neoplasms, by comparing the variability within and between...... count should be the preferred method for assessing microvascularity in thyroid neoplasms. The diagnostic evaluation revealed a tendency towards higher degree of vascularity in FA compared to both FC and PC for all methods. No statistically significant association was seen between vascular density and...

  7. Poikiloderma vasculare atrophicans

    Padmavathy L

    1994-01-01

    Full Text Available A 65 year old lady presented with generalised pruritus and discolouration of skin and mucous membranes of 5 years duration. The histopathology from the cutaneous lesions revealed features suggestive of poikiloderma vasculare atrophicans (PVA. Investigations did not reveal any underlying connective tissue disease,lymphoma or systemic disease. A diagnosis of idiopathic poikiloderma vasculare atrophicans was made.

  8. Poikiloderma vasculare atrophicans

    Padmavathy L; Prasad PVS; Prasanna K; Rao L

    1994-01-01

    A 65 year old lady presented with generalised pruritus and discolouration of skin and mucous membranes of 5 years duration. The histopathology from the cutaneous lesions revealed features suggestive of poikiloderma vasculare atrophicans (PVA). Investigations did not reveal any underlying connective tissue disease,lymphoma or systemic disease. A diagnosis of idiopathic poikiloderma vasculare atrophicans was made.

  9. Vascular grading of angiogenesis

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt; Bak, M; Vach, W; Rose, C

    2000-01-01

    The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11...... years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers...... had clinical impact for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer....

  10. [Vascular factors in glaucoma].

    Mottet, B; Aptel, F; Geiser, M; Romanet, J P; Chiquet, C

    2015-12-01

    The exact pathophysiology of glaucoma is not fully understood. Understanding of the vascular pathophysiology of glaucoma requires: knowing the techniques for measuring ocular blood flow and characterizing the topography of vascular disease and the mechanisms involved in this neuropathy. A decreased mean ocular perfusion pressure and a loss of vascular autoregulation are implicated in glaucomatous disease. Early decrease in ocular blood flow has been identified in primary open-angle glaucoma and normal pressure glaucoma, contributing to the progression of optic neuropathy. The vascular damage associated with glaucoma is present in various vascular territories within the eye (from the ophthalmic artery to the retina) and is characterized by a decrease in basal blood flow associated with a dysfunction of vasoregulation. PMID:26597554

  11. Future accelerators (?)

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made

  12. Future accelerators (?)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  13. Accelerating Value Creation with Accelerators

    Jonsson, Eythor Ivar

    2015-01-01

    accelerator programs. Microsoft runs accelerators in seven different countries. Accelerators have grown out of the infancy stage and are now an accepted approach to develop new ventures based on cutting-edge technology like the internet of things, mobile technology, big data and virtual reality. It is also......Accelerators can help to accelerate value creation. Accelerators are short-term programs that have the objective of creating innovative and fast growing ventures. They have gained attraction as larger corporations like Microsoft, Barclays bank and Nordea bank have initiated and sponsored...

  14. Thyroid Hormone and Vascular Remodeling.

    Ichiki, Toshihiro

    2016-03-01

    Both hyperthyroidism and hypothyroidism affect the cardiovascular system. Hypothyroidism is known to be associated with enhanced atherosclerosis and ischemic heart diseases. The accelerated atherosclerosis in the hypothyroid state has been traditionally ascribed to atherogenic lipid profile, diastolic hypertension, and impaired endothelial function. However, recent studies indicate that thyroid hormone has direct anti-atherosclerotic effects, such as production of nitric oxide and suppression of smooth muscle cell proliferation. These data suggest that thyroid hormone inhibits atherogenesis through direct effects on the vasculature as well as modification of risk factors for atherosclerosis. This review summarizes the basic and clinical studies on the role of thyroid hormone in vascular remodeling. The possible application of thyroid hormone mimetics to the therapy of hypercholesterolemia and atherosclerosis is also discussed. PMID:26558400

  15. Pediatric vascular access

    Pediatric interventional radiologists are ideally suited to provide vascular access services to children because of inherent safety advantages and higher success from using image-guided techniques. The performance of vascular access procedures has become routine at many adult interventional radiology practices, but this service is not as widely developed at pediatric institutions. Although interventional radiologists at some children's hospitals offer full-service vascular access, there is little or none at others. Developing and maintaining a pediatric vascular access service is a challenge. Interventionalists skilled in performing such procedures are limited at pediatric institutions, and institutional support from clerical staff, nursing staff, and technologists might not be sufficiently available to fulfill the needs of such a service. There must also be a strong commitment by all members of the team to support such a demanding service. There is a slippery slope of expected services that becomes steeper and steeper as the vascular access service grows. This review is intended primarily as general education for pediatric radiologists learning vascular access techniques. Additionally, the pediatric or adult interventional radiologist seeking to expand services might find helpful tips. The article also provides education for the diagnostic radiologist who routinely interprets radiographs containing vascular access devices. (orig.)

  16. Pediatric vascular access

    Donaldson, James S. [Northwestern University, Feinberg School of Medicine, Department of Medical Imaging, Children' s Memorial Hospital, Chicago, IL (United States)

    2006-05-15

    Pediatric interventional radiologists are ideally suited to provide vascular access services to children because of inherent safety advantages and higher success from using image-guided techniques. The performance of vascular access procedures has become routine at many adult interventional radiology practices, but this service is not as widely developed at pediatric institutions. Although interventional radiologists at some children's hospitals offer full-service vascular access, there is little or none at others. Developing and maintaining a pediatric vascular access service is a challenge. Interventionalists skilled in performing such procedures are limited at pediatric institutions, and institutional support from clerical staff, nursing staff, and technologists might not be sufficiently available to fulfill the needs of such a service. There must also be a strong commitment by all members of the team to support such a demanding service. There is a slippery slope of expected services that becomes steeper and steeper as the vascular access service grows. This review is intended primarily as general education for pediatric radiologists learning vascular access techniques. Additionally, the pediatric or adult interventional radiologist seeking to expand services might find helpful tips. The article also provides education for the diagnostic radiologist who routinely interprets radiographs containing vascular access devices. (orig.)

  17. Vascular Access for Hemodialysis

    ... for short-term use. [ Top ] What is an arteriovenous fistula? An AV fistula is a connection, made by ... to remove and return blood during hemodialysis. An arteriovenous (AV) fistula is a connection, made by a vascular surgeon, ...

  18. Congenital Vascular Malformation

    ... clots, obstruction of major vessels, causing progressive limb asymmetry by overgrowth, and for cosmetic indications or because ... t he Vascular Disease Foundation (VDF) develops educational information and initiatives for patients, their families and friends, ...

  19. Heart and vascular services

    ... Repair of aneurysms (dilated/enlarged portions) of the aorta and its branches Procedures may also be used ... Nutrition and lifestyle counseling, including smoking cessation and diabetes education Supervised exercise Alternative Names Circulatory system; Vascular ...

  20. Management of Vascular Malformations

    Sadanori Akita, MD, PhD

    2014-03-01

    Conclusions: Treatment of vascular malformations is an integral part of multidisciplinary approaches. Venous malformations are more frequent in combination surgery, and if there are fewer complications, the patients’ satisfaction increases.

  1. Thrombolysis in vascular surgery

    Smith, Linn

    2015-01-01

    Background and aims: Thrombolysis is in common use in the treatment of acute forms of vascular disease. It may be used both systemically and locally, in the latter case through an endovascular approach, socalled catheter-directed thrombolysis. The aims of this thesis were to investigate how thrombolysis affects performance-related outcomes pertaining to vascular patency after thrombolysis, and how it affects patient safety and the development of complications. Metho...

  2. Vascular Effects of Histamine.

    Ebeigbe, Anthony B; Talabi, Olufunke O

    2014-01-01

    Four subtypes of receptors (H1, H2, H3 and H4) mediate the actions of histamine. In the vascular wall, the effects of histamine are mediated via H1 and H2 receptors and the actions are modulated by H3 receptor subtype located on presynaptic neurones. Alterations in vascular responses to histamine are associated with experimental as well as a human form of hypertension, suggesting a role for histanine in cardiovascular regulation. PMID:26196559

  3. Digital vascular imaging (DVI)

    Digitization of the video signals from an image intensifier/TV chain, followed by subtraction, contrast enchancement and reconversion to analogue signals, enables high quality angiographic images to be obtained from an intravenous injection of contrast medium. As the examination is basically noninvasive it can be used in outpatients. The possibilities of Digital Vascular Imaging are demonstrated by images obtained from the various vascular regions using a triple-mode 14 in. image intensifier with a Plumbicon. TV tube. (Auth.)

  4. [Zaidemberg's vascularized radial graft].

    Saint-Cast, Y

    2010-12-01

    In 1991, Carlos Zaidemberg described a new technique to repair scaphoid non-unions with a vascularized bone graft harvested from the radial styloid process. An anatomic study based on 30 dissections after colorized latex injection established the constancy of the radial styloid process's artery, while showing that its origin, course and length were subject to variations. In a retrospective series of 38 cases over a period of 10 years, the vascularized bone graft was indicated for: (1) scaphoid non-union with the presence of avascular changes of the proximal fragment (23 cases); (2) failed prior reconstruction with bone graft and internal fixation (nine cases); (3) degenerative styloid-scaphoid arthritis (three cases); (4) fracture on Preiser dystrophy (three cases). The five steps of the simplified operative technique without dissection of the vascular pedicle include: (1) longitudinal dorso-radial approach, identification of the periosteal portion of the radial styloid process artery; (2) incision of the first and second compartments, longitudinal arthrotomy under the second compartment; (3) styloidectomy and transversal resection of the scaphoid non-union and sclerotic bone; (4) elevation of the vascularized bone graft; (5) transversal and radial insertion of the vascularized bone graft, osteosynthesis by two or three K-wire touching the scaphoid's radial edge. Scaphoid union was obtained in 33 cases out of 38. The only postoperative complications were two transient radial paresthesia. The standardized surgical procedure using vascularized bone graft harvested from the radial styloid process provides an efficient scaphoid reconstruction. PMID:21087882

  5. Laser accelerator

    Vigil, Ricardo

    2014-01-01

    Approved for public release; distribution is unlimited In 1979,W. B. Colson and S. K. Ride proposed a new kind of electron accelerator using a uniform magnetic field in combination with a circularly-polarized laser field. A key concept is to couple the oscillating electric field to the electron’s motion so that acceleration is sustained. This dissertation investigates the performance of the proposed laser accelerator using modern high powered lasers and mag-netic fields that are significan...

  6. Antioxidants and vascular health.

    Bielli, Alessandra; Scioli, Maria Giovanna; Mazzaglia, Donatella; Doldo, Elena; Orlandi, Augusto

    2015-12-15

    Oxygen free radicals and other reactive oxygen species (ROS) are common products of normal aerobic cellular metabolism, but high levels of ROS lead to oxidative stress and cellular damage. Increased production of ROS favors vascular dysfunction, inducing altered vascular permeability and inflammation, accompanied by the loss of vascular modulatory function, the imbalance between vasorelaxation and vasoconstriction, and the aberrant expression of inflammatory adhesion molecules. Inflammatory stimuli promote oxidative stress generated from the increased activity of mitochondrial nicotinamide adenine dinucleotide phosphate oxidase, particularly of the Nox4 isoform, with the consequent impairment of mitochondrial β-oxidation. Vascular dysfunction due to the increase in Nox4 activity and ROS overproduction leads to the progression of cardiovascular diseases, diabetes, inflammatory bowel disease, and neurological disorders. Considerable research into the development of effective antioxidant therapies using natural derivatives or new synthetic molecules has been conducted. Antioxidants may prevent cellular damage by reducing ROS overproduction or interfering in reactions that involve ROS. Vitamin E and ascorbic acid are well known as natural antioxidants that counteract lipid peroxidative damage by scavenging oxygen-derived free radicals, thus restoring vascular function. Recently, preliminary studies on natural antioxidants such as goji berries, thymus, rosemary, green tea ginseng, and garlic have been conducted for their efficacy in preventing vascular damage. N-acetyl-cysteine and propionyl-L-carnitine are synthetic compounds that regulate ROS production by replacing endogenous antioxidants in both endothelial and smooth muscle cells. In this review, we consider the molecular mechanisms underlying the generation of oxidative stress-induced vascular dysfunction as well as the beneficial effects of antioxidant therapies. PMID:26585821

  7. LIBO accelerates

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  8. Influence of Androgen Receptor in Vascular Cells on Reperfusion following Hindlimb Ischaemia

    Wu, Junxi; Hadoke, Patrick W.F.; Takov, Kaloyan; Korczak, Agnieszka; Denvir, Martin A.; Smith, Lee B.

    2016-01-01

    Aims Studies in global androgen receptor knockout (G-ARKO) and orchidectomised mice suggest that androgen accelerates reperfusion of the ischaemic hindlimb by stimulating angiogenesis. This investigation used novel, vascular cell-specific ARKO mice to address the hypothesis that the impaired hindlimb reperfusion in G-ARKO mice was due to loss of AR from cells in the vascular wall. Methods and Results Mice with selective deletion of AR (ARKO) from vascular smooth muscle cells (SM-ARKO), endoth...

  9. Induction accelerators

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  10. Plant vascular development

    Rybel, De Bert; Mähönen, Ari Pekka; Helariutta, Yrjö; Weijers, Dolf

    2016-01-01

    Vascular tissues in plants are crucial to provide physical support and to transport water, sugars and hormones and other small signalling molecules throughout the plant. Recent genetic and molecular studies have identified interconnections among some of the major signalling networks that regulate

  11. Renal posttransplant's vascular complications

    Bašić Dragoslav

    2003-01-01

    Full Text Available INTRODUCTION Despite high graft and recipient survival figures worldwide today, a variety of technical complications can threaten the transplant in the postoperative period. Vascular complications are commonly related to technical problems in establishing vascular continuity or to damage that occurs during donor nephrectomy or preservation [13]. AIM The aim of the presenting study is to evaluate counts and rates of vascular complications after renal transplantation and to compare the outcome by donor type. MATERIAL AND METHODS A total of 463 kidneys (319 from living related donor LD and 144 from cadaveric donor - CD were transplanted during the period between June 1975 and December 1998 at the Urology & Nephrology Institute of Clinical Centre of Serbia in Belgrade. Average recipients' age was 33.7 years (15-54 in LD group and 39.8 (19-62 in CD group. Retrospectively, we analyzed medical records of all recipients. Statistical analysis is estimated using Hi-squared test and Fischer's test of exact probability. RESULTS Major vascular complications including vascular anastomosis thrombosis, internal iliac artery stenosis, internal iliac artery rupture obliterant vasculitis and external iliac vein rupture were analyzed. In 25 recipients (5.4% some of major vascular complications were detected. Among these cases, 22 of them were from CD group vs. three from LD group. Relative rate of these complications was higher in CD group vs. LD group (p<0.0001. Among these complications dominant one was vascular anastomosis thrombosis which occurred in 18 recipients (17 from CD vs. one from LD. Of these recipients 16 from CD lost the graft, while the rest of two (one from each group had lethal outcome. DISCUSSION Thrombosis of renal allograft vascular anastomosis site is the most severe complication following renal transplantation. In the literature, renal allograft thrombosis is reported with different incidence rates, from 0.5-4% [14, 15, 16]. Data from the

  12. Vascular manifestations of Behcet's disease

    Regina Georgiyeva Goloeva

    2010-04-01

    Conclusion. Vascular disorders in BD were diagnosed in one fourth of the patients, mainly in young male patients. Severe thromboses with the development of chronic venous insignificance, Budd-Chiari syndrome, pulmonary and iliac artery aneurysms, and arterial thromboses were observed in male patients only. Vascular events were associated with erythema nodosum and epididymitis; in these concomitances, the vascular risk was substantially increased. Vascular death rates were 2,2%.

  13. Tandem accelerators

    After the installation of Ti-acceleration tubes and substantial modifications and additions to the EN tandem accelerator the performance of the machine has stabilized. The voltage behaviour of the tubes obviously improves as conditioning times necessary to run up to 6 MV decrease. A gridded lens has been added at the entrance of the first acceleration tube, and a second foil stripper is now installed in the short dead section between the high-energy tubes. The MP tandem also has been running stably during most of the year. However, beam instabilities originating from the last tube section and wear problems at the low-energy set of pelletron-chains caused some loss of beam time. During the fall, one set of pelletron charging chains has to be replaced after 49,000 hours of operation. In the course of the year, the MP and the EN tandem accelerators finished their 100,000th and 150,000th hours of operations, respectively. Preparations for the installation of the 3 MV negative heavy ion injector for the MP are progressing steadily. External beam transport, terminal ion optics, and data acquisition and control systems are to a major extent completed; the integration of the terminal power supplies has started. After the final assembly of the accelerator column structure, first voltage runs can be performed. (orig.)

  14. Plant Vascular Biology 2010

    Ding, Biao

    2014-11-17

    This grant supported the Second International Conference on Plant Vascular Biology (PVB 2010) held July 24-28, 2010 on the campus of Ohio State University, Columbus, Ohio. Biao Ding (Ohio State University; OSU) and David Hannapel (Iowa State University; ISU) served as co-chairs of this conference. Biao Ding served as the local organizer. PVB is defined broadly here to include studies on the biogenesis, structure and function of transport systems in plants, under conditions of normal plant growth and development as well as of plant interactions with pathogens. The transport systems cover broadly the xylem, phloem, plasmodesmata and vascular cell membranes. The PVB concept has emerged in recent years to emphasize the integrative nature of the transport systems and approaches to investigate them.

  15. Vascular cognitive impairment

    N.V. Vakhnina

    2014-05-01

    Full Text Available Vascular pathology of the brain is the second most common cause of cognitive impairment after Alzheimer's disease. The article describes the modern concepts of etiology, pathogenetic mechanisms, clinical features and approaches to diagnosis and therapy of vascular cognitive impairment (VCI. Cerebrovascular accident, chronic cerebral circulatory insufficiency and their combination, sometimes in combination with a concomitant neurodegenerative process, are shown to be the major types of brain lesions leading to VCI. The clinical presentation of VCI is characterized by the neuropsychological status dominated by impairment of the executive frontal functions (planning, control, attention in combination with focal neurological symptoms. The diagnosis is based on comparing of the revealed neuropsychological and neurological features with neuroimaging data. Neurometabolic, acetylcholinergic, glutamatergic, and other vasoactive drugs and non-pharmacological methods are widely used to treat VCI. 

  16. Pathophysiology of vascular dementia

    Rizzo Claudia

    2009-11-01

    Full Text Available Abstract The concept of Vascular Dementia (VaD has been recognized for over a century, but its definition and diagnostic criteria remain unclear. Conventional definitions identify the patients too late, miss subjects with cognitive impairment short of dementia, and emphasize consequences rather than causes, the true bases for treatment and prevention. We should throw out current diagnostic categories and describe cognitive impairment clinically and according to commonly agreed instruments that document the demographic data in a standardized manner and undertake a systematic effort to identify the underlying aetiology in each case. Increased effort should be targeted towards the concept of and criteria for Vascular Cognitive Impairment and Post-Stroke Dementia as well as for genetic factors involved, especially as these categories hold promise for early prevention and treatment.

  17. Self-Replenishing Vascularized Fouling-Release Surfaces

    Howell, C; Vu, TL; Lin, JJ; Kolle, S; Juthani, N; Watson, E; Weaver, JC; Alvarenga, J; Aizenberg, J

    2014-08-13

    Inspired by the long-term effectiveness of living antifouling materials, we have developed a method for the self-replenishment of synthetic biofouling-release surfaces. These surfaces are created by either molding or directly embedding 3D vascular systems into polydimethylsiloxane (PDMS) and filling them with a silicone oil to generate a nontoxic oil-infused material. When replenished with silicone oil from an outside source, these materials are capable of self-lubrication and continuous renewal of the interfacial fouling-release layer. Under accelerated lubricant loss conditions, fully infused vascularized samples retained significantly more lubricant than equivalent nonvascularized controls. Tests of lubricant-infused PDMS in static cultures of the infectious bacteria Staphylococcus aureus and Escherichia coli as well as the green microalgae Botryococcus braunii, Chlamydomonas reinhardtii, Dunaliella sauna, and Nannochloropsis oculata showed a significant reduction in biofilm adhesion compared to PDMS and glass controls containing no lubricant. Further experiments on vascularized versus nonvascularized samples that had been subjected to accelerated lubricant evaporation conditions for up to 48 h showed significantly less biofilm adherence on the vascularized surfaces. These results demonstrate the ability of an embedded lubricant-filled vascular network to improve the longevity of fouling-release surfaces.

  18. Pathophysiology of vascular dementia

    Rizzo Claudia; Duro Giovanni; Iemolo Francesco; Castiglia Laura; Hachinski Vladimir; Caruso Calogero

    2009-01-01

    Abstract The concept of Vascular Dementia (VaD) has been recognized for over a century, but its definition and diagnostic criteria remain unclear. Conventional definitions identify the patients too late, miss subjects with cognitive impairment short of dementia, and emphasize consequences rather than causes, the true bases for treatment and prevention. We should throw out current diagnostic categories and describe cognitive impairment clinically and according to commonly agreed instruments th...

  19. Preserved saphenous vein allografts for vascular access.

    Piccone, V A; Sika, J; Ahmed, N; LeVeen, H H; DiScala, V

    1978-09-01

    Preserved venous allografts were used as an alternate access procedure in 70 patients receiving dialysis during a three year period. The clinical experience with allograft fistulas revealed an extremely high initial patency rate; absence of infection postoperatively and during three years of dialysis; suitability for dialysis a week after implantation, thus greatly obviating the need for Silastic shunts; a low long term thrombosis rate and the weakly antigenic allograft veins produced no accelerated rejection of subsequently transplanted kidneys. Surviving patients average 172 dialysis treatments per allograft. Allograft fistulas constituted 45 per cent of the last 100 vascular procedures, an indication of the extent of usage. Microscopic examination of grafts retrieved from patients who died during the late follow-up period demonstrated that structural components of the wall of the vein were still identifiable. Allograft venous fistulas offer dependable, safe vascular access, especially in the infection prone patient with diabetes who is receiving dialysis treatment. The clinical results of allograft fistulas suggests a major role for this technique in vascular access operations. PMID:684591

  20. Local Augmented Angiotensinogen Secreted from Apoptotic Vascular Endothelial Cells Is a Vital Mediator of Vascular Remodelling.

    Shyh-Jong Wu

    Full Text Available Vascular remodelling is a critical vasculopathy found in atheromatous diseases and allograft failures. The local renin angiotensin system (RAS has been implicated in vascular remodelling. However, the mechanisms by which the augmented local RAS is associated with the initial event of endothelial cell apoptosis in injured vasculature remain undefined. We induced the apoptosis of human umbilical vein endothelial cells (HUVECs and vascular smooth muscle cells (VSMCs through serum starvation (SS. After the cells were subjected to SS, we found that the mRNA expression of angiotensinogen (AGT was increased by >3-fold in HUVECs and by approximately 2.5-fold in VSMCs. In addition, the expression of angiotensin-converting enzyme (ACE mRNA was increased in VSMCs but decreased to 50% in HUVECs during the same apoptotic process. Increases in the expression of AGT protein and angiotensin II (Ang II were found in a serum-free medium conditioned by HUVECs (SSC. The increased Ang II was suppressed using lisinopril (an ACE inhibitor treatment. Moreover, the activation of ERK1/2 induced by the SSC in VSMCs was also suppressed by losartan. In conclusion, we first demonstrated that the augmented AGT released from apoptotic endothelial cells acts as a vital progenitor of Ang II to accelerate vascular remodelling, and we suggest that blocking local augmented Ang II might be an effective strategy for restraining intimal hyperplasia.

  1. Update on Vascular Dementia.

    Khan, Ayesha; Kalaria, Raj N; Corbett, Anne; Ballard, Clive

    2016-09-01

    Vascular dementia (VaD) is a major contributor to the dementia syndrome and is described as having problems with reasoning, planning, judgment, and memory caused by impaired blood flow to the brain and damage to the blood vessels resulting from events such as stroke. There are a variety of etiologies that contribute to the development of vascular cognitive impairment and VaD, and these are often associated with other dementia-related pathologies such as Alzheimer disease. The diagnosis of VaD is difficult due to the number and types of lesions and their locations in the brain. Factors that increase the risk of vascular diseases such as stroke, high blood pressure, high cholesterol, and smoking also raise the risk of VaD. Therefore, controlling these risk factors can help lower the chances of developing VaD. This update describes the subtypes of VaD, with details of their complex presentation, associated pathological lesions, and issues with diagnosis, prevention, and treatment. PMID:27502303

  2. Vascular Cambium Development

    Nieminen, Kaisa; Blomster, Tiina; Helariutta, Ykä; Mähönen, Ari Pekka

    2015-01-01

    Secondary phloem and xylem tissues are produced through the activity of vascular cambium, the cylindrical secondary meristem which arises among the primary plant tissues. Most dicotyledonous species undergo secondary development, among them Arabidopsis. Despite its small size and herbaceous nature, Arabidopsis displays prominent secondary growth in several organs, including the root, hypocotyl and shoot. Together with the vast genetic resources and molecular research methods available for it, this has made Arabidopsis a versatile and accessible model organism for studying cambial development and wood formation. In this review, we discuss and compare the development and function of the vascular cambium in the Arabidopsis root, hypocotyl, and shoot. We describe the current understanding of the molecular regulation of vascular cambium and compare it to the function of primary meristems. We conclude with a look at the future prospects of cambium research, including opportunities provided by phenotyping and modelling approaches, complemented by studies of natural variation and comparative genetic studies in perennial and woody plant species. PMID:26078728

  3. Accelerator design

    The feasibility of constructing a TeV region electron-positron linear collider in Japan is discussed. The design target of the collider is given as follows: Energy, 1 TeV + 1 TeV; luminosity, 1032-1033/cm2/s; total length, 25km; electric power, 250MW; energy dispersion, 1%-10%; the start of the first experiment, early 1990s. For realizing the above target, the following research and developmental works are necessary. (a) Development of an acceleration tube with short filling time and high shunt resistance. (b) Short pulse microwave source with high peak power. (c) High current, single bunch linac. (d) Beam dynamics. As for the acceleration tube, some possibility is considered: For example, the use of DAW (Disk and Washer) which is being developed for TRISTAN as a traveling-wave tube; and the Jungle Gym-type acceleration tube. As a promising candidate for the microwave source, the Lasertron has been studied. The total cost of the collider construction is estimated to be about 310 billion yen, of which 120 billion yen is for the tunnel and buildings, and 190 billion yen for the accelerator facilities. The operation cost is estimated to be about 3 billion yen per month. (Aoki, K.)

  4. Particle acceleration

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  5. Accelerator operations

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  6. Advanced accelerators

    This report discusses the suitability of four novel particle acceleration technologies for multi-TeV particle physics machines: laser driven linear accelerators (linac), plasma beat-wave devices, plasma wakefield devices, and switched power and cavity wakefield linacs. The report begins with the derivation of beam parameters practical for multi-TeV devices. Electromagnetic field breakdown of materials is reviewed. The two-beam accelerator scheme for using a free electron laser as the driver is discussed. The options recommended and the conclusions reached reflect the importance of cost. We recommend that more effort be invested in achieving a self-consistent range of TeV accelerator design parameters. Beat-wave devices have promise for 1-100 GeV applications and, while not directly scalable to TeV designs, the current generation of ideas are encouraging for the TeV regime. In particular, surfatrons, finite-angle optical mixing devices, plasma grating accelerator, and the Raman forward cascade schemes all deserve more complete analysis. The exploitation of standard linac geometry operated in an unconventional mode is in a phase of rapid evolution. While conceptual projects abound, there are no complete designs. We recommend that a fraction of sponsored research be devoted to this approach. Wakefield devices offer a great deal of potential; trades among their benefits and constraints are derived and discussed herein. The study of field limitation processes has received inadequate attention; this limits experiment designers. The costs of future experiments are such that investment in understanding these processes is prudent. 34 refs., 12 figs., 3 tabs

  7. [How Treatable is Vascular Dementia?].

    Mori, Etsuro

    2016-04-01

    Vascular dementia is an umbrella term, encompassing the pathological changes in the brain due to cerebrovascular disease that result in dementia. Vascular dementia is the second most common form of dementia, after Alzheimer's disease. In this paper, I outline the concept of vascular dementia, the key aspects of the disease that are yet to be clarified, and the current status of clinical trials. Assessing these factors, I discuss how treatable vascular dementia presently is. Use of the term'vascular dementia'is riddled with uncertainties regarding disease classification, and non-standardized diagnostic criteria. There are difficulties in determining the exact relationship between cerebrovascular pathology and cognitive impairment. The comorbid effects of Alzheimer's pathology in some individuals also present an obstacle to reliable clinical diagnosis, and hinder research into effective management approaches. Vascular dementia is preventable and treatable, as there are established primary and secondary prevention measures for the causative cerebrovascular diseases, such as vascular risk factor intervention, antiplatelet therapy, and anticoagulation, amongst others. However, unlike Alzheimer's disease, there are no established symptomatic treatments for vascular dementia. Clinical trials of cholinesterase inhibitors and memantine indicate that they produce small cognitive benefits in patients with vascular dementia, though the exact clinical significance of these is uncertain. Data are insufficient to support the widespread use of these drugs in vascular dementia. Rehabilitation and physical and cognitive exercise may be beneficial, but evidence of cognitive benefit and relief of neuropsychiatric symptoms due to exercise is lacking. PMID:27056862

  8. The Vascular Depression Hypothesis: Mechanisms Linking Vascular Disease with Depression

    Taylor, Warren D.; Aizenstein, Howard J.; Alexopoulos, George S.

    2013-01-01

    The ‘Vascular Depression’ hypothesis posits that cerebrovascular disease may predispose, precipitate, or perpetuate some geriatric depressive syndromes. This hypothesis stimulated much research that has improved our understanding of the complex relationships between late-life depression (LLD), vascular risk factors, and cognition. Succinctly, there are well-established relationships between late-life depression, vascular risk factors, and cerebral hyperintensities, the radiological hallmark o...

  9. Abdominal Vascular Catastrophes.

    Singh, Manpreet; Koyfman, Alex; Martinez, Joseph P

    2016-05-01

    Abdominal vascular catastrophes are among the most challenging and time sensitive for emergency practitioners to recognize. Mesenteric ischemia remains a highly lethal entity for which the history and physical examination can be misleading. Laboratory tests are often unhelpful, and appropriate imaging must be quickly obtained. A multidisciplinary approach is required to have a positive impact on mortality rates. Ruptured abdominal aortic aneurysm likewise may present in a cryptic fashion. A specific type of ruptured aneurysm, the aortoenteric fistula, often masquerades as the more common routine gastrointestinal bleed. The astute clinician recognizes that this is a more lethal variant of gastrointestinal hemorrhage. PMID:27133247

  10. MUON ACCELERATION

    BERG,S.J.

    2003-11-18

    One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of muons. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.

  11. KEKB accelerator

    KEKB, the B-Factory at High Energy Accelerator Research Organization (KEK) recently achieved the luminosity of 1 x 1034 cm-2s-1. This luminosity is two orders higher than the world's level at 1990 when the design of KEKB started. This unprecedented result was made possible by KEKB's innovative design and technology in three aspects - beam focusing optics, high current storage, and beam - beam interaction. Now KEKB is leading the luminosity frontier of the colliders in the world. (author)

  12. Microfluidic Technology in Vascular Research

    A. D. van der Meer

    2009-01-01

    Full Text Available Vascular cell biology is an area of research with great biomedical relevance. Vascular dysfunction is involved in major diseases such as atherosclerosis, diabetes, and cancer. However, when studying vascular cell biology in the laboratory, it is difficult to mimic the dynamic, three-dimensional microenvironment that is found in vivo. Microfluidic technology offers unique possibilities to overcome this difficulty. In this review, an overview of the recent applications of microfluidic technology in the field of vascular biological research will be given. Examples of how microfluidics can be used to generate shear stresses, growth factor gradients, cocultures, and migration assays will be provided. The use of microfluidic devices in studying three-dimensional models of vascular tissue will be discussed. It is concluded that microfluidic technology offers great possibilities to systematically study vascular cell biology with setups that more closely mimic the in vivo situation than those that are generated with conventional methods.

  13. Accelerating networks

    Evolving out-of-equilibrium networks have been under intense scrutiny recently. In many real-world settings the number of links added per new node is not constant but depends on the time at which the node is introduced in the system. This simple idea gives rise to the concept of accelerating networks, for which we review an existing definition and-after finding it somewhat constrictive-offer a new definition. The new definition provided here views network acceleration as a time dependent property of a given system as opposed to being a property of the specific algorithm applied to grow the network. The definition also covers both unweighted and weighted networks. As time-stamped network data becomes increasingly available, the proposed measures may be easily applied to such empirical datasets. As a simple case study we apply the concepts to study the evolution of three different instances of Wikipedia, namely, those in English, German, and Japanese, and find that the networks undergo different acceleration regimes in their evolution

  14. MRI evaluation of vascular dementia

    Yicheng Liu; Hongxing Zhang; Wei Huang; Wenjun Wan; Hongfen Peng

    2006-01-01

    OBJECTTVE: To explain the association between vascular dementia and the cranial MRI manifestations, and recognize the value of cranial MRI in the early diagnosis of vascular dementia and the assessment of disease conditions.DATA SOURCES: Pubmed database was searched to identify articles about the cranial MRI manifestations of patients with vascular dementia published in English from January 1992 to June 2006 by using the key words of "MRI, vascular dementia". Others were collected by searching the name of journals and title of articles in the Chinese full-text journal database.STUDY SELECTTON: The collected articles were primarily checked, those correlated with the cranial MRI manifestations of patients with vascular dementia were selected, while the obviously irrelative ones were excluded, and the rest were retrieved manually, the full-texts were searched.DATA EXTRACTION: Totally 255 articles were collected, 41 of them were involved, and the other 214 were excluded.DATA SYNTHESIS: MRI can be taken as one of the effective methods for the early diagnosis and disease evaluation of vascular dementia. White matter lesions are the important risk factors of vascular dementia.Vascular dementia is accompanied by the atrophy of related brain sites, but further confirmation is needed to investigate whether there is significant difference. MRI can be used to quantitatively investigate the infarcted sites and sizes of patients with vascular dementia after infarction, but there is still lack of systematic investigation on the association of the infarcted sites and sizes with the cognitive function of patients with vascular dementia.CONCLUSTON: Cranial MRI can detect the symptoms of vascular dementia at early period, so that corresponding measures can be adopted to prevent and treat vascular dementia in time.

  15. Vascular Remodeling in Experimental Hypertension

    Norma R. Risler

    2005-01-01

    Full Text Available The basic hemodynamic abnormality in hypertension is an increased peripheral resistance that is due mainly to a decreased vascular lumen derived from structural changes in the small arteries wall, named (as a whole vascular remodeling. The vascular wall is an active, flexible, and integrated organ made up of cellular (endothelial cells, smooth muscle cells, adventitia cells, and fibroblasts and noncellular (extracellular matrix components, which in a dynamic way change shape or number, or reorganize in response to physiological and pathological stimuli, maintaining the integrity of the vessel wall in physiological conditions or participating in the vascular changes in cardiovascular diseases such as hypertension. Research focused on new signaling pathways and molecules that can participate in the mechanisms of vascular remodeling has provided evidence showing that vascular structure is not only affected by blood pressure, but also by mechanisms that are independent of the increased pressure. This review will provide an overview of the evidence, explaining some of the pathophysiologic mechanisms participating in the development of the vascular remodeling, in experimental models of hypertension, with special reference to the findings in spontaneously hypertensive rats as a model of essential hypertension, and in fructose-fed rats as a model of secondary hypertension, in the context of the metabolic syndrome. The understanding of the mechanisms producing the vascular alterations will allow the development of novel pharmacological tools for vascular protection in hypertensive disease.

  16. Spinal vascular malformations

    Krings, Timo [University Hospital Aachen, Department of Neuroradiology, Aachen (Germany); University Hospital Aachen, Department of Neurosurgery, Aachen (Germany); Mull, Michael; Thron, Armin [University Hospital Aachen, Department of Neuroradiology, Aachen (Germany); Gilsbach, Joachim M. [University Hospital Aachen, Department of Neurosurgery, Aachen (Germany)

    2005-02-01

    Spinal vascular malformations are rare diseases that consist of true inborn cavernomas and arteriovenous malformations (including perimedullary fistulae, glomerular and juvenile AVMs) and presumably acquired dural arteriovenous fistulae. This review article gives an overview of the imaging features both on MRI and angiography, the differential diagnoses, the clinical symptomatology and the potential therapeutic approaches to these diseases. It is concluded that MRI is the diagnostic modality of first choice in suspected spinal vascular malformation and should be complemented by selective spinal angiography. Treatment in symptomatic patients offers an improvement in the prognosis, but should be performed in specialized centers. Patients with spinal cord cavernomas and perimedullary fistulae type I are surgical candidates. Dural arteriovenous fistulae can either be operated upon or can be treated by an endovascular approach, the former being a simple, quick and secure approach to obliterate the fistula, while the latter is technically demanding. In spinal arteriovenous malformations, the endovascular approach is the method of first choice; in selected cases, a combined therapy might be sensible. (orig.)

  17. Pulmonary vascular diseases.

    Mélot, C; Naeije, R

    2011-04-01

    Diseases of the pulmonary vasculature are a cause of increased pulmonary vascular resistance (PVR) in pulmonary embolism, chronic thromboembolic pulmonary hypertension (CTEPH), and pulmonary arterial hypertension or decreased PVR in pulmonary arteriovenous malformations on hereditary hemorrhagic telangiectasia, portal hypertension, or cavopulmonary anastomosis. All these conditions are associated with a decrease in both arterial PO2 and PCO2. Gas exchange in pulmonary vascular diseases with increased PVR is characterized by a shift of ventilation and perfusion to high ventilation-perfusion ratios, a mild to moderate increase in perfusion to low ventilation-perfusion ratios, and an increased physiologic dead space. Hypoxemia in these patients is essentially explained by altered ventilation-perfusion matching amplified by a decreased mixed venous PO2 caused by a low cardiac output. Hypocapnia is accounted for by hyperventilation, which is essentially related to an increased chemosensitivity. A cardiac shunt on a patent foramen ovale may be a cause of severe hypoxemia in a proportion of patients with pulmonary hypertension and an increase in right atrial pressure. Gas exchange in pulmonary arteriovenous malformations is characterized by variable degree of pulmonary shunting and/or diffusion-perfusion imbalance. Hypocapnia is caused by an increased ventilation in relation to an increased pulmonary blood flow with direct peripheral chemoreceptor stimulation by shunted mixed venous blood flow. PMID:23737196

  18. Spinal vascular malformations

    Spinal vascular malformations are rare diseases that consist of true inborn cavernomas and arteriovenous malformations (including perimedullary fistulae, glomerular and juvenile AVMs) and presumably acquired dural arteriovenous fistulae. This review article gives an overview of the imaging features both on MRI and angiography, the differential diagnoses, the clinical symptomatology and the potential therapeutic approaches to these diseases. It is concluded that MRI is the diagnostic modality of first choice in suspected spinal vascular malformation and should be complemented by selective spinal angiography. Treatment in symptomatic patients offers an improvement in the prognosis, but should be performed in specialized centers. Patients with spinal cord cavernomas and perimedullary fistulae type I are surgical candidates. Dural arteriovenous fistulae can either be operated upon or can be treated by an endovascular approach, the former being a simple, quick and secure approach to obliterate the fistula, while the latter is technically demanding. In spinal arteriovenous malformations, the endovascular approach is the method of first choice; in selected cases, a combined therapy might be sensible. (orig.)

  19. Accelerators and the Accelerator Community

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  20. Macrophage mediated PCI enhanced gene-directed enzyme prodrug therapy

    Christie, Catherine E.; Zamora, Genesis; Kwon, Young J.; Berg, Kristian; Madsen, Steen J.; Hirschberg, Henry

    2015-03-01

    Photochemical internalization (PCI) is a photodynamic therapy-based approach for improving the delivery of macromolecules and genes into the cell cytosol. Prodrug activating gene therapy (suicide gene therapy) employing the transduction of the E. coli cytosine deaminase (CD) gene into tumor cells, is a promising method. Expression of this gene within the target cell produces an enzyme that converts the nontoxic prodrug, 5-FC, to the toxic metabolite, 5-fluorouracil (5-FU). 5-FC may be particularly suitable for brain tumors, because it can readily cross the bloodbrain barrier (BBB). In addition the bystander effect, where activated drug is exported from the transfected cancer cells into the tumor microenvironment, plays an important role by inhibiting growth of adjacent tumor cells. Tumor-associated macrophages (TAMs) are frequently found in and around glioblastomas. Monocytes or macrophages (Ma) loaded with drugs, nanoparticles or photosensitizers could therefore be used to target tumors by local synthesis of chemo attractive factors. The basic concept is to combine PCI, to enhance the ex vivo transfection of a suicide gene into Ma, employing specially designed core/shell NP as gene carrier.

  1. Macrophage mediated endothelial injury and proliferation in renal transplant rejection.

    Adair, Anya

    2008-01-01

    Macrophages (Mφ) have previously been implicated in both acute and chronic renal allograft rejection however the mechanisms remain unclear. In this thesis I set out to explore the effect of the Mφ on the endothelium in the context of renal graft rejection. Initial studies focussed upon human renal allograft tissue from transplant nephrectomies performed because of chronic allograft nephropathy (CAN). Immunostaining was carried out on these tissues (n=29) and control kidne...

  2. Macrophage-mediated response to hypoxia in disease

    Tazzyman S

    2014-11-01

    Full Text Available Simon Tazzyman,1 Craig Murdoch,2 James Yeomans,1 Jack Harrison,1 Munitta Muthana3 1Department of Oncology, 2School of Clinical Dentistry, 3Department of Infection and Immunity, University of Sheffield, Sheffield, UK Abstract: Hypoxia plays a critical role in the pathobiology of various inflamed, diseased tissues, including malignant tumors, atherosclerotic plaques, myocardial infarcts, the synovia of rheumatoid arthritic joints, healing wounds, and sites of bacterial infection. These areas of hypoxia form when the blood supply is occluded and/or the oxygen supply is unable to keep pace with cell growth and/or infiltration of inflammatory cells. Macrophages are ubiquitous in all tissues of the body and exhibit great plasticity, allowing them to perform divergent functions, including, among others, patrolling tissue, combating invading pathogens and tumor cells, orchestrating wound healing, and restoring homeostasis after an inflammatory response. The number of tissue macrophages increases markedly with the onset and progression of many pathological states, with many macrophages accumulating in avascular and necrotic areas, where they are exposed to hypoxia. Recent studies show that these highly versatile cells then respond rapidly to the hypoxia present by altering their expression of a wide array of genes. Here we review the evidence for hypoxia-driven macrophage inflammatory responses in various disease states, and how this influences disease progression and treatment. Keywords: macrophage, hypoxia, inflammation, cytokine

  3. accelerating cavity

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  4. Dynamic adaption of vascular morphology

    Okkels, Fridolin; Jacobsen, Jens Christian Brings

    2012-01-01

    The structure of vascular networks adapts continuously to meet changes in demand of the surrounding tissue. Most of the known vascular adaptation mechanisms are based on local reactions to local stimuli such as pressure and flow, which in turn reflects influence from the surrounding tissue. Here ...

  5. Electron Accelerator Facilities

    Lecture presents main aspects of progress in development of industrial accelerators: adaptation of accelerators primary built for scientific experiments, electron energy and beam power increase in certain accelerator constructions, computer control system managing accelerator start-up, routine operation and technological process, maintenance (diagnostics), accelerator technology perfection (electrical efficiency, operation cost), compact and more efficient accelerator constructions, reliability improvement according to industrial standards, accelerators for MW power levels and accelerators tailored for specific use

  6. Accelerator system and method of accelerating particles

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  7. Vascular Aging: Lessons From Pediatric Hypertension.

    Litwin, Mieczyslaw; Feber, Janusz; Ruzicka, Marcel

    2016-05-01

    Hypertension (HTN) in children is associated with early vascular aging (EVA) and underlying immunologic-metabolic abnormalities and accelerated biological maturation. Morphologic and functional vascular changes underlying EVA and HTN in children resemble those seen in the elderly including but not limited to an increase in intima-media thickness (IMT) and arterial stiffness and endothelial dysfunction. Although progeria syndrome leading to EVA and the development of clinically manifested cardiovascular (CV) disease in the second decade of life is a rare hereditary disorder, primary HTN, which is also associated with EVA, is much more common (reported in up to 10% in adolescents). EVA associated with HTN in children leads to the premature development of target organ injury in childhood and CV events in early adulthood. Limited evidence from prospective observational studies in children and adolescents indicates that early lifestyle measures (low salt/low sugar intake and exercise) or pharmacologic treatment of HTN, or both, partially reverses morphologic and functional changes underlying EVA such as an increase in carotid IMT and pulse wave velocity, a decrease in flow-mediated dilation of the brachial artery, and an increase in oxidative stress and visceral fat. Future mechanistic and therapeutic clinical trials are desirable to assess the mechanisms and treatment strategies of EVA in the context of HTN in children and their effect on CV events in early adulthood. PMID:27040097

  8. Abdominopelvic vascular injuries.

    Sriussadaporn, S

    2000-01-01

    The clinical records of 25 patients with 32 abdominopelvic vascular injuries were reviewed. Sixty per cent of patients sustained blunt trauma and 40 per cent sustained penetrating trauma. Nineteen patients (76%) were in shock on arrival, 2 of them underwent ER thoracotomy when they first arrived in the emergency room. Nine patients (36%) had signs of lower extremity ischemia. The Injury Severity Score (ISS) ranged from 16-50, mean 29 +/- 10.0. Nineteen patients (76%) had 35 associated injuries. Of the 32 injured vessels; 8 were external iliac artery, 5 were renal vein, 4 were abdominal aorta, 3 were common iliac artery, common iliac vein, external iliac vein and inferior vena cava, and 1 was superior mesenteric artery, superior mesenteric vein and median sacral artery. Treatments included: 13 lateral repair, 4 prosthetic grafting, 4 nephrectomy, 3 ligation, 3 reversed saphenous vein grafting, 2 end to end anastomosis, 1 internal iliac artery grafting, 1 intravascular shunt and packing and 1 perihepatic packing. Nine patients (36%) died. High mortality was observed in injuries to the abdominal aorta (75%), inferior vena cava (66.7%), common iliac vein (66.7%) and associated major pelvic fractures (50%). Factors significantly associated with mortality were the presence of shock on arrival, associated injuries and high Injury Severity Score. The author concludes that short prehospital time, effective resuscitation and proper surgical decision making are important for survival in these critically injured patients. PMID:10710864

  9. Retina vascular network recognition

    Tascini, Guido; Passerini, Giorgio; Puliti, Paolo; Zingaretti, Primo

    1993-09-01

    The analysis of morphological and structural modifications of the retina vascular network is an interesting investigation method in the study of diabetes and hypertension. Normally this analysis is carried out by qualitative evaluations, according to standardized criteria, though medical research attaches great importance to quantitative analysis of vessel color, shape and dimensions. The paper describes a system which automatically segments and recognizes the ocular fundus circulation and micro circulation network, and extracts a set of features related to morphometric aspects of vessels. For this class of images the classical segmentation methods seem weak. We propose a computer vision system in which segmentation and recognition phases are strictly connected. The system is hierarchically organized in four modules. Firstly the Image Enhancement Module (IEM) operates a set of custom image enhancements to remove blur and to prepare data for subsequent segmentation and recognition processes. Secondly the Papilla Border Analysis Module (PBAM) automatically recognizes number, position and local diameter of blood vessels departing from optical papilla. Then the Vessel Tracking Module (VTM) analyses vessels comparing the results of body and edge tracking and detects branches and crossings. Finally the Feature Extraction Module evaluates PBAM and VTM output data and extracts some numerical indexes. Used algorithms appear to be robust and have been successfully tested on various ocular fundus images.

  10. Diabetes and Retinal Vascular Dysfunction

    Eui Seok Shin

    2014-01-01

    Full Text Available Diabetes predominantly affects the microvascular circulation of the retina resulting in a range of structural changes unique to this tissue. These changes ultimately lead to altered permeability, hyperproliferation of endothelial cells and edema, and abnormal vascularization of the retina with resulting loss of vision. Enhanced production of inflammatory mediators and oxidative stress are primary insults with significant contribution to the pathogenesis of diabetic retinopathy (DR. We have determined the identity of the retinal vascular cells affected by hyperglycemia, and have delineated the cell autonomous impact of high glucose on function of these cells. We discuss some of the high glucose specific changes in retinal vascular cells and their contribution to retinal vascular dysfunction. This knowledge provides novel insight into the molecular and cellular defects contributing to the development and progression of diabetic retinopathy, and will aid in the development of innovative, as well as target specific therapeutic approaches for prevention and treatment of DR.

  11. Ultrasound in vascular disease & introduction

    Deane, C; S.Castellani; B. Brkljacic

    2012-01-01

    Il capitolo descrive i prin cipi generali fondamentali delle tecniche per la valutazione ultrasonografica con doppler vascolare The chapter describes the fundamental principles underlying the use of ultrasonographic techniques of vascular doppler

  12. Vascular graft infections with Mycoplasma

    Levi-Mazloum, Niels Donald; Skov Jensen, J; Prag, J;

    1995-01-01

    laboratory techniques, the percentage of culture-negative yet grossly infected vascular grafts seems to be increasing and is not adequately explained by the prior use of antibiotics. We have recently reported the first case of aortic graft infection with Mycoplasma. We therefore suggest the hypothesis that...... the large number of culture-negative yet grossly infected vascular grafts may be due to Mycoplasma infection not detected with conventional laboratory technique....

  13. The relationships of vascular plants.

    Kenrick, P

    2000-01-01

    Recent phylogenetic research indicates that vascular plants evolved from bryophyte-like ancestors and that this involved extensive modifications to the life cycle. These conclusions are supported by a range of systematic data, including gene sequences, as well as evidence from comparative morphology and the fossil record. Within vascular plants, there is compelling evidence for two major clades, which have been termed lycophytes (clubmosses) and euphyllophytes (seed plants, ferns, horsetails)...

  14. The pathobiology of vascular dementia

    Iadecola, Costantino

    2013-01-01

    Vascular cognitive impairment defines alterations in cognition, ranging from subtle deficits to full-blown dementia, attributable to cerebrovascular causes. Often coexisting with Alzheimer’s disease, mixed vascular and neurodegenerative dementia has emerged as the leading cause of age-related cognitive impairment. Central to the disease mechanism is the crucial role that cerebral blood vessels play in brain health, not only for the delivery of oxygen and nutrients, but also for the trophic si...

  15. Calcium dynamics in vascular smooth muscle

    Amberg, Gregory C.; Navedo, Manuel F.

    2013-01-01

    Smooth muscle cells are ultimately responsible for determining vascular luminal diameter and blood flow. Dynamic changes in intracellular calcium are a critical mechanism regulating vascular smooth muscle contractility. Processes influencing intracellular calcium are therefore important regulators of vascular function with physiological and pathophysiological consequences. In this review we discuss the major dynamic calcium signals identified and characterized in vascular smooth muscle cells....

  16. Pulsed DC accelerator for laser wakefield accelerator

    For the acceleration of ultra-short, high-brightness electron bunches, a pulsed DC accelerator was constructed. The pulser produced megavolt pulses of 1 ns duration in a vacuum diode. Results are presented from field emission of electrons in the diode. The results indicate that the accelerating gradient in the diode is approximately 1.5 GV/m

  17. Linear Accelerator (LINAC)

    ... News Physician Resources Professions Site Index A-Z Linear Accelerator A linear accelerator (LINAC) customizes high energy x-rays to ... ensured? What is this equipment used for? A linear accelerator (LINAC) is the device most commonly used ...

  18. Obesity in Indian subjects with Vascular Dementia

    CHANDRA, Mina; Anand, Kuljeet Singh Anand

    2015-01-01

    ABSTRACT Background: Obesity is considered a public health challenge in South Asia. Obesity is an independent risk factor in vascular dementia. It also contributes to other risk factors of vascular dementia like hypertension, coronary artery disease, dyslipidaemia and diabetes. As the rate of obesity in Indian subjects with vascular dementia is not known, we decided to assess obesity in subjects with vascular dementia. Methods: Subjects with vascular dementia presenting to Mem...

  19. Vascular Aging across the Menopause Transition in Healthy Women

    Kerrie L. Moreau

    2014-01-01

    Full Text Available Vascular aging, featuring endothelial dysfunction and large artery stiffening, is a major risk factor for developing cardiovascular disease (CVD. In women, vascular aging appears to be accelerated during the menopause transition, particularly around the late perimenopausal period, presumably related to declines in ovarian function and estrogen levels. The mechanisms underlying endothelial dysfunction and large artery stiffening with the menopause transition are not completely understood. Oxidative stress and the proinflammatory cytokine tumor necrosis factor-α contribute to endothelial dysfunction and large artery stiffening in estrogen-deficient postmenopausal women. Habitual endurance exercise attenuates the age-related increase in large artery stiffness in estrogen-deficient postmenopausal women and can reverse arterial stiffening to premenopausal levels in estrogen-replete postmenopausal women. In contrast, estrogen status appears to play a key permissive role in the adaptive response of the endothelium to habitual endurance exercise in that endothelial improvements are absent in estrogen-deficient women but present in estrogen-replete women. We review here the current state of knowledge on the biological defects underlying vascular aging across the menopause transition, with particular focus on potential mechanisms, the role of habitual exercise in preserving vascular health, and key areas for future research.

  20. Vascular calcification: Inducers and inhibitors

    Lee, Donghyun, E-mail: dhlee@cau.ac.kr [Department of Biomedical Engineering, Division of Integrative Engineering, Chung-Ang University, 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756 (Korea, Republic of)

    2011-09-15

    Highlights: {center_dot} Types of vascular calcification processes. {center_dot} Inducers of vascular calcification. {center_dot} Inhibitors of vascular calcifications. {center_dot} Clinical utility for vascular calcification therapy. {center_dot} Implications for the development of new tissue engineering strategies. - Abstract: Unlike the traditional beliefs, there are mounting evidences suggesting that ectopic mineral depositions, including vascular calcification are mostly active processes, many times resembling that of the bone mineralization. Numbers of agents are involved in the differentiation of certain subpopulation of smooth muscle cells (SMCs) into the osteoblast-like entity, and the activation and initiation of extracellular matrix ossification process. On the other hand, there are factors as well, that prevent such differentiation and ectopic calcium phosphate formation. In normal physiological environments, activities of such procalcific and anticalcific regulatory factors are in harmony, prohibiting abnormal calcification from occurring. However, in certain pathophysiological conditions, such as atherosclerosis, chronic kidney disease (CKD), and diabetes, such balances are altered, resulting in abnormal ectopic mineral deposition. Understanding the factors that regulate the formation and inhibition of ectopic mineral formation would be beneficial in the development of tissue engineering strategies for prevention and/or treatment of such soft-tissue calcification. Current review focuses on the factors that seem to be clinically relevant and/or could be useful in developing future tissue regeneration strategies. Clinical utilities and implications of such factors are also discussed.

  1. Vascular Injury in Orthopedic Trauma.

    Mavrogenis, Andreas F; Panagopoulos, George N; Kokkalis, Zinon T; Koulouvaris, Panayiotis; Megaloikonomos, Panayiotis D; Igoumenou, Vasilios; Mantas, George; Moulakakis, Konstantinos G; Sfyroeras, George S; Lazaris, Andreas; Soucacos, Panayotis N

    2016-07-01

    Vascular injury in orthopedic trauma is challenging. The risk to life and limb can be high, and clinical signs initially can be subtle. Recognition and management should be a critical skill for every orthopedic surgeon. There are 5 types of vascular injury: intimal injury (flaps, disruptions, or subintimal/intramural hematomas), complete wall defects with pseudoaneurysms or hemorrhage, complete transections with hemorrhage or occlusion, arteriovenous fistulas, and spasm. Intimal defects and subintimal hematomas with possible secondary occlusion are most commonly associated with blunt trauma, whereas wall defects, complete transections, and arteriovenous fistulas usually occur with penetrating trauma. Spasm can occur after either blunt or penetrating trauma to an extremity and is more common in young patients. Clinical presentation of vascular injury may not be straightforward. Physical examination can be misleading or initially unimpressive; a normal pulse examination may be present in 5% to 15% of patients with vascular injury. Detection and treatment of vascular injuries should take place within the context of the overall resuscitation of the patient according to the established principles of the Advanced Trauma Life Support (ATLS) protocols. Advances in the field, made mostly during times of war, have made limb salvage the rule rather than the exception. Teamwork, familiarity with the often subtle signs of vascular injuries, a high index of suspicion, effective communication, appropriate use of imaging modalities, sound knowledge of relevant technique, and sequence of surgical repairs are among the essential factors that will lead to a successful outcome. This article provides a comprehensive literature review on a subject that generates significant controversy and confusion among clinicians involved in the care of trauma patients. [Orthopedics. 2016; 39(4):249-259.]. PMID:27322172

  2. Vascular Gene Expression: A Hypothesis

    Angélica Concepción eMartínez-Navarro

    2013-07-01

    Full Text Available The phloem is the conduit through which photoassimilates are distributed from autotrophic to heterotrophic tissues and is involved in the distribution of signaling molecules that coordinate plant growth and responses to the environment. Phloem function depends on the coordinate expression of a large array of genes. We have previously identified conserved motifs in upstream regions of the Arabidopsis genes, encoding the homologs of pumpkin phloem sap mRNAs, displaying expression in vascular tissues. This tissue-specific expression in Arabidopsis is predicted by the overrepresentation of GA/CT-rich motifs in gene promoters. In this work we have searched for common motifs in upstream regions of the homologous genes from plants considered to possess a primitive vascular tissue (a lycophyte, as well as from others that lack a true vascular tissue (a bryophyte, and finally from chlorophytes. Both lycophyte and bryophyte display motifs similar to those found in Arabidopsis with a significantly low E-value, while the chlorophytes showed either a different conserved motif or no conserved motif at all. These results suggest that these same genes are expressed coordinately in non- vascular plants; this coordinate expression may have been one of the prerequisites for the development of conducting tissues in plants. We have also analyzed the phylogeny of conserved proteins that may be involved in phloem function and development. The presence of CmPP16, APL, FT and YDA in chlorophytes suggests the recruitment of ancient regulatory networks for the development of the vascular tissue during evolution while OPS is a novel protein specific to vascular plants.

  3. Plant Vascular Biology and Agriculture

    William J.Lucas

    2010-01-01

    @@ The evolution of animal and plant vascular systems played a pivotal role in the advancement from simple to complex organisms,through the provision of a delivery system for the distribution of components essential for both metabolism and growth.Interestingly,although these two vascular systems conform to the same generel rules of fluid dynamics(Murray1926;McCulloh et al.2003),the developmental mechanisms adopted by plants and animals,to generate these long-distance transport systems.have little in common.

  4. Vascular Function in Alzheimer's Disease and Vascular Dementia.

    Tachibana, Hisatsugu; Washida, Kazuo; Kowa, Hisatomo; Kanda, Fumio; Toda, Tatsushi

    2016-08-01

    We investigated vascular functioning in patients with a clinical and radiological diagnosis of either Alzheimer's disease (AD) or vascular dementia (VaD) and examined a possible relationship between vascular function and cognitive status. Twenty-seven patients with AD, 23 patients with VaD, and 26 healthy control patients underwent measurements of flow-mediated dilation (FMD), ankle-brachial index (ABI), cardioankle vascular index (CAVI), and intima-media thickness (IMT). The FMD was significantly lower in patients with AD or VaD compared to controls. There were no significant differences in ABI, CAVI, or IMT among the 3 groups. A significant correlation was found between Mini-Mental State Examination (MMSE) scores and FMD. Furthermore, a multiple regression analysis revealed that FMD was significantly predicted by MMSE scores. These results suggest that endothelial involvement plays a role in AD pathogenesis, and FMD may be more sensitive than other surrogate methods (ABI, CAVI, and IMT) for detecting early-stage atherosclerosis and/or cognitive decline. PMID:27284205

  5. Acceleration without Horizons

    Doria, Alaric; Munoz, Gerardo

    2015-01-01

    We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} < c$. The motion of the accelerating observer is completely determined by the distance of closest approach and terminal velocity or, equivalently, by an acceleration parameter and terminal velocity.

  6. Vascular complications in glioma patients.

    Le Rhun, Emilie; Perry, James R

    2016-01-01

    Vascular complications in patients with glioma most commonly include venous and arterial thromboembolism; however, treatment-induced vasculopathies are also problematic, especially in long-term survivors. The interactions between treatment such as radiation and chemotherapy, the coagulation cascade, endothelium, and regulators of angiogenesis are complex, drive glioma growth and invasion, and create common management problems in the clinic. We review the incidence of thrombotic complications in glioma, the biology of the coagulome as related to glioma progression, prevention and treatment of thrombosis, the role of anticoagulants as anticancer therapy, and vascular complications such as ischemic stroke and intracranial bleeding. The coagulation cascade is intimately involved in cancer-related thrombosis, glioma progression, and vascular complications of glioma therapy. Tissue factor is the principal initiator of coagulation and is upregulated in a glioma subtype-specific fashion. Short-term (perioperative) antithrombotic prophylaxis is effective, but long-term anticoagulation, although attractive, is not routinely indicated. Most patients with symptomatic venous thromboembolism can be safely anticoagulated, including those on anti-vascular endothelial growth factor therapeutics such as bevacizumab. Initial therapy should include low-molecular-weight heparin, and protracted anticoagulant treatment, perhaps indefinitely, is indicated. Many complex interactions resulting in vessel wall injury can lead to ischemic stroke, intracranial and intratumoral hemorrhage, and long-term sequelae such as cognitive impairment. PMID:26948359

  7. Surface modification and endothelialization of biomaterials as potential scaffolds for vascular tissue engineering applications.

    Ren, Xiangkui; Feng, Yakai; Guo, Jintang; Wang, Haixia; Li, Qian; Yang, Jing; Hao, Xuefang; Lv, Juan; Ma, Nan; Li, Wenzhong

    2015-08-01

    Surface modification and endothelialization of vascular biomaterials are common approaches that are used to both resist the nonspecific adhesion of proteins and improve the hemocompatibility and long-term patency of artificial vascular grafts. Surface modification of vascular grafts using hydrophilic poly(ethylene glycol), zwitterionic polymers, heparin or other bioactive molecules can efficiently enhance hemocompatibility, and consequently prevent thrombosis on artificial vascular grafts. However, these modified surfaces may be excessively hydrophilic, which limits initial vascular endothelial cell adhesion and formation of a confluent endothelial lining. Therefore, the improvement of endothelialization on these grafts by chemical modification with specific peptides and genes is now arousing more and more interest. Several active peptides, such as RGD, CAG, REDV and YIGSR, can be specifically recognized by endothelial cells. Consequently, graft surfaces that are modified by these peptides can exhibit targeting selectivity for the adhesion of endothelial cells, and genes can be delivered by targeting carriers to specific tissues to enhance the promotion and regeneration of blood vessels. These methods could effectively accelerate selective endothelial cell recruitment and functional endothelialization. In this review, recent developments in the surface modification and endothelialization of biomaterials in vascular tissue engineering are summarized. Both gene engineering and targeting ligand immobilization are promising methods to improve the clinical outcome of artificial vascular grafts. PMID:26023741

  8. Pediatric central nervous system vascular malformations

    Pediatric central nervous system (CNS) vascular anomalies include lesions found only in the pediatric population and also the full gamut of vascular lesions found in adults. Pediatric-specific lesions discussed here include infantile hemangioma, vein of Galen malformation and dural sinus malformation. Some CNS vascular lesions that occur in adults, such as arteriovenous malformation, have somewhat distinct manifestations in children, and those are also discussed. Additionally, children with CNS vascular malformations often have associated broader vascular conditions, e.g., PHACES (posterior fossa anomalies, hemangioma, arterial anomalies, cardiac anomalies, eye anomalies and sternal anomalies), hereditary hemorrhagic telangiectasia, and capillary malformation-arteriovenous malformation syndrome (related to the RASA1 mutation). The treatment of pediatric CNS vascular malformations has greatly benefited from advances in endovascular therapy, including technical advances in adult interventional neuroradiology. Dramatic advances in therapy are expected to stem from increased understanding of the genetics and vascular biology that underlie pediatric CNS vascular malformations. (orig.)

  9. Pediatric central nervous system vascular malformations

    Burch, Ezra A. [Brigham and Women' s Hospital, Department of Radiology, Boston, MA (United States); Orbach, Darren B. [Boston Children' s Hospital, Neurointerventional Radiology, Boston, MA (United States)

    2015-09-15

    Pediatric central nervous system (CNS) vascular anomalies include lesions found only in the pediatric population and also the full gamut of vascular lesions found in adults. Pediatric-specific lesions discussed here include infantile hemangioma, vein of Galen malformation and dural sinus malformation. Some CNS vascular lesions that occur in adults, such as arteriovenous malformation, have somewhat distinct manifestations in children, and those are also discussed. Additionally, children with CNS vascular malformations often have associated broader vascular conditions, e.g., PHACES (posterior fossa anomalies, hemangioma, arterial anomalies, cardiac anomalies, eye anomalies and sternal anomalies), hereditary hemorrhagic telangiectasia, and capillary malformation-arteriovenous malformation syndrome (related to the RASA1 mutation). The treatment of pediatric CNS vascular malformations has greatly benefited from advances in endovascular therapy, including technical advances in adult interventional neuroradiology. Dramatic advances in therapy are expected to stem from increased understanding of the genetics and vascular biology that underlie pediatric CNS vascular malformations. (orig.)

  10. Diagnosis advances in vascular cognitive impairment

    Hua Zhou; Zhong Zhao

    2009-01-01

    Vascular cognitive impairment(VCI) encompasses the entire range of cognitive deficits associated with cerebrovascular disease(CVD), from mild deficits with little or no functional impairment, such as vascular cognitive impairment-no dementia(VCIND), to full-blown vascular dementia(VaD). Accurate diagnosis of vascular cognitive impairment is important but may be difficult. In this review we report advances in VCI in the following areas: etiology, subtypes, neuropsychology, biomarkers, neuroimaging, and diagnostic criteria.

  11. Congenital vascular malformations in scintigraphic evaluation

    Pilecki, Stanisław; Gierach, Marcin; Gierach, Joanna; Świętaszczyk, Cyprian; Junik, Roman; Lasek, Władysław

    2014-01-01

    Summary Background Congenital vascular malformations are tumour-like, non-neoplastic lesions caused by disorders of vascular tissue morphogenesis. They are characterised by a normal cell replacement cycle throughout all growth phases and do not undergo spontaneous involution. Here we present a scintigraphic image of familial congenital vascular malformations in two sisters. Material/Methods A 17-years-old young woman with a history of multiple hospitalisations for foci of vascular anomalies a...

  12. Dealing with vascular conundrums with MR imaging.

    Angthong, Wirana; Semelka, Richard C

    2014-07-01

    Magnetic resonance (MR) imaging is a robust imaging modality for evaluation of vascular diseases. Technological advances have made MR imaging widely available for accurate and time-efficient vascular assessment. In this article the clinical usefulness of MR imaging techniques and their application are reviewed, using examples of vascular abnormalities commonly encountered in clinical practice, including abdominal, pelvic, and thoracic vessels. Common pitfalls and problem solving in interpretation of vascular findings in body MR imaging are also discussed. PMID:24889175

  13. MicroRNAs in Vascular Biology

    Munekazu Yamakuchi

    2012-01-01

    Vascular inflammation is an important component of the pathophysiology of cardiovascular diseases, such as hypertension, atherosclerosis, and aneurysms. All vascular cells, including endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), and infiltrating cells, such as macrophages, orchestrate a series of pathological events. Despite dramatic improvements in the treatment of atherosclerosis, the molecular basis of vascular inflammation is not well understood. In the last decade, mi...

  14. The direction of acceleration

    Wilhelm, Thomas; Burde, Jan-Philipp; Lück, Stephan

    2015-11-01

    Acceleration is a physical quantity that is difficult to understand and hence its complexity is often erroneously simplified. Many students think of acceleration as equivalent to velocity, a ˜ v. For others, acceleration is a scalar quantity, which describes the change in speed Δ|v| or Δ|v|/Δt (as opposed to the change in velocity). The main difficulty with the concept of acceleration therefore lies in developing a correct understanding of its direction. The free iOS app AccelVisu supports students in acquiring a correct conception of acceleration by showing acceleration arrows directly at moving objects.

  15. High intensity hadron accelerators

    In this paper we give an introductory discussion of high intensity hadron accelerators with special emphasis on the high intensity feature. The topics selected for this discussion are: Types of acclerator - The principal actions of an accelerator are to confine and to accelerate a particle beam. Focusing - This is a discussion of the confinement of single particles. Intensity limitations - These are related to confinement of intense beams of particles. Power economics - Considerations related to acceleration of intense beams of particles. Heavy ion kinematics - The adaptation of accelerators to accelerate all types of heavy ions

  16. 2014 CERN Accelerator Schools: Plasma Wake Acceleration

    2014-01-01

    A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

  17. Near-infraread spectroscopy during peripheral vascular surgery

    Schroeder, Torben Veith; Eiberg, Jonas Peter; Vogt, Katja; Secher, Niels Henry

    Original,Near-infraread spectroscopy,Vascular disease,Vascular by-pass surgery,Perioperative oxymetry......Original,Near-infraread spectroscopy,Vascular disease,Vascular by-pass surgery,Perioperative oxymetry...

  18. Identification of molecular processes needed for vascular formation through transcriptome analysis of different vascular systems

    Xu, Peng; Kong, Yimeng; Li, Xuan; Li, Laigeng

    2013-01-01

    Background Vascular system formation has been studied through molecular and genetic approaches in Arabidopsis, a herbaceous dicot that is used as a model system. Different vascular systems have developed in other plants such as crops and trees. Uncovering shared mechanisms underlying vascular development by transcriptome analysis of different vascular systems may help to transfer knowledge acquired from Arabidopsis to other economically important species. Results Conserved vascular genes and ...

  19. Improved plasma accelerator

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  20. San Francisco Accelerator Conference

    'Where are today's challenges in accelerator physics?' was the theme of the open session at the San Francisco meeting, the largest ever gathering of accelerator physicists and engineers

  1. Dielectric Laser Acceleration

    England, R. Joel; Noble, Robert J.; Wu, Ziran; Qi, Minghao

    2013-01-01

    We describe recent advances in the study of particle acceleration using dielectric near-field structures driven by infrared lasers, which we refer to as Dielectric Laser Accelerators. Implications for high energy physics and other applications are discussed.

  2. Standing wave linear accelerator

    Consideration is being given to standing wave linear accelerator containing generator, phase shifter, two accelerating resonator sections, charged particle injector and waveguide bridge. Its first arm is oined up with generator via the phase shifter, the second and the third ones-with accelerating sections and the fourth one - with HF-power absorber. HF-power absorber represents a section of circular diaphragmatic wavequide with transformer with input wave and intrawaveguide output load located between injector and the first accelerating section. The section possesses holes in side walls lying on accelerator axis. The distances between centers of the last cell of the fast accelerating section and the first cell of the second accelerating sectiOn equal (2n+3)lambda/4, where n=1, 2, 3..., lambda - wave length of generator. The suggested system enables to improve by one order spectral characteristics of accelerators as compared to the prototype in which magnetrons are used as generator

  3. High Energy Particle Accelerators

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  4. Vascularized osseous graft for scaphoid

    The most commonly used technique for treatment of pseudo-arthrosis of the scaphoid is osteo-synthesis with Kirschnet wires and cortical sponge grafts. Results reported by different teams using this procedure show no more than 90% osseous consolidation, especially in cases where vascularisation of the proximal fragment of the scaphoid is compromised. Here we present a series of ten cases of pseudo-arthrosis of the scaphoid, treated using a new surgical technique involving a vascularized osseous graft of the distal radius. Using this procedure we obtained 100% consolidation, with no complications either during the procedure or immediately post-operatively. Patients returned to work in week 15 on average. In 4 cases we observed discomfort in the area of the scar, which was successfully treated using local cortisone injection. The results obtained are very similar to those seen in the literature on the different techniques for vascularized osseous grafts for pseudo-arthrosis of the scaphoid

  5. Maximal Acceleration Is Nonrotating

    Page, Don N.

    1997-01-01

    In a stationary axisymmetric spacetime, the angular velocity of a stationary observer that Fermi-Walker transports its acceleration vector is also the angular velocity that locally extremizes the magnitude of the acceleration of such an observer, and conversely if the spacetime is also symmetric under reversing both t and phi together. Thus a congruence of Nonrotating Acceleration Worldlines (NAW) is equivalent to a Stationary Congruence Accelerating Locally Extremely (SCALE). These congruenc...

  6. Accelerators at school

    Latest subject covered by the CERN Accelerator School was 'Applied Geodesy of Particle Accelerators', which attracted an impressive number of outside participants to CERN for a week in April. Since the forerunners of today's particle accelerators were demonstrated over 50 years ago, the positioning of accelerator components has progressed from the laboratory bench-top to tunnels tens of kilometres long. Despite this phenomenal growth in size, sub-millimetre accuracy is still required

  7. A Solid state accelerator

    We present a solid state accelerator concept utilizing particle acceleration along crystal channels by longitudinal electron plasma waves in a metal. Acceleration gradients of order 100 GV/cm are theoretically possible, but channeling radiation limits the maximum attainable energy to 105 TeV for protons. Beam dechanneling due to multiple scattering is substantially reduced by the high acceleration gradient. Plasma wave dissipation and generation in metals are also discussed

  8. Superconducting accelerator technology

    Modern and future accelerators for high energy and nuclear physics rely increasingly on superconducting components to achieve the required magnetic fields and accelerating fields. This paper presents a practical overview of the phenomenon of superconductivity, and describes the design issues and solutions associated with superconducting magnets and superconducting rf acceleration structures. Further development and application of superconducting components promises increased accelerator performance at reduced electric power cost

  9. Applications of particle accelerators

    Particle accelerators are now widely used in a variety of applications for scientific research, applied physics, medicine, industrial processing, while possible utilisation in power engineering is envisaged. Earlier presentations of this subject, given at previous CERN Accelerator School sessions have been updated with papers contributed to the first European Conference on Accelerators in Applied Research and Technology (ECAART) held in September 1989 in Frankfurt and to the Second European Particle Accelerator Conference in Nice in June 1990. (orig.)

  10. Radiology of peripheral vascular diseases

    This volume provides a comprehensive account of the use of modern imaging procedures for the diagnosis of arterial and venous diseases. Each imaging modality is separately considered and applications in individual diseases are then explained with the aid of excellent illustrations. In addition, vascular interventions such as balloon angioplasty, local thrombolysis, and stent implantation are discussed and appraised. Special attention is devoted to the problem of radiation burden for patients. The authors are all recognized experts in angiology, phlebology, and interventional radiology. (orig.)

  11. Tbx1 regulates brain vascularization.

    Cioffi, Sara; Martucciello, Stefania; Fulcoli, Filomena Gabriella; Bilio, Marchesa; Ferrentino, Rosa; Nusco, Edoardo; Illingworth, Elizabeth

    2014-01-01

    The transcription factor TBX1 is the major gene involved in 22q11.2 deletion syndrome (22q11.2DS). Using mouse models of these diseases, we have previously shown that TBX1 activates VEGFR3 in endothelial cells (EC), and that this interaction is critical for the development of the lymphatic vasculature. In this study, we show that TBX1 regulates brain angiogenesis. Using loss-of-function genetics and molecular approaches, we show that TBX1 regulates the VEGFR3 and DLL4 genes in brain ECs. In mice, loss of TBX1 causes global brain vascular defects, comprising brain vessel hyperplasia, enhanced angiogenic sprouting and vessel network disorganization. This phenotype is recapitulated in EC-specific Tbx1 conditional mutants and in an EC-only 3-dimensional cell culture system (matrigel), indicating that the brain vascular phenotype is cell autonomous. Furthermore, EC-specific conditional Tbx1 mutants have poorly perfused brain vessels and brain hypoxia, indicating that the expanded vascular network is functionally impaired. In EC-matrigel cultures, a Notch1 agonist is able to partially rescue microtubule hyperbranching induced by TBX1 knockdown. Thus, we have identified a novel transcriptional regulator of angiogenesis that exerts its effect in brain by negatively regulating angiogenesis through the DLL4/Notch1-VEGFR3 regulatory axis. Given the similarity of the phenotypic consequences of TBX1 mutation in humans and mice, this unexpected role of TBX1 in murine brain vascularization should stimulate clinicians to search for brain microvascular anomalies in 22q11.2DS patients and to evaluate whether some of the anatomical and functional brain anomalies in patients may have a microvascular origin. PMID:23945394

  12. Cocaine-related vascular headaches.

    Dhuna, A; Pascual-Leone, A; Belgrade, M

    1991-01-01

    The records of 21 patients admitted to hospital from January 1985 to December 1988 for acute headache associated with cocaine intoxication were reviewed. Fifteen patients were identified who experienced headaches with migrainous features in the absence of neurological or systemic complications. None of them had a history of cocaine-unrelated headaches or a family history of migraine, and all had a favourable outcome. Three possible mechanisms of cocaine-related vascular headaches are discusse...

  13. Hydrogen sulfide and vascular relaxation

    SUN Yan; TANG Chao-shu; DU Jun-bao; JIN Hong-fang

    2011-01-01

    Objective To review the vasorelaxant effects of hydrogen sulfide (H2S) in arterial rings in the cardiovascular system under both physiological and pathophysiological conditions and the possible mechanisms involved.Data sources The data in this review were obtained from Medline and Pubmed sources from 1997 to 2011 using the search terms "hydrogen sulfide" and ""vascular relaxation".Study selection Articles describing the role of hydrogen sulfide in the regulation of vascular activity and its vasorelaxant effects were selected.Results H2S plays an important role in the regulation of cardiovascular tone.The vasomodulatory effects of H2S depend on factors including concentration,species and tissue type.The H2S donor,sodium hydrosulfide (NarS),causes vasorelaxation of rat isolated aortic rings in a dose-dependent manner.This effect was more pronounced than that observed in pulmonary arterial rings.The expression of KATP channel proteins and mRNA in the aortic rings was increased compared with pulmonary artery rings.H2S is involved in the pathogenesis of a variety of cardiovascular diseases.Downregulation of the endogenous H2S pathway is an important factor in the pathogenesis of cardiovascular diseases.The vasorelaxant effects of H2S have been shown to be mediated by activation of KATP channels in vascular smooth muscle cells and via the induction of acidification due to activation of the CI/HCO3 exchanger.It is speculated that the mechanisms underlying the vasoconstrictive function of H2S in the aortic rings involves decreased NO production and inhibition of cAMP accumulation.Conclusion H2S is an important endogenous gasotransmitter in the cardiovascular system and acts as a modulator of vascular tone in the homeostatic regulation of blood pressure.

  14. Vascular parameters from angiographic images

    This paper measures geometric and dynamic vascular parameters using digital angiographic image sequences: An image analysis system for neuroangiography is being developed by the Medical Imaging Division and Endovascular Therapy section of our department. Angiographic images are obtained from a GE Digital Fluoricon 5000 system. The image sets are analyzed on a Stellar GS2000 graphics mini-supercomputer using software modules written for use with the Application Visualization System (AVS). Flow phantoms are used to evaluate analysis routines and bolus injection techniques

  15. Cellular mechanisms during vascular development

    Blum, Yannick

    2012-01-01

    The vascular system is an essential organ in vertebrate animals and provides the organism with enough oxygen and nutrients. It is composed of an interconnected network of blood vessels, which form using a number of different morphogenetic mechanisms. Angiogenesis describes the formation of new blood vessels from preexisting vessels. A number of molecular pathways have been shown to be essential during angiogenesis. However, cellular architecture of blood vessels as well as cellular mechanisms...

  16. Fascia and Primo Vascular System

    Chun Yang; Yi-kuan Du; Jian-bin Wu; Jun Wang; Ping Luan; Qin-lao Yang; Lin Yuan

    2015-01-01

    The anatomical basis for the concept of acupuncture points/meridians in traditional Chinese medicine (TCM) has not been resolved. This paper reviews the fascia research progress and the relationship among acupuncture points/meridians, primo vascular system (PVS), and fascia. Fascia is as a covering, with common origins of layers of the fascial system despite diverse names for individual parts. Fascia assists gliding and fluid flow and holds memory and is highly innervated. Fascia is intimatel...

  17. Quantitative analysis of vascular calcification

    Joh, Jin Hyun; Kim, Dong Ik

    2013-01-01

    Vascular calcification is a prominent feature of atherosclerosis. The mineral composition and quantity within calcified arterial plaques remains unelucidated; therefore, the aim of this study was to analyze the mineral composition of such plaques. Calcified arterial plaques were obtained from patients with abdominal aortic aneurysms (AAAs) and carotid artery stenoses. Calcified aneurysmal plaques were obtained during the routine open repair of AAAs, while calcified carotid plaques were collec...

  18. Vascular instruction of pancreas development

    Cleaver, Ondine; Dor, Yuval

    2012-01-01

    Blood vessels course through organs, providing them with essential nutrient and gaseous exchange. However, the vasculature has also been shown to provide non-nutritional signals that play key roles in the control of organ growth, morphogenesis and homeostasis. Here, we examine a decade of work on the contribution of vascular paracrine signals to developing tissues, with a focus on pancreatic β-cells. During the early stages of embryonic development, blood vessels are required for pancreas spe...

  19. NADPH Oxidases in Vascular Pathology

    Konior, Anna; Schramm, Agata; Czesnikiewicz-Guzik, Marta; Tomasz J. Guzik

    2014-01-01

    Significance: Reactive oxygen species (ROS) play a critical role in vascular disease. While there are many possible sources of ROS, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases play a central role. They are a source of “kindling radicals,” which affect other enzymes, such as nitric oxide synthase endothelial nitric oxide synthase or xanthine oxidase. This is important, as risk factors for atherosclerosis (hypertension, diabetes, hypercholesterolemia, and smoking) regulate the ...

  20. Vascular gene expression: a hypothesis

    Martínez-Navarro, Angélica C.; Galván-Gordillo, Santiago V.; Xoconostle-Cázares, Beatriz; Ruiz-Medrano, Roberto

    2013-01-01

    The phloem is the conduit through which photoassimilates are distributed from autotrophic to heterotrophic tissues and is involved in the distribution of signaling molecules that coordinate plant growth and responses to the environment. Phloem function depends on the coordinate expression of a large array of genes. We have previously identified conserved motifs in upstream regions of the Arabidopsis genes, encoding the homologs of pumpkin phloem sap mRNAs, displaying expression in vascular ti...

  1. Endangered vascular plants in Japan

    IWATSUKI, Kunio

    2008-01-01

    The history of the Red List of Japanese vascular plants is briefly reviewed for editing and research. Especially on the results of recent monitoring, the present status of information and conservation activities on the endangered plants in Japan is discussed and the dynamics of the Japanese flora are taken up, in relation to basic research on plant biodiversity on the Japanese Archipelago. The figures of endangered plants are not very variable during the past quarter of a century, but we can ...

  2. Vascular Complications of Cancer Chemotherapy.

    Cameron, Alan C; Touyz, Rhian M; Lang, Ninian N

    2016-07-01

    Development of new anticancer drugs has resulted in improved mortality rates and 5-year survival rates in patients with cancer. However, many of the modern chemotherapies are associated with cardiovascular toxicities that increase cardiovascular risk in cancer patients, including hypertension, thrombosis, heart failure, cardiomyopathy, and arrhythmias. These limitations restrict treatment options and might negatively affect the management of cancer. The cardiotoxic effects of older chemotherapeutic drugs such as alkylating agents, antimetabolites, and anticancer antibiotics have been known for a while. The newer agents, such as the antiangiogenic drugs that inhibit vascular endothelial growth factor signalling are also associated with cardiovascular pathology, especially hypertension, thromboembolism, myocardial infarction, and proteinuria. Exact mechanisms by which vascular endothelial growth factor inhibitors cause these complications are unclear but impaired endothelial function, vascular and renal damage, oxidative stress, and thrombosis might be important. With increasing use of modern chemotherapies and prolonged survival of cancer patients, the incidence of cardiovascular disease in this patient population will continue to increase. Accordingly, careful assessment and management of cardiovascular risk factors in cancer patients by oncologists and cardiologists working together is essential for optimal care so that prolonged cancer survival is not at the expense of increased cardiovascular events. PMID:26968393

  3. [Vascular Ehlers-Danlos syndrome].

    Frank, Michael

    2009-04-20

    Vascular type Ehlers-Danlos syndrome (EDS) is a rare inherited disease with an autosomal dominant trait. The mutation of the COL3A1 gene which encodes type III collagen, is responsible of early vascular (spontaneous arterial rupture or dissection), digestive (perforation) and obstetrical events (uterine and arterial rupture). Diagnosis of the disease is primarily clinical, especially in case of characteristic morphologic features. Diagnostic certainty is obtained by evidencing the mutation of the COL3A1 gene. Some arterial lesions are suggestive of the disease, as dissecting aneurysms of the internal carotid, of the iliac arteries, and of the anterior visceral aortic branches, fusiform aneurisms of the splenic artery, and the occurrence of a non traumatic direct carotid-cavernous fistula. The occurrence of a spontaneous peritonitis or of an extensive perineal tear after delivery should also draw physician's attention. Because of the unpredictability of arterial or organ rupture, any patient diagnosed with vascular type EDS presenting with an acute pain syndrome should be considered as a trauma situation and be investigated straightaway by CT-scan or MRI testing, in order to eliminate a life threatening complication. PMID:19462862

  4. Acceleration: It's Elementary

    Willis, Mariam

    2012-01-01

    Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between…

  5. The CERN Accelerator School

    2016-01-01

    Introduction to accelerator physics The CERN Accelerator School: Introduction to Accelerator Physics, which should have taken place in Istanbul, Turkey, later this year has now been relocated to Budapest, Hungary.  Further details regarding the new hotel and dates will be made available as soon as possible on a new Indico site at the end of May.

  6. Accelerator development in BARC

    Charged particle accelerators have played crucial role in the field of both basic and applied sciences. This has been possible because the accelerators have been extensively utilized from unraveling the secrets of nature to diverse applications such as implantation, material modification, medical diagnostics and therapy, nuclear energy and clean air and water. The development of accelerators in BARC can be categorized in two broad categories namely proton and heavy ion based accelerators and electron based accelerators. The heavy ion accelerators with sufficiently high energies are currently being used for conducting frontline nuclear and allied research whereas the electron accelerators are being routinely used for various industrial applications. Recently, there is a strong interest for developing the high energy and high intensity accelerators due to their possibility of effective utilization towards concept of energy amplification (Accelerator Driven System), incineration nuclear waste and transmutation. This talk will discuss details of the accelerator development program in BARC with particular emphasis on the recent development at Low Energy High Intensity Proton Accelerator (LEHIPA) Facility in Ion Accelerator Development Division, BARC. (author)

  7. Far field acceleration

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail

  8. Accelerators and Dinosaurs

    Turner, Michael Stanley

    2003-01-01

    Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

  9. Changing demographics in patients with vascular disease.

    Kwolek, Christopher J; Clagett, G Patrick

    2009-02-01

    The United States population with vascular disease has changed dramatically during the past 2 decades, with large increases in the proportion of Hispanic, African American, and other minority patients. Not only has the number of these patients increased, but the types and distribution of vascular disease in minority populations is also different from that encountered in non-Hispanic whites. Although genetic makeup accounts for some of these differences, access to vascular care is also an important determinant, with many minority patients presenting late in the course of the disease process. These factors create significant challenges for the vascular specialists caring for these patients. The vascular surgery workforce is composed of >90% white men and does not currently represent the changes in the population of patients with vascular disease. In addition, women with vascular disease comprise up to 50% of many vascular surgery practices. In many parts of the country, Hispanics and African Americans outnumber non-Hispanic whites with vascular disease. Yet, women and minority physicians are still significantly under-represented in the field of vascular surgery. This year's E. Stanley Crawford Critical Issues Forum at the Society for Vascular Surgery meeting addressed the disconnect between the vascular surgery workforce and the patients whom we serve. This article reviews the projected demographic changes in the population of the United States, which supports the need for training a vascular surgery workforce that is more diverse. This article also reviews the current status of minority and female representation in medical schools, surgical training programs, and vascular surgery programs in the United States. PMID:19216973

  10. The Accelerator Reliability Forum

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  11. Direct Laser Acceleration in Laser Wakefield Accelerators

    Shaw, Jessica

    2016-01-01

    In this dissertation, the direct laser acceleration (DLA) of ionization-injected electrons in a laser wakefield accelerator (LWFA) operating in the quasi-blowout regime has been investigated through experiment and simulation. In the blowout regime of LWFA, the radiation pressure of an intense laser pulse can push a majority of the plasma electrons out and around the main body of the pulse. The expelled plasma electrons feel the electrostatic field of the relatively-stationary ions and are t...

  12. DNA Damage: A Main Determinant of Vascular Aging.

    Bautista-Niño, Paula K; Portilla-Fernandez, Eliana; Vaughan, Douglas E; Danser, A H Jan; Roks, Anton J M

    2016-01-01

    Vascular aging plays a central role in health problems and mortality in older people. Apart from the impact of several classical cardiovascular risk factors on the vasculature, chronological aging remains the single most important determinant of cardiovascular problems. The causative mechanisms by which chronological aging mediates its impact, independently from classical risk factors, remain to be elucidated. In recent years evidence has accumulated that unrepaired DNA damage may play an important role. Observations in animal models and in humans indicate that under conditions during which DNA damage accumulates in an accelerated rate, functional decline of the vasculature takes place in a similar but more rapid or more exaggerated way than occurs in the absence of such conditions. Also epidemiological studies suggest a relationship between DNA maintenance and age-related cardiovascular disease. Accordingly, mouse models of defective DNA repair are means to study the mechanisms involved in biological aging of the vasculature. We here review the evidence of the role of DNA damage in vascular aging, and present mechanisms by which genomic instability interferes with regulation of the vascular tone. In addition, we present potential remedies against vascular aging induced by genomic instability. Central to this review is the role of diverse types of DNA damage (telomeric, non-telomeric and mitochondrial), of cellular changes (apoptosis, senescence, autophagy), mediators of senescence and cell growth (plasminogen activator inhibitor-1 (PAI-1), cyclin-dependent kinase inhibitors, senescence-associated secretory phenotype (SASP)/senescence-messaging secretome (SMS), insulin and insulin-like growth factor 1 (IGF-1) signaling), the adenosine monophosphate-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR)-nuclear factor kappa B (NFκB) axis, reactive oxygen species (ROS) vs. endothelial nitric oxide synthase (eNOS)-cyclic guanosine monophosphate (c

  13. Peptide-modified PELCL electrospun membranes for regulation of vascular endothelial cells.

    Zhou, Fang; Jia, Xiaoling; Yang, Yang; Yang, Qingmao; Gao, Chao; Zhao, Yunhui; Fan, Yubo; Yuan, Xiaoyan

    2016-11-01

    The efficiency of biomaterials used in small vascular repair depends greatly on their ability to interact with vascular endothelial cells (VECs). Rapid endothelialization of the vascular grafts is a promising way to prevent thrombosis and intimal hyperplasia. In this work, modification of electrospun membranes of poly(ethylene glycol)-b-poly(l-lactide-co-ε-caprolactone) (PELCL) by three different peptides for regulation of VECs were studied in order to obtain ideal bioactive biomaterials as small diameter vascular grafts. QK (a mimetic peptide to vascular endothelial growth factor), Arg-Glu-Asp-Val (REDV, a specific adhesive peptide to VECs) and Val-Ala-Pro-Gly (VAPG, a specific adhesive peptide to vascular smooth muscle cells) were investigated. Surface properties of the modified membranes and the response of VECs were verified. It was found that protein adsorption and platelet adhesion were effectively suppressed with the introduction of QK, REDV or VAPG peptides on the PELCL electrospun membranes. Both QK- and REDV-modified electrospun membranes could accelerate the proliferation of VECs in the first 9days, and the QK-modified electrospun membrane promoted cell proliferation more significantly than the REDV-modified one. The REDV-modified PELCL membrane was the most favorable for VECs adhesion than QK- and VAPG-modified membranes. It was suggested that QK- or REDV-modified PELCL electrospun membranes may have great potential applications in cardiovascular biomaterials for rapid endothelialization in situ. PMID:27524062

  14. The future of particle accelerators

    Plasma-based accelerators are developing as credible, and compact, accelerators for the future. We review the status and prospects for electron and proton accelerators using laser Wakefield acceleration. (author)

  15. Clinical pharmacology and vascular risk.

    Silvestrelli, G; Corea, F; Micheli, S; Lanari, A

    2010-01-01

    Pharmacological treatment and several drugs of abuse have been associated with ischemic heart disease (IHD) and cerebrovascular diseases (CVD). However, there is a paucity of data on the independent risk of vascular disease (VD) associated with pharmacological treatment and no controlled trials demonstrating a reduction in risk with abstinence. Information about IHD and CVD-related drug abuse is mainly limited to epidemiological studies focused on urban populations. The potential link between some pharmacological treatments (estrogen, some oncologic drugs and some atypical antipsychotics) and cerebrovascular adverse events was analyzed, but disagreement about an association persists. Drugs of abuse, including cocaine, amphetamines and heroin, have been associated with an increased vascular risk. These drugs can cause abrupt changes in blood pressure, vasculitic-type changes, lead to embolization caused by infective endocarditis, and hemostatic and hematologic abnormalities that can result in increased blood viscosity and platelet aggregation. Long-term treatment strategies based on medication, psychological support, and outreach programs play an important role in treatment of drug dependency. In these last years public interest in risk factors for VD has been constantly increasing and the successful identification and management of pharmacological treatment and drug abuse can be challenging. One of the major public health issues for the future will be to focus more on new vascular risk factor recognition and management. The objective of this chapter is to review the relevance of IHD and CVD associated with various pharmacological treatments and drug abuse with focusing on ischemic disease. This chapter reports the clinical evidence of this association and analyzes the experimental role of new drugs as a growing risk factor of VD with the hypothetical new association. In conclusion, in this chapter great attention is paid to evaluating the scientific and real

  16. Particle-accelerator decommissioning

    Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given

  17. An introduction to acceleration mechanisms

    This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free Electron Laser Acceleration, Inverse Cerenkov Acceleration, Gravity Acceleration, 2D Linac Acceleration and Conventional Iris Loaded Linac Structure Acceleration

  18. Spinal vascular malformations; Spinale Gefaessmalformationen

    Yilmaz, U. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg/Saar (Germany)

    2012-05-15

    Spinal vascular malformations are a group of rare diseases with different clinical presentations ranging from incidental asymptomatic findings to progressive tetraplegia. This article provides an overview about imaging features as well as clinical and therapeutic aspects of spinal arteriovenous malformations, cavernomas and capillary telangiectasia. (orig.) [German] Spinale Gefaessmalformationen sind eine Gruppe seltener Erkrankungen mit unterschiedlichen klinischen Praesentationen, die vom asymptomatischen Zufallsbefund bis zur progredienten Tetraparese reichen. Dieser Artikel gibt einen Ueberblick ueber radiologische Befunde sowie klinische und therapeutische Aspekte von spinalen arteriovenoesen Malformationen, Kavernomen und kapillaeren Teleangiektasien. (orig.)

  19. DNA Damage and Repair in Vascular Disease.

    Uryga, Anna; Gray, Kelly; Bennett, Martin

    2016-01-01

    DNA damage affecting both genomic and mitochondrial DNA is present in a variety of both inherited and acquired vascular diseases. Multiple cell types show persistent DNA damage and a range of lesions. In turn, DNA damage activates a variety of DNA repair mechanisms, many of which are activated in vascular disease. Such DNA repair mechanisms either stall the cell cycle to allow repair to occur or trigger apoptosis or cell senescence to prevent propagation of damaged DNA. Recent evidence has indicated that DNA damage occurs early, is progressive, and is sufficient to impair function of cells composing the vascular wall. The consequences of persistent genomic and mitochondrial DNA damage, including inflammation, cell senescence, and apoptosis, are present in vascular disease. DNA damage can thus directly cause vascular disease, opening up new possibilities for both prevention and treatment. We review the evidence for and the causes, types, and consequences of DNA damage in vascular disease. PMID:26442438

  20. Extraordinary Vessels Needling for Vascular Dementia

    YU Jin; LAI Xin-sheng; HUANG Qiu-tang; XIAO Yuan-chun

    2003-01-01

    Purpose To observe the clinical efficacy of extraordinary vessels needling in treating vascular dementia. Method 39 cases vascular dementia were treated by acupoints selected from the eight extraordinary meridians and the time needling techniques such as eight methods of spiritual turtle, in accordance with time period and pattern identifition. Results 2 cases were cured, 30 cases improved and 7 cases failed; the total effective rate was 82.1%. Conclusion Extraordinary vessels needling has positive effects in treating vascular dementia.

  1. Blood Flow Restricted Exercise and Vascular Function

    Masahiro Horiuchi; Koichi Okita

    2012-01-01

    It is established that regular aerobic training improves vascular function, for example, endothelium-dependent vasodilatation and arterial stiffness or compliance and thereby constitutes a preventative measure against cardiovascular disease. In contrast, high-intensity resistance training impairs vascular function, while the influence of moderate-intensity resistance training on vascular function is still controversial. However, aerobic training is insufficient to inhibit loss in muscular str...

  2. Vascular Risk Factors: Imaging and Neuropathologic Correlates

    Knopman, David S; Roberts, Rosebud

    2010-01-01

    Cerebrovascular disease plays an important role in cognitive disorders in the elderly. Cerebrovascular disease and Alzheimer’s disease interact on several levels, one important level being the overlap in risk factors. The major vascular risk factors such as diabetes and impaired glycemic control, hypertension, obesity and hyper- or dyslipidemia have been associated both with Alzheimer’s disease and vascular dementia. The purpose of this review is to consider the context in which vascular deme...

  3. Accelerator and radiation physics

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  4. Switched Matrix Accelerator

    We describe a new concept for a microwave circuit functioning as a charged-particle accelerator at mm-wavelengths, permitting an accelerating gradient higher than conventional passive circuits can withstand consistent with cyclic fatigue. The device provides acceleration for multiple bunches in parallel channels, and permits a short exposure time for the conducting surface of the accelerating cavities. Our analysis includes scalings based on a smooth transmission line model and a complementary treatment with a coupled-cavity simulation. We provide also an electromagnetic design for the accelerating structure, arriving at rough dimensions for a seven-cell accelerator matched to standard waveguide and suitable for bench tests at low power in air at 91.392. GHz. A critical element in the concept is a fast mm-wave switch suitable for operation at high-power, and we present the considerations for implementation in an H-plane tee. We discuss the use of diamond as the photoconductor switch medium

  5. Accelerator reliability workshop

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop

  6. Leaky Fermi accelerators

    Shah, Kushal; Rom-Kedar, Vered; Turaev, Dmitry

    2015-01-01

    A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

  7. Accelerator reliability workshop

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  8. Nuclear physics accelerator facilities

    This paper describes many of the nuclear physics heavy-ion accelerator facilities in the US and the research programs being conducted. The accelerators described are: Argonne National Laboratory--ATLAS; Brookhaven National Laboratory--Tandem/AGS Heavy Ion Facility; Brookhaven National Laboratory--Relativistic Heavy Ion Collider (RHIC) (Proposed); Continuous Electron Beam Accelerator Facility; Lawrence Berkeley Laboratory--Bevalac; Lawrence Berkeley Laboratory--88-Inch Cyclotron; Los Alamos National Laboratory--Clinton P. Anderson Meson Physics Facility (LAMPF); Massachusetts Institute of Technology--Bates Linear Accelerator Center; Oak Ridge National Laboratory--Holifield Heavy Ion Research Facility; Oak Ridge National Laboratory--Oak Ridge Electron Linear Accelerator; Stanford Linear Accelerator Center--Nuclear Physics Injector; Texas AandM University--Texas AandM Cyclotron; Triangle Universities Nuclear Laboratory (TUNL); University of Washington--Tandem/Superconducting Booster; and Yale University--Tandem Van de Graaff

  9. Vascular endothelium - Gatekeeper of vessel health.

    Cahill, Paul A; Redmond, Eileen M

    2016-05-01

    The vascular endothelium is an interface between the blood stream and the vessel wall. Changes in this single cell layer of the artery wall are believed of primary importance in the pathogenesis of vascular disease/atherosclerosis. The endothelium responds to humoral, neural and especially hemodynamic stimuli and regulates platelet function, inflammatory responses, vascular smooth muscle cell growth and migration, in addition to modulating vascular tone by synthesizing and releasing vasoactive substances. Compromised endothelial function contributes to the pathogenesis of cardiovascular disease; endothelial 'dysfunction' is associated with risk factors, correlates with disease progression, and predicts cardiovascular events. Therapies for atherosclerosis have been developed, therefore, that are directed towards improving endothelial function. PMID:26994427

  10. Proatherogenic pathways leading to vascular calcification

    Mazzini, Michael J. [Department of Cardiology, Boston University Medical Center, Boston, MA (United States); Schulze, P. Christian [Department of Medicine, Boston University Medical Center, Boston, MA (United States)]. E-mail: christian.schulze@bmc.org

    2006-03-15

    Cardiovascular disease is the leading cause of morbidity and mortality in the western world and atherosclerosis is the major common underlying disease. The pathogenesis of atherosclerosis involves local vascular injury, inflammation and oxidative stress as well as vascular calcification. Vascular calcification has long been regarded as a degenerative process leading to mineral deposition in the vascular wall characteristic for late stages of atherosclerosis. However, recent studies identified vascular calcification in early stages of atherosclerosis and its occurrence has been linked to clinical events in patients with cardiovascular disease. Its degree correlates with local vascular inflammation and with the overall impact and the progression of atherosclerosis. Over the last decade, diverse and highly regulated molecular signaling cascades controlling vascular calcification have been described. Local and circulating molecules such as osteopontin, osteoprogerin, leptin and matrix Gla protein were identified as critical regulators of vascular calcification. We here review the current knowledge on molecular pathways of vascular calcification and their relevance for the progression of cardiovascular disease.

  11. Vascular grafting strategies in coronary intervention

    Knight, Darryl; Gillies, Elizabeth; Mequanint, Kibret

    2014-06-01

    With the growing need for coronary revascularizations globally, several strategies to restore blood flow to the heart have been explored. Bypassing the atherosclerotic coronary arteries with autologous grafts, synthetic prostheses and tissue-engineered vascular grafts continue to be evaluated in search of a readily available vascular graft with clinically acceptable outcomes. The development of such a vascular graft including tissue engineering approaches both in situ and in vitro is herein reviewed, facilitating a detailed comparison on the role of seeded cells in vascular graft patency.

  12. VASCULAR MALFORMATION OF CHEEK: A CASE REPORT

    Faiz

    2015-02-01

    Full Text Available Vascular lesions are among the most common congenital and neonatal abnormalities. Most of the congenital vascular malformations are often misdiagnosed and left untreated. These lesions are the result of an embryonic abnormality of the vascular system. This is a case report of 13 year male patient who came with a chief complaint of swelling on the right side of face since birth. It was diagnosed as vascular malformations of buccal mucosa of right side. It is emphasized that the management of these cases requ ires a multidisciplinary approach. Laser therapy, embolization followed by surgical excision is the favourable treatment modalities.

  13. CAS - CERN Accelerator School: RF for Accelerators

    2012-01-01

    These proceedings present the lectures given at the twenty-fourth specialized course organized by the CERN Accelerator School (CAS). The course was held in Ebeltoft, Denmark, from 8-17 June, 2010 in collaboration with Aarhus University, with the topic 'RF for Accelerators' While this topic has been covered by CAS previously, early in the 1990s and again in 2000, it was recognized that recent advances in the field warranted an updated course. Following introductory courses covering the background physics, the course attempted to cover all aspects of RF for accelerators; from RF power generation and transport, through cavity and coupler design, electronics and low level control, to beam diagnostics and RF gymnastics. The lectures were supplemented with several sessions of exercises, which were completed by discussion sessions on the solutions.

  14. Accelerator shielding benchmark problems

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author)

  15. The foxhole accelerating structure

    This report examines some properties of a new type of open accelerating structure. It consists of a series of rectangular cavities, which we call foxholes, joined by a beam channel. The power for accelerating the particles comes from an external radiation source and enters the cavities through their open upper surfaces. Analytic and computer calculations are presented showing that the foxhole is a suitable structure for accelerating relativistic electrons

  16. Japan Accelerator Conference

    At the international level, the high energy accelerator scene evolves rapidly and the International Conference on High Energy Accelerators is where its strong pulse can best be felt. This year, the Conference was held for the first time in Japan, with the 14th meeting in the series having been hosted in August by the Japanese KEK National Laboratory for High Energy Physics, Tsukuba. The venue was a recognition of the premier accelerator physics and technology status achieved by this diligent nation

  17. Accelerator shielding benchmark problems

    Hirayama, H.; Ban, S.; Nakamura, T. [and others

    1993-01-01

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author).

  18. Diffuse and vascular hepatic diseases

    In addition to focal liver lesions, diffuse and vascular disorders of the liver represent a wide spectrum of liver diseases which are from the radiological point of view often difficult or nearly impossible to diagnose. Classical diagnostic methods are computed tomography and magnetic resonance imaging in addition to ultrasound. Diffuse parenchymal damage caused by diseases of various etiologies is therefore difficult to evaluate because it often lacks characteristic morphological features. For hepatic steatosis, hemochromatosis/siderosis as an example of a diffuse storage disease and sarcoidosis and candidiasis as infectious/inflammatory diseases, an image-based diagnosis is appropriate in some cases. For most diffuse liver diseases, however only nonspecific changes are visualized. Vascular pathologies of the liver, such as the Budd-Chiari syndrome and portal vein thrombosis, however, can usually be diagnosed very clearly using radiology and there is also a very effective interventional radiological treatment. Chronic diseases very often culminate in liver cirrhosis which is highly associated with an increased risk of liver cancer. (orig.)

  19. Orthopedic issues in vascular anomalies.

    Spencer, Samantha A; Sorger, Joel

    2014-08-01

    Vascular malformations impact the musculoskeletal system depending on the tissue involved (skin, subcutis, muscle, cartilage, or bone), the extent of involvement, and the type of anomalous vessels (arteries, capillaries, veins, or lymphatics). These malformations can cause a multitude of musculoskeletal problems for the patient and their Orthopedic Surgeon to manage. Leg-length discrepancy, intra-articular involvement, muscular lesions, and primary or secondary scoliosis are just to name a few. All of these problems can cause pain, deformity, and a range of functional limitations. Surgical and nonsurgical treatment plans both have a role in the care of these patients. Patients with vascular malformations may also suffer from life-threatening cardiovascular and hematologic abnormalities. For those patients who undergo surgery, thromboembolic risk is elevated, wound breakdown and infection are much more common, and bleeding risk continues well into the postoperative course. Because of the complex nature of these disorders, the clinician must have a full understanding of the types of lesions, their natural history, appropriate diagnostic studies, associated medical problems, indications for treatment, and all the treatment options. For severe malformations, especially syndromes such as CLOVES and Klippel-Trenaunay syndrome, interdisciplinary team management is essential for the best outcomes. PMID:25241103

  20. CIRSE Vascular Closure Device Registry

    Purpose: Vascular closure devices are routinely used after many vascular interventional radiology procedures. However, there have been no major multicenter studies to assess the safety and effectiveness of the routine use of closure devices in interventional radiology. Methods: The CIRSE registry of closure devices with an anchor and a plug started in January 2009 and ended in August 2009. A total of 1,107 patients were included in the registry. Results: Deployment success was 97.2%. Deployment failure specified to access type was 8.8% [95% confidence interval (95% CI) 5.0–14.5] for antegrade access and 1.8% (95% CI 1.1–2.9) for retrograde access (P = 0.001). There was no difference in deployment failure related to local PVD at the access site. Calcification was a reason for deployment failure in only 5.9 cm, and two vessel occlusions. Conclusion: The conclusion of this registry of closure devices with an anchor and a plug is that the use of this device in interventional radiology procedures is safe, with a low incidence of serious access site complications. There seems to be no difference in complications between antegrade and retrograde access and other parameters.

  1. Neuroradiological findings in vascular dementia

    Guermazi, Ali; Miaux, Yves; Suhy, Joyce; Pauls, Jon; Lopez, Ria [Synarc, Inc., Department of Radiology Services, San Francisco, CA (United States); Rovira-Canellas, Alex [Hospital General Universitari Vall d' Hebron, Unita de Resonancia Magnetica, Barcelona (Spain); Posner, Holly [Eisai, Inc., Teaneck, NJ (United States)

    2007-01-15

    There are multiple diagnostic criteria for vascular dementia (VaD) that may define different populations. Utilizing the criteria of the National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) has provided improved consistency in the diagnosis of VaD. The criteria include a table listing brain imaging lesions associated with VaD. The different neuroradiological aspects of the criteria are reviewed based on the imaging data from an ongoing large-scale clinical trial testing a new treatment for VaD. The NINDS-AIREN criteria were applied by a centralized imaging rater to determine eligibility for enrollment in 1,202 patients using brain CT or MRI. Based on the above data set, the neuroradiological features that are associated with VaD and that can result from cerebral small-vessel disease with extensive leukoencephalopathy or lacunae (basal ganglia or frontal white matter), or may be the consequence of single strategically located infarcts or multiple infarcts in large-vessel territories, are illustrated. These features may also be the consequence of global cerebral hypoperfusion, intracerebral hemorrhage, or other mechanisms such as genetically determined arteriopathies. Neuroimaging confirmation of cerebrovascular disease in VaD provides information about the topography and severity of vascular lesions. Neuroimaging may also assist with the differential diagnosis of dementia associated with normal pressure hydrocephalus, chronic subdural hematoma, arteriovenous malformation or tumoral diseases. (orig.)

  2. Superconducting accelerator magnets

    In the near future, a large number of high quality superconducting dipole and quadrupole magnets will be required for construction of the next generation multi-TeV high energy hadron accelerator-colliders. To establish the construction technology of such accelerator- colliders, extensive and world-wide R and D programs are now carrying out at several laboratories. In this paper the important issues in superconducting accelerator magnets such as cables, design, fabrication, testing and cryogenic system are discussed together with some details on coil cross- sectional current configurations, quality control of materials, quench protections, radiation heating and etc. The key technology in superconducting accelerator magnets is summarized

  3. High-intensity accelerators

    The design of high-intensity accelerators is described, using examples of machines being built at the Los Alamos National Laboratory. The major design problem with these accelerators is associated with control of beam loss when accelerator intensity is increased. Beam dynamics, beam loss, and the radio-frequency quadrupole structure are discussed in the first part of the chapter followed by an explanation of plans to achieve high-intensity operation in three projects: the Fusion Material Irradiation Tests (a joint effort with the Hanford Development Laboratory in Richland, Washington), the Proton Storage Ring (an addition to the LAMPF accelerator), and the Racetrack Microtron Project

  4. High Gradient Accelerator Research

    Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics. Plasma Science and Fusion Center

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  5. Biomarkers of vascular function in pre- and recent post-menopausal women of similar age

    Nyberg, Michael Permin; Seidelin, Kaare; Rostgaard Andersen, Thomas; Neumann Overby, Nickie; Hellsten, Ylva; Bangsbo, Jens

    2014-01-01

    Menopause is associated with an accelerated decline in vascular function, however, whether this is an effect of age and/or menopause and how exercise training may affect this decline remains unclear. We examined a range of molecular measures related to vascular function in matched pre- and post-menopausal...... women before and after 12 weeks of exercise training. Thirteen pre-menopausal and ten recently post-menopausal (1.6±0.3 (mean±SEM) years after final menstrual period) women only separated by three years (48±1 vs. 51±1 years) were included. Before training, diastolic blood pressure, soluble intercellular...... adhesion molecule-1 (sICAM-1) and skeletal muscle expression of thromboxane A synthase were higher in the post-menopausal women compared to the pre-menopausal women, all indicative of impaired vascular function. In both groups, exercise training lowered diastolic blood pressure, the levels of sICAM-1...

  6. Systemic and forearm vascular resistance changes after upright bicycle exercise in man.

    Coats, A J; Conway, J; Isea, J E; Pannarale, G; Sleight, P; Somers, V K

    1989-06-01

    1. Blood pressure, cardiac function and forearm blood flow following voluntary maximal upright bicycle exercise were studied in thirteen normal volunteers in a cross-over design against a control day. 2. After exercise there was a short-lived (5-10 min) increase in systolic blood pressure, peak aortic blood velocity and aortic acceleration suggesting a persistence of the positive inotropic influence of exercise. 3. Systemic vasodilation, which was seen immediately exercise stopped, lasted at least 60 min. This was associated with a reduction in diastolic blood pressure for the whole hour. After 30 min systolic blood pressure was also reduced. Heart rate and cardiac output were still significantly elevated and systemic vascular resistance still reduced at 60 min post-exercise. 4. A non-exercising limb vascular bed (forearm) showed a marked vasodilation for 1 h after predominately leg exercise indicating the presence of a vasodilatory influence affecting vascular beds other than the exercising muscle groups. PMID:2600851

  7. Vascular effects of multiwalled carbon nanotubes in dyslipidemic ApoE-/- mice and cultured endothelial cells

    Cao, Yi; Jacobsen, Nicklas Raun; Danielsen, Pernille Høgh;

    2014-01-01

    Accumulating evidences indicate that pulmonary exposure to carbon nanotubes (CNTs) is associated with increased risk of lung diseases, whereas the effect on the vascular system is less studied. We investigated vascular effects of 2 types of multiwalled CNTs (MWCNTs) in apolipoprotein E(-/-) mice......, wild-type mice, and cultured cells. The ApoE(-/-) mice had accelerated plaque progression in aorta after 5 intracheal instillations of MWCNT (25.6 μg/mouse weekly for 5 weeks). The exposure was associated with pulmonary inflammation, lipid peroxidation, and increased expression of inflammatory......, oxidative stress, DNA repair, and vascular activation response genes. The level of oxidatively damaged DNA in lung tissue was unaltered, probably due to increased DNA repair capacities. Despite upregulation of inflammatory genes in the liver, effects on systemic cytokines and lipid peroxidation were minimal...

  8. Displacement of plasma protein and conduction velocity in rats under action of acceleration forces and hypokinesia

    Baranski, S.; Edelwejn, Z.; Wojtkowiak, M.

    1980-01-01

    The permeability of capillary vessels was investigated in order to determine if acceleration alone or following prolonged hypokinesia would induce changes in the vascular wall leading to the penetration by l-albumins and/or proteins with larger molecules. In rats undergoing action of +5 Gz accelerations, no increase in vascular permeability, as tested with the use of (Cr-5k)-globulin, was demostrated. In rats immobilized for 4 weeks before centrifugation, rather weak migration of (Cr-51)-globulin from the vessels was observed. Immobilization resulted also in lowering of conduction velocity in the sciatic nerve.

  9. Advance in molecular imaging research of vascular smooth muscle cells in the vascular diseases

    Vascular smooth muscle cells (VSMCs) are the primary cells within the vascular wall structure and maintain the tension of blood vessels, playing a key role in the restenosis, atherosclerosis and some other vascular diseases. With the development of molecular imaging, VSMCs cellular level of imaging studies is becoming more and more attention. The phenotype modulation, proliferation, migration and molecular imaging research progress of VSMCs in pathologic state were reviewed, to improve the management of vascular restenosis and atherosclerosis. (authors)

  10. Diabetes and ageing-induced vascular inflammation.

    Assar, Mariam El; Angulo, Javier; Rodríguez-Mañas, Leocadio

    2016-04-15

    Diabetes and the ageing process independently increase the risk for cardiovascular disease (CVD). Since incidence of diabetes increases as people get older, the diabetic older adults represent the largest population of diabetic subjects. This group of patients would potentially be threatened by the development of CVD related to both ageing and diabetes. The relationship between CVD, ageing and diabetes is explained by the negative impact of these conditions on vascular function. Functional and clinical evidence supports the role of vascular inflammation induced by the ageing process and by diabetes in vascular impairment and CVD. Inflammatory mechanisms in both aged and diabetic vasculature include pro-inflammatory cytokines, vascular hyperactivation of nuclear factor-кB, increased expression of cyclooxygenase and inducible nitric oxide synthase, imbalanced expression of pro/anti-inflammatory microRNAs, and dysfunctional stress-response systems (sirtuins, Nrf2). In contrast, there are scarce data regarding the interaction of these mechanisms when ageing and diabetes co-exist and its impact on vascular function. Older diabetic animals and humans display higher vascular impairment and CVD risk than those either aged or diabetic, suggesting that chronic low-grade inflammation in ageing creates a vascular environment favouring the mechanisms of vascular damage driven by diabetes. Further research is needed to determine the specific inflammatory mechanisms responsible for exacerbated vascular impairment in older diabetic subjects in order to design effective therapeutic interventions to minimize the impact of vascular inflammation. This would help to prevent or delay CVD and the specific clinical manifestations (cognitive decline, frailty and disability) promoted by diabetes-induced vascular impairment in the elderly. PMID:26435167

  11. Angular velocities, angular accelerations, and coriolis accelerations

    Graybiel, A.

    1975-01-01

    Weightlessness, rotating environment, and mathematical analysis of Coriolis acceleration is described for man's biological effective force environments. Effects on the vestibular system are summarized, including the end organs, functional neurology, and input-output relations. Ground-based studies in preparation for space missions are examined, including functional tests, provocative tests, adaptive capacity tests, simulation studies, and antimotion sickness.

  12. Accelerator Modeling with MATLAB Accelerator Toolbox

    This paper introduces Accelerator Toolbox (AT)--a collection of tools to model storage rings and beam transport lines in the MATLAB environment. The objective is to illustrate the flexibility and efficiency of the AT-MATLAB framework. The paper discusses three examples of problems that are analyzed frequently in connection with ring-based synchrotron light sources

  13. Vascular health in children and adolescents: effects of obesity and diabetes

    Short, Kevin R.; Blackett, Piers R.; Andrew W Gardner; et al.

    2009-01-01

    Kevin R Short, Piers R Blackett, Andrew W Gardner, Kenneth C CopelandDepartment of Pediatrics, Section of Diabetes and Endocrinology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USAAbstract: The foundations for cardiovascular disease in adults are laid in childhood and accelerated by the presence of comorbid conditions, such as obesity, diabetes, hypertension, and dyslipidemia. Early detection of vascular dysfunction is an important clinical objective to identif...

  14. Do Thoroughbred and Standardbred horses have similar increases in pulmonary vascular pressures during exertion?

    Hackett, R. P.; Ducharme, N G; Gleed, R. D.; Mitchell, L; Soderholm, L. V.; Erickson, B. K.; Erb, H. N.

    2003-01-01

    To test the hypothesis that the pulmonary vascular pressures of Thoroughbred and Standardbred horses behave similarly during exertion. Measurements were made on 5 Thoroughbred and 5 Standardbred horses on a treadmill at rest and during 3-minute exercise intervals at speeds predicted to produce 75%, 90%, and 100% maximal heart rate. Left forelimb acceleration, heart rate, esophageal pressure, and pulmonary artery pressure were measured continuously. Pulmonary capillary and wedge pressures were...

  15. Piperlongumine inhibits atherosclerotic plaque formation and vascular smooth muscle cell proliferation by suppressing PDGF receptor signaling

    Son, Dong Ju; Kim, Soo Yeon; Han, Seong Su; Kim, Chan Woo; Kumar, Sandeep; Park, Byeoung Soo; Lee, Sung Eun; Yun, Yeo Pyo; Jo, Hanjoong; Park, Young Hyun

    2012-01-01

    Piperlongumine (piplartine, PL) is an alkaloid found in the long pepper (Piper longum L.) and has well-documented anti-platelet aggregation, anti-inflammatory, and anti-cancer properties; however, the role of PL in prevention of atherosclerosis is unknown. We evaluated the anti-atherosclerotic potential of PL in an in vivo murine model of accelerated atherosclerosis and defined its mechanism of action in aortic vascular smooth muscle cells (VSMCs) in vitro. Local treatment with PL significant...

  16. Hamburg Accelerator Conference (2)

    From 20-24 July, Hamburg welcomed the Fifteenth International Conference on High Energy Accelerators (HEACC). The HEACC Conference traditionally reviews the status of all major accelerator projects whether they are already running like clockwork, still in the construction phase, or waiting impatiently for financial approval

  17. Asia honours accelerator physicists

    2010-01-01

    "Steve Meyers of Cern and Jie Wei of Beijing's Tsinghua University are the first recipients of a new prize for particle physics. The pair were honoured for their contributions to numerous particle-accelerator projects - including Cern's Large Hadron Collider - by the Asian Committee for Future Accelerators (ACFA)..." (1 paragraph)

  18. Accelerator-based BNCT

    The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the 9Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases. - Highlights: • The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. • Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. • The present status and recent progress of the Argentine project will be reviewed. • Topics cover intense ion sources, accelerator tubes, transport of intense beams and beam diagnostics, among others

  19. COLLECTIVE-FIELD ACCELERATION

    Sessler, Andrew M.

    1969-07-04

    Diverse methods proposed for the acceleration of particles by means of collective fields are reviewed. A survey is made of the various currently active experimental programs devoted to investigating collective acceleration, and the present status of the research is briefly noted.

  20. Racetrack linear accelerators

    An improved recirculating electron beam linear accelerator of the racetrack type is described. The system comprises a beam path of four straight legs with four Pretzel bending magnets at the end of each leg to direct the beam into the next leg of the beam path. At least one of the beam path legs includes a linear accelerator. (UK)

  1. Thoughts of accelerator tubes

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  2. Accelerators for energy production

    A tremendous progress of accelerators for these several decades, has been motivated mainly by the research on subnuclear physics. The culmination in high energy accelerators might be SSC, 20 TeV collider in USA, probably the ultimate accelerator being built with the conventional principle. The technology cultivated and integrated for the accelerator development, can now stably offer the high power beam which could be used for the energy problems. The Inertial Confinement Fusion (ICF) with high current, 10 kA and short pulse, 20 ns heavy ion beam (HIB) of mass number ∼200, would be the most promising application of accelerators for energy production. In this scenario, the fuel containing D-T mixture, will be compressed to the high temperature, ∼10 keV and to the high density state, ∼1000 times the solid density with the pressure of ablative plasma or thermal X ray produced by bombarding of high power HIB. The efficiency, beam power/electric power for accelerator, and the repetition rate of HIB accelerators could be most suitable for the energy production. In the present paper, the outline of HIB ICF (HIF) is presented emphasizing the key issues of high current heavy ion accelerator system. (author)

  3. Accelerators Beyond The Tevatron?

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  4. Accelerator for nuclear transmutation

    A review on nuclear transmutation of radioactive wastes using particle accelerators is given. Technical feasibility, nuclear data, costs of various projects are discussed. It appears that one high energy accelerator (1500 MeV, 300 mA proton) could probably handle the amount of actinides generated by the actual French nuclear program

  5. KEK digital accelerator

    Iwashita, T.; Adachi, T.; Takayama, K.; Leo, K. W.; Arai, T.; Arakida, Y.; Hashimoto, M.; Kadokura, E.; Kawai, M.; Kawakubo, T.; Kubo, Tomio; Koyama, K.; Nakanishi, H.; Okazaki, K.; Okamura, K.; Someya, H.; Takagi, A.; Tokuchi, A.; Wake, M.

    2011-07-01

    The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  6. Vascular malformations of the spine

    The vascular malformations of the spine and spinal cord are rare diseases. Possible symptoms may consist in a transient neurological deficit, a progressive sensorimotor transverse lesion or an acute para- or tetraplegia. Damage to the spinal cord occurs by bleeding, space-occupying effects and venous congestion, rarely by steal effects. Classification of the true inborn malformations differentiates between arteriovenous malformations (AVMs), cavernomas and capillary teleangiectasias. The more frequent spinal dural arteriovenous fistula (SDAVF) of the elderly patient is a probably acquired lesion which is presented in a separate paper. Capillary teleangiectasias are mostly incidental findings but may cause differential diagnostic problems. Cavernomas are important causes of hemorrhage and may initially be obscured within the bleeding. MRI is the most relevant imaging procedure in the early diagnostic workup. In case of an AVM selective spinal angiography is required to define the type of the lesion and to decide about the appropriate therapy which may be endovascular-interventional, neurosurgical, combined or attentive. (orig.)

  7. Multinephron dynamics on the renal vascular network

    Marsh, Donald J; Wexler, Anthony S; Brazhe, Alexey;

    2012-01-01

    ensemble. Ensembles may synchronize. Smooth muscle cells in the ensemble depolarize periodically, generating electrical signals that propagate along the vascular network. We developed a mathematical model of a nephron-vascular network, with 16 versions of a single nephron model containing representations...

  8. Vascular surgery and diabetic foot revascularization

    GU Yong-quan

    2010-01-01

    @@ Patients with diabetes mellitus have an increased incidence of atherosclerotic vascular disease and infection involving the lower extremities.Lower limb arterial disease is more common among patients with diabetes, and lower limb atherosclerosis is the main cause of lower limb ischemia for these patients.Two types of vascular disease are seen in patients with diabetes.

  9. Covariance of lichen and vascular plant floras

    Bennett, J.P.; Wetmore, C.M.

    1999-01-01

    The geographic relationships among taxonomic groups are important to study to determine patterns of biodiversity and whether or not associations occur between large groups, e.g., birds and vascular plants. This study was undertaken to determine relationships between higher plants and lower plants, specifically vascular plant and lichen floras in nine national parks of the Great Lakes region. No significant relationship was found between vascular plant floras and lichen floras in this area, which spans 1200 km longitudinally, or between an additional 19 areas from North America that were less than 1000 km(2) in area. For areas larger than 1000 km(2), however, a significant positive relationship existed for 33 areas that span one to approximately 150 million km(2). The ratio of numbers of vascular plants to lichens appeared to average just over 6 across the 33 areas. In the Great Lakes parks, between 28-30% of either the vascular plant or lichen species were singletons (occurring in only one park), but the parks that contained the most singletons were not congruent: Isle Royale had the most singleton lichens, while Indiana Dunes had the most vascular plant singletons. Fewer lichen species (2%) than vascular plants (4%) occurred in all nine parks. Latitude appeared to explain some of the variation between the two groups: vascular plants decreased with increasing latitude, while lichens increased.

  10. Megadolicho vascular malformation of the intracranial arteries.

    Lodder, J; Janevski, B; van der Lugt, P J

    1981-01-01

    A patient is presented suffering a hemiparesis. Megadolicho-vascular malformation of the intracranial part of the internal carotid arteries and some of its branches and of the basilar artery was suggested by CT and confirmed by angiography. The value of CT compared with angiography in relation to intracranial megadolicho vascular malformations is discussed. PMID:6273040

  11. What "helps" tumors evade vascular targeting treatment?

    SI Zhi-chao; LIU Jie

    2008-01-01

    Objective To throw a light on the possible factors which might induce resistance of vascular targeting treatment in tumors by reviewing the recent publications in the field of tumor angiogenesis and vascular targeting treatment.Data sources The data used in this review were mainly from Medline and PubMed for relevant English language articles published from 1971 to January 2008. The search terms were "angiogenesis", "vascular targeting treatment" and "endothelial progenitor cells".Study selection Articles involved in the possible influence factors during angiogenesis and vascular targeting treatment were selected, including angiogenic or anti-angiogenic mechanism, tumor vasculature, tumor cells, cancer stem cells and endothelial progenitor cells.Results As a promising strategy vascular targeting treatment still has experimental and clinical setbacks which may term tumor vasculature's resistance to anti-angiogenesis agents. There are several possible explanations for such a resistance that might account for clinical and preclinical failures of anti-angiogenic treatment against tumor.Proangiogenic effect of hypoxia, normal tumor vasculature, escape of tumor cells and tumor vasculogenesis are included.This review reveals some clues which might be helpful to direct future research in order to remove obstacles to vascular targeting treatment.Conclusions Generally and undoubtedly vascular targeting treatment remains a promising strategy. But we still have to realize the existence of a challenging future. Further research is required to enhance our knowledge of vascular targeting treatment strategy before it could make a more substantial success.

  12. Biomarkers of drug-induced vascular injury

    In pre-clinical safety studies, drug-induced vascular injury is an issue of concern because there are no obvious diagnostic markers for pre-clinical or clinical monitoring and there is an intellectual gap in our understanding of the pathogenesis of this lesion. While vasodilatation and increased shear stress appear to play a role, the exact mechanism(s) of injury to the primary targets, smooth muscle and endothelial cells are unknown. However, evaluation of novel markers for potential clinical monitoring with a mechanistic underpinning would add value in risk assessment and management. This mini review focuses on the progress to identify diagnostic markers of drug-induced vascular injury. Von Willebrand factor (vWF), released upon perturbation of endothelial cells, is transiently increased in plasma prior to morphological evidence of damage in dogs or rats treated with vascular toxicants. Therefore, vWF might be a predictive biomarker of vascular injury. However, vWF is not an appropriate biomarker of lesion progression or severity since levels return to baseline values when there is morphological evidence of injury. A potential mechanistically linked biomarker of vascular injury is caveolin-1. Expression of this protein, localized primarily to smooth muscle and endothelial cells, decreases with the onset of vascular damage. Since vascular injury involves multiple mediators and cell types, evaluation of a panel rather than a single biomarker may be more useful in monitoring early and severe progressive vascular injury

  13. Maximal Acceleration Is Nonrotating

    Page, D N

    1998-01-01

    In a stationary axisymmetric spacetime, the angular velocity of a stationary observer that Fermi-Walker transports its acceleration vector is also the angular velocity that locally extremizes the magnitude of the acceleration of such an observer, and conversely if the spacetime is also symmetric under reversing both t and phi together. Thus a congruence of Nonrotating Acceleration Worldlines (NAW) is equivalent to a Stationary Congruence Accelerating Locally Extremely (SCALE). These congruences are defined completely locally, unlike the case of Zero Angular Momentum Observers (ZAMOs), which requires knowledge around a symmetry axis. The SCALE subcase of a Stationary Congruence Accelerating Maximally (SCAM) is made up of stationary worldlines that may be considered to be locally most nearly at rest in a stationary axisymmetric gravitational field. Formulas for the angular velocity and other properties of the SCALEs are given explicitly on a generalization of an equatorial plane, infinitesimally near a symmetry...

  14. Collinear wake field acceleration

    In the Voss-Weiland scheme of wake field acceleration a high current, ring-shaped driving bunch is used to accelerate a low current beam following along on axis. In such a structure, the transformer ratio, i.e., the ratio of maximum voltage that can be gained by the on-axis beam and the voltage lost by the driving beam, can be large. In contrast, it has been observed that for an arrangement in which driving and driven bunches follow the same path, and where the current distribution of both bunches is gaussian, the transformer ratio is not normally greater than two. This paper explores some of the possibilities and limitations of a collinear acceleration scheme. In addition to its application to wake field acceleration in structures, this study is also of interest for the understanding of the plasma wake field accelerator. 11 refs., 4 figs

  15. Plasma based accelerators

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  16. Controllable Laser Ion Acceleration

    Kawata, S.; Kamiyama, D.; Ohtake, Y.; Takano, M.; Barada, D.; Kong, Q.; Wang, P. X.; Gu, Y. J.; Wang, W. M.; Limpouch, J.; Andreev, A.; Bulanov, S. V.; Sheng, Z. M.; Klimo, O.; Psikal, J.; Ma, Y. Y.; Li, X. F.; Yu, Q. S.

    2016-02-01

    In this paper a future laser ion accelerator is discussed to make the laser-based ion accelerator compact and controllable. Especially a collimation device is focused in this paper. The future laser ion accelerator should have an ion source, ion collimators, ion beam bunchers, and ion post acceleration devices [Laser Therapy 22, 103(2013)]: the ion particle energy and the ion energy spectrum are controlled to meet requirements for a future compact laser ion accelerator for ion cancer therapy or for other purposes. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching would be successfully realized by a multistage laser-target interaction.

  17. Linear induction accelerator

    This paper examines a new layout for the injector and accelerating sectins of a linear induction accelerator. The sections are combined in a single housing: an induction system with a current-pulse generator based on double strip shaping lines laid over ferromagnetic cores; a multichannel spark discharger with forced current division among channels; and a system for core demagnetization and electron-beam formation and transport. The results of formation of an electron beam in the injector system and its acceleration in the first accelerating section of the accelerator for injection of beams with energies of 0.2-0.4 MeV, currents of 1-2 kA, and pulse durations of 60 nsec are given

  18. Mechanics of Vascular Smooth Muscle.

    Ratz, Paul H

    2015-01-01

    Vascular smooth muscle (VSM; see Table 1 for a list of abbreviations) is a heterogeneous biomaterial comprised of cells and extracellular matrix. By surrounding tubes of endothelial cells, VSM forms a regulated network, the vasculature, through which oxygenated blood supplies specialized organs, permitting the development of large multicellular organisms. VSM cells, the engine of the vasculature, house a set of regulated nanomotors that permit rapid stress-development, sustained stress-maintenance and vessel constriction. Viscoelastic materials within, surrounding and attached to VSM cells, comprised largely of polymeric proteins with complex mechanical characteristics, assist the engine with countering loads imposed by the heart pump, and with control of relengthening after constriction. The complexity of this smart material can be reduced by classical mechanical studies combined with circuit modeling using spring and dashpot elements. Evaluation of the mechanical characteristics of VSM requires a more complete understanding of the mechanics and regulation of its biochemical parts, and ultimately, an understanding of how these parts work together to form the machinery of the vascular tree. Current molecular studies provide detailed mechanical data about single polymeric molecules, revealing viscoelasticity and plasticity at the protein domain level, the unique biological slip-catch bond, and a regulated two-step actomyosin power stroke. At the tissue level, new insight into acutely dynamic stress-strain behavior reveals smooth muscle to exhibit adaptive plasticity. At its core, physiology aims to describe the complex interactions of molecular systems, clarifying structure-function relationships and regulation of biological machines. The intent of this review is to provide a comprehensive presentation of one biomachine, VSM. PMID:26756629

  19. The Vascular Microenvironment and Systemic Sclerosis

    Tracy Frech

    2010-01-01

    Full Text Available The role of the vascular microenvironment in the pathogenesis Systemic Sclerosis (SSc is appreciated clinically as Raynaud's syndrome with capillary nail bed change. This manifestation of vasculopathy is used diagnostically in both limited and diffuse cutaneous subsets of SSc, and is thought to precede fibrosis. The degree of subsequent fibrosis may also be determined by the vascular microenvironment. This paper describes why the vascular microenvironment might determine the degree of end-organ damage that occurs in SSc, with a focus on vascular cell senescence, endothelial progenitor cells (EPC including multipotential mesenchymal stem cells (MSC, pericytes, and angiogenic monocytes. An explanation of the role of EPC, pericytes, and angiogenic monocytes is important to an understanding of SSc pathogenesis. An evolving understanding of the vascular microenvironment in SSc may allow directed treatment.

  20. Vascular Stiffness in Insulin Resistance and Obesity

    Guanghong eJia

    2015-08-01

    Full Text Available Obesity, insulin resistance, and type 2 diabetes are associated with a substantially increased prevalence of vascular fibrosis and stiffness, with attendant increased risk of cardiovascular and chronic kidney disease. Although the underlying mechanisms and mediators of vascular stiffness are not well understood, accumulating evidence supports the role of metabolic and immune dysregulation related to increased adiposity, activation of the renin angiotensin aldosterone system, reduced bioavailable nitric oxide, increased vascular extracellular matrix (ECM and ECM remodeling in the pathogenesis of vascular stiffness. This review will give a brief overview of the relationship between obesity, insulin resistance and increased vascular stiffness to provide a contemporary understanding of the proposed underlying mechanisms and potential therapeutic strategies.

  1. PanVascular medicine. 2. ed.

    Lanzer, Peter (ed.) [Health Care Center Bitterfeld (Germany). Division of Cardiovascular Disease

    2015-06-01

    Vascular management and care has become a truly multidisciplinary enterprise as the number of specialists involved in the treatment of patients with vascular diseases has steadily increased. While in the past, treatments were delivered by individual specialists, in the twenty-first century a team approach is without doubt the most effective strategy. In order to promote professional excellence in this dynamic and rapidly evolving field, a shared knowledge base and interdisciplinary standards need to be established. Pan Vascular Medicine, 2nd edition has been designed to offer such an interdisciplinary platform, providing vascular specialists with state-of-the art descriptive and procedural knowledge. Basic science, diagnostics, and therapy are all comprehensively covered. In a series of succinct, clearly written chapters, renowned specialists introduce and comment on the current international guidelines and present up-to-date reviews of all aspects of vascular care.

  2. Geometry optimization of branchings in vascular networks

    Khamassi, Jamel; Bierwisch, Claas; Pelz, Peter

    2016-06-01

    Progress has been made in developing manufacturing technologies which enable the fabrication of artificial vascular networks for tissue cultivation. However, those networks are rudimentary designed with respect to their geometry. This restricts long-term biological functionality of vascular cells which depends on geometry-related fluid mechanical stimuli and the avoidance of vessel occlusion. In the present work, a bioinspired geometry optimization for branchings in artificial vascular networks has been conducted. The analysis could be simplified by exploiting self-similarity properties of the system. Design rules in the form of two geometrical parameters, i.e., the branching angle and the radius ratio of the daughter branches, are derived using the wall shear stress as command variable. The numerical values of these parameters are within the range of experimental observations. Those design rules are not only beneficial for tissue engineering applications. Moreover, they can be used as indicators for diagnoses of vascular diseases or for the layout of vascular grafts.

  3. Electrospun PELCL membranes loaded with QK peptide for enhancement of vascular endothelial cell growth.

    Yang, Yang; Yang, Qingmao; Zhou, Fang; Zhao, Yunhui; Jia, Xiaoling; Yuan, Xiaoyan; Fan, Yubo

    2016-06-01

    One of the major challenges in tissue engineering of small-diameter vascular grafts is to inhibit intimal hyperplasia and keep long-term patency after implantation. Rapid endothelialization of the grafts could be an effective approach. In this study, QK, a peptide mimicking vascular endothelial growth factor, was selected as the bioactive substrate and loaded in electrospun membranes for enhancement of vascular endothelial cell growth. In detail, QK peptide was firstly introduced with poly(ethylene glycol) diacrylate into a thiolated chitosan solution that could transfer into hydrogel. Then, suspensions or emulsions of poly(ethylene glycol)-b-poly(L-lactide-co-ε-caprolactone) (PELCL) containing QK peptide (with or without chitosan hydrogel) were electrospun into fibrous membranes. For comparison, the electrospun PELCL membrane without QK was also fabricated. Results of release behaviors showed that the electrospun membranes, especially that contained chitosan hydrogel prepared by suspension electrospinning, could successfully encapsulate QK peptide and maintain its secondary structure after released. In vitro cell culture studies exhibited that the release of QK peptide could accelerate the proliferation of vascular endothelial cells in the 9 days. It was suggested that the electrospun PELCL membranes loaded with QK peptide might have potential applications in vascular tissue engineering. PMID:27107890

  4. Accelerator programme at CAT

    The Accelerator Programme at the Centre for Advanced Technology (CAT), Indore, has very broad based concept under which all types of accelerators are to be taken up for design and fabrication. This centre will be housing a wide variety of accelerators to serve as a common facility for the universities, national laboratories in addition to laboratories under the Department of Atomic Energy. In the first phase of the programme, a series of electron accelerators are designed and fabricated. They are synchrotron radiation sources of 450 MeV (INDUS-I) and of 2 GeV (INDUS-II), microtron upto energy of 20 MeV, linear accelerator upto 20 MeV, and DC Accelerator for industrial irradiation upto 750 KeV and 20 KW. A proton accelerator of 300 MeV with 20 MeV linac injector is also designed. CAT is also developing a strong base for support technologies like ultra high vacuum, radio frequency and microwaves, DC pulsed and superconducting magnets, power supplies and controls etc. These technologies are very useful for other industrial applications also. To develop user groups to utilise INDUS-II synchrotron radiation source, a batch production of rotating Anode X-ray generators with power supplies has been initiated. So also, the sputter ion pumps, electron guns, turbo molecular pumps are brought into batch production. (author)

  5. Large electrostatic accelerators

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators.

  6. The miniature accelerator

    Antonella Del Rosso

    2015-01-01

    The image that most people have of CERN is of its enormous accelerators and their capacity to accelerate particles to extremely high energies. But thanks to some cutting-edge studies on beam dynamics and radiofrequency technology, along with innovative construction techniques, teams at CERN have now created the first module of a brand-new accelerator, which will be just 2 metres long. The potential uses of this miniature accelerator will include deployment in hospitals for the production of medical isotopes and the treatment of cancer. It’s a real David-and-Goliath story.   Serge Mathot, in charge of the construction of the "mini-RFQ", pictured with the first of the four modules that will make up the miniature accelerator. The miniature accelerator consists of a radiofrequency quadrupole (RFQ), a component found at the start of all proton accelerator chains around the world, from the smallest to the largest. The LHC is designed to produce very high-intensity beams ...

  7. Collective ion acceleration

    Godfrey, B.B.; Faehl, R.J.; Newberger, B.S.; Shanahan, W.R.; Thode, L.E.

    1977-01-01

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed.

  8. Collective ion acceleration

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed

  9. Risk factors for vascular dementia: Hypotension as a key point

    Rita Moretti

    2008-04-01

    Full Text Available Rita Moretti, Paola Torre, Rodolfo M Antonello, Davide Manganaro, Cristina Vilotti, Gilberto PizzolatoDepartment of Internal Medicine and Clinical Neurology University of Trieste, ItalyAbstract: Physiologically, the cerebral autoregulation system allows maintenance of constant cerebral blood flow over a wide range of blood pressure. In old people, there is a progressive reshape of cerebral autoregulation from a sigmoid curve to a straight line. This implies that any abrupt change in blood pressure will result in a rapid and significant change in cerebral blood flow. Hypertension has often been observed to be a risk factor for vascular dementia (VaD and sometimes for Alzheimer disease although not always. Indeed, high blood pressure may accelerate cerebral white matter lesions, but white matter lesions have been found to be facilitated by excessive fall in blood pressure, including orthostatic dysregulation and postprandial hypotension. Many recent studies observed among other data, that there was a correlation between systolic pressure reduction and cognitive decline in women, which was not accounted for by other factors. Baseline blood pressure level was not significantly related to cognitive decline with initial good cognition. Some researchers speculate that blood pressure reduction might be an early change of the dementing process. The most confounding factor is that low pressure by itself might be a predictor of death; nevertheless, the effect of low blood pressure on cognition is underestimated because of a survival bias. Another explanation is that clinically unrecognized vascular lesions in the brain or atherosclerosis are responsible for both cognitive decline and blood pressure reduction. We discuss the entire process, and try to define a possible mechanism that is able to explain the dynamic by which hypotension might be related to dementia.Keywords: vascular dementia, hypotension, low blood pressure, alzheimer disease

  10. Hypertensive organ damage in patients with vascular disease

    Vlek, A.L.M.

    2009-01-01

    Hypertension is one of the most common vascular risk factors, and is an important cause of development of different vascular diseases. The main aim of this thesis was to determine the burden of hypertension-associated vascular diseases and end-organ damage in patients with manifest vascular disease. Patients with manifest vascular diseases are at high risk for recurrent vascular diseases. We studied the effect of the metabolic syndrome and type 2 diabetes mellitus on the occurrence of cardiov...