Sample records for accelerates animal hemostasis

  1. The Design and Testing of a Dual Fiber Textile Matrix for Accelerating Surface Hemostasis

    PubMed Central

    Fischer, Thomas H.; Vournakis, John N.; Manning, James E.; McCurdy, Shane L.; Rich, Preston B.; Nichols, Timothy C.; Scull, Christopher M.; McCord, Marian G.; Decorta, Joseph A.; Johnson, Peter C.; Smith, Carr J.

    2011-01-01

    The standard treatment for severe traumatic injury is frequently compression and application of gauze dressing to the site of hemorrhage. However, while able to rapidly absorb pools of shed blood, gauze fails to provide strong surface (topical) hemostasis. The result can be excess hemorrhage-related morbidity and mortality. We hypothesized that cost-effective materials (based on widespread availability of bulk fibers for other commercial uses) could be designed based on fundamental hemostatic principles to partially emulate the wicking properties of gauze while concurrently stimulating superior hemostasis. A panel of readily available textile fibers was screened for the ability to activate platelets and the intrinsic coagulation cascade in vitro. Type E continuous filament glass and a specialty rayon fiber were identified from the material panel as accelerators of hemostatic reactions and were custom woven to produce a dual fiber textile bandage. The glass component strongly activated platelets while the specialty rayon agglutinated red blood cells. In comparison with gauze in vitro, the dual fiber textile significantly enhanced the rate of thrombin generation, clot generation as measured by thromboelastography, adhesive protein adsorption and cellular attachment and activation. These results indicate that hemostatic textiles can be designed that mimic gauze in form but surpass gauze in ability to accelerate hemostatic reactions. PMID:19489008

  2. Laboratory hemostasis: from biology to the bench.

    PubMed

    Lippi, Giuseppe; Favaloro, Emmanuel J

    2018-06-27

    Physiological hemostasis is an intricate biological system, where procoagulant and anticoagulant forces interplay and preserves blood fluidity when blood vessels are intact, or trigger clot formation to prevent excessive bleeding when blood vessels are injured. The modern model of hemostasis is divided into two principal phases. The first, defined as primary hemostasis, involves the platelet-vessel interplay, whilst the second, defined as secondary hemostasis, mainly involves coagulation factors, damaged cells and platelet surfaces, where the so-called coagulation cascade rapidly develops. The activation and amplification of the coagulation cascade is finely modulated by the activity of several physiological inhibitors. Once bleeding has been efficiently stopped by blood clot formation, dissolution of the thrombus is essential to restore vessel permeability. This process, known as fibrinolysis, also develops through coordinate action of a vast array of proteins and enzymes. An accurate diagnosis of hemostasis disturbance entails a multifaceted approach, encompassing family and personal history of hemostatic disorders, accurate collection of clinical signs and symptoms, integrated with laboratory hemostasis testing. Regarding laboratory testing, a reasonable approach entails classifying hemostasis testing according to cost, complexity and available clinical information. Laboratory workout may hence initiate with some rapid and inexpensive "screening" tests, characterized by high negative predictive value, then followed by second- or third-line analyses, specifically aimed to clarify the nature and severity of bleeding or thrombotic phenotype. This article aims to provide a general overview of the hemostatic process, and to provide some general suggestions to optimally facilitate laboratory hemostasis testing.

  3. Hemostasis in the Very Young.

    PubMed

    Kenet, Gili; Barg, Assaf Arie; Nowak-Göttl, Ulrike

    2018-06-18

    Hemostasis is a dynamic process that starts in utero. The coagulation system evolves with age, as evidenced by marked physiological differences in the concentration of the majority of hemostatic proteins in early life compared with adulthood. This concept, known as "developmental hemostasis," has important biological and clinical implications. Overall, impaired platelet function, along with physiologically reduced levels of vitamin K-dependent and contact coagulation factors, may cause poorer clot firmness even in healthy neonates. However, increased activity of von Willebrand factor and low levels of coagulation inhibitors that promote hemostasis counterbalance the delicate and immature hemostatic system. Since this hemostatic system has little reserve capacity, preterm neonates or sick infants are extremely vulnerable and predisposed to either hemorrhagic or thrombotic complications. This review will address the concept and manifestations of developmental hemostasis with respect to clinical disease phenotypes. It will discuss bleeding diagnosis in neonates, dealing especially with the devastating complications of intracerebral and pulmonary hemorrhage in preterm infants. Neonates, especially the sickest preterm ones, are also extremely susceptible to thrombotic complications; thus, thrombosis in neonates will be reviewed, with special focus on arterial ischemic perinatal stroke. Based on the concept of developmental hemostasis, the phenotypes of clinically relevant bleeding or thrombotic disorders among neonates may differ from those of older infants and children. Treatment options for these conditions will be suggested and reviewed. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. Hemostasis in a noncompressible hemorrhage model: an end-user evaluation of hemostatic agents in a proximal arterial injury.

    PubMed

    Satterly, Steven; Nelson, Daniel; Zwintscher, Nathan; Oguntoye, Morohunranti; Causey, Wayne; Theis, Bryan; Huang, Raywin; Haque, Mohamad; Martin, Matthew; Bickett, Gerald; Rush, Robert M

    2013-01-01

    1. Evaluate hemostatic bandages by the end user using subjective and objective criteria. 2. Determine if user training and education level impact overall hemostatic outcomes. 3. Our hypothesis was that prior medical training would be directly linked to improved hemostatic outcomes in noncompressible hemorrhage indepen- dent of dressing used. Military personnel were given standardized instruction on hemostatic dressings as part of a tactical combat casualty care course (TC3). Soldiers were randomized to a hemostatic dressing. Proximal arterial (femoral and axillary) injuries were created in extremities of live tissue models (goat or pig). Participants attempted hemostasis through standardized dressing application. Evaluation of hemostasis was performed at 2- and 4-minute intervals by physicians blinded to participants' training level. Military personnel that are due to deploy are given "refresher" instruction by their units as well as participating in the TC3 to further hone their medical skills prior to deployment. The TC3 is simulation training designed to simulate combat environments and real-life trauma scenarios. Military personnel due to deploy, physicians (residents and board certified surgeons), animal care technicians, and veterinarian support. Celox 42 (33%), ChitoGauze 11 (9%), Combat Gauze 45 (35%), and HemCon wafer 28 (22%) bandages were applied in 126 arterial injuries created in 45 animals in a standardized model of hemorrhage. Overall, no significant difference in hemostasis and volume of blood loss was seen between the 4 dressings at 2 or 4 minutes. Combat gauze was the most effective at controlling hemorrhage, achieving 83% hemostasis by 4 minutes. Combat gauze was also rated as the easiest dressing to use by the soldiers (p<0.05). When compared to nonmedical personnel, active duty soldiers with prior medical training improved hemostasis at 4 minutes by 20% (p = 0.05). There is no significant difference in hemostasis between hemostatic bandages for

  5. Hyaluronic Acid and Polyethylene Glycol Hybrid Hydrogel Encapsulating Nanogel with Hemostasis and Sustainable Antibacterial Property for Wound Healing.

    PubMed

    Zhu, Jie; Li, Faxue; Wang, Xueli; Yu, Jianyong; Wu, Dequn

    2018-04-25

    Immediate hemorrhage control and anti-infection play important roles in the wound management. Besides, a moist environment is also beneficial for wound healing. Hydrogels are promising materials in urgent hemostasis and drug release. However, hydrogels have the disadvantage of rapid release profiles, leading to the exposure to high drug concentrations. In this study, we constructed hybrid hydrogels with rapid hemostasis and sustainable antibacterial property combining aminoethyl methacrylate hyaluronic acid (HA-AEMA) and methacrylated methoxy polyethylene glycol (mPEG-MA) hybrid hydrogels and chlorhexidine diacetate (CHX)-loaded nanogels. The CHX-loaded nanogels (CLNs) were prepared by the enzyme degradation of CHX-loaded lysine-based hydrogels. The HA-AEMA and mPEG-MA hybrid hydrogel loaded with CLNs (labeled as Gel@CLN) displayed a three-dimensional microporous structure and exhibited excellent swelling, mechanical property, and low cytotoxicity. The Gel@CLN hydrogel showed a prolonged release period of CHX over 240 h and the antibacterial property over 10 days. The hemostasis and wound-healing properties were evaluated in vivo using a mouse model. The results showed that hydrogel had the rapid hemostasis capacity and accelerated wound healing. In summary, CLN-loaded hydrogels may be excellent candidates as hemostasis and anti-infection materials for the wound dressing application.

  6. Curcumin, hemostasis, thrombosis, and coagulation.

    PubMed

    Keihanian, Faeze; Saeidinia, Amin; Bagheri, Ramin Khameneh; Johnston, Thomas P; Sahebkar, Amirhossein

    2018-06-01

    Atherothrombotic cardiovascular disease is a major cause of mortality throughout the world. Platelet activation and aggregation play a central role in hemostasis and thrombosis. Herbal medicines have been traditionally used in the management of cardiovascular disease and can help in modifying its progression, particularly in hemostasis and the coagulation process, as well as altering platelet function tests and some coagulation parameters. Curcumin is a polyphenol derived from the Curcuma longa plant and has been used extensively in complementary and alternative medicine, as it is nontoxic and safe with various therapeutic properties. Modern scientific research has demonstrated its anti-inflammatory, antioxidant, anti-carcinogenic, antithrombotic, and cardiovascular protective effects. The present study reviewed previous studies in the literature, which support the positive activity of curcumin in hemostasis, anticoagulation, and fibrinolysis. We also presented molecular mechanisms associated with the antiplatelet and anticoagulant activities of curcumin and potential implications for the treatment of cardiovascular disease. © 2017 Wiley Periodicals, Inc.

  7. New models of hemostasis.

    PubMed

    McMichael, Maureen

    2012-05-01

    Hemostasis is an essential protective mechanism that depends on a delicate balance of procoagulant and anticoagulant processes. The waterfall/cascade models of coagulation are useful for understanding several essential steps of coagulation in vitro. These have resulted in the creation of the plasma-based tests used commonly and the ability to identify deficiencies in the extrinsic, intrinsic, and common pathways of coagulation. The model was also essential in elucidating the role of several of the inhibitors of coagulation and is currently used to demonstrate coagulation as it occurs in plasma in a static environment that is devoid of endothelial interactions. The intrinsic pathway originally described by these models does not appear to be essential for in vivo hemostasis but may play a role in pathologic thrombosis. The waterfall/cascade models' lack of cellular elements sets the stage for the cell-based model of coagulation. The cell-based model of blood coagulation, which includes the varied, complicated network of factors necessary for appropriate in vivo coagulation to occur, was the next step in the evolution of our understanding of coagulation. Recently, researchers have focused on real-time, in vivo models of hemostasis and this research reveals unexpected phenomena. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Laboratory hemostasis: milestones in Clinical Chemistry and Laboratory Medicine.

    PubMed

    Lippi, Giuseppe; Favaloro, Emmanuel J

    2013-01-01

    Hemostasis is a delicate, dynamic and intricate system, in which pro- and anti-coagulant forces cooperate for either maintaining blood fluidity under normal conditions, or else will prompt blood clot generation to limit the bleeding when the integrity of blood vessels is jeopardized. Excessive prevalence of anticoagulant forces leads to hemorrhage, whereas excessive activation of procoagulant forces triggers excessive coagulation and thrombosis. The hemostasis laboratory performs a variety of first, second and third line tests, and plays a pivotal role in diagnostic and monitoring of most hemostasis disturbances. Since the leading targets of Clinical Chemistry and Laboratory Medicine include promotion of progress in fundamental and applied research, along with publication of guidelines and recommendations in laboratory diagnostics, this journal is an ideal source of information on current developments in the laboratory technology of hemostasis, and this article is aimed to celebrate some of the most important and popular articles ever published by the journal in the filed of laboratory hemostasis.

  9. The academic challenge of teaching psychomotor skills for hemostasis of solid organ injury.

    PubMed

    Lucas, Charles E; Ledgerwood, Anna M

    2009-03-01

    This study highlights the inherent challenges of achieving psychomotor skills in an era of nonoperative therapy for solid organ injuries. Technical procedures on the liver, the most frequent intra-abdominal solid organ injured, were assessed in five decades. Guided by prospective assessment and registry data, all patients with liver injury seen during 24 months in five consecutive decades were reviewed. Initially (1960s), all injuries were explored; currently (2000s), most injuries are observed. The number of patients was 235 (1960s), 228 (1970s), 79 (1980s), 116 (1990s), and 64 (2000s). The greater number in the 1990s reflects the diagnosis of minor, clinically insignificant, blunt injuries after abdominal CAT scan became available. Each injury was categorized by cause, severity (Abbreviated Injury Scale), associated shock, and primary therapy (observe [OBS], operation alone [OR], hepatorrhaphy [SUT], tractotomy [TRACT] with intraparenchymal hemostasis, hepatic dearterialization [HAL], and resection [RESECT]). Packing, used in each decade, was placed in one of the above primary treatment groups. The primary techniques for hemostasis are shown in the text table.Shock and Abbreviated Injury Scale correlated with mortality averaged 16%; 40 of 116 deaths (34%) exsanguinated from hepatic injury. During training, a resident performed an average of 12.0, 12.0, 2.4, 4.0, and 1.3 procedures for hemostasis. Reduced incidence and decreased therapeutic laparotomies for liver injury have created a training vacuum for future trauma surgeons. Surgical residents will need to supplement their clinical experience with solid organ hemostasis by practice on appropriate animal models of injury and cadaver dissections.

  10. Achieving femoral artery hemostasis after cardiac catheterization: a comparison of methods.

    PubMed

    Schickel, S I; Adkisson, P; Miracle, V; Cronin, S N

    1999-11-01

    Cardiac catheterization is a common procedure that involves the introduction of a small sheath (5F-8F) into the femoral artery for insertion of other diagnostic catheters. After cardiac catheterization, local compression of the femoral artery is required to prevent bleeding and to achieve hemostasis. Traditional methods of achieving hemostasis require significant time and close supervision by medical personnel and can contribute to patients' discomfort. VasoSeal is a recently developed device that delivers absorbable collagen into the supra-arterial space to promote hemostasis. To compare outcomes between patients receiving a collagen plug and patients in whom a traditional method of achieving hemostasis was used after diagnostic cardiac catheterization. An outcomes tracking tool was used to analyze the medical records of 95 patients in whom a traditional method was used (traditional group) and 81 patients in whom VasoSeal was used (device group) to achieve hemostasis. Complications at the femoral access site, patients' satisfaction, and times to hemostasis, ambulation, and discharge were compared. Hematomas of 6-cm diameter occurred in 5.3% of the traditional group; no complications occurred in the device group. The device group also achieved hemostasis faster and had earlier ambulation (P < .001). Patients in the device group were discharged a mean of 5 hours sooner than patients in the traditional group (P < .05). No significant differences were found in patients' satisfaction. VasoSeal is a safe and effective method of achieving hemostasis after cardiac catheterization that can hasten time to hemostasis, ambulation, and discharge.

  11. Critical laboratory values in hemostasis: toward consensus.

    PubMed

    Lippi, Giuseppe; Adcock, Dorothy; Simundic, Ana-Maria; Tripodi, Armando; Favaloro, Emmanuel J

    2017-09-01

    The term "critical values" can be defined to entail laboratory test results that significantly lie outside the normal (reference) range and necessitate immediate reporting to safeguard patient health, as well as those displaying a highly and clinically significant variation compared to previous data. The identification and effective communication of "highly pathological" values has engaged the minds of many clinicians, health care and laboratory professionals for decades, since these activities are vital to good laboratory practice. This is especially true in hemostasis, where a timely and efficient communication of critical values strongly impacts patient management. Due to the heterogeneity of available data, this paper is hence aimed to analyze the state of the art and provide an expert opinion about the parameters, measurement units and alert limits pertaining to critical values in hemostasis, thus providing a basic document for future consultation that assists laboratory professionals and clinicians alike. KEY MESSAGES Critical values are laboratory test results significantly lying outside the normal (reference) range and necessitating immediate reporting to safeguard patient health. A broad heterogeneity exists about critical values in hemostasis worldwide. We provide here an expert opinion about the parameters, measurement units and alert limits pertaining to critical values in hemostasis.

  12. Platelets are versatile cells: New discoveries in hemostasis, thrombosis, immune responses, tumor metastasis and beyond.

    PubMed

    Xu, Xiaohong Ruby; Zhang, Dan; Oswald, Brigitta Elaine; Carrim, Naadiya; Wang, Xiaozhong; Hou, Yan; Zhang, Qing; Lavalle, Christopher; McKeown, Thomas; Marshall, Alexandra H; Ni, Heyu

    2016-12-01

    documented for more than half a century as essential for platelet aggregation, recent studies demonstrated that fibrinogen-independent platelet aggregation occurs in both gene deficient animals and human patients under physiological and pathological conditions (non-anti-coagulated blood). This indicates that other unidentified platelet ligands may play important roles in thrombosis and might be novel antithrombotic targets. In addition to their critical roles in hemostasis and thrombosis, emerging evidence indicates that platelets are versatile cells involved in many other pathophysiological processes such as innate and adaptive immune responses, atherosclerosis, angiogenesis, lymphatic vessel development, liver regeneration and tumor metastasis. This review summarizes the current knowledge of platelet biology, highlights recent advances in the understanding of platelet production and clearance, molecular and cellular events of thrombosis and hemostasis, and introduces the emerging roles of platelets in the immune system, vascular biology and tumorigenesis. The clinical implications of these basic science and translational research findings will also be discussed.

  13. HIFU Hemostasis of Liver Injuries Enhanced by Ultrasound Contrast Agents

    NASA Astrophysics Data System (ADS)

    Zderic, Vesna; Vaezy, Shahram; Brayman, Andrew A.; Matula, Thomas J.; O'Keefe, Grant E.; Crum, Lawrence A.

    2005-03-01

    Our objective was to investigate whether High-Intensity Focused Ultrasound (HIFU) hemostasis can be achieved faster in the presence of ultrasound contrast agents (UCA). Incisions (3 cm long and 0.5 cm deep) were made in surgically exposed rabbit liver. Optison at a concentration of 0.18 ml/kg was injected into the mesenteric vein, immediately before the incision was made. The HIFU applicator (frequency of 5.5 MHz, and intensity of 3,700 W/cm2) was scanned manually over the incision (at an approximate rate of 1 mm/s) until hemostasis was achieved. The times to complete hemostasis were measured and normalized with the initial blood loss. The hemostasis times were 59±23 s in the presence of Optison and 70±23 s without Optison. The presence of Optison produced a 37% reduction in the normalized hemostasis times (p<0.05). Optison also provided faster (by 34%) formation of the coagulum seal over the lesion. Gross observations showed that the lesion size did not change due to the presence of Optison. Histological analysis showed that lesions consisted of an area of coagulation necrosis in vicinity of the incision, occasionally surrounded by a congestion zone filled with blood. Our results suggest the potential utility of microbubble contrast agents for increasing efficiency of HIFU hemostasis of internal organ injuries.

  14. Hemostasis in Overt and Subclinical Hyperthyroidism

    PubMed Central

    Ordookhani, Arash; Burman, Kenneth D.

    2017-01-01

    Context There are contradictory results on the effect of hyperthyroidism on hemostasis. Inadequate population-based studies limited their clinical implications, mainly on the risk of venous thromboembolism (VTE). The present review focuses on hemostatic changes in overt and subclinical hyperthyroidism. Methods A systematic literature search was conducted employing MEDLINE database. The following words were used for the search: Hyperthyroidism; thyrotoxicosis; Graves disease; goiter, nodular; hemostasis; blood coagulation factors; blood coagulation disorders; venous thromboembolism; bleeding; fibrinolysis. The articles that were related to hyperthyroidism and hemostasis are used in this manuscript. Results Hyperthyroidism, either overt or subclinical, renders a hypercoagulable state, although there are several studies with contradictory findings in the literature. Hypercoagulability may be caused by an increase in the level of various coagulation factors such as factor (F) VIII, FX, FIX, von Willebrand F (vWF), and fibrinogen, while hypofibrinolysis by changes in coagulation parameters such as a decrease in plasmin and plasmin activator or an increase in α2-antiplasmin, plasminogen activator inhibitor-1 and thrombin activatable fibrinolysis inhibitor Conclusions Although many reports are in favor of a hypercoagulable state in overt hyperthyroidism but this finding at the biochemical level and its clinical implication, on the occurrence of VTE, has yet to be confirmed. PMID:29201071

  15. Platelets: versatile effector cells in hemostasis, inflammation, and the immune continuum

    PubMed Central

    Vieira-de-Abreu, Adriana; Campbell, Robert A.; Weyrich, Andrew S.

    2015-01-01

    Platelets are chief effector cells in hemostasis. In addition, however, their specializations include activities and intercellular interactions that make them key effectors in inflammation and in the continuum of innate and adaptive immunity. This review focuses on the immune features of human platelets and platelets from experimental animals and on interactions between inflammatory, immune, and hemostatic activities of these anucleate but complex and versatile cells. The experimental findings and evidence for physiologic immune functions include previously unrecognized biologic characteristics of platelets and are paralleled by new evidence for unique roles of platelets in inflammatory, immune, and thrombotic diseases. PMID:21818701

  16. A refined model of the genomic basis for phenotypic variation in vertebrate hemostasis.

    PubMed

    Ribeiro, Ângela M; Zepeda-Mendoza, M Lisandra; Bertelsen, Mads F; Kristensen, Annemarie T; Jarvis, Erich D; Gilbert, M Thomas P; da Fonseca, Rute R

    2015-06-30

    Hemostasis is a defense mechanism that enhances an organism's survival by minimizing blood loss upon vascular injury. In vertebrates, hemostasis has been evolving with the cardio-vascular and hemodynamic systems over the last 450 million years. Birds and mammals have very similar vascular and hemodynamic systems, thus the mechanism that blocks ruptures in the vasculature is expected to be the same. However, the speed of the process varies across vertebrates, and is particularly slow for birds. Understanding the differences in the hemostasis pathway between birds and mammals, and placing them in perspective to other vertebrates may provide clues to the genetic contribution to variation in blood clotting phenotype in vertebrates. We compiled genomic data corresponding to key elements involved in hemostasis across vertebrates to investigate its genetic basis and understand how it affects fitness. We found that: i) fewer genes are involved in hemostasis in birds compared to mammals; and ii) the largest differences concern platelet membrane receptors and components from the kallikrein-kinin system. We propose that lack of the cytoplasmic domain of the GPIb receptor subunit alpha could be a strong contributor to the prolonged bleeding phenotype in birds. Combined analysis of laboratory assessments of avian hemostasis with the first avian phylogeny based on genomic-scale data revealed that differences in hemostasis within birds are not explained by phylogenetic relationships, but more so by genetic variation underlying components of the hemostatic process, suggestive of natural selection. This work adds to our understanding of the evolution of hemostasis in vertebrates. The overlap with the inflammation, complement and renin-angiotensin (blood pressure regulation) pathways is a potential driver of rapid molecular evolution in the hemostasis network. Comparisons between avian species and mammals allowed us to hypothesize that the observed mammalian innovations might have

  17. Animal surgery in microgravity

    NASA Technical Reports Server (NTRS)

    Campbell, Mark R.; Billica, Roger D.; Johnston, Smith L., III

    1993-01-01

    Prototype hardware and procedures which could be applied to a surgical support system on SSF are realistically evaluated in microgravity using an animal model. Particular attention is given to the behavior of bleeding in a surgical scenario and techniques for hemostasis and fluid management.

  18. Using NU-KNIT® for hemostasis around recurrent laryngeal nerve during transthoracic esophagectomy with lymphadenectomy for esophageal cancer.

    PubMed

    Rino, Yasushi; Yukawa, Norio; Sato, Tsutomu; Yamamoto, Naoto; Tamagawa, Hiroshi; Hasegawa, Shinichi; Oshima, Takashi; Yoshikawa, Takaki; Masuda, Munetaka; Imada, Toshio

    2014-03-06

    We thought that using electrocautery for hemostasis caused recurrent laryngeal nerve palsy. We reflected the prolonged use of electrocautery and employed NU-KNIT® to achieve hemostasis nearby the recurrent laryngeal nerve. We assessed that using NU-KNIT® hemostasis prevented or not postoperative recurrent laryngeal nerve palsy, retrospectively. The present study was evaluated to compare using electrocautery hemostasis with using NU-KNIT® hemostasis during lymphadenectomy along recurrent laryngeal nerve. The variables compared were morbidity rate of recurrent laryngeal nerve palsy, operation time, and blood loss. We use NU-KNIT® to achieve hemostasis without strong compression. This group is named group N. On the other hand, we use electrocautery to achieve hemostasis. This group is named group E. Complication rate of recurrent laryngeal nerve palsy was higher in group E (55.6%) than group N (5.3%) (p = 0.007). Even hemostasis using NU-KNIT® was slightly more time-consuming than using electrocautery, we concluded that it would be useful to prevent recurrent laryngeal nerve palsy.

  19. Thermal ablation for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism.

    PubMed

    Duan, Ya-Qi; Liang, Ping

    2013-05-01

    Many studies have been conducted on splenic thermal ablation for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism. In this article, we review the evolution and current status of radiofrequency and microwave ablation in the treatment of spleen diseases. All publications from 1990 to 2011 on radiofrequency and microwave ablation for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism were retrieved by searching PubMed. Thermal ablation in the spleen for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism can preserve part of the spleen and maintain splenic immunologic function. Thermal ablation for assisting hemostasis in partial splenectomy minimizes blood loss during operation. Thermal ablation for spleen trauma reduces the number of splenectomy and the amount of blood transfusion. Thermal ablation for splenic metastasis is minimally invasive and can be done under the guidance of an ultrasound, which helps shorten the recovery time. Thermal ablation for hypersplenism increases platelet (PLT) and white blood cell (WBC) counts and improves liver function. It also helps to maintain splenic immunologic function and even improves splenic immunologic function in the short-term. In conclusion, thermal ablative approaches are promising for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism. In order to improve therapeutic effects, directions for future studies may include standardized therapeutic indications, prolonged observation periods and enlarged sample sizes.

  20. Secure hemostasis in transhiatal esophagectomy for esophageal cancer with gauze packing.

    PubMed

    Hirahara, Noriyuki; Matsubara, Takeshi; Hari, Yoko; Fujii, Yusuke; Wake, Hitomi; Tajima, Yoshitsugu

    2012-12-19

    Transhiatal esophagectomy for esophageal cancer implies blind manipulation of the intrathoracic esophagus. We report a secure hemostatic method with gauze packing in transhiatal esophagectomy. The gauze-packing technique is utilized for hemostasis just after removal of the thoracic esophagus during transhiatal esophagectomy. After confirming cancer-free margins, the abdominal esophagus and cervical esophagus are transected. A vein stripper is inserted into the oral-side stump of the esophagus and led to exit from the abdominal-side stump of the esophagus. The vein stripper and the oral stump of the esophagus are affixed by silk thread. A polyester tape is then affixed to the vein stripper, as the polyester tape is left in the posterior mediastinum after removal of the esophagus toward the abdominal side. The polyester tape on the cervical side is ligated with gauze and the polyester tape is removed toward the abdominal side. The oral stump of gauze and new additional gauze are affixed. As the first gauze is pulled out from the abdominal side, the second gauze gets drawn from the cervical wound into the mediastinum. The posterior mediastinum is finally packed with gauze and possible bleeding at this site undergoes a complete astriction. The status of hemostasis with the gauze packing is checked by an observation of color and bloodstain on the gauze. Between January 2005 and February 2012, 13 consecutive patients with esophageal cancer underwent a transhiatal esophagectomy with the gauze-packing hemostatic technique. Hemostasis at the posterior mediastinum was performed successfully and quickly in all cases with this method, requiring up to four pieces of gauze for a complete hemostasis. Median required time for hemostasis was 1219 (range 1896 to 1293) seconds and estimated blood loss was 20.4 (range 15 to 25) ml during gauze packing. Our technique could minimize bleeding after the removal of the thoracic esophagus. The gauze-packing method is a simple and easy

  1. Secure hemostasis in transhiatal esophagectomy for esophageal cancer with gauze packing

    PubMed Central

    2012-01-01

    Background Transhiatal esophagectomy for esophageal cancer implies blind manipulation of the intrathoracic esophagus. We report a secure hemostatic method with gauze packing in transhiatal esophagectomy. Methods The gauze-packing technique is utilized for hemostasis just after removal of the thoracic esophagus during transhiatal esophagectomy. After confirming cancer-free margins, the abdominal esophagus and cervical esophagus are transected. A vein stripper is inserted into the oral-side stump of the esophagus and led to exit from the abdominal-side stump of the esophagus. The vein stripper and the oral stump of the esophagus are affixed by silk thread. A polyester tape is then affixed to the vein stripper, as the polyester tape is left in the posterior mediastinum after removal of the esophagus toward the abdominal side. The polyester tape on the cervical side is ligated with gauze and the polyester tape is removed toward the abdominal side. The oral stump of gauze and new additional gauze are affixed. As the first gauze is pulled out from the abdominal side, the second gauze gets drawn from the cervical wound into the mediastinum. The posterior mediastinum is finally packed with gauze and possible bleeding at this site undergoes a complete astriction. The status of hemostasis with the gauze packing is checked by an observation of color and bloodstain on the gauze. Results Between January 2005 and February 2012, 13 consecutive patients with esophageal cancer underwent a transhiatal esophagectomy with the gauze-packing hemostatic technique. Hemostasis at the posterior mediastinum was performed successfully and quickly in all cases with this method, requiring up to four pieces of gauze for a complete hemostasis. Median required time for hemostasis was 1219 (range 1896 to 1293) seconds and estimated blood loss was 20.4 (range 15 to 25) ml during gauze packing. Conclusions Our technique could minimize bleeding after the removal of the thoracic esophagus. The gauze

  2. Hemostasis in Hypothyroidism and Autoimmune Thyroid Disorders.

    PubMed

    Ordookhani, Arash; Burman, Kenneth D

    2017-04-01

    There are contradictory results on the effect of hypothyroidism on the changes in hemostasis. Inadequate population-based studies limited their clinical implications, mainly on the risk of venous thromboembolism (VTE). This paper reviews the studies on laboratory and population-based findings regarding hemostatic changes and risk of VTE in hypothyroidism and autoimmune thyroid disorders. A comprehensive literature search was conducted employing MEDLINE database. The following words were used for the search: Hypothyroidism; thyroiditis, autoimmune; blood coagulation factors; blood coagulation tests; hemostasis, blood coagulation disorders; thyroid hormones; myxedema; venous thromboembolism; fibrinolysis, receptors thyroid hormone. The papers that were related to hypothyroidism and autoimmune thyroid disorder and hemostasis are used in this review. Overt hypothyroidism is more associated with a hypocoagulable state. Decreased platelet count, aggregation and agglutination, von Willebrand factor antigen and activity, several coagulation factors such as factor VIII, IX, XI, VII, and plasminogen activator-1 are detected in overt hypothyrodism. Increased fibrinogen has been detected in subclinical hypothyroidism and autoimmune thyroid disease rendering a tendency towards a hypercoagulability state. Increased factor VII and its activity, and plasminogen activator inhibitor-1 are among several findings contributing to a prothrombotic state in subclinical hypothyroidism. Overt hypothyroidism is associated with a hypocoagulable state and subclinical hypothyroidism and autoimmune thyroid disorders may induce a prothrombotic state. However, there are contradictory findings for the abovementioned thyroid disorders. Prospective studies on the risk of VTE in various levels of hypofunctioning of the thyroid and autoimmune thyroid disorders are warranted.

  3. Evaluation of hemostasis parameters and the role of the oxidative damage to plasma proteins in the modulation of hemostasis in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy.

    PubMed

    Woźniak, Paweł; Kontek, Bogdan; Różański, Waldemar; Olas, Beata

    2017-01-01

    Extracorporeal shock wave lithotripsy (ESWL) is a commonly-used method in urology, which may modulate hemostasis and may induce lipid peroxidation in patients with nephrolithiasis. However, previous studies only examine changes occurring in patients 30-240 min after ESWL. The main aim of the present study was to determine whether oxidative stress may modulate the hemostatic activity of plasma in patients with nephrolithiasis before ESWL and the day after treatment ESWL. This will be performed by measuring selected parameters of hemostasis in these patients, both before ESWL and the following day, and assessing the level of oxidative damage to plasma proteins in these patients by measuring two biomarkers. Twelve patients with nephrolithiasis and 10 healthy participants were included. The following parameters of hemostasis were measured: the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) of plasma, the level of fibrinogen, the level of D-dimer and blood platelet count. In addition, two selected biomarkers of oxidative stress were measured: protein carbonylation level and the number of protein thiol groups. No difference was observed between patients with nephrolithiasis before and after ESWL and healthy controls with regard to PT, TT or APTT. Fibrinogen concentration and blood platelet count were lower in the nephrolithiasis patients in the period after ESWL than before ESWL. The nephrolithiasis patients demonstrated elevated D-dimer concentration after ESWL. However, although oxidative damage was observed in the plasma proteins in the nephrolithiasis patients, this was not influenced by ESWL. Oxidative stress may induce changes of hemostasis in patients with nephrolithiasis, both before and after ESWL. In addition, changes of hemostasis parameters such as fibrinogen, blood platelet count and D-dimer level can be observed in these patients, especially after ESWL, and this may suggest that ESWL modulates hemostasis. By

  4. Achieving hemostasis in dermatology – Part 1: Preoperative, intraoperative, and postoperative management

    PubMed Central

    Kaur, Ravneet Ruby; Glick, Jaimie B.; Siegel, Daniel

    2013-01-01

    As dermatological procedures continue to become increasingly complex, improved methods and tools to achieve appropriate hemostasis become necessary. The methods for achieving adequate hemostasis are variable and depend greatly on the type of procedure performed and the unique characteristics of the individual patient. In Part 1 of this review, we discuss the preoperative, intraoperative, and postoperative management of patients undergoing dermatologic surgery. We address oral medications and supplements that affect hemostasis, hemostatic anesthesia, and intraoperative interventions such as suture ligation and heat-generating cautery devices. In Part 2 of this review, we will discuss topical hemostats. The authors conducted an extensive literature review using the following keywords: “hemostasis,” “dermatology,” “dermatological surgery,” “dermatologic sutures,” “electrosurgery,” “hemostatic anesthesia,” and “laser surgery.” Sources for this article were identified by searching the English literature in the Pubmed database for the time period from 1940 to March 2012. A thorough bibliography search was also conducted and key references were examined. PMID:23741660

  5. Facilitating Hemostasis After Proximal Aortic Surgery: Results of The PROTECT Trial.

    PubMed

    Khoynezhad, Ali; DelaRosa, Jacob; Moon, Marc R; Brinkman, William T; Thompson, Richard B; Desai, Nimesh D; Malaisrie, S Chris; Girardi, Leonard N; Bavaria, Joseph E; Reece, T Brett

    2018-05-01

    This study intended to evaluate the safety and hemostatic efficacy of a novel vascular sealant (Tridyne; Neomend, Inc, Irvine, CA) compared with an accepted adjunctive hemostatic agent applied to aortotomy and sutures lines in cardiovascular operations. Patients undergoing aortic valve replacement, ascending aortic replacement, or aortic root replacement were randomly assigned 2:1 to Tridyne (n = 107) or Gelfoam Plus (Baxter Healthcare Corp, Hayward, CA) (n = 51). These groups were similar with regard to age, sex, race, medical history, duration of bypass and cross-clamping, and number of suture lines treated. Suture lines were treated after confirmation of some leakage but before formal removal of the clamp. The median bleeding time was significantly lower for Tridyne versus Gelfoam Plus (0 versus 10.0 minutes, p < 0.0001). Immediate hemostasis was achieved in 59.4% of the Tridyne group versus 16.0% of Gelfoam Plus group (p < 0.0001). A significantly greater proportion of patients in the Tridyne group achieved successful hemostasis at the aortic suture line than patients in the Gelfoam Plus group (85.7% versus 40.0%, p < 0.0001). The Clinical Events Committee adjudicated 7 patients with possible device-related serious adverse events: 3 patients (2.9%) in the Tridyne group and 4 patients (8.2%) in the Gelfoam Plus group (p = 0.2097). Tridyne was safe and effective when used as an adjunct to conventional hemostasis to treat high-pressure vessels in patients who receive anticoagulation agents, in reducing time to hemostasis, and in promoting both immediate and persistent hemostasis. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  6. Toward a computational model of hemostasis

    NASA Astrophysics Data System (ADS)

    Leiderman, Karin; Danes, Nicholas; Schoeman, Rogier; Neeves, Keith

    2017-11-01

    Hemostasis is the process by which a blood clot forms to prevent bleeding at a site of injury. The formation time, size and structure of a clot depends on the local hemodynamics and the nature of the injury. Our group has previously developed computational models to study intravascular clot formation, a process confined to the interior of a single vessel. Here we present the first stage of an experimentally-validated, computational model of extravascular clot formation (hemostasis) in which blood through a single vessel initially escapes through a hole in the vessel wall and out a separate injury channel. This stage of the model consists of a system of partial differential equations that describe platelet aggregation and hemodynamics, solved via the finite element method. We also present results from the analogous, in vitro, microfluidic model. In both models, formation of a blood clot occludes the injury channel and stops flow from escaping while blood in the main vessel retains its fluidity. We discuss the different biochemical and hemodynamic effects on clot formation using distinct geometries representing intra- and extravascular injuries.

  7. Hemostasis of the liver, spleen, and bone achieved by electrocautery greased with lidocaine gel.

    PubMed

    Petroianu, Andy

    2011-02-01

    Despite advances in surgical techniques, achieving hemostasis of the liver, spleen, and bone during major surgery, especially after trauma, is still difficult. I describe a new procedure my colleagues and I devised to achieve parenchymatous hemostasis using electrocautery greased with lidocaine gel. After achieving good results in experimental studies and obtaining approval from our ethics committee, we used electrocautery greased with lidocaine gel for hemostasis in the following 36 procedures: multisegmental hepatectomy to remove hepatic tumors (n = 6); partial hepatectomy to allow hepatojejunostomy for intrahepatic biliary obstruction (n = 10); laparoscopic liver biopsy (n = 4); subtotal splenectomy (n = 8; for portal hypertension in 5 patients, splenic ischemia in 2, and Gaucher's disease in 1); laparoscopic splenic biopsy (n = 1); and bone resection (n = 7; as pelvic-femoral resection in 6 patients and to remove a rectal tumor invading the coccyx in 1). This procedure was easy to perform and achieved complete hemostasis of the minor blood vessels in all patients. No postoperative bleeding occurred and the follow-up course was satisfactory. Electrocautery greased with lidocaine gel is an inexpensive, readily available, and efficient method to achieve hemostasis of minor vessels in hepatic, splenic, and bone operations.

  8. Hemostasis in Hypothyroidism and Autoimmune Thyroid Disorders

    PubMed Central

    Ordookhani, Arash; Burman, Kenneth D.

    2017-01-01

    Context There are contradictory results on the effect of hypothyroidism on the changes in hemostasis. Inadequate population-based studies limited their clinical implications, mainly on the risk of venous thromboembolism (VTE). This paper reviews the studies on laboratory and population-based findings regarding hemostatic changes and risk of VTE in hypothyroidism and autoimmune thyroid disorders. Evidence Acquisition A comprehensive literature search was conducted employing MEDLINE database. The following words were used for the search: Hypothyroidism; thyroiditis, autoimmune; blood coagulation factors; blood coagulation tests; hemostasis, blood coagulation disorders; thyroid hormones; myxedema; venous thromboembolism; fibrinolysis, receptors thyroid hormone. The papers that were related to hypothyroidism and autoimmune thyroid disorder and hemostasis are used in this review. Results Overt hypothyroidism is more associated with a hypocoagulable state. Decreased platelet count, aggregation and agglutination, von Willebrand factor antigen and activity, several coagulation factors such as factor VIII, IX, XI, VII, and plasminogen activator-1 are detected in overt hypothyrodism. Increased fibrinogen has been detected in subclinical hypothyroidism and autoimmune thyroid disease rendering a tendency towards a hypercoagulability state. Increased factor VII and its activity, and plasminogen activator inhibitor-1 are among several findings contributing to a prothrombotic state in subclinical hypothyroidism. Conclusions Overt hypothyroidism is associated with a hypocoagulable state and subclinical hypothyroidism and autoimmune thyroid disorders may induce a prothrombotic state. However, there are contradictory findings for the abovementioned thyroid disorders. Prospective studies on the risk of VTE in various levels of hypofunctioning of the thyroid and autoimmune thyroid disorders are warranted. PMID:29026409

  9. Limiting prothrombin activation to meizothrombin is compatible with survival but significantly alters hemostasis in mice

    PubMed Central

    Shaw, Maureen A.; Kombrinck, Keith W.; McElhinney, Kathryn E.; Sweet, David R.; Flick, Matthew J.; Palumbo, Joseph S.; Cheng, Mei; Esmon, Naomi L.; Esmon, Charles T.; Brill, Alexander; Wagner, Denisa D.; Degen, Jay L.

    2016-01-01

    Thrombin-mediated proteolysis is central to hemostatic function but also plays a prominent role in multiple disease processes. The proteolytic conversion of fII to α-thrombin (fIIa) by the prothrombinase complex occurs through 2 parallel pathways: (1) the inactive intermediate, prethrombin; or (2) the proteolytically active intermediate, meizothrombin (fIIaMZ). FIIaMZ has distinct catalytic properties relative to fIIa, including diminished fibrinogen cleavage and increased protein C activation. Thus, fII activation may differentially influence hemostasis and disease depending on the pathway of activation. To determine the in vivo physiologic and pathologic consequences of restricting thrombin generation to fIIaMZ, mutations were introduced into the endogenous fII gene, resulting in expression of prothrombin carrying 3 amino acid substitutions (R157A, R268A, and K281A) to limit activation events to yield only fIIaMZ. Homozygous fIIMZ mice are viable, express fII levels comparable with fIIWT mice, and have reproductive success. Although in vitro studies revealed delayed generation of fIIaMZ enzyme activity, platelet aggregation by fIIMZ is similar to fIIWT. Consistent with prior analyses of human fIIaMZ, significant prolongation of clotting times was observed for fIIMZ plasma. Adult fIIMZ animals displayed significantly compromised hemostasis in tail bleeding assays, but did not demonstrate overt bleeding. More notably, fIIMZ mice had 2 significant phenotypic advantages over fIIWT animals: protection from occlusive thrombosis after arterial injury and markedly diminished metastatic potential in a setting of experimental tumor metastasis to the lung. Thus, these novel animals will provide a valuable tool to assess the role of both fIIa and fIIaMZ in vivo. PMID:27252233

  10. Enzymatic lipid oxidation by eosinophils propagates coagulation, hemostasis, and thrombotic disease

    PubMed Central

    Uderhardt, Stefan; Ackermann, Jochen A.; Fillep, Tobias; Hammond, Victoria J.; Willeit, Johann; Stark, Konstantin; Rossaint, Jan; Schubert, Irene; Mielenz, Dirk; Dietel, Barbara; Raaz-Schrauder, Dorette; Ay, Cihan; Thaler, Johannes; Heim, Christian; Collins, Peter W.; Schabbauer, Gernot; Mackman, Nigel; Voehringer, David; Nadler, Jerry L.; Lee, James J.; Massberg, Steffen; Rauh, Manfred; O’Donnell, Valerie B.

    2017-01-01

    Blood coagulation is essential for physiological hemostasis but simultaneously contributes to thrombotic disease. However, molecular and cellular events controlling initiation and propagation of coagulation are still incompletely understood. In this study, we demonstrate an unexpected role of eosinophils during plasmatic coagulation, hemostasis, and thrombosis. Using a large-scale epidemiological approach, we identified eosinophil cationic protein as an independent and predictive risk factor for thrombotic events in humans. Concurrent experiments showed that eosinophils contributed to intravascular thrombosis by exhibiting a strong endogenous thrombin-generation capacity that relied on the enzymatic generation and active provision of a procoagulant phospholipid surface enriched in 12/15-lipoxygenase–derived hydroxyeicosatetraenoic acid–phosphatidylethanolamines. Our findings reveal a previously unrecognized role of eosinophils and enzymatic lipid oxidation as regulatory elements that facilitate both hemostasis and thrombosis in response to vascular injury, thus identifying promising new targets for the treatment of thrombotic disease. PMID:28566277

  11. Fibrin Sealant Improves Hemostasis in Peripheral Vascular Surgery: A Randomized Prospective Trial

    PubMed Central

    Schenk, Worthington G.; Burks, Sandra G.; Gagne, Paul J.; Kagan, Steven A.; Lawson, Jeffrey H.; Spotnitz, William D.

    2003-01-01

    Objective To evaluate the efficacy and safety of an investigational fibrin sealant (FS) in a randomized prospective, partially blinded, controlled, multicenter trial. Summary Background Data Upper extremity vascular access surgery using polytetrafluorethylene (PTFE) graft placement for dialysis was chosen as a reproducible, clinically relevant model for evaluating the usefulness of FS. The FS consisted of pooled human fibrinogen (60 mg/mL) and thrombin (500 NIH U/mL). Time to hemostasis was measured, and adverse events were monitored. Methods Consenting adult patients (n = 48) undergoing placement of a standard PTFE graft were randomized in a 2:1:1 ratio to the treatment group using FS (ZLB Bioplasma AG, Bern, Switzerland), oxidized regenerated cellulose (Surgicel, Johnson & Johnson, New Brunswick, NJ), or pressure. Patients received heparin (3,000 IU IVP) before placement of vascular clamps. If the treatment was FS, clamps were left in place for 120 seconds after the application of study material to permit polymerization. If treatment was Surgicel, clamps were left in place until the agent had been applied according to manufacturer’s instructions. If the treatment was pressure, clamps were released as soon as the investigator was ready to apply compression. Immediately after release of the last clamp, the arterial and venous suture lines were evaluated for bleeding. The time to hemostasis at both the venous and arterial sites was recorded. Results Significant (P ≤ .005) reduction in time to hemostasis was achieved in the FS group. Thirteen (54.2%) patients randomized to FS experienced immediate hemostasis at both suture lines following clamp removal compared to no patients using Surgicel or pressure. Only one patient (7.1%) in the Surgicel group and no patients in the pressure group experienced hemostasis at 120 seconds from clamp removal, compared to 13 (54.2%) patients for FS. Adverse events were comparable in all groups. There were no seroconversions

  12. [CHANGES OF THE HEMOSTASIS SYSTEM IN THE INJURED PERSONS IN FRACTURES OF LONG BONES OF THE LOWER EXTREMITIES].

    PubMed

    Tarabrin, O O; Grichushenko, I S

    2015-09-01

    The changes of hemostasis in the injured persons, in the lower extremities long bones fracture were analyzed. Complex dynamic investigation of the hemostasis system was conducted preoperatively in 76 injured persons, in whom long bones of the lower extremities fracture have occurred, and in 31--with injury of meniscus. Instrumental diagnostic method--a low-frequency piezoelectric thromboelastography--was applied for investigation of the blood coagulation system. The shift in a system of hemostasis towards hypercoagulation, fibrinolytic and the thrombine activity inhibition, the thrombocytes spontaneous aggregation intensity, duration of formation of a clot fibrinthrombocytic structure; the blood fibrinthrombocytic constanta enhancement, a summary index of the clot retraction and spontaneous lysis reduction were revealed in a hemostasis system before start of the treatment. The hemostasis system disorders in the injured persons may cause thrombohemorrhagic complications, what trusts a necessity for rational choice of preoperative methods of prophylaxis and intensive therapy in a system of hemostasis.

  13. TAM receptors, Gas6, and protein S: roles in inflammation and hemostasis.

    PubMed

    van der Meer, Jonathan H M; van der Poll, Tom; van 't Veer, Cornelis

    2014-04-17

    TAM receptors (Tyro3, Axl, and Mer) belong to a family of receptor tyrosine kinases that have important effects on hemostasis and inflammation. Also, they affect cell proliferation, survival, adhesion, and migration. TAM receptors can be activated by the vitamin K-dependent proteins Gas6 and protein S. Protein S is more commonly known as an important cofactor for protein C as well as a direct inhibitor of multiple coagulation factors. To our knowledge, the functions of Gas6 are limited to TAM receptor activation. When activated, the TAM receptors have effects on primary hemostasis and coagulation and display an anti-inflammatory or a proinflammatory effect, depending on cell type. To comprehend the effects that the TAM receptors and their ligands have on hemostasis and inflammation, we compare studies that report the different phenotypes displayed by mice with deficiencies in the genes of this receptor family and its ligands (protein S(+/-), Gas6(-/-), TAM(-/-), and variations of these). In this manner, we aim to display which features are attributable to the different ligands. Because of the effects TAM receptors have on hemostasis, inflammation, and cancer growth, their modulation could make interesting therapeutic targets in thromboembolic disease, atherosclerosis, sepsis, autoimmune disease, and cancer.

  14. Comparison of Floseal(r) and electrocautery in hemostasis after total knee arthroplasty

    PubMed Central

    Helito, Camilo Partezani; Gobbi, Riccardo Gomes; Castrillon, Lucas Machado; Hinkel, Betina Bremer; Pécora, José Ricardo; Camanho, Gilberto Luis

    2013-01-01

    Objective To evaluate whether hemostasis with eletrocauterization in comparison with Floseal(r) leads to different bleeding rates during total knee arthroplasty. Methods A comparative study was performed between two groups: group with ten consecutive total knee arthroplasties with Floseal(r) used as hemostatic method and control group with ten consecutive total knee arthroplasties with eletrocauterization as hemostatic method. Bleeding parameters such as debit of the drain, liquid infusion and blood transfusion rate were recorded. Results Floseal(r) group received less blood transfusion, less liquid infusion and lower drainage in absolute numbers compared to the control group. However, no parameter was statistically significant. Conclusion Hemostasis with Floseal(r) is as effective as hemostasis with eletrocauterization, what makes it a viable alternative to patients with contraindication to electric scalpel use. Level of Evidence II, Prospective Comparative Study. PMID:24453689

  15. Post-analytical Issues in Hemostasis and Thrombosis Testing.

    PubMed

    Favaloro, Emmanuel J; Lippi, Giuseppe

    2017-01-01

    Analytical concerns within hemostasis and thrombosis testing are continuously decreasing. This is essentially attributable to modern instrumentation, improvements in test performance and reliability, as well as the application of appropriate internal quality control and external quality assurance measures. Pre-analytical issues are also being dealt with in some newer instrumentation, which are able to detect hemolysis, icteria and lipemia, and, in some cases, other issues related to sample collection such as tube under-filling. Post-analytical issues are generally related to appropriate reporting and interpretation of test results, and these are the focus of the current overview, which provides a brief description of these events, as well as guidance for their prevention or minimization. In particular, we propose several strategies for improved post-analytical reporting of hemostasis assays and advise that this may provide the final opportunity to prevent serious clinical errors in diagnosis.

  16. Collective interaction effects associated with mammalian behavioral traits reveal genetic factors connecting fear and hemostasis.

    PubMed

    Woo, Hyung Jun; Reifman, Jaques

    2018-06-05

    Investigation of the genetic architectures that influence the behavioral traits of animals can provide important insights into human neuropsychiatric phenotypes. These traits, however, are often highly polygenic, with individual loci contributing only small effects to the overall association. The polygenicity makes it challenging to explain, for example, the widely observed comorbidity between stress and cardiac disease. We present an algorithm for inferring the collective association of a large number of interacting gene variants with a quantitative trait. Using simulated data, we demonstrate that by taking into account the non-uniform distribution of genotypes within a cohort, we can achieve greater power than regression-based methods for high-dimensional inference. We analyzed genome-wide data sets of outbred mice and pet dogs, and found neurobiological pathways whose associations with behavioral traits arose primarily from interaction effects: γ-carboxylated coagulation factors and downstream neuronal signaling were highly associated with conditioned fear, consistent with our previous finding in human post-traumatic stress disorder (PTSD) data. Prepulse inhibition in mice was associated with serotonin transporter and platelet homeostasis, and noise-induced fear in dogs with hemostasis. Our findings suggest a novel explanation for the observed comorbidity between PTSD/anxiety and cardiovascular diseases: key coagulation factors modulating hemostasis also regulate synaptic plasticity affecting the learning and extinction of fear.

  17. A Synthetic Fibrin-Crosslinking Polymer for Modulating Clot Properties and Inducing Hemostasis

    PubMed Central

    Chan, Leslie W.-G.; Wang, Xu; Wei, Hua; Pozzo, Lilo D.; White, Nathan J.; Pun, Suzie H.

    2015-01-01

    Clotting factor replacement is the standard management of acute bleeding in congenital and acquired bleeding disorders. We present a synthetic approach to hemostasis using an engineered hemostatic polymer (PolySTAT) that circulates innocuously in the blood, identifies sites of vascular injury, and promotes clot formation to stop bleeding. PolySTAT induces hemostasis by crosslinking the fibrin matrix within clots, mimicking the function of the transglutaminase Factor XIII. Furthermore, synthetic PolySTAT binds specifically to fibrin monomers and is uniformly integrated into fibrin fibers during fibrin polymerization, resulting in a fortified, hybrid polymer network with enhanced resistance to enzymatic degradation. In vivo hemostatic activity was confirmed in a rat model of trauma and fluid resuscitation in which intravenous administration of PolySTAT improved survival by reducing blood loss and resuscitation fluid requirements. PolySTAT-induced fibrin crosslinking is a novel approach to hemostasis utilizing synthetic polymers for non-invasive modulation of clot architecture with potentially wide-ranging therapeutic applications. PMID:25739763

  18. Effect of intraosseous anesthesia on control of hemostasis in pigs.

    PubMed

    Baker, Tyler F; Torabinejad, Mahmoud; Schwartz, Stephen F; Wolf, David

    2009-11-01

    Intraosseous anesthesia is used to deliver anesthetic into cancellous bone adjacent to the root apices. No study has assessed the effect of this anesthetic technique on hemostasis. The purpose of this study was to compare the amount of bleeding from soft tissue and bone in pig jaws after preoperative intraosseous or infiltration anesthesia with 2% lidocaine containing 1:50,000 epinephrine. Twelve pigs were divided into 3 groups. The first group received infiltration anesthesia on one half of the jaw and no anesthesia on the other half. The second group received intraosseous anesthesia on one half of the jaw and no anesthesia on the other half. The third group received infiltration anesthesia on one half of the jaw and intraosseous anesthesia on the second half. Blood was collected during flap reflection to measure the volume of soft tissue bleeding. Osteotomies were then prepared with blood collected from the surgical site to measure the volume of osseous bleeding. The median soft tissue blood loss observed in animals receiving infiltration anesthesia (1.14 mL) was significantly less as compared with animals that received no anesthesia (4.49 mL) or intraosseous anesthesia (2.45 mL). Compared with median hard tissue blood loss observed in animals without anesthesia (1.51 mL), significantly less blood loss was observed in animals receiving either infiltration anesthesia (0.67 mL) or intraosseous anesthesia (0.76 mL). Infiltration anesthesia resulted in significantly less soft tissue bleeding (p = .004) as compared with no anesthesia. Infiltration and intraosseous anesthesia resulted in significantly less osseous bleeding than the use of no anesthetic (p < .001). The volume of blood loss for each animal was shown to be below the maximum safe volume of blood loss for a single procedure.

  19. The search for new antithrombotic mechanisms and therapies that may spare hemostasis.

    PubMed

    Plow, Edward F; Wang, Yunmei; Simon, Daniel I

    2018-04-26

    Current antithrombotic drugs, including widely used antiplatelet agents and anticoagulants, are associated with significant bleeding risk. Emerging experimental evidence suggests that the molecular and cellular mechanisms of hemostasis and thrombosis can be separated, thereby increasing the possibility of new antithrombotic therapeutic targets with reduced bleeding risk. We review new coagulation and platelet targets and highlight the interaction between integrin α M β 2 (Mac-1, CD11b/CD18) on leukocytes and GPIbα on platelets that seems to distinguish thrombosis from hemostasis. © 2018 by The American Society of Hematology.

  20. 8(th) Symposium on Hemostasis: Translational and Basic Science Discoveries.

    PubMed

    Margaritis, Paris; Key, Nigel S

    2016-05-01

    It has been 14 years since the first symposium on hemostasis at UNC Chapel Hill that focused primarily on the tissue factor (TF) and Factor VIIa (FVIIa) biology, biochemistry and translational work for the treatment of bleeding. Concepts, mechanistic data and therapeutic agents have since emerged that permeate not only aspects of the TF and FVIIa functions, but also broader processes in hemostasis and thrombosis. These processes involve circulating proteins, receptors, cells and cellular components that interact within the coagulation system as well as with additional systems that are dysregulated in disorders seemingly unrelated to bleeding/thrombosis. The reviews in this symposium provide the research background to understand such interactions and integrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. A novel, simple method for achieving hemostasis of fingertip dermal avulsion injuries.

    PubMed

    Lin, Brian Wai

    2015-06-01

    Distal fingertip pad dermal avulsion injuries can be challenging for emergency physicians. A common occurrence with these injuries is difficult-to-control bleeding. The nature of these wounds is such that conventional primary closure to achieve hemostasis is not feasible. Often, direct pressure, even for prolonged periods, will not adequately control the bleeding. Currently recommended techniques are inadequate to control bleeding, and commercially available hemostatic products may be more costly and not widely available. To present a simple method to achieve permanent hemostasis of these injuries using a tourniquet and tissue adhesive glue. A tourniquet is placed around the proximal digit, and the digit is exsanguinated and elevated to achieve short-term hemostasis. Several layers of commercially available tissue adhesive glue are applied sequentially over the avulsed region of the digit and allowed to dry. The tourniquet is then removed. A clean, bloodless dressing is created over the avulsed fingertip. This technique provides a rapid, simple, and likely safe means to control bleeding from a fingertip dermal avulsion injury. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Effect of transdermic acetylsalicylic acid on hemostasis in healthy volunteers.

    PubMed

    Martínez, Adriana B; Funosas, Esteban; Maestri, Lorella; Lucena, Perla Hermida

    2007-01-01

    Acetylsalicylic acid (ASA) exerts an antiaggregatory effect on platelets by irreversible inhibition of the enzyme thrombocyte cyclooxigenase when it is administered orally at doses above 80 mg/day. For several years ASA has been available as a solution that can be topically applied on the skin. It is widely used by athletes and individuals with chronic rheumatic disorders. However, it has not been established to date whether the plasma levels that result from these doses of ASA affect hemostasis during odontological procedures that involve bleeding, causing platelet dysfunction. The aim of the present study was to evaluate whether topical application is capable of affecting hemostasis. Three studies were conducted: A, B y C. Each of the 3 groups included 12 healthy volunteers of both sexes. The aim of study A was to evaluate if the formulation for topical application resulted in plasma levels of ASA that resembled those observed for the oral formulation and affect hemostasis. In experiment A, plasma levels of salicylic acid (SA) were assessed for each volunteer at 30 minutes, 60 minutes, 6 hours, 12 hours and 24 hours after oral administration of a dose of 500 mg ASA. Experiment B was identical to experiment A except for the fact that ASA was topically applied employing a commercial preparation Aspirub in a predetermined area at a rate of 2 ml/day over a period of 15 days. Experiment C was designed in the same way as experiment B, for a higher dose and a longer period of time (4 ml/day over a period of 30 days). One of the volunteers exhibited detectable salicylemia that could affect hemostasis as occurs with the oral formulation. The following two studies (C1 and C2) employed doses of Aspirub of 8 and 16 ml/day respectively, over a period of 30 days. We measured biochemical parameters associated to platelet function. The dose of 8 ml/day induced moderate alterations in all the parameters related to platelet function and the daily dose of 16 ml inhibited platelet

  3. Venous hemostasis postcatheter ablation of atrial fibrillation while under therapeutic levels of oral and intravenous anticoagulation.

    PubMed

    Issa, Ziad F; Amr, Bashar S

    2015-11-01

    Catheter ablation of atrial fibrillation (AF) requires utilizing multiple venous femoral sheaths in conjunction with aggressive periprocedural anticoagulation, which can lead to increased risk of vascular access complications. The objective of this study is to evaluate the safety and efficacy of the "figure-of-eight" ("F-8") suture technique for femoral venous hemostasis while on therapeutic doses of intravenous anticoagulation at the time of sheath removal. In this case-control analysis, 376 consecutive patients underwent AF ablation while on uninterrupted oral anticoagulation and received intraprocedural heparin. In the first 253 patients (the control group), manual pressure was used for femoral venous hemostasis after reversal of heparin effects. The subsequent 123 patients (the F-8 group) had femoral venous hemostasis using the F-8 suture technique and while under therapeutic heparin effects. The F-8 subcutaneous suture technique achieved adequate venous hemostasis in 98.4% of patients. As compared to the control group, there was significantly less frequent utilization of the FemoStop compression assist device (1.2 vs. 16.8%, p < 0.0001) and in a significantly shorter interval (6.8 ± 5.7 vs. 50.7 ± 12.2 min, p < 0.0001). Vascular access complications and thromboembolic events occurred in 9.8% in the F-8 group vs. 13.0% in the control group (p = 0.678). Immediate hemostasis of the femoral venous access sites after insertion of multiple sheaths for AF ablation in the presence of anticoagulation can be safely and effectively achieved using the F-8 suture technique. This technique helps minimize the period of inadequate anticoagulation immediately following ablation and shortens the time required to achieve adequate hemostasis.

  4. Beneficial effects of early hemostasis on spinal cord injury in the rat

    PubMed Central

    Fan, H; Chen, K; Duan, L; Wang, Y-Z; Ju, G

    2016-01-01

    Study design: Experimental study. Objectives: To investigate the effect of early hemostasis on spinal cord injury (SCI). Setting: Fourth Military Medical University, Xi'an, China. Methods: Sprague Dawley rats were used. Hematoxylin and eosin (HE) staining was performed to observe hemorrhage at different time points (2, 6, 12, 24 and 48 h) after SCI to determine the time window of hemostatic drug administration (n=3 per time point). Three different concentrations of Etamsylate (0.025, 0.05 and 0.1 g kg−1) were administered immediately and 5 and 10 h after SCI to evaluate the effective dosage (n=6 per group). Another 82 rats were then randomly divided into two groups, Etamsylate group (0.1 g kg−1, n=41) and glucose control group (n=41). Nissl staining was performed to observe neurons at 10 days post injury. Immunohistochemistry, western blot and quantitative real-time PCR were performed to detect tissue necrosis at 7 d.p.i., the activation of astrocytes and microglia/macrophages and lesion cavity at 10 d.p.i. Basso–Beattie–Bresnahan scoring and rump height index assay were used to examine locomotion recovery. Results: Early hemostasis reduced the lesion area and tissue necrosis, enhanced neuronal survival, alleviated the activation of microglia/macrophages and astrocytes and facilitated functional recovery after spinal cord contusion in rats. Early hemostasis decreased hemorrhage area and lesion area after spinal cord transection in rats. Conclusion: The present study demonstrated that early hemostasis has beneficial effects on SCI in the rat. It has the potential to be translated into clinical practice. PMID:27137123

  5. SU-E-T-124: Anthropomorphic Phantoms for Confirmation of Linear Accelerator Based Small Animal Irradiation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Perks, J; Benedict, S; Lucero, S

    Purpose: To document the support of radiobiological small animal research by a modern radiation oncology facility. This study confirms that a standard, human use linear accelerator can cover the range of experiments called for by researchers performing animal irradiation. A number of representative, anthropomorphic murine phantoms were made. The phantoms confirmed the small field photon and electron beams dosimetry validated the use of the linear accelerator for rodents. Methods: Laser scanning a model, CAD design and 3D printing produced the phantoms. The phantoms were weighed and CT scanned to judge their compatibility to real animals. Phantoms were produced to specificallymore » mimic lung, gut, brain, and othotopic lesion irradiations. Each phantom was irradiated with the same protocol as prescribed to the live animals. Delivered dose was measured with small field ion chambers, MOS/FETs or TLDs. Results: The density of the phantom material compared to density range across the real mice showed that the printed material would yield sufficiently accurate measurements when irradiated. The whole body, lung and gut irradiations were measured within 2% of prescribed doses with A1SL ion chamber. MOSFET measurements of electron irradiations for the orthotopic lesions allowed refinement of the measured small field output factor to better than 2% and validated the immunology experiment of irradiating one lesion and sparing another. Conclusion: Linacs are still useful tools in small animal bio-radiation research. This work demonstrated a strong role for the clinical accelerator in small animal research, facilitating standard whole body dosing as well as conformal treatments down to 1cm field. The accuracy of measured dose, was always within 5%. The electron irradiations of the phantom brain and flank tumors needed adjustment; the anthropomorphic phantoms allowed refinement of the initial output factor measurements for these fields which were made in a large block of

  6. Rediscovering the wound hematoma as a site of hemostasis during major arterial hemorrhage.

    PubMed

    White, N J; Mehic, E; Wang, X; Chien, D; Lim, E; St John, A E; Stern, S A; Mourad, P D; Rieger, M; Fries, D; Martinowitz, U

    2015-12-01

    Treatments for major internal bleeding after injury include permissive hypotension to decrease the rate of blood loss, intravenous infusion of plasma or clotting factors to improve clot formation, and rapid surgical hemostasis or arterial embolization to control bleeding vessels. Yet, little is known regarding major internal arterial hemostasis, or how these commonly used treatments might influence hemostasis. (i) To use a swine model of femoral artery bleeding to understand the perivascular hemostatic response to contained arterial hemorrhage. (ii) To directly confirm the association between hemodynamics and bleeding velocity. (iii) To observe the feasibility of delivering an activated clotting factor directly to internal sites of bleeding using a simplified angiographic approach. Ultrasound was used to measure bleeding velocity and in vivo clot formation by elastography in a swine model of contained femoral artery bleeding with fluid resuscitation. A swine model of internal pelvic and axillary artery hemorrhage was also used to demonstrate the feasibility of local delivery of an activated clotting factor. In this model, clots formed slowly within the peri-wound hematoma, but eventually contained the bleeding. Central hemodynamics correlated positively with bleeding velocity. Infusion of recombinant human activated factor VII into the injured artery near the site of major internal hemorrhage in the pelvis and axillae was feasible. We rediscovered that clot formation within the peri-wound hematoma is an integral component of hemostasis and a feasible target for the treatment of major internal bleeding using activated clotting factors delivered using a simplified angiographic approach. © 2015 International Society on Thrombosis and Haemostasis.

  7. Extract of Aronia melanocarpa-modified hemostasis: in vitro studies.

    PubMed

    Sikora, Joanna; Markowicz-Piasecka, Magdalena; Broncel, Marlena; Mikiciuk-Olasik, Elżbieta

    2014-10-01

    Aronia melanocarpa has an extremely high content of procyanidins and anthocyanins. The multidirectional benefits of consumption of these berries are widely reported. Although numerous studies confirmed the influence of polyphenols on various stages of hemostasis, the exact mechanism of this phenomenon is not understood. The aim of our study was to evaluate the in vitro effect of A. melanocarpa extract on various parameters of hemostasis. Adenosine 5'-diphosphate (ADP)-induced aggregation was measured with turbidimetric method. Spontaneous and ADP-activated platelet adhesion were investigated using a colorimetric method. The global assay of coagulation and fibrinolysis was performed with the use of optical clotting and lysis (CL) test. Thrombin (0.5 IU/mL) and tissue plasminogen activator (60 ng/mL) were used to obtain a CL curve. The activity of thrombin and plasmin was determined by means of chromogenic substrate (S-2238, S-2251) RESULTS: The aronia extract contributed to the reduction in spontaneous and ADP-activated platelet adhesion. A significant increase in overall potential of CL as well as significant changes in key parameters of these processes (T t-thrombin time, F vo-initial plasma clotting velocity, and L max-maximum lysis) was reported. Chokeberry extract significantly inhibited the amidolytic activity of thrombin and plasmin. Our in vitro findings indicate a complex mechanism of influence of chokeberry polyphenols on platelet activity and the overall potential of CL. We confirmed that chokeberry inhibits the amidolytic activity of thrombin. It was demonstrated for the first time that chokeberry polyphenols inhibit the amidolytic activity of another serine protease, i.e., plasmin, which is the main fibrinolytic enzyme. Furthermore, our research points out a significant contribution of other plasma components and fibrinogen in the modulation of hemostasis by polyphenols.

  8. Alternative approaches to surgical hemostasis in patients with morbidly adherent placenta undergoing fertility-sparing surgery.

    PubMed

    Shmakov, Roman G; Vinitskiy, Aleksandr A; Chuprinin, Vladimir D; Yarotskaya, Ekaterina L; Sukhikh, Gennady T

    2018-02-05

    To evaluate the efficacy of different methods of surgical hemostasis, including the ligation of internal iliac arteries (IIA), temporary occlusion of the common iliac artery (CIA) and combined compression hemostasis, during cesarean section in patients with morbidly adherent placenta (MAP). The study included 54 patients with MAP. All patients underwent cesarean section with application of surgical hemostasis techniques. In Group 1 (n = 15), ligation of IIA was performed, in Group 2 (n = 18) extravasal temporary occlusion of CIA, and in Group 3 (n = 21) combined compression hemostasis was applied. The latter technique included placement of bilateral tourniquets on the upper uterine pedicles and on the cervicoisthmic segment, and controlled Zhukovsky balloon tamponade of the uterus, with subsequent resection of the uterine wall with abnormal placental invasion, evacuation of placenta from the uterine cavity and closure of the uterine wall defect with a double suture. The studied outcomes were total blood loss, duration of surgery, the hemoglobin level alteration, hysterectomy rate, and length of postoperative hospital stay. Total blood loss in Group 1 was 2440 ± 1215 ml, in Group 2 - 2186 ± 1353 ml, and in Group 3 - 1295 ± 520.3 ml (p = .0045). In Group 3, the lowest number of cases with blood loss >2000 ml was observed [8 (53.3%) versus 9 (50.0%) and 2 (9.5%), respectively; p = .0411]. The duration of surgery, the hemoglobin level alteration, hysterectomy rate, and length of hospital stay after delivery did not differ significantly between the groups. All surgical techniques used in the study were effective to decrease the blood loss during cesarean section in patients with MAP; however, the combined compression hemostasis showed the highest efficacy.

  9. ebb® Complete Tamponade System: effective hemostasis for postpartum hemorrhage

    PubMed Central

    McQuivey, Ross W; Block, Jon E; Massaro, Robert A

    2018-01-01

    As a leading cause of maternal death, postpartum hemorrhage (PPH) remains a worldwide obstetrical problem. However, in most cases, mortality and morbidity can be averted if efforts are immediately undertaken to achieve hemostasis. Uterine balloon tamponade has been shown to provide effective control of PPH and avoid more invasive surgical procedures and even the emergency peripartum hysterectomy. Recent clinical recommendation suggests that balloon tamponade should be considered earlier in the treatment cascade in conjunction with uterotonic agents to ensure hemostasis in the most timely fashion and maximize clinical outcomes. This paper profiles the ebb® Complete Tamponade System, a unique dual-balloon single-use device that was developed specifically for hemostatic management of PPH. The ebb system combines a uterine conforming balloon that can be rapidly deployed with a vaginal balloon that eliminates the need for vaginal packing. The description, indications for use, procedural steps, and clinical characterization of this device are presented. PMID:29535559

  10. ebb® Complete Tamponade System: effective hemostasis for postpartum hemorrhage.

    PubMed

    McQuivey, Ross W; Block, Jon E; Massaro, Robert A

    2018-01-01

    As a leading cause of maternal death, postpartum hemorrhage (PPH) remains a worldwide obstetrical problem. However, in most cases, mortality and morbidity can be averted if efforts are immediately undertaken to achieve hemostasis. Uterine balloon tamponade has been shown to provide effective control of PPH and avoid more invasive surgical procedures and even the emergency peripartum hysterectomy. Recent clinical recommendation suggests that balloon tamponade should be considered earlier in the treatment cascade in conjunction with uterotonic agents to ensure hemostasis in the most timely fashion and maximize clinical outcomes. This paper profiles the ebb ® Complete Tamponade System, a unique dual-balloon single-use device that was developed specifically for hemostatic management of PPH. The ebb system combines a uterine conforming balloon that can be rapidly deployed with a vaginal balloon that eliminates the need for vaginal packing. The description, indications for use, procedural steps, and clinical characterization of this device are presented.

  11. A new method for hepatic resection and hemostasis: absorbable plaque and suture.

    PubMed

    Ozer, M Tahir; Eryilmaz, Mehmet; Coskun, Kagan; Demirbas, Sezai; Uzar, A Ihsan; Kozak, Orhan

    2010-04-01

    Blunt and penetrating hepatic injuries are conditions that are frequently encountered in emergency surgeries, and they involve high mortality morbidity. In the handling of such injuries, methods ranging from the application of simple cauterization and suturing for hemostasis to hepatic lobectomies, which might involve the removal of the greater part of the organ, have been defined. Due to the organ's fragility and susceptibility to bleeding, elective hepatic resections necessitate both surgical experience and technological equipment. Therefore, the demand still exists for an affordable and easy-to-use-method that could be applied by all centers. To meet this demand, we have developed a method of hemorrhage control via sutures supported by absorbable plaques that provide effective compression and prevent the suture from cutting the tissue during the application of the sutures in the treatment of such fragile organs as the liver. In our method, we have achieved hemostasis by bilaterally compressing the tissue through strong ties after placing, on the part of the tissue on which the sutures are applied, absorbable and flexible plaques that prevent the suture from cutting the tissue during the application of a polyglactin suture to the solid organ. To prevent dislocation of the plaques, we have fastened the sutures by reeving them through the holes made in the plaques. We have demonstrated the success and the practicality of our method by applying it on four pigs; we experimentally inflicted hepatic injuries on two pigs, and we performed resection on the other two pigs. The hepatic hemorrhages we developed in both of the animals were successfully restrained by the use of our method. On the other hand, two resections were performed on the right and left lobes of the other two animals. There were no hemorrhages during the surgery, and the procedure took 45 minutes in total. No postoperative complications occurred. While the liver function test values were high on the

  12. Low-cost 420nm blue laser diode for tissue cutting and hemostasis

    NASA Astrophysics Data System (ADS)

    Linden, Kurt J.

    2016-03-01

    This paper describes the use of a 420 nm blue laser diode for possible surgery and hemostasis. The optical absorption of blood-containing tissue is strongly determined by the absorption characteristics of blood. Blood is primarily comprised of plasma (yellowish extracellular fluid that is approximately 95% water by volume) and formed elements: red blood cells (RBCs), white blood cells (WBCs) and platelets. The RBCs (hemoglobin) are the most numerous, and due to the spectral absorption characteristics of hemoglobin, the optical absorption of blood has a strong relative maximum value in the 420 nm blue region of the optical spectrum. Small, low-cost laser diodes emitting at 420 nm with tens of watts of continuous wave (CW) optical power are becoming commercially available. Experiments on the use of such laser diodes for tissue cutting with simultaneous hemostasis were carried out and are here described. It was found that 1 mm deep x 1 mm wide cuts can be achieved in red meat at a focused laser power level of 3 W moving at a velocity of ~ 1 mm/s. The peripheral necrosis and thermal damage zone extended over a width of approximately 0.5 mm adjacent to the cuts. Preliminary hemostasis experiments were carried out with fresh equine blood in Tygon tubing, where it was demonstrated that cauterization can occur in regions of intentional partial tubing puncture.

  13. Airflow-directed in situ electrospinning of a medical glue of cyanoacrylate for rapid hemostasis in liver resection

    NASA Astrophysics Data System (ADS)

    Jiang, Kai; Long, Yun-Ze; Chen, Zhao-Jun; Liu, Shu-Liang; Huang, Yuan-Yuan; Jiang, Xingyu; Huang, Zhi-Qiang

    2014-06-01

    Rapid hemostasis of solitary organs is still a big challenge in surgical procedures or after major trauma in both civilians and on the battlefield. Here, we report the first use of an airflow-directed in situ electrospinning method to precisely and homogeneously deposit a medical glue of n-octyl-2-cyanoacrylate (OCA) ultrathin fibers onto a wound surface to realize rapid hemostasis in dozens of seconds. In vivo and in vitro experiments on pig liver resection demonstrate that the self-assembled electrospun OCA membrane with high strength, good flexibility and integrity is very compact and no fluid seeping is observed even under a pressure of 147 mm Hg. A similar effect has been achieved in an in vivo experiment on pig lung resection. The results provide a very promising alternative for rapid hemostasis of solitary organs as well as other traumas, providing evidence that the postoperative drainage tube may not be always necessary for surgery in the near future.Rapid hemostasis of solitary organs is still a big challenge in surgical procedures or after major trauma in both civilians and on the battlefield. Here, we report the first use of an airflow-directed in situ electrospinning method to precisely and homogeneously deposit a medical glue of n-octyl-2-cyanoacrylate (OCA) ultrathin fibers onto a wound surface to realize rapid hemostasis in dozens of seconds. In vivo and in vitro experiments on pig liver resection demonstrate that the self-assembled electrospun OCA membrane with high strength, good flexibility and integrity is very compact and no fluid seeping is observed even under a pressure of 147 mm Hg. A similar effect has been achieved in an in vivo experiment on pig lung resection. The results provide a very promising alternative for rapid hemostasis of solitary organs as well as other traumas, providing evidence that the postoperative drainage tube may not be always necessary for surgery in the near future. Electronic supplementary information (ESI) available

  14. Surgical Education: Attitudes toward Animal Use in Teaching Surgery at Louisiana State University.

    ERIC Educational Resources Information Center

    Hedlund, Cheryl S.; Hosgood, Giselle; Naugler, Sasha

    2002-01-01

    Surveyed students and faculty at Louisiana State University about the use of animals for teaching surgery. Found that they favored the practice, finding it helpful for learning aseptic technique and suturing skills but less so for learning tissue handling, dissection, hemostasis, or anesthesia. (EV)

  15. Comparison of a priori versus provisional heparin therapy on radial artery occlusion after transradial coronary angiography and patent hemostasis (from the PHARAOH Study).

    PubMed

    Pancholy, Samir B; Bertrand, Olivier F; Patel, Tejas

    2012-07-15

    Systemic anticoagulation decreases the risk of radial artery occlusion (RAO) after transradial catheterization and standard occlusive hemostasis. We compared the efficacy and safety of provisional heparin use only when the technique of patent hemostasis was not achievable to standard a priori heparin administration after radial sheath introduction. Patients referred for coronary angiography were randomized in 2 groups. In the a priori group, 200 patients received intravenous heparin (50 IU/kg) immediately after sheath insertion. In the provisional group, 200 patients did not receive heparin during the procedure. After sheath removal, hemostasis was obtained using a TR band (Terumo corporation, Tokyo, Japan) with a plethysmography-guided patent hemostasis technique. In the provisional group, no heparin was given if radial artery patency could be obtained and maintained. If radial patency was not achieved, a bolus of heparin (50 IU/kg) was given. Radial artery patency was evaluated at 24 hours (early RAO) and 30 days after the procedure (late RAO) by plethysmography. Patent hemostasis was obtained in 67% in the a priori group and 74% in the provisional group (p = 0.10). Incidence of RAO remained similar in the 2 groups at the early (7.5% vs 7.0%, p = 0.84) and late (4.5% vs 5.0%, p = 0.83) evaluations. Women, patients with diabetes, patients having not received heparin, and patients without radial artery patency during hemostasis had more RAO. By multivariate analysis, patent radial artery during hemostasis (odds ratio [OR] 0.03, 95% confidence interval [CI] 0.004 to 0.28, p = 0.002) and diabetes (OR 11, 95% CI 3 to 38,p <0.0001) were independent predictors of late RAO, whereas heparin was not (OR 0.45 95% CI 0.13 to 1.54, p = 0.20). In conclusion, our results suggest that maintenance of radial artery patency during hemostasis is the most important parameter to decrease the risk of RAO. In selected cases, provisional use of heparin appears feasible and safe when

  16. Comparison of TR Band™ and VasoStat™ Hemostasis Devices following Transpedal Catheterization for Lower Extremity Revascularization for Peripheral Arterial Disease.

    PubMed

    Kwan, Tak W; Patel, Apurva; Parikh, Roosha; Auguste, Uschi; Rosero, Hugo; Huang, Yili; Liou, Michael; Ratcliffe, Justin; Puma, Joseph

    2016-08-01

    Transpedal access is increasingly utilized for peripheral vascular catheterization. There is a paucity of data on the use of radial hemostasis devices as an alternative to manual compression for achievement of hemostasis after this approach. To compare safety and efficacy of two hemostasis devices following transpedal catheterization for lower extremity revascularization for peripheral arterial disease. A consecutive cohort of patients with bilateral Rutherford 2-5 disease who underwent transpedal catheterization for peripheral vascular interventions were retrospectively analyzed. In each patient, retrograde tibial artery access was obtained, a 4 French sheath was placed, and all revascularization was performed via tibial access. In all patients, a TR Band™ (Terumo Medical, n = 215) and/or VasoStat™ (Forge Medical, n = 99) were used to apply puncture site compression, following removal of the tibial sheath until hemostasis was achieved. Safety and efficacy of each device was compared. Puncture site hemostasis was achieved in all patients within 2 hours of sheath removal facilitating early discharge. Two access site pseudoaneurysms occurred within 30 days of revascularization, one of which followed TR Band™ placement and the other following VasoStat™ placement (P = 0.53). Each patient was successfully treated with ultrasound-guided thrombin injection. Loss of access site patency by duplex ultrasound occurred in 2 patients following the TR Band™ and a single patient following the VasoStat™ (P = 1.0). Both the TR Band™ and the VasoStat™ were effective in achieving hemostasis following transpedal catheterization with low rates of complications. © 2016, Wiley Periodicals, Inc.

  17. Comparison of Hemostasis Times With a Kaolin-Based Hemostatic Pad (QuikClot Radial) vs Mechanical Compression (TR Band) Following Transradial Access: A Pilot Prospective Study.

    PubMed

    Roberts, Jonathan S; Niu, Jianli; Pastor-Cervantes, Juan A

    2017-10-01

    Hemostasis following transradial access (TRA) is usually achieved by mechanical compression. We investigated use of the QuikClot Radial hemostasis pad (Z-Medica) compared with the TR Band (Terumo Medical) to shorten hemostasis after TRA. Thirty patients undergoing TRA coronary angiography and/or percutaneous coronary intervention were randomized into three cohorts post TRA: 10 patients received mechanical compression with the TR Band, 10 patients received 30 min of compression with the QuikClot Radial pad, and 10 patients received 60 min of compression with the QuikClot Radial pad. Times to hemostasis and access-site complications were recorded. Radial artery patency was evaluated 1 hour after hemostasis by the reverse Barbeau's test. There were no differences in patient characteristics, mean dose of heparin (7117 ± 1054 IU), or mean activated clotting time value (210 ± 50 sec) at the end of procedure among the three groups. Successful hemostasis was achieved in 100% of patients with both the 30-min and 60-min compression groups using the QuikClot pad. Hemostasis failure occurred in 50% of patients when the TR Band was initially weaned at the protocol-driven time (40 min after sheath removal). Mean compression time for hemostasis with the TR Band was 149.4 min compared with 30.7 min and 60.9 min for the 30-min and 60-min QuikClot groups, respectively. No radial artery occlusion occurred in any subject at the end of the study. Use of the QuikClot Radial pad following TRA in this pilot trial significantly shortened hemostasis times when compared with the TR Band, with no increased complications noted.

  18. Hemostasis and sealing of air leaks in the lung using high-intensity focused ultrasound.

    PubMed

    Vaezy, Shahram; Zderic, Vesna; Karmy-Jones, Riyad; Jurkovich, Gregory J; Cornejo, Carol; Martin, Roy W

    2007-06-01

    Operative management of parenchymal lung injury can be complicated by persistent hemorrhage and air leak, which might require resection. Techniques that preserve parenchyma are associated with improved survival. High-intensity focused ultrasound (HIFU) has been demonstrated as a useful method for hemostasis in experimental solid organ injuries. We wished to investigate whether this could be applied to lung injuries. An intraoperative HIFU device (frequency of 5.7 MHz, acoustic power of 65 W), equipped with a titanium coupler, was used. Incisions (average length of 2.5 cm, and depth of 5 mm) were made in the lungs of 11 pigs, which created both parenchymal hemorrhage and air leakage. In treatment experiments, 70 incisions were sealed with HIFU. The HIFU application started within 10 seconds of inducing the injury. Hemostasis was assessed by visual observation of sealed incisions. The possible air leakage was determined by submersing the sealed incision under the layer of water and observing for air bubble formation. In control experiments, five incisions were left untreated to monitor air leaks and bleeding for 2 minutes. Hemostasis and pneumostasis (sealing of air leaks) of the treated incisions were achieved in 51 +/- 37 seconds (mean +/- SD) (range of 10-210 seconds) of HIFU application time. Over 95% of incisions were hemostatic within 2 minutes of HIFU application. The treatment time was not dependent on the incision length or depth. In control experiments, the air leaking and bleeding were still present at 2 minutes after the injury. Intraoperative HIFU might provide an effective method of hemostasis and control of air leaks from lacerations caused by trauma.

  19. Gasomediators (·NO, CO, and H₂S) and their role in hemostasis and thrombosis.

    PubMed

    Olas, Beata

    2015-05-20

    Hemostasis is a group of mechanisms used to prevent the outflow of blood from its vessels, and to ensure its liquidity and flow within them. The system incorporates aspects of the blood vessel wall (mainly the intima), the clotting process, together with its factors (i.e. fibrinogen) and coagulation inhibitors, as well as fibrinolysis, blood platelets and the phagocyte system. The modulation of hemostasis is associated with the pathogenesis of cardiovascular diseases, such as thrombosis. The study examines the action of three selected gasomediators, nitric oxide ((•)NO), carbon monoxide (CO) and hydrogen sulfide (H2S), on hemostasis and thrombosis, although these gasses are also involved in a multitude of other physiological functions. (•)NO inhibits blood platelet activation, relaxes blood vessels and, as a free radical chain, may rapidly react with superoxide anion (O2(-•)) in blood platelets to form peroxynitrite (ONOO(-)). ONOO(-) is a reactive nitrating and nitrosating agent which induces oxidative/nitrative stress in blood platelets and plasma. Moreover, ONOO(-) changes the structure and function of fibrinogen and proteins associated with fibrinolysis. Recently, proteomic studies have provided unequivocal evidence that human platelets lack any expression of nitric oxide synthase isoforms. Other studies have demonstrated that CO and H2S, reduce blood platelet reactivity. Moreover, H2S has been reported to demonstrate anticoagulatory activity, and CO may act not only as an anticoagulant, but also aprocoagulant. This review article summarizes current knowledge of the biological roles of gasomediators (NO, CO, H2S) in hemostasis and in cardiovascular diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Use of absorbable hemostatic gauze with medical adhesive is effective for achieving hemostasis in presacral hemorrhage.

    PubMed

    Zhang, Chang-Hua; Song, Xin-Ming; He, Yu-Long; Han, Fanghai; Wang, Liang; Xu, Jian-Bo; Chen, Chuang-Qi; Cai, Shi-Rong; Zhan, Wen-Hua

    2012-04-01

    Management of presacral hemorrhage is always challenging. Herein we describe the use of an absorbable hemostatic gauze with α-cyanoacrylate medical adhesive to achieve hemostasis. In this study, we conducted total mesorectal excision for the treatment of rectal cancer in 258 patients from March 2006 to May 2009. Intraoperative presacral hemorrhage developed in 5 (2%) patients during rectal mobilization. In these 5 patients, massive bleeding could not be controlled by pressure and pelvic packing with gauze. An absorbable hemostatic gauze spread with medical adhesive was compressed onto the bleeding vessel for at least 20 minutes. Hemostasis was achieved successfully and was maintained during the surgery. Patients recovered uneventfully and no postoperative events were noted. The use of an absorbable hemostatic gauze with medical adhesive is a simple and effective method for achieving hemostasis when massive presacral hemorrhage occurs. However, its effectiveness needs to be confirmed in a controlled study in a properly selected patient population. Copyright © 2012. Published by Elsevier Inc.

  1. Application of overall dynamic body acceleration as a proxy for estimating the energy expenditure of grazing farm animals: relationship with heart rate.

    PubMed

    Miwa, Masafumi; Oishi, Kazato; Nakagawa, Yasuhiro; Maeno, Hiromichi; Anzai, Hiroki; Kumagai, Hajime; Okano, Kanji; Tobioka, Hisaya; Hirooka, Hiroyuki

    2015-01-01

    Estimating the energy expenditure of farm animals at pasture is important for efficient animal management. In recent years, an alternative technique for estimating energy expenditure by measuring body acceleration has been widely performed in wildlife and human studies, but the availability of the technique in farm animals has not yet been examined. In the present study, we tested the potential use of an acceleration index, overall dynamic body acceleration (ODBA), as a new proxy for estimating the energy expenditure of grazing farm animals (cattle, goats and sheep) at pasture with the simultaneous evaluation of a conventional proxy, heart rate. Body accelerations in three axes and heart rate for cows (n = 8, two breeds), goats (n = 6) and sheep (n = 5) were recorded, and the effect of ODBA calculated from the body accelerations on heart rate was analyzed. In addition, the effects of the two other activity indices, the number of steps and vectorial dynamic body acceleration (VeDBA), on heart rate were also investigated. The results of the comparison among three activity indices indicated that ODBA was the best predictor for heart rate. Although the relationship between ODBA and heart rate was different between the groups of species and breeds and between individuals (P<0.01), the difference could be explained by different body weights; a common equation could be established by correcting the body weights (M: kg): heart rate (beats/min) = 147.263∙M-0.141 + 889.640∙M-0.179∙ODBA (g). Combining this equation with the previously reported energy expenditure per heartbeat, we estimated the energy expenditure of the tested animals, and the results indicated that ODBA is a good proxy for estimating the energy expenditure of grazing farm animals across species and breeds. The utility and simplicity of the procedure with acceleration loggers could make the accelerometry technique a worthwhile option in field research and commercial farm use.

  2. Effects of dipyrone, meloxicam, or the combination on hemostasis in conscious dogs.

    PubMed

    Zanuzzo, Felipe S; Teixeira-Neto, Francisco J; Thomazini, Camila M; Takahira, Regina K; Conner, Bobbi; Diniz, Miriely S

    2015-01-01

    To compare the effects of dipyrone, meloxicam, and of the combination of these drugs on hemostasis in dogs. Prospective, blinded, randomized crossover study. Research laboratory at a veterinary teaching hospital. Six adult dogs. Animals received 4 intravenous treatments with 15-day washout intervals: control (physiological saline, 0.1 mL/kg), meloxicam (0.2 mg/kg), dipyrone (25 mg/kg), and dipyrone-meloxicam (25 and 0.2 mg/kg, respectively). A jugular catheter was placed for drug injection and for collecting samples for whole blood platelet aggregation (WBPA) and thromboelastometry assays at baseline, 1, 2, 3, 5, and 8 hours after treatment administration. The percent change from baseline of lag time and of the area under the curve (AUC) of impedance changes in response to collagen-induced platelet activation were recorded during WBPA. Thromboelastometry-derived parameters included clotting time, clot formation time, alpha-angle, and maximum clot firmness. The buccal mucosal bleeding time was evaluated by a blinded observer at baseline, 1, 3, and 5 hours after treatment injection. No significant changes in WBPA and thromboelastometry were recorded in the control treatment. Dipyrone significantly (P < 0.05) increased the lag time for 2 hours and decreased the AUC for 3 hours after injection. Meloxicam did not alter WBPA. Dipyrone-meloxicam significantly increased lag time for 2 hours and decreased the AUC for 5 hours after treatment injection. Experimental treatments did not differ from the control treatment for thromboelastometry and buccal mucosal bleeding time. While meloxicam does not alter hemostasis by the methods evaluated, dipyrone inhibits platelet aggregation for up to 3 hours. Meloxicam-dipyrone combination causes more prolonged inhibition of platelet function than dipyrone alone. Decreased platelet aggregation induced by dipyrone and dipyrone-meloxicam does not appear to impact the viscoelastic properties of the blood clot nor increase the risk of

  3. Ultrasound contrast agents for bleeding detection and acoustic hemostasis

    NASA Astrophysics Data System (ADS)

    Zderic, Vesna; Luo, Wenbo; Brayman, Andrew; Crum, Lawrence; Vaezy, Shahram

    2005-04-01

    Objective: To investigate the application of ultrasound contrast agents (UCA) in improving both therapeutic and diagnostic aspects of ultrasound-guided High Intensity Focused Ultrasound (HIFU) therapy. Methods: Incisions (3 cm long, 0.5 cm deep) were made in rabbit livers (in anterior surface for HIFU treatment, or posterior surface for bleeding detection). UCA Optison (~0.1 ml/kg) was injected into mesenteric vein or ear vein. A HIFU applicator (5.5 MHz, 6400 W/cm2) was scanned manually over the incision until hemostasis was achieved. Occult bleeding was monitored with Doppler ultrasound. Results: The presence of Optison produced 37% reduction in hemostasis times normalized to initial bleeding rates. Gross and histological observations showed similar appearance of HIFU lesions produced in the presence of Optison and control HIFU lesions. The temperature reached 100°C in both HIFU only and HIFU+UCA treatments. Tension strength of hemostatic liver incisions was 0.9+/-0.5 N. Almost no bleeding could be detected before Optison injection. First appearance of contrast enhancement localized at the bleeding site was 15 s after Optison injection, and lasted for ~50 s. Conclusion: The presence of UCA during HIFU treatment of liver incisions resulted in shortening of HIFU application times and better visualization of bleeding sites.

  4. Insights into abnormal hemostasis in the Quebec platelet disorder from analyses of clot lysis.

    PubMed

    Diamandis, M; Adam, F; Kahr, W H A; Wang, P; Chorneyko, K A; Arsenault, A L; Rivard, G E; Hayward, C P M

    2006-05-01

    The Quebec platelet disorder (QPD) is inherited and characterized by delayed-onset bleeding following hemostatic challenge. Other characteristics include increased expression and storage of active urokinase-type plasminogen activator (u-PA) in platelets in the setting of normal to increased u-PA in plasma. There is also consumption of platelet plasminogen activator inhibitor-1 and increased generation of plasmin in platelets accompanied by proteolysis of stored alpha-granule proteins, including Factor V. Although fibrinolysis has been proposed to contribute to QPD bleeding, the effects of QPD blood and platelets on clot lysis have not been evaluated. We used thromboelastography (TEG), biochemical evaluations of whole blood clot lysis, assessments of clot ultrastructure, and perfusion of blood over preformed fibrin to gain insights into the disturbed hemostasis in the QPD. Thromboelastography was not sensitive to the increased u-PA in QPD blood. However, there was abnormal plasmin generation in QPD whole blood clots, generated at low shear, with biochemical evidence of increased fibrinolysis. The incorporation of QPD platelets into a forming clot led to progressive disruption of fibrin and platelet aggregates unless drugs were added to inhibit plasmin. In whole blood perfusion studies, QPD platelets showed normal adherence to fibrin, but their adhesion was followed by accelerated fibrinolysis. The QPD is associated with "gain-of-function" abnormalities that increase the lysis of forming or preformed clots. These findings suggest accelerated fibrinolysis is an important contributor to QPD bleeding.

  5. D-dimer: An Overview of Hemostasis and Fibrinolysis, Assays, and Clinical Applications.

    PubMed

    Olson, John D

    2015-01-01

    D-dimer is the smallest fibrinolysis-specific degradation product found in the circulation. The origins, assays, and clinical use of D-dimer will be addressed. Hemostasis (platelet and vascular function, coagulation, fibrinolysis, hemostasis) is briefly reviewed. D-dimer assays are reviewed. The D-dimer is very sensitive to intravascular thrombus and may be markedly elevated in disseminated intravascular coagulation, acute aortic dissection, and pulmonary embolus. Because of its exquisite sensitivity, negative tests are useful in the exclusion venous thromboembolism. Elevations occur in normal pregnancy, rising two- to fourfold by delivery. D-dimer also rises with age, limiting its use in those >80 years old. There is a variable rise in D-dimer in active malignancy and indicates increased thrombosis risk in active disease. Elevated D-dimer following anticoagulation for a thrombotic event indicates increased risk of recurrent thrombosis. These and other issues are addressed. © 2015 Elsevier Inc. All rights reserved.

  6. Microparticle Analysis in Disorders of Hemostasis and Thrombosis

    PubMed Central

    Mooberry, Micah J.; Key, Nigel S.

    2015-01-01

    Microparticles (MPs) are submicron vesicles released from the plasma membrane of eukaryotic cells in response to activation or apoptosis. MPs are known to be involved in numerous biologic processes, including inflammation, the immune response, cancer metastasis, and angiogenesis. Their earliest recognized and most widely accepted role, however, is the ability to promote and support the process of blood coagulation. Consequently, there is ongoing interest in studying MPs in disorders of hemostasis and thrombosis. Both phosphatidylserine (PS) exposure and the presence of tissue factor (TF) in the MP membrane may account for their procoagulant properties, and elevated numbers of MPs in plasma have been reported in numerous prothrombotic conditions. To date, however, there are few data on true causality linking MPs to the genesis of thrombosis. A variety of methodologies have been employed to characterize and quantify MPs, although detection is challenging due to their submicron size. Flow cytometry (FCM) remains the most frequently utilized strategy for MP detection; however, it is associated with significant technological limitations. Additionally, pre-analytical and analytical variables can influence the detection of MPs by FCM, rendering data interpretation difficult. Lack of methodologic standardization in MP analysis by FCM confounds the issue further, although efforts are currently underway to address this limitation. Moving forward, it will be important to address these technical challenges as a scientific community if we are to better understand the role that MPs play in disorders of hemostasis and thrombosis. PMID:25704723

  7. Diaminopropionic Acid Reinforced Graphene Sponge and Its Use for Hemostasis.

    PubMed

    Quan, Kecheng; Li, Guofeng; Tao, Lei; Xie, Qian; Yuan, Qipeng; Wang, Xing

    2016-03-01

    2,3-Diaminopropionic acid (DapA), a medicinal amino acid, is used for the first time to prepare a DapA cross-linked graphene sponge (DCGS) for hemostasis treatment. In a comparison with the reported ethanediamine (EDA) cross-linked graphene sponge (CGS), this carboxyl-functionalized DCGS can not only quickly absorb plasma, but also stimulate erythrocytes and platelets to change their normal form and structure at the interface, which largely affects a cell's metabolism and biofunction, thus further promoting blood coagulation. Whole blood clotting and rat-tail amputation tests indicated that on the basis of the additional interfacial stimulation, the hemostatic efficiency of the DCGS has been significantly improved in comparison with that of the CGS control (P < 0.05). In-depth insight revealed that the increased oxidation degree and the negative charge density play the crucial rule in the enhanced hemostatic performance. The chiral effect contributes mainly to the selective adhesion of erythrocytes and platelets rather than practical hemostasis. Nevertheless, this presentation demonstrated that, on the premise of keeping the fast absorbability, this is an effective method to improve the hemostatic efficiency by enhancing the cell/graphene interface interaction.

  8. Natural history of definitive diverticular hemorrhage based upon stigmata of recent hemorrhage and colonoscopic Doppler blood flow monitoring for risk stratification and definitive hemostasis

    PubMed Central

    Jensen, Dennis M.; Ohning, Gordon V.; Kovacs, Thomas O.G.; Jutabha, Rome; Ghassemi, Kevin; Dulai, Gareth S.; Machicado, Gustavo A.

    2015-01-01

    BACKGROUND AND AIMS Few prospective reports describe the short term natural history of colon diverticular hemorrhage based upon stigmata of recent hemorrhage and none include blood flow detection for risk stratification or as a guide to definitive hemostasis. Our purposes are to report the 30 day natural history of definitive diverticular hemorrhage based upon stigmata and to describe Doppler probe blood flow detection and as a guide to definitive hemostasis. METHODS Different cohorts of patients with severe diverticular bleeding and stigmata on urgent colonoscopy are reported. For 30 day natural history, patients were treated medically. If severe rebleeding occurred, they had surgical or angiographic treatment. Natural history with major stigmata (active bleeding, visible vessel, or adherent clot) and no stigmata or flat spots after washing away clots are reported. Doppler probe detection of arterial blood flow underneath stigmata before and after hemostasis is also reported in a recent cohort. RESULTS For natural history patients with major stigmata treated medically had 65.8% (25/38) rebleeding rates and 44.7% (17/38) had intervention for hemostasis. Patients with spots or clean bases had no rebleeding. Doppler probe detected arterial blood flow in 92% of major stigmata, none after hemostasis and no one rebled. CONCLUSIONS 1. Patients with major stigmata treated medically had high rates of rebleeding and intervention for hemostasis. 2. Patients with clean diverticula or only flat spots had no rebleeding. 3. High rates of arterial blood flow were detected under major stigmata with Doppler probe but with obliteration by hemostasis no rebleeding occurred. PMID:26227931

  9. Transport physics and biorheology in the setting of hemostasis and thrombosis.

    PubMed

    Brass, L F; Diamond, S L

    2016-05-01

    The biophysics of blood flow can dictate the function of molecules and cells in the vasculature with consequent effects on hemostasis, thrombosis, embolism, and fibrinolysis. Flow and transport dynamics are distinct for (i) hemostasis vs. thrombosis and (ii) venous vs. arterial episodes. Intraclot transport changes dramatically the moment hemostasis is achieved or the moment a thrombus becomes fully occlusive. With platelet concentrations that are 50- to 200-fold greater than platelet-rich plasma, clots formed under flow have a different composition and structure compared with blood clotted statically in a tube. The platelet-rich, core/shell architecture is a prominent feature of self-limiting hemostatic clots formed under flow. Importantly, a critical threshold concentration of surface tissue factor is required for fibrin generation under flow. Once initiated by wall-derived tissue factor, thrombin generation and its spatial propagation within a clot can be modulated by γ'-fibrinogen incorporated into fibrin, engageability of activated factor (FIXa)/activated FVIIIa tenase within the clot, platelet-derived polyphosphate, transclot permeation, and reduction of porosity via platelet retraction. Fibrin imparts tremendous strength to a thrombus to resist embolism up to wall shear stresses of 2400 dyne cm(-2) . Extreme flows, as found in severe vessel stenosis or in mechanical assist devices, can cause von Willebrand factor self-association into massive fibers along with shear-induced platelet activation. Pathological von Willebrand factor fibers are A Disintegrin And Metalloprotease with ThromboSpondin-1 domain 13 resistant but are a substrate for fibrin generation due to FXIIa capture. Recently, microfluidic technologies have enhanced the ability to interrogate blood in the context of stenotic flows, acquired von Willebrand disease, hemophilia, traumatic bleeding, and drug action. © 2016 International Society on Thrombosis and Haemostasis.

  10. Determining position, velocity and acceleration of free-ranging animals with a low-cost unmanned aerial system.

    PubMed

    Harvey, Richard J; Roskilly, Kyle; Buse, Chris; Evans, Hannah K; Hubel, Tatjana Y; Wilson, Alan M

    2016-09-01

    Unmanned aerial systems (UASs), frequently referred to as 'drones', have become more common and affordable and are a promising tool for collecting data on free-ranging wild animals. We used a Phantom-2 UAS equipped with a gimbal-mounted camera to estimate position, velocity and acceleration of a subject on the ground moving through a grid of GPS surveyed ground control points (area ∼1200 m(2)). We validated the accuracy of the system against a dual frequency survey grade GPS system attached to the subject. When compared with GPS survey data, the estimations of position, velocity and acceleration had a root mean square error of 0.13 m, 0.11 m s(-1) and 2.31 m s(-2), respectively. The system can be used to collect locomotion and localisation data on multiple free-ranging animals simultaneously. It does not require specialist skills to operate, is easily transported to field locations, and is rapidly and easily deployed. It is therefore a useful addition to the range of methods available for field data collection on free-ranging animal locomotion. © 2016. Published by The Company of Biologists Ltd.

  11. [Effects of epithalon and cortagene on immunity and hemostasis in neonatally hypophysectomized chicken and old birds].

    PubMed

    Kuznik, B I; Pateiuk, A V; Baranchugova, L M; Rusaeva, N S

    2008-01-01

    It has been found that chicken hypophysectomized early in the neonatal period develop anemia, cellular and humoral immune deficiency, hypercoagulation and inhibited fibrinolysis by their 45th postnatal day. An analogous operation performed on old birds produces less significant changes in erythrocytes, immunity and hemostasis. Injections of epithalon tetrapeptide (Ala-Glu-Asp-Gly) administered to either hypophysectomized chicken or old birds during a period of 40 days completely eliminate the shifts registered in erythrocytes, immunity and hemostasis, while injections of cortagene (Ala-Glu-Asp-Pro) which is distinguished from epithalon by a different terminal aminoacid (with Gly being replaced by Pro) do not affect the parameters studied.

  12. Starclose SE® hemostasis after 6F direct antegrade superficial femoral artery access distal to the femoral head for peripheral endovascular procedures in obese patients.

    PubMed

    Spiliopoulos, Stavros; Kitrou, Panagiotis; Christeas, Nikolaos; Karnabatidis, Dimitris

    2016-01-01

    Direct superficial femoral artery (SFA) antegrade puncture is a valid alternative to common femoral artery (CFA) access for peripheral vascular interventions. Data investigating vascular closure device (VCD) hemostasis of distant SFA 6F access are limited. We aimed to investigate the safety and effectiveness of the Starclose SE® VCD for hemostasis, following direct 6F antegrade SFA access distal to the femoral head. This prospective, single-center study included patients who were not suitable for CFA puncture and were scheduled to undergo peripheral endovascular interventions using direct antegrade SFA 6F access, at least 2 cm below the inferior edge of femoral head. Hemostasis was obtained with the Starclose SE® VCD (Abbott Laboratories). Primary endpoints were successful hemostasis rate and periprocedural (30-day) major complication rate. Secondary endpoint was the rate of minor complications. Clinical and Doppler ultrasound follow-up was performed at discharge and at one month. Between September 2014 and August 2015, a total of 30 patients (21 male; 70.0%) with a mean body mass index of 41.2 kg/m2 were enrolled. Mean age was 72±9 years (range, 67-88 years). Most patients suffered from critical limb ischemia (87.1%) and diabetes (61.3%). Calcifications were present in eight cases (26.6%). Reason for direct SFA puncture was obesity (100%). Successful hemostasis was achieved in 100% of the cases. No major complications were noted after one-month follow-up. Minor complications included two <5 cm hematomas (6.6%) not necessitating treatment. In this prospective study, Starclose SE® VCD was safe and effective for hemostasis of antegrade direct SFA puncture. Uncomplicated hemostasis was achieved even in cases of puncturing 2 to 7 cm below the inferior edge of the femoral head.

  13. Comparison between self-assembling peptide nanofiber scaffold (SAPNS) and fibrin sealant in neurosurgical hemostasis.

    PubMed

    Xu, Fei-Fan; Wang, Yue-Chun; Sun, Stella; Ho, Amy S W; Lee, Derek; Kiang, Karrie M Y; Zhang, Xiao-Qin; Lui, Wai-Man; Liu, Bai-Yun; Wu, Wu-Tian; Leung, Gilberto K K

    2015-10-01

    RADA16-I is a synthetic type I self-assembling peptide nanofiber scaffold (SAPNS) which may serve as a novel biocompatible hemostatic agent. Its application in neurosurgical hemostasis, however, has not been explored. Although RADA16-I is nontoxic and nonimmunogenic, its intrinsic acidity may potentially provoke inflammation in the surgically injured brain. We conducted an animal study to compare RADA16-I with fibrin sealant, a commonly used agent, with the hypothesis that the former would be a comparable alternative. Using a standardized surgical brain injury model, 30 Sprague-Dawley rats were randomized into three treatment groups: RADA16-I, fibrin sealant or gelatin sponge (control). Animals were sacrificed on day 3 and 42. Astrocytic and microglial infiltrations within the cerebral parenchyma adjacent to the operative site were significantly lower in the RADA16-I and fibrin sealant groups than control. RADA16-I did not cause more cellular inflammatory response despite its acidity when compared with fibrin sealant. Immunohistochemical studies showed infiltration by astrocytes and microglia into the fibrin sealant and RADA16-I grafts, suggesting their potential uses as tissue scaffolds. RADA16-I is a promising candidate for further translational and clinical studies that focus on its applications as a safe and effective hemostat, proregenerative nanofiber scaffold as well as drug and cell carrier. © 2015 Wiley Periodicals, Inc.

  14. Autologous fibrin glue: the last step in operative hemostasis.

    PubMed

    Tawes, R L; Sydorak, G R; DuVall, T B

    1994-08-01

    Fibrin glue may be the perfect hemostatic agent for operative use as it seals in minutes, has no tissue toxicity, reabsorbs, and promotes local tissue growth and repair. Use in the United States has been limited because of lack of Food and Drug Administration approval of the commercial homologous products, lack of a concentrated source of fibrinogen, and because of the potential for viral transmission, particularly hepatitis, with pooled homologous plasma and cryoprecipitate-based methods. Autologous fibrin glue (AFG) obviates these problems. During the past year, we obtained AFG through the same routine predonation procedure as with red blood cells before major elective surgery. Intraoperatively, we made AFG from the platelet-rich plasma derived from the Plasma-Saver. Our experience has been with 36 patients undergoing aortic, thoracoabdominal, and thoracic surgery, as well as patch graft angioplasty cases. Fibrin glue formation mimics the final stage in the coagulation cascade. The AFG from predonation acts more like an epoxy glue, while the AFG made during surgery is less viscous and acts more like a sealant because of the lesser concentration of fibrinogen in platelet-rich plasma. In emergencies, however, the intraoperative method is obviously the only choice available, and it is a useful adjunct to hemostasis at the end of the procedure. The technique will be described. This relatively new approach to hemostasis should gain popularity because it is easy and fairly inexpensive to produce, and because the patient's own blood is used.

  15. Vestibular short latency responses to pulsed linear acceleration in unanesthetized animals

    NASA Technical Reports Server (NTRS)

    Jones, T. A.

    1992-01-01

    Linear acceleration transients were used to elicit vestibular compound action potentials in non-invasively prepared, unanesthetized animals for the first time (chicks, Gallus domesticus, n = 33). Responses were composed of a series of up to 8 dominant peaks occurring within 8 msec of the stimulus. Response amplitudes for 1.0 g stimulus ranged from 1 to 10 microV. A late, slow, triphasic, anesthesia-labile component was identified as a dominant response feature in unanesthetized animals. Amplitudes increased and latencies decreased as stimulus intensity was increased (MANOVA P less than 0.05). Linear regression slope ranges were: amplitudes = 1.0-5.0 microV/g; latencies = -300 to -1100 microseconds/g. Thresholds for single polarity stimuli (0.035 +/- 0.022 g, n = 11) were significantly lower than those of alternating polarity (0.074 +/- 0.028 g, n = 18, P less than 0.001). Bilateral labyrinthectomy eliminated responses whereas bilateral extirpation of cochleae did not significantly change response thresholds. Intense acoustic masking (100/104 dB SL) produced no effect in 2 animals, but did produce small to moderate effects on response amplitudes in 7 others. Changes were attributed to effects on vestibular end organs. Results of unilateral labyrinth blockade (tetrodotoxin) suggest that P1 and N1 preferentially reflect ipsilateral eighth nerve compound action potentials whereas components beyond approximately 2 msec reflect activity from vestibular neurons that depend on both labyrinths. The results demonstrate that short latency vestibular compound action potentials can be measured in unanesthetized, non-invasively prepared animals.

  16. The Use of a Hemostasis Introducer for Percutaneous Extraction of Bile Duct Stones

    PubMed Central

    Feisthammel, Juergen; Moche, Micheal; Mossner, Joachim; Hoffmeister, Albrecht

    2012-01-01

    Background Choledocholithiasis is defined as presence of at least one gallstone in the bile duct. Those bile duct stones (BDS) usually are extracted by ERCP. In case the bile duct is not accessible endoscopically (e.g. after major abdominal surgery), PTCD has to be performed. Extraction of the stones via PTCD has several risks as are hemorrhage, pancreatitis and injuries of the liver tissue. Methods We here report about our experience with a significant modification of this technique by use of a 13-french hemostasis introducer as a sheath to track the transhepatic access to the bile ducts in order to reduce time and risk. Results Three patients were treated by use of the reported modification. In all cases, the stones were successfully removable without complications. Conclusion We demonstrate that the use of a hemostasis introducer for percutaneous extraction of common bile duct stones seems to be promising in terms of shortening hospital stay and increasing patient safety. PMID:27785172

  17. The Use of a Hemostasis Introducer for Percutaneous Extraction of Bile Duct Stones.

    PubMed

    Feisthammel, Juergen; Moche, Micheal; Mossner, Joachim; Hoffmeister, Albrecht

    2012-02-01

    Choledocholithiasis is defined as presence of at least one gallstone in the bile duct. Those bile duct stones (BDS) usually are extracted by ERCP. In case the bile duct is not accessible endoscopically (e.g. after major abdominal surgery), PTCD has to be performed. Extraction of the stones via PTCD has several risks as are hemorrhage, pancreatitis and injuries of the liver tissue. We here report about our experience with a significant modification of this technique by use of a 13-french hemostasis introducer as a sheath to track the transhepatic access to the bile ducts in order to reduce time and risk. Three patients were treated by use of the reported modification. In all cases, the stones were successfully removable without complications. We demonstrate that the use of a hemostasis introducer for percutaneous extraction of common bile duct stones seems to be promising in terms of shortening hospital stay and increasing patient safety.

  18. Prevalence of Post-tonsillectomy Bleeding as Day-case Surgery with Combination Method; Cold Dissection Tonsillectomy and Bipolar Diathermy Hemostasis

    PubMed Central

    Faramarzi, Abolahassan; Heydari, Seyed Taghi

    2010-01-01

    Objective Post-tonsillectomy hemorrhage remains an important factor in determining the safety of performing tonsillectomy as a day case procedure. The aim of this study was to determine the safety of day case tonsillectomy by using combination method, cold dissection tonsillectomy and bipolar diathermy hemostasis. Methods A prospective randomized clinical study conducted on the patients who had undergone day case tonsillectomy (DCT). There were two groups (DCT and control group) each group consisting of 150 cases. Tonsillectomy was performed by using combination method; cold dissection and hemostasis was achieved by ligation of vessels with bipolar electerocautery. Findings We found 3 cases of post-tonsillectomy bleeding in DCT group and 4 cases in the control group. There was no statistically significant difference in the rate of post-operative hemorrhage between the two groups. Conclusion The findings suggest the safety of the combination of cold dissection tonsillectomy and bipolar diathermy hemostasis as day case tonsillectomy. PMID:23056702

  19. Successful Endoscopic Hemostasis Is a Protective Factor for Rebleeding and Mortality in Patients with Nonvariceal Upper Gastrointestinal Bleeding.

    PubMed

    Han, Yong Jae; Cha, Jae Myung; Park, Jae Hyun; Jeon, Jung Won; Shin, Hyun Phil; Joo, Kwang Ro; Lee, Joung Il

    2016-07-01

    Rebleeding and mortality rates remain high in patients with nonvariceal upper gastrointestinal bleeding. To identify clinical and endoscopic risk factors for rebleeding and mortality in patients with nonvariceal upper gastrointestinal bleeding. This study was performed in patients with nonvariceal upper gastrointestinal bleeding who underwent upper endoscopic procedures between July 2006 and February 2013. Clinical and endoscopic characteristics were compared among patients with and without rebleeding and mortality. Logistic regression analysis was performed to determine independent risk factors for rebleeding and mortality. After excluding 64 patients, data for 689 patients with nonvariceal upper gastrointestinal bleeding were analyzed. Peptic ulcer (62.6 %) was by far the most common source of bleeding. Endoscopic intervention was performed within 24 h in 99.0 % of patients, and successful endoscopic hemostasis was possible in 80.7 % of patients. The 30-day rebleeding rate was 13.1 % (n = 93). Unsuccessful endoscopic hemostasis was found to be the only independent risk factor for rebleeding (odds ratio 79.6; 95 % confidence interval 37.8-167.6; p = 0.000). The overall 30-day mortality rate was 3.2 % (n = 23). Unsuccessful endoscopic hemostasis (odds ratio 4.9; 95 % confidence interval 1.7-13.9; p = 0.003) was also associated with increased 30-day mortality in patients with nonvariceal upper gastrointestinal bleeding. Successful endoscopic hemostasis is an independent protective factor for both rebleeding and mortality in patients with nonvariceal upper gastrointestinal bleeding.

  20. Magnesium, hemostasis, and outcomes in patients with intracerebral hemorrhage.

    PubMed

    Liotta, Eric M; Prabhakaran, Shyam; Sangha, Rajbeer S; Bush, Robin A; Long, Alan E; Trevick, Stephen A; Potts, Matthew B; Jahromi, Babak S; Kim, Minjee; Manno, Edward M; Sorond, Farzaneh A; Naidech, Andrew M; Maas, Matthew B

    2017-08-22

    We tested the hypothesis that admission serum magnesium levels are associated with hematoma volume, hematoma growth, and functional outcomes in patients with intracerebral hemorrhage (ICH). Patients presenting with spontaneous ICH were enrolled in an observational cohort study that prospectively collected demographic, clinical, laboratory, radiographic, and outcome data. We performed univariate and adjusted multivariate analyses to assess for associations between serum magnesium levels and initial hematoma volume, final hematoma volume, and in-hospital hematoma growth as radiographic measures of hemostasis, and functional outcome measured by the modified Rankin Scale (mRS) at 3 months. We included 290 patients for analysis. Admission serum magnesium was 2.0 ± 0.3 mg/dL. Lower admission magnesium levels were associated with larger initial hematoma volumes on univariate ( p = 0.02), parsimoniously adjusted ( p = 0.002), and fully adjusted models ( p = 0.006), as well as greater hematoma growth ( p = 0.004, p = 0.005, and p = 0.008, respectively) and larger final hematoma volumes ( p = 0.02, p = 0.001, and p = 0.002, respectively). Lower admission magnesium level was associated with worse functional outcomes at 3 months (i.e., higher mRS; odds ratio 0.14, 95% confidence interval 0.03-0.64, p = 0.011) after adjustment for age, admission Glasgow Coma Scale score, initial hematoma volume, time from symptom onset to initial CT, and hematoma growth, with evidence that the effect of magnesium is mediated through hematoma growth. These data support the hypothesis that magnesium exerts a clinically meaningful influence on hemostasis in patients with ICH. © 2017 American Academy of Neurology.

  1. The effects of nanomaterials on blood coagulation in hemostasis and thrombosis.

    PubMed

    Simak, Jan; De Paoli, Silvia

    2017-09-01

    The blood coagulation balance in the organism is achieved by the interaction of the blood platelets (PLTs) with the plasma coagulation system (PCS) and the vascular endothelial cells. In healthy organism, these systems prevent thrombosis and, in events of vascular damage, enable blood clotting to stop bleeding. The dysregulation of hemostasis may cause serious thrombotic and/or hemorrhagic pathologies. Numerous engineered nanomaterials are being investigated for biomedical purposes and are unavoidably exposed to the blood. Also, nanomaterials may access vascular system after occupational, environmental, or other types of exposure. Thus, it is essential to evaluate the effects of engineered nanomaterials on hemostasis. This review focuses on investigations of nanomaterial interactions with the blood components involved in blood coagulation: the PCS and PLTs. Particular emphases include the pathophysiology of effects of nanomaterials on the PCS, including the kallikrein-kinin system, and on PLTs. Methods for investigating these interactions are briefly described, and a review of the most important studies on the interactions of nanomaterials with plasma coagulation and platelets is provided. WIREs Nanomed Nanobiotechnol 2017, 9:e1448. doi: 10.1002/wnan.1448 For further resources related to this article, please visit the WIREs website. © Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  2. A noninvasive method of examination of the hemostasis system.

    PubMed

    Kuznik, B I; Fine, I W; Kaminsky, A V

    2011-09-01

    We propose a noninvasive method of in vivo examination the hemostasis system based on speckle pattern analysis of coherent light scattering from the skin. We compared the results of measuring basic blood coagulation parameters by conventional invasive and noninvasive methods. A strict correlation was found between the results of measurement of soluble fibrin monomer complexes, international normalized ratio (INR), prothrombin index, and protein C content. The noninvasive method of examination of the hemostatic system enable rough evaluation of the intensity of the intravascular coagulation and correction of the dose of indirect anticoagulants maintaining desired values of INR or prothrombin index.

  3. Endoscopic hemostasis using endoclip in early gastrointestinal hemorrhage after gastric bypass surgery.

    PubMed

    Tang, Shou-Jiang; Rivas, Homero; Tang, Linda; Lara, Luis F; Sreenarasimhaiah, Jayaprakash; Rockey, Don C

    2007-09-01

    Roux-en-Y gastric bypass (RYGBP) is the most commonly performed bariatric operation in the USA. In the early postoperative stage, gastrointestinal (GI) bleeding is an infrequent but potentially serious complication that usually results from bleeding at the gastrojejunostomy staple-line. Observant management with transfusion for stable patients and surgical exploration for unstable patients is typically recommended for early GI bleeding. We hypothesized that use of endoclips, which do not cause thermal injury to the surrounding tissues (or anastomosis), may be preferable to thermal approaches which could cause tissue injury. We report 2 cases of early GI bleeding after RYGBP that were successfully managed with endoclip application to bleeding lesions. Emergent endoscopy was performed, and major stigmata such as active spurting vessel and adherent clot were noted at the gastrojejunostomy staple-lines. Endoscopic hemostasis using endoclips was readily applied to bleeding lesions at staple-lines. Primary hemostasis was achieved, and there was no recurrent bleeding or complication. We conclude that therapeutic endoscopy can be performed safely for early bleeding after RYGBP. In patients with early bleeding after RYGBP, use of endoclips is mechanistically preferable to other options.

  4. [The first experience with the concurrent effect of YAG-neodymium and YAG-erbium laser on experimental animal tissues and the possibility of its use in surgery].

    PubMed

    Roshal', L M; Gorbatova, N E; Livshits, Iu L; Parkhomenko, Iu G; Osiko, V V; Danileĭko, Iu K; Sidorin, A V; Tylaĭkova, T B; Ivanov, A D

    1991-08-01

    To guarantee the necessary rate of cutting live tissues with adequate hemostasis along the line of the incision, the authors studied isolated and joint effect of radiations of AIG-neodymium and AIG-erbium lasers on the tissues of laboratory animals. The possibility of accomplishing intraoperative hemostasis on the parenchymal organs was studied in experiments with AIG-neodymium laser. A good dissection effect in cutting various tissues was produced in the second series of experiments with AIG-erbium laser. The simultaneous action of AIG-neodymium and AIG-erbium beams converged at one point on the surface of the biological object was studied in the third series of experiments. It was found that the effect ensures a good dissection of tissues with sufficient hemostasis. The results of dynamic morphological studies are shown. The possibility of using the device in surgery is discussed.

  5. Platelets as Contractile Nanomachines for Targeting Drug Delivery in Hemostasis and Thrombosis

    DTIC Science & Technology

    2015-12-01

    capsules were suspended in platelet - rich plasma , which was subsequently exposed to 1 U/mL of thrombin, the capsules successfully targeted target...activated platelets . As thrombi in myocardial infarctions and strokes are platelet - rich , this is an ideal system to achieve high concentrations of...AWARD NUMBER: W81XWH-13-1-0495 TITLE: Platelets as Contractile Nanomachines for Targeting Drug Delivery in Hemostasis and Thrombosis PRINCIPAL

  6. Impact of a pneumatic tube system transport on hemostasis parameters measurement: the experiment of Cochin universitary hospital (AP-HP, Paris, France).

    PubMed

    Calmette, Leyla; Ibrahim, Firas; Gouin, Isabelle; Horellou, Marie-Hélène; Mazoyer, Élisabeth; Fontenay, Michaela; Flaujac, Claire

    2017-02-01

    Samples transported by pneumatic tube system are submitted to forces of acceleration and deceleration which can affect laboratory parameters. At Cochin hospital, majority of samples of hemostasis, except for platelets tests, are transported by pneumatic tube system. The objective of this study was to evaluate the impact of a pneumatic tube system (PTS) transport compared to hand-delivered transport on samples and to qualify Cochin hospital PTS according to requirements of standard ISO 15189. A bibliographical study was made and showed that pneumatic tube system particularly influences platelets tests. Four citrate tubes were collected in 5 healthy volunteers in the maternity: 2 tubes were transported by PTS and 2 others were hand-delivered to the laboratory. Five coagulation tests were analyzed: prothrombine time (PT), activated partial thromboplastin time (aPTT), factor (F) V, FVIII and platelet closure time with PFA-100TM collagen/epinephrine. For each volunteer, the results obtained by PTS and by hand-delivered transport were compared with formula usually used for biological analysis retake: 2.8 x standard deviation of reproductibility variation coefficient (SH GTA 01, COFRAC). This study did not show an impact of PTS on PT, aPTT, FV and FVIII. For PFA-100TM collagen/epinephrine, we noted an impact on 2/5 volunteers. These results, in agreement with the literature, led to the conclusion that Cochin hospital PTS is in compliance to transport samples for usual coagulation tests except platelet tests. This study allowed to issue French recommendations for PTS transport of hemostasis tubes qualification available on "Groupe français d'hémostase et thrombose" Web site.

  7. Prophylactic Transcatheter Arterial Embolization After Successful Endoscopic Hemostasis in the Management of Bleeding Duodenal Ulcer.

    PubMed

    Mille, Markus; Huber, Juliane; Wlasak, Rüdiger; Engelhardt, Thomas; Hillner, Yvette; Kriechling, Henri; Aschenbach, Rene; Ende, Katrin; Scharf, Jens-Gerd; Puls, Ralf; Stier, Albrecht

    2015-10-01

    The aim of this study was to demonstrate the new strategy of prophylactic transcatheter arterial embolization (TAE) of the gastroduodenal artery after endoscopic hemostasis of bleeding duodenal ulcers. TAE is a well-established method for the treatment of recurrent or refractory ulcer bleeding resistant to endoscopic intervention, which increasingly replaces surgical procedures. A new approach for improving outcome and reducing rebleeding episodes is the supplemental and prophylactic TAE after successful endoscopic hemostasis. This retrospective study included all patients (n=117) treated from 2008 to 2012 for duodenal ulcer bleeding. After initial endoscopic hemostasis, patients were assessed regarding their individual rebleeding risk. Patients with a low rebleeding risk (n=47) were conservatively treated, patients with a high risk for rebleeding (n=55) had prophylactic TAE of the gastroduodenal artery, and patients with endoscopically refractory ulcer bleeding received immediate TAE. The technical success of prophylactic TAE was 98% and the clinical success was 87% of cases. Rebleeding occurred in 11% of patients with prophylactic TAE and was successfully treated with repeated TAE or endoscopy. The major complication rate was 4%. Surgery was necessary in only 1 prophylactic TAE patient (0.9%) during the whole study period. Mortality associated with ulcer bleeding was 4% in patients with prophylactic TAE. Prophylactic TAE in patients with duodenal ulcers at high risk for rebleeding was feasible, effective at preventing the need for surgery, and had low major complication rates. Given these promising outcomes, prophylactic TAE should be further evaluated as a preventative therapy in high-risk patients.

  8. Molecular aspects in clinical hemostasis research at Karolinska Institutet.

    PubMed

    Blombäck, Margareta

    2010-05-21

    The development of hemostasis research at Karolinska Institutet is described, focusing first on the initial findings of the fibrinogen structure and the hereditary bleeding disorders, hemophilia A and von Willebrand's disease. Basic research has focused on new biomarkers for cardiovascular/thromboembolic disorders, such as myocardial infarction and stroke, including preeclampsia and diabetes, with studies on the importance of decreased fibrinolysis in these disorders. Since long, the structure of the fibrin network has been evaluated, and recently the influence of aspirin and new thrombin and factor Xa inhibitors has been investigated. Research on the contact pathway of coagulation has also started at the Unit. 2010 Elsevier Inc. All rights reserved.

  9. Relationship of pericardial fat with biomarkers of inflammation and hemostasis, and cardiovascular disease: The Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Ong, Kwok-Leung; Ding, Jingzhong; McClelland, Robyn L.; Cheung, Bernard M.Y.; Criqui, Michael H.; Barter, Philip J.; Rye, Kerry-Anne; Allison, Matthew A.

    2015-01-01

    Objective Pericardial fat may increase the risk of cardiovascular disease (CVD) by increasing circulating levels of inflammation and hemostasis biomarkers. We investigated the associations of pericardial fat with inflammation and hemostasis biomarkers, as well as incident CVD events, and whether there are any ethnic differences in these associations. Methods We analyzed results from 6415 participants from the Multi-Ethnic Study of Atherosclerosis who had measurements of pericardial fat volume and circulating levels of C-reactive protein (CRP), fibrinogen, interleukin (IL)-6, factor VIII, D-dimer and plasmin-antiplasmin complex (PAP), and had a mean follow-up period of 9.5 years. Incident CVD event was defined as any adjudicated CVD event. Results After adjusting for confounding factors, pericardial fat volume was positively associated with natural log (ln) of IL-6 levels, but inversely associated with ln D-dimer and ln PAP levels (β=0.067, −0.032, and −0.105 respectively, all P<0.05). Although a larger pericardial fat volume was associated with a higher risk of incident CVD, the association was attenuated to borderline significance after adjusting for traditional cardiovascular risk factors (P=0.050). There was a borderline significant ethnicity interaction (P=0.080), whereby the association between pericardial fat volume and incident CVD was significant in Hispanic Americans, even after further adjusting for biomarkers of inflammation and hemostasis (hazard ratio=1.31 per SD increase, 95% confidence interval 1.09-1.57, P=0.004). Conclusion Pericardial fat was associated with several inflammation and hemostasis biomarkers. The association of pericardial fat with incident CVD events was independent of these biomarkers only among Hispanic Americans. PMID:25682037

  10. Comparison of polyurethane with cyanoacrylate in hemostasis of vascular injury in guinea pigs.

    PubMed

    Kubrusly, Luiz Fernando; Formighieri, Marina Simões; Lago, José Vitor Martins; Graça, Yorgos Luiz Santos de Salles; Sobral, Ana Cristina Lira; Lago, Marianna Martins

    2015-01-01

    To evaluate the behavior of castor oil-derived polyurethane as a hemostatic agent and tissue response after abdominal aortic injury and to compare it with 2-octyl-cyanoacrylate. Twenty-four Guinea Pigs were randomly divided into three groups of eight animals (I, II, and III). The infrarenal abdominal aorta was dissected, clamped proximally and distally to the vascular puncture site. In group I (control), hemostasis was achieved with digital pressure; in group II (polyurethane) castor oil-derived polyurethane was applied, and in group III (cyanoacrylate), 2-octyl-cyanoacrylate was used. Group II was subdivided into IIA and IIB according to the time of preparation of the hemostatic agent. Mean blood loss in groups IIA, IIB and III was 0.002 grams (g), 0.008 g, and 0.170 g, with standard deviation of 0.005 g, 0.005 g, and 0.424 g, respectively (P=0.069). The drying time for cyanoacrylate averaged 81.5 seconds (s) (standard deviation: 51.5 seconds) and 126.1 s (standard deviation: 23.0 s) for polyurethane B (P=0.046). However, there was a trend (P=0.069) for cyanoacrylate to dry more slowly than polyurethane A (mean: 40.5 s; SD: 8.6 s). Furthermore, polyurethane A had a shorter drying time than polyurethane B (P=0.003), mean IIA of 40.5 s (standard deviation: 8.6 s). In group III, 100% of the animals had mild/severe fibrosis, while in group II only 12.5% showed this degree of fibrosis (P=0.001). Polyurethane derived from castor oil showed similar hemostatic behavior to octyl-2-cyanoacrylate. There was less perivascular tissue response with polyurethane when compared with cyanoacrylate.

  11. The changing face of hemostasis testing in modern laboratories: consolidation, automation, and beyond.

    PubMed

    Lippi, Giuseppe; Plebani, Mario; Favaloro, Emmanuel J

    2015-04-01

    The reality of laboratory diagnostics as a whole, and hemostasis testing in particular, is evolving under new paradigms of efficiency. The driving forces of health care and laboratory diagnostics in the third millennium are mainly represented by macro- and microeconomics. In a world with limited resources, shattered by an unprecedented economic crisis, laboratory diagnostics is undergoing a substantial reorganization, with emergence of new models under the imperative of terms, such as bedside testing, consolidation, and networking. The paradigms under which these changes are being developed include a variety of environment, preanalytical, technological, professional, and health-care aspects. The maintenance of continued quality is indeed the major challenge to be faced in the foreseeable future. In fact, some challenges prepotently emerge during a consolidation process, which basically involve delayed testing, centrifugation, transportation, and stability of the specimens, as well as the potential mismatch of sample matrix. This article is aimed to provide an overview of the current economic scenario of laboratory diagnostics and discuss the changing face of hemostasis testing in modern laboratories, providing a synthetic overview about potential drawbacks of actualized solutions. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  12. The Use of Acceleration to Code for Animal Behaviours; A Case Study in Free-Ranging Eurasian Beavers Castor fiber

    PubMed Central

    Graf, Patricia M.; Wilson, Rory P.; Qasem, Lama; Hackländer, Klaus; Rosell, Frank

    2015-01-01

    Recent technological innovations have led to the development of miniature, accelerometer-containing electronic loggers which can be attached to free-living animals. Accelerometers provide information on both body posture and dynamism which can be used as descriptors to define behaviour. We deployed tri-axial accelerometer loggers on 12 free-ranging Eurasian beavers Castor fiber in the county of Telemark, Norway, and on four captive beavers (two Eurasian beavers and two North American beavers C. canadensis) to corroborate acceleration signals with observed behaviours. By using random forests for classifying behavioural patterns of beavers from accelerometry data, we were able to distinguish seven behaviours; standing, walking, swimming, feeding, grooming, diving and sleeping. We show how to apply the use of acceleration to determine behaviour, and emphasise the ease with which this non-invasive method can be implemented. Furthermore, we discuss the strengths and weaknesses of this, and the implementation of accelerometry on animals, illustrating limitations, suggestions and solutions. Ultimately, this approach may also serve as a template facilitating studies on other animals with similar locomotor modes and deliver new insights into hitherto unknown aspects of behavioural ecology. PMID:26317623

  13. The Use of ExoSeal Vascular Closure Device for Direct Antegrade Superficial Femoral Artery Puncture Site Hemostasis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rimon, Uri, E-mail: rimonu@sheba.health.gov.il; Khaitovich, Boris, E-mail: borislena@012.net.il; Yakubovich, Dmitry, E-mail: Dmitry.Yakubovitch@sheba.health.gov.il

    2015-06-15

    PurposeThis study was designed to assess the efficacy and safety of the ExoSeal vascular closure device (VCD) to achieve hemostasis in antegrade access of the superficial femoral artery (SFA).MethodsWe retrospectively reviewed the outcome of ExoSeal VCD used for hemostasis in 110 accesses to the SFA in 93 patients between July 2011 and July 2013. All patients had patent proximal SFA based on computer tomography angiography or ultrasound duplex. Arterial calcifications at puncture site were graded using fluoroscopy. The SFA was accessed in an antegrade fashion with ultrasound or fluoroscopic guidance. In all patients, 5–7F vascular sheaths were used. The ExoSealmore » VCD was applied to achieve hemostasis at the end of the procedure. All patients were clinically examined and had ultrasound duplex exam for any puncture site complications during the 24 h postprocedure.ResultsIn all procedures, the ExoSeal was applied successfully. We did not encounter any device-related technical failure. There were four major complications in four patients (3.6 %): three pseudoaneurysms, which were treated with direct thrombin injection, and one hematoma, which necessitated transfusion of two blood units. All patients with complications were treated with anticoagulation preprocedure or received thrombolytic therapy.ConclusionsThe ExoSeal VCD can be safely used for antegrade puncture of the SFA, with a high procedural success rate (100 %) and a low rate of access site complications (3.6 %)« less

  14. An animal model of co-existing sarcopenia and osteoporotic fracture in senescence accelerated mouse prone 8 (SAMP8).

    PubMed

    Zhang, Ning; Chow, Simon Kwoon Ho; Leung, Kwok Sui; Lee, Ho Hin; Cheung, Wing Hoi

    2017-10-15

    Sarcopenia and osteoporotic fracture are common aging-related musculoskeletal problems. Recent evidences report that osteoporotic fracture patients showed high prevalence of sarcopenia; however, current clinical practice basically does not consider sarcopenia in the treatment or rehabilitation of osteoporotic fracture. There is almost no report studying the relationship of the co-existing of sarcopenia and osteoporotic fracture healing. In this study, we validated aged senescence accelerated mouse prone 8 (SAMP8) and senescence accelerated mouse resistant 1 (SAMR1) as animal models of senile osteoporosis with/without sarcopenia. Bone mineral density (BMD) at the 5th lumbar and muscle testing of the two animal strains were measured to confirm the status of osteoporosis and sarcopenia, respectively. Closed fracture was created on the right femur of 8-month-old animals. Radiographs were taken weekly post-fracture. MicroCT and histology of the fractured femur were performed at week 2, 4 and 6 post-fracture, while mechanical test of both femora at week 4 and 6 post-fracture. Results showed that the callus of SAMR1 was significantly larger at week 2 but smaller at week 6 post-fracture than SAMP8. Mechanical properties were significantly better at week 4 post-fracture in SAMR1 than SAMP8, indicating osteoporotic fracture healing was delayed in sarcopenic SAMP8. This study validated an animal model of co-existing sarcopenia and osteoporotic fracture, where a delayed fracture healing might be resulted in the presence of sarcopenia. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Platelets in thrombosis and hemostasis: old topic with new mechanisms.

    PubMed

    Wang, Yiming; Andrews, Marc; Yang, Yan; Lang, Sean; Jin, Joseph W; Cameron-Vendrig, Alison; Zhu, Guangheng; Reheman, Adili; Ni, Heyu

    2012-12-01

    Platelets are small anucleate cells generated from megakaryocytes in the bone marrow. After being released into the circulation, platelets play key roles in the surveillance of vascular injury, and can quickly adhere and aggregate at the site of injury, which are critical events for vascular repair and hemostasis. However, the same biological processes of platelet adhesion and aggregation may also cause thrombotic disorders. The formation of a platelet plug at sites of atherosclerotic lesion rupture is the most common mechanism leading to myocardial or cerebral infarction. Platelet-related deep vein thrombosis is also one of the leading causes of mortality worldwide. The contribution of several platelet receptors and their ligands has been highlighted in these processes. In platelet adhesion, particularly at high shear stress, GPIbα-von Willebrand factor (VWF) interaction may initiate this event, which is followed by GPVI signalling and firm platelet adhesion mediated by members of the integrin family, such as β3 (αIIbβ3) and β1 (α2β1, α5β1) integrins. In platelet aggregation, although GPIbα-VWF, P selectin-sulfatides, and other molecules, may be involved, the process is mainly mediated by β3 (αIIbβ3) integrin and its ligands, such as fibrinogen and VWF. It is intriguing that platelet adhesion and aggregation still occur in mice lacking both fibrinogen and VWF, suggesting that other unforeseen molecule(s) may also be important in these processes. Identification and characterization of these molecules will enrich our knowledge in the basic science of hemostasis and thrombosis, and may lead to the development of new therapies against bleeding disorders and thrombotic diseases.

  16. Percutaneous Portal Vein Access and Transhepatic Tract Hemostasis

    PubMed Central

    Saad, Wael E. A.; Madoff, David C.

    2012-01-01

    Percutaneous portal vein interventions require minimally invasive access to the portal venous system. Common approaches to the portal vein include transjugular hepatic vein to portal vein access and direct transhepatic portal vein access. A major concern of the transhepatic route is the risk of postprocedural bleeding, which is increased when patients are anticoagulated or receiving pharmaceutical thrombolytic therapy. Thus percutaneous portal vein access and subsequent closure are important technical parts of percutaneous portal vein procedures. At present, various techniques have been used for either portal access or subsequent transhepatic tract closure and hemostasis. Regardless of the method used, meticulous technique is required to achieve the overall safety and effectiveness of portal venous procedures. This article reviews the various techniques of percutaneous transhepatic portal vein access and the various closure and hemostatic methods used to reduce the risk of postprocedural bleeding. PMID:23729976

  17. [Pharmacological study on hemostasis, analgesic and anti inflammation effects of the alcohol extract of Hibiscus tiliaceus].

    PubMed

    Qiu, Fen; Tian, Hui; Zhang, Zhi; Yuan, Xian-Ling; Tan, Yuan-Feng; Ning, Xiao-Qing

    2013-10-01

    To study the effects of hemostasis, analgesic and anti inflammation of the alcohol extract of Hibiscus tiliaceus and offer pharmacological and experimental basis for its safe and effective use in clinic. The effects of hemostasist were observed with tail breaking method, capillary tube method and slide method; Hot board and body distortion induced by acetic acid methods were applied in mice analgesia experiment, the mice model of acute auricle swelling induced by dmi ethylbenzene and capillary permeability induced by acetic acid were applied to observe the anti inflammatory effects. The alcohol extract of Hibiscus tiliaceus could significantly reduce the bleeding time and the clotting time, delay the plant reaction time and reduce the writhing times of the mice, and it also had effect on inhibiting swelling of mice ear and the permeability of the capillary. These results suggest that the alcohol extract of Hibiscus tiliaceus has the effects of hemostasis, analgesic and anti inflammation.

  18. Comparison of polyurethane with cyanoacrylate in hemostasis of vascular injury in guinea pigs

    PubMed Central

    Kubrusly, Luiz Fernando; Formighieri, Marina Simões; Lago, José Vitor Martins; Graça, Yorgos Luiz Santos de Salles; Sobral, Ana Cristina Lira; Lago, Marianna Martins

    2015-01-01

    Objective To evaluate the behavior of castor oil-derived polyurethane as a hemostatic agent and tissue response after abdominal aortic injury and to compare it with 2-octyl-cyanoacrylate. Methods Twenty-four Guinea Pigs were randomly divided into three groups of eight animals (I, II, and III). The infrarenal abdominal aorta was dissected, clamped proximally and distally to the vascular puncture site. In group I (control), hemostasis was achieved with digital pressure; in group II (polyurethane) castor oil-derived polyurethane was applied, and in group III (cyanoacrylate), 2-octyl-cyanoacrylate was used. Group II was subdivided into IIA and IIB according to the time of preparation of the hemostatic agent. Results Mean blood loss in groups IIA, IIB and III was 0.002 grams (g), 0.008 g, and 0.170 g, with standard deviation of 0.005 g, 0.005 g, and 0.424 g, respectively (P=0.069). The drying time for cyanoacrylate averaged 81.5 seconds (s) (standard deviation: 51.5 seconds) and 126.1 s (standard deviation: 23.0 s) for polyurethane B (P=0.046). However, there was a trend (P=0.069) for cyanoacrylate to dry more slowly than polyurethane A (mean: 40.5 s; SD: 8.6 s). Furthermore, polyurethane A had a shorter drying time than polyurethane B (P=0.003), mean IIA of 40.5 s (standard deviation: 8.6 s). In group III, 100% of the animals had mild/severe fibrosis, while in group II only 12.5% showed this degree of fibrosis (P=0.001). Conclusion Polyurethane derived from castor oil showed similar hemostatic behavior to octyl-2-cyanoacrylate. There was less perivascular tissue response with polyurethane when compared with cyanoacrylate. PMID:25859876

  19. The role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding

    PubMed Central

    Schatz, Frederick; Guzeloglu-Kayisli, Ozlem; Arlier, Sefa; Kayisli, Umit A.; Lockwood, Charles J.

    2016-01-01

    BACKGROUND Human pregnancy requires robust hemostasis to prevent hemorrhage during extravillous trophoblast (EVT) invasion of the decidualized endometrium, modification of spiral arteries and post-partum processes. However, decidual hemorrhage (abruption) can occur throughout pregnancy from poorly transformed spiral arteries, causing fetal death or spontaneous preterm birth (PTB), or it can promote the aberrant placentation observed in intrauterine growth restriction (IUGR) and pre-eclampsia; all leading causes of perinatal or maternal morbidity and mortality. In non-fertile cycles, the decidua undergoes controlled menstrual bleeding. Abnormal uterine bleeding (AUB) accompanying progestin-only, long-acting, reversible contraception (pLARC) accounts for most discontinuations of these safe and highly effective agents, thereby contributing to unwanted pregnancies and abortion. The aim of this study was to investigate the role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding. METHODS We conducted a critical review of the literature arising from PubMed searches up to December 2015, regarding in situ and in vitro expression and regulation of several specific proteins involved in uterine hemostasis in decidua and cycling endometrium. In addition, we discussed clinical and molecular mechanisms associated with pLARC-induced AUB and pregnancy complications with abruptions, chorioamnionitis or pre-eclampsia. RESULTS Progestin-induced decidualization of estradiol-primed human endometrial stromal cells (HESCs) increases in vivo and in vitro expression of tissue factor (TF) and type-1 plasminogen activator inhibitor (PAI-1) while inhibiting plasminogen activators (PAs), matrix metalloproteinases (MMPs), and the vasoconstrictor, endothelin-1 (ET-1). These changes in decidual cell-derived regulators of hemostasis, fibrinolysis, extracellular matrix (ECM) turnover, and vascular tone prevent hemorrhage

  20. A novel suction/coagulation integrated probe for achieving better hemostasis: development and clinical use.

    PubMed

    Takahashi, Hidekazu; Haraguchi, Naotsugu; Nishimura, Junichi; Hata, Taishi; Matsuda, Chu; Yamamoto, Hirofumi; Mizushima, Tsunekazu; Mori, Masaki; Doki, Yuichiro; Nakajima, Kiyokazu

    2018-06-01

    Modern electrosurgical tools have a specific coagulation mode called "soft coagulation". However, soft coagulation has not been widely accepted for surgical operations. To optimize the soft coagulation environment, we developed a novel suction device integrated with an electrosurgical probe, called the "Suction ball coagulator" (SBC). In this study, we aimed to optimize the SBC design with a prototyping process involving a bench test and preclinical study; then, we aimed to demonstrate the feasibility, safety, and potential effectiveness of the SBC for laparoscopic surgery in clinical settings. SBC prototyping was performed with a bench test. Device optimization was performed in a preclinical study with a domestic swine bleeding model. Then, SBC was tested in a clinical setting during 17 clinical laparoscopic colorectal surgeries. In the bench tests, two tip hole sizes and patterns showed a good suction capacity. The preclinical study indicated the best tip shape for accuracy. In clinical use, no device-related adverse event was observed. Moreover, the SBC was feasible for prompt hemostasis and blunt dissections. In addition, SBC could evacuate vapors generated by tissue ablation using electroprobe during laparoscopic surgery. We successfully developed a novel, integrated suction/coagulation probe for hemostasis and commercialized it.

  1. Effectiveness of Accelerator and Inoculum in Fermentation of Goat’s Rumen Contents as Animal Feed Ingredients

    NASA Astrophysics Data System (ADS)

    Bakrie, B.; Sente, U.; Mayasari, K.; Syah, R. F.

    2018-02-01

    The goat’s rumen contents is slaughterhouse waste that has potential to be used as animal feed, but it has to be first processed into silage. This study aims to determine the type of accelerator and to investigate whether the addition of inoculum was required during the fermentation process. The research was conducted using a Completely Randomized Factorial Design, consisting of 2 treatment factors and 6 replications. The treatment factors were: a) Accelerator (rice bran or cassava pomade/onggok); b) Inoculum Lactobacillus plantarum (with or without using inoculant). Results showed that there was an increase in crude protein (CP) content with the use of rice bran at after fermentation compared to before fermentation. The CP contents with the use of onggok almost the same at after and before fermentation. Increase in the content of crude fiber (CF) after fermentation was both for using rice bran or onggok. However, the content of CF using onggok was much higher than with rice bran. There was no significant effect for both types of accelerators used in CP and CF contents at after fermentation with or without the addition of Lactobacillus plantarum as the inoculant. It can be concluded that for the fermentation of goat’s rumen contents it is better to use rice bran rather than onggok as the accelerator and inoculant is not required during the fermentationprocess.

  2. The assessment of the influence of the method for obtaining hemostasis on the occurrence of postoperative complications after thyroid surgery.

    PubMed

    Grajek, Zbysław W; Dadan, Jacek; Ładny, Jerzy R; Opolski, Marcin

    2015-01-01

    The need to obtain successful surgical hemostasis had a significant impact on the development of electrosurgery. Innovative technical solutions necessitate the continuous training of surgeons in the use of more modern technologies. The diversity of solutions is also associated with the need to adapt the methods for obtaining hemostasis to the type of operation. Each time, the introduction of new technologies requires a critical evaluation of the results of surgical treatment. The most important measure of quality in thyroid surgery is the presence of chronic complications, such as the recurrent laryngeal nerve palsy and parathyroid insufficiency. Transient disorders also have a significant impact on the patient's comfort and quality of life. The report is preliminary in nature and it requires further investigation. The aim of the study was to evaluate the effect of three methods for obtaining hemostasis on the occurrence of hypoparathyroidism, recurrent laryngeal nerve palsy, bleeding and the surgical site infection after thyroid surgery. A retrospective analysis included patients who underwent thyroidectomy (n=654). Three methods of hemostasis were used. The first group (n=339) had blood vessels tied off. In the second (n=192) bipolar electrocoagulation was used and in the third one (n=123) bipolar electrocoagulation with integrated cutting mechanism. The transient hypoparathyroidism was found in 1.4% patients in the first group, 8.3% in the second and 27.6% in the third one. Chronic hypoparathyroidism was found in 0.29% in the first group, 0% in the second group and 2.4% in the third group. Significantly statistical differences were found in the incidence of transient hypoparathyroidism. Significant statistical differences were found in incidences of transient hypoparthyroidism in the group where bipolar electrosurgery was used.

  3. Hemostasis in tubeless PNL: point of technique.

    PubMed

    Aron, Monish; Goel, Rajiv; Kesarwani, Pawan K; Gupta, Narmada P

    2004-01-01

    Tubeless PNL (percutaneous nephrolithotomy), in a highly selected group of patients, is a modification aimed at reducing the morbidity of PNL. We present a simple technique of achieving tract hemostasis as an adjunct to the safe performance of a tubeless PNL. Charts of 40 consecutive patients who underwent tubeless PNL at our center were reviewed. In the latter 20 consecutive patients, diathermy coagulation of the intrarenal bleeders and tract was done and these patients were compared with the earlier 20 patients in whom fulguration was not done. Drop in hemoglobin, postoperative analgesic requirement, operating time, length of hospitalization and postoperative complications were compared. No statistical difference was found between the operative times and drop in hemoglobin for both the groups. The length of hospitalization and postoperative analgesic requirement were significantly less in the fulguration group. No significant complications were noted in either of the two groups. Fulguration of visible intrarenal and tract bleeders is a simple, safe and effective hemostatic adjunct in patients undergoing tubeless PNL. copyright 2004 S. Karger AG, Basel

  4. The role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding.

    PubMed

    Schatz, Frederick; Guzeloglu-Kayisli, Ozlem; Arlier, Sefa; Kayisli, Umit A; Lockwood, Charles J

    2016-06-01

    Human pregnancy requires robust hemostasis to prevent hemorrhage during extravillous trophoblast (EVT) invasion of the decidualized endometrium, modification of spiral arteries and post-partum processes. However, decidual hemorrhage (abruption) can occur throughout pregnancy from poorly transformed spiral arteries, causing fetal death or spontaneous preterm birth (PTB), or it can promote the aberrant placentation observed in intrauterine growth restriction (IUGR) and pre-eclampsia; all leading causes of perinatal or maternal morbidity and mortality. In non-fertile cycles, the decidua undergoes controlled menstrual bleeding. Abnormal uterine bleeding (AUB) accompanying progestin-only, long-acting, reversible contraception (pLARC) accounts for most discontinuations of these safe and highly effective agents, thereby contributing to unwanted pregnancies and abortion. The aim of this study was to investigate the role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding. We conducted a critical review of the literature arising from PubMed searches up to December 2015, regarding in situ and in vitro expression and regulation of several specific proteins involved in uterine hemostasis in decidua and cycling endometrium. In addition, we discussed clinical and molecular mechanisms associated with pLARC-induced AUB and pregnancy complications with abruptions, chorioamnionitis or pre-eclampsia. Progestin-induced decidualization of estradiol-primed human endometrial stromal cells (HESCs) increases in vivo and in vitro expression of tissue factor (TF) and type-1 plasminogen activator inhibitor (PAI-1) while inhibiting plasminogen activators (PAs), matrix metalloproteinases (MMPs), and the vasoconstrictor, endothelin-1 (ET-1). These changes in decidual cell-derived regulators of hemostasis, fibrinolysis, extracellular matrix (ECM) turnover, and vascular tone prevent hemorrhage during EVT invasion and

  5. Doppler endoscopic probe as a guide to risk stratification and definitive hemostasis of peptic ulcer bleeding.

    PubMed

    Jensen, Dennis M; Ohning, Gordon V; Kovacs, Thomas O G; Ghassemi, Kevin A; Jutabha, Rome; Dulai, Gareth S; Machicado, Gustavo A

    2016-01-01

    For more than 4 decades endoscopists have relied on ulcer stigmata for risk stratification and as a guide to hemostasis. None used arterial blood flow underneath stigmata to predict outcomes. For patients with severe peptic ulcer bleeding (PUB), we used a Doppler endoscopic probe (DEP) for (1) detection of blood flow underlying stigmata of recent hemorrhage (SRH), (2) quantitating rates of residual arterial blood flow under SRH after visually directed standard endoscopic treatment, and (3) comparing risks of rebleeding and actual 30-day rebleed rates for spurting arterial bleeding (Forrest [F] IA) and oozing bleeding (F IB). Prospective cohort study of 163 consecutive patients with severe PUB and different SRH. All blood flow detected by the DEP was arterial. Detection rates were 87.4% in major SRH-spurting arterial bleeding (F IA), non-bleeding visible vessel (F IIA), clot (F IIB)-and were significantly lower at 42.3% (P < .0001) for an intermediate group of oozing bleeding (F IB) or flat spot (F IIC). For spurting bleeding (F IA) versus oozing (F IB), baseline DEP arterial flow was 100% versus 46.7%, residual blood flow detected after endoscopic hemostasis was 35.7% versus 0%, and 30-day rebleed rates were 28.6% versus 0% (all P < .05). (1) For major SRH versus oozing or spot, the arterial blood flow detection rate by the DEP was significantly higher, indicating a higher rebleed risk. (2) Before and after endoscopic treatment, spurting (F IA) PUB had significantly higher rates of blood flow detection than oozing (F IB) PUB and a significantly higher 30-day rebleed rate. (3) The DEP is recommended as a new endoscopic guide with SRH to improve risk stratification and potentially definitive hemostasis for PUB. Published by Elsevier Inc.

  6. Doppler Endoscopic Probe as a Guide to Risk Stratification and Definitive Hemostasis of Peptic Ulcer Bleeding

    PubMed Central

    Jensen, Dennis M.; Ohning, Gordon V.; Kovacs, Thomas OG; Ghassemi, Kevin A.; Jutabha, Rome; Dulai, Gareth S.; Machicado, Gustavo A.

    2015-01-01

    Background and Aims For more than 4 decades endoscopists have relied on ulcer stigmata for risk stratification and as a guide to hemostasis. None used arterial blood flow underneath stigmata to predict outcomes. For patients with severe peptic ulcer bleeding (PUBs), we used Doppler endoscopic probe (DEP) for: 1. detection of blood flow underlying stigmata of recent hemorrhage (SRH), 2. quantitating rates of residual arterial blood flow under SRH after visually directed standard endoscopic treatment, and 3. comparing risks of rebleeding and actual 30 day rebleed rates for spurting arterial bleeding (Forrest – FIA) and oozing bleeding (FIB). Methods Prospective cohort study of 163 consecutive patients with severe PUBs and different SRH. Results All blood flow detected by DEP was arterial. Detection rates were 87.4% in major SRH - spurting arterial bleeding (FIA), non bleeding visible vessel (FIIA), clot (FIIB) - and significantly lower at 42.3% (p<0.0001) for intermediate group of oozing bleeding (FIB) or flat spot (FIIC). For spurting bleeding (FIA) vs. oozing (FIB), baseline DEP arterial flow was 100% vs. 46.7%; residual blood flow detected after endoscopic hemostasis was 35.7% vs. 0%; and 30 day rebleed rates were 28.6% vs. 0% (all p<0.05). Conclusions 1. For major SRH vs. oozing or spot, the arterial blood flow detection rates by DEP was significantly higher, indicating a higher rebleed risk. 2. Before and after endoscopic treatment, spurting FIA PUB’s had significantly higher rates of blood flow detection than oozing FIB PUB’s and a significantly higher 30 rebleed rate. 3. DEP is recommended as a new endoscopic guide with SRH to improve risk stratification and potentially definitive hemostasis for PUBs. PMID:26318834

  7. Compare Complication of Classic versus Patent Hemostasis in Transradial Coronary Angiography

    PubMed Central

    Roghani, Farshad; Tajik, Mohammad Nasim; Khosravi, Alireza

    2017-01-01

    Background: Coronary artery disease (CAD) is multifactorial disease, in which thrombotic occlusion and calcification occur usually. New strategies have been made for diagnosis and treatment of CAD, such as transradial catheterization. Hemostasis could be done in two approaches: traditional and patent. Our aim is to find the best approach with lowest complication. Materials and Methods: In a comparative study, 120 patients were recruited and divided randomly into two subgroups, including traditional group (60 patients; 24 females, 36 males; mean age: 64.35 ± 10.56 years) and patent group (60 patients; 28 females, 32 males; mean age: 60.15 ± 8.92 years). All demographic data including age, gender, body mass index, and CAD-related risk factors (smoking, diabetes, hypertension) and technical data including the number of catheters, procedure duration, and hemostatic compression time and clinical outcomes (radial artery occlusion [RAO], hematoma, bleeding) were collected. Data were analyzed by SPSS version 16. Results: Our findings revealed that the incidence of RAO was significantly lower in patent groups compared with traditional group (P = 0.041). Furthermore, the difference incidence of RAO was higher in early occlusion compare with late one (P = 0.041). Moreover, there were significant relationship between some factors in patients of traditional group with occlusion (gender [P = 0.038], age [P = 0.031], diabetes mellitus [P = 0.043], hemostatic compression time [P = 0.036]) as well as in patent group (age [P = 0.009], hypertension [P = 0.035]). Conclusion: Our findings showed that RAO, especially type early is significantly lower in patent method compared classic method; and patent hemostasis is the safest method and good alternative for classical method. PMID:29387670

  8. Compare Complication of Classic versus Patent Hemostasis in Transradial Coronary Angiography.

    PubMed

    Roghani, Farshad; Tajik, Mohammad Nasim; Khosravi, Alireza

    2017-01-01

    Coronary artery disease (CAD) is multifactorial disease, in which thrombotic occlusion and calcification occur usually. New strategies have been made for diagnosis and treatment of CAD, such as transradial catheterization. Hemostasis could be done in two approaches: traditional and patent. Our aim is to find the best approach with lowest complication. In a comparative study, 120 patients were recruited and divided randomly into two subgroups, including traditional group (60 patients; 24 females, 36 males; mean age: 64.35 ± 10.56 years) and patent group (60 patients; 28 females, 32 males; mean age: 60.15 ± 8.92 years). All demographic data including age, gender, body mass index, and CAD-related risk factors (smoking, diabetes, hypertension) and technical data including the number of catheters, procedure duration, and hemostatic compression time and clinical outcomes (radial artery occlusion [RAO], hematoma, bleeding) were collected. Data were analyzed by SPSS version 16. Our findings revealed that the incidence of RAO was significantly lower in patent groups compared with traditional group ( P = 0.041). Furthermore, the difference incidence of RAO was higher in early occlusion compare with late one ( P = 0.041). Moreover, there were significant relationship between some factors in patients of traditional group with occlusion (gender [ P = 0.038], age [ P = 0.031], diabetes mellitus [ P = 0.043], hemostatic compression time [ P = 0.036]) as well as in patent group (age [ P = 0.009], hypertension [ P = 0.035]). Our findings showed that RAO, especially type early is significantly lower in patent method compared classic method; and patent hemostasis is the safest method and good alternative for classical method.

  9. Inflammation and hemostasis biomarkers for predicting stroke in postmenopausal women: The Women’s Health Initiative Observational Study

    PubMed Central

    Kaplan, Robert C; McGinn, Aileen P; Baird, Alison E; Hendrix, Susan L; Kooperberg, Charles; Lynch, John; Rosenbaum, Daniel M; Johnson, Karen C; Strickler, Howard D; Wassertheil-Smoller, Sylvia

    2009-01-01

    Background Inflammatory and hemostasis-related biomarkers may identify women at risk of stroke. Methods Hormones and Biomarkers Predicting Stroke is a study of ischemic stroke among postmenopausal women participating in the Women’s Health Initiative Observational Study (n = 972 case-control pairs). A Biomarker Risk Score was derived from levels of seven inflammatory and hemostasis-related biomarkers that appeared individually to predict risk of ischemic stroke: C-reactive protein, interleukin-6, tissue plasminogen activator, D-dimer, white blood cell count, neopterin, and homocysteine. The c index was used to evaluate discrimination. Results Of all the individual biomarkers examined, C-reactive protein emerged as the only independent single predictor of ischemic stroke (adjusted odds ratio comparing Q4 versus Q1 = 1.64, 95% confidence interval: 1.15–2.32, p = 0.01) after adjustment for other biomarkers and standard stroke risk factors. The Biomarker Risk Score identified a gradient of increasing stroke risk with a greater number of elevated inflammatory/hemostasis biomarkers, and improved the c index significantly compared with standard stroke risk factors (p = 0.02). Among the subset of individuals who met current criteria for “high risk” levels of C-reactive protein (> 3.0 mg/L), the Biomarker Risk Score defined an approximately two-fold gradient of risk. We found no evidence for a relationship between stroke and levels of E-selectin, fibrinogen, tumor necrosis factor-alpha, vascular cell adhesion molecule-1, prothrombin fragment 1+2, Factor VIIC, or plasminogen activator inhibitor-1 antigen (p >0.15). Discussion The findings support the further exploration of multiple-biomarker panels to develop approaches for stratifying an individual’s risk of stroke. PMID:18984425

  10. Prognostic Performance Evaluation of the International Society on Thrombosis and Hemostasis and the Korean Society on Thrombosis and Hemostasis Scores in the Early Phase of Trauma.

    PubMed

    Kim, Hong Sug; Lee, Dong Hun; Lee, Byung Kook; Cho, Yong Soo

    2018-01-15

    Disseminated intravascular coagulation (DIC) contributes to poor outcome in the early phase of trauma. We aimed to analyze and compare the prognostic performances of the International Society on Thrombosis and Hemostasis (ISTH) and the Korean Society on Thrombosis and Hemostasis (KSTH) scores in the early phase of trauma. Receiver operating characteristics analysis was used to examine the prognostic performance of both scores, and multivariate analysis was used to estimate the prognostic impact of the ISTH and KSTH scores in the early phase of trauma. The primary outcome was 24-hour mortality and the secondary outcome was massive transfusion. Of 1,229 patients included in the study, the 24-hour mortality rate was 7.6% (n = 93), and 8.1% (n = 99) of patients who received massive transfusions. The area under the curves (AUCs) of the KSTH and ISTH scores for 24-hour mortality were 0.784 (95% confidence interval [CI], 0.760-0.807) and 0.744 (95% CI, 0.718-0.768), respectively. The AUC of KSTH and ISTH scores for massive transfusion were 0.758 (95% CI, 0.734-0.782) and 0.646 (95% CI, 0.619-0.673), respectively. The AUCs of the KSTH score was significantly different from those of the ISTH score. Overt DIC according to KSTH criteria only, was independently associated with 24-hour mortality (odds ratio [OR], 2.630; 95% CI, 1.456-4.752). Only the KSTH score was independently associated with massive transfusion (OR, 1.563; 95% CI, 1.182-2.068). The KSTH score demonstrates a better prognostic performance for outcomes than the ISTH score in the early phase of trauma. © 2018 The Korean Academy of Medical Sciences.

  11. Normal levels of anticoagulant heparan sulfate are not essential for normal hemostasis

    PubMed Central

    HajMohammadi, Sassan; Enjyoji, Keiichi; Princivalle, Marc; Christi, Patricia; Lech, Miroslav; Beeler, David; Rayburn, Helen; Schwartz, John J.; Barzegar, Samad; de Agostini, Ariane I.; Post, Mark J.; Rosenberg, Robert D.; Shworak, Nicholas W.

    2003-01-01

    Endothelial cell production of anticoagulant heparan sulfate (HSact) is controlled by the Hs3st1 gene, which encodes the rate-limiting enzyme heparan sulfate 3-O-sulfotransferase-1 (3-OST-1). In vitro, HSact dramatically enhances the neutralization of coagulation proteases by antithrombin. The in vivo role of HSact was evaluated by generating Hs3st1–/– knockout mice. Hs3st1–/– animals were devoid of 3-OST-1 enzyme activity in plasma and tissue extracts. Nulls showed dramatic reductions in tissue levels of HSact but maintained wild-type levels of tissue fibrin accumulation under both normoxic and hypoxic conditions. Given that vascular HSact predominantly occurs in the subendothelial matrix, mice were subjected to a carotid artery injury assay in which ferric chloride administration induces de-endothelialization and occlusive thrombosis. Hs3st1–/– and Hs3st1+/+ mice yielded indistinguishable occlusion times and comparable levels of thrombin•antithrombin complexes. Thus, Hs3st1–/– mice did not show an obvious procoagulant phenotype. Instead, Hs3st1–/– mice exhibited genetic background–specific lethality and intrauterine growth retardation, without evidence of a gross coagulopathy. Our results demonstrate that the 3-OST-1 enzyme produces the majority of tissue HSact. Surprisingly, this bulk of HSact is not essential for normal hemostasis in mice. Instead, 3-OST-1–deficient mice exhibited unanticipated phenotypes suggesting that HSact or additional 3-OST-1–derived structures may serve alternate biologic roles. PMID:12671048

  12. Pulsed ultrasounds accelerate healing of rib fractures in an experimental animal model: an effective new thoracic therapy?

    PubMed

    Santana-Rodríguez, Norberto; Clavo, Bernardino; Fernández-Pérez, Leandro; Rivero, José C; Travieso, María M; Fiuza, María D; Villar, Jesús; García-Castellano, José M; Hernández-Pérez, Octavio; Déniz, Antonio

    2011-05-01

    Rib fractures are a frequent traumatic injury associated with a relatively high morbidity. Currently, the treatment of rib fractures is symptomatic. Since it has been reported that pulsed ultrasounds accelerates repair of limb fractures, we hypothesized that the application of pulsed ultrasounds will modify the course of healing in an animal model of rib fracture. We studied 136 male Sprague-Dawley rats. Animals were randomly assigned to different groups of doses (none, 50, 100, and 250 mW/cm(2) of intensity for 3 minutes per day) and durations (2, 10, 20, and 28 days) of treatment with pulsed ultrasounds. In every subgroup, we analyzed radiologic and histologic changes in the bone callus. In addition, we examined changes in gene expression of relevant genes involved in wound repair in both control and treated animals. Histologic and radiologic consolidation was significantly increased by pulsed ultrasound treatment when applied for more than 10 days. The application of 50 mW/cm(2) was the most effective dose. Only the 100 and 250 mW/cm(2) doses were able to significantly increase messenger RNA expression of insulin-like growth factor 1, suppressor of cytokine signaling-2 and -3, and vascular endothelial growth factor and decrease monocyte chemoattractant protein-1 and collagen type II-alpha 1. Our findings indicate that pulsed ultrasound accelerates the consolidation of rib fractures. This study is the first to show that pulsed ultrasound promotes the healing of rib fractures. From a translational point of view, this easy, cheap technique could serve as an effective new therapeutic modality in patients with rib fractures. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  13. Trauma Hemostasis and Oxygenation Research Network position paper on the role of hypotensive resuscitation as part of remote damage control resuscitation.

    PubMed

    Woolley, Thomas; Thompson, Patrick; Kirkman, Emrys; Reed, Richard; Ausset, Sylvain; Beckett, Andrew; Bjerkvig, Christopher; Cap, Andrew P; Coats, Tim; Cohen, Mitchell; Despasquale, Marc; Dorlac, Warren; Doughty, Heidi; Dutton, Richard; Eastridge, Brian; Glassberg, Elon; Hudson, Anthony; Jenkins, Donald; Keenan, Sean; Martinaud, Christophe; Miles, Ethan; Moore, Ernest; Nordmann, Giles; Prat, Nicolas; Rappold, Joseph; Reade, Michael C; Rees, Paul; Rickard, Rory; Schreiber, Martin; Shackelford, Stacy; Skogran Eliassen, Håkon; Smith, Jason; Smith, Mike; Spinella, Philip; Strandenes, Geir; Ward, Kevin; Watts, Sarah; White, Nathan; Williams, Steve

    2018-06-01

    The Trauma Hemostasis and Oxygenation Research (THOR) Network has developed a consensus statement on the role of permissive hypotension in remote damage control resuscitation (RDCR). A summary of the evidence on permissive hypotension follows the THOR Network position on the topic. In RDCR, the burden of time in the care of the patients suffering from noncompressible hemorrhage affects outcomes. Despite the lack of published evidence, and based on clinical experience and expertise, it is the THOR Network's opinion that the increase in prehospital time leads to an increased burden of shock, which poses a greater risk to the patient than the risk of rebleeding due to slightly increased blood pressure, especially when blood products are available as part of prehospital resuscitation.The THOR Network's consensus statement is, "In a casualty with life-threatening hemorrhage, shock should be reversed as soon as possible using a blood-based HR fluid. Whole blood is preferred to blood components. As a part of this HR, the initial systolic blood pressure target should be 100 mm Hg. In RDCR, it is vital for higher echelon care providers to receive a casualty with sufficient physiologic reserve to survive definitive surgical hemostasis and aggressive resuscitation. The combined use of blood-based resuscitation and limiting systolic blood pressure is believed to be effective in promoting hemostasis and reversing shock".

  14. Protein kinase Cι/λ is dispensable for platelet function in thrombosis and hemostasis in mice.

    PubMed

    Beck, Sarah; Leitges, Michael; Stegner, David

    2017-10-01

    Platelet activation at sites of vascular injury is crucial for hemostasis, but it may also cause myocardial infarction or ischemic stroke. Upon platelet activation, cytoskeletal reorganization is essential for platelet secretion and thrombus formation. Members of the protein kinase C family, which includes 12 isoforms, are involved in most platelet responses required for thrombus formation. The atypical protein kinase Cι/λ (PKCι/λ) has been implicated as an important mediator of cell polarity, carcinogenesis and immune cell responses. PKCι/λ is known to be associated with the small GTPase Cdc42, an important mediator of multiple platelet functions; however, its exact function in platelets is not known. To study the role of PKCι/λ, we generated platelet- and megakaryocyte-specific PKCι/λ knockout mice (Prkci fl/fl, Pf4-Cre ) and used them to investigate the function of PKCι/λ in platelet activation and aggregation in vitro and in vivo. Surprisingly, lack of PKCι/λ had no detectable effect on platelet spreading and function in vitro and in vivo under all tested conditions. These results indicate that PKCι/λ is dispensable for Cdc42-triggered processes and for thrombosis and hemostasis in mice. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Intravenous pantoprazole versus ranitidine for prevention of rebleeding after endoscopic hemostasis of bleeding peptic ulcers

    PubMed Central

    Hsu, Ping-I; Lo, Gin-Ho; Lo, Ching-Chu; Lin, Chiun-Ku; Chan, Hoi-Hung; Wu, Chung-Jen; Shie, Chang-Bih; Tsai, Pei-Min; Wu, Deng-Chyang; Wang, Wen-Ming; Lai, Kwok-Hung

    2004-01-01

    AIM: The role of intravenous pantoprazole in treatment of patients with high-risk bleeding peptic ulcers following endoscopic hemostasis remains uncertain. We therefore conducted the pilot prospective randomized study to assess whether intravenous pantoprazole could improve the efficacy of H2-antagonist as an adjunct treatment following endoscopic injection therapy for bleeding ulcers. METHODS: Patients with active bleeding ulcers or ulcers with major signs of recent bleeding were treated with distilled water injection. After hemostasis was achieved, they were randomly assigned to receive intravenous pantoprazole or ranitidine. RESULTS: One hundred and two patients were enrolled in this prospective trial. Bleeding recurred in 2 patients (4%) in the pantoprazole group (n = 52), as compared with 8 (16%) in the ranitidine group (n = 50). The rebleeding rate was significantly lower in the pantoprazole group (P = 0.04). There were no statistically significant differences between the groups with regard to the need for emergency surgery (0% vs 2%), transfusion requirements (4.9 ± 5.9 vs 5.7 ± 6.8 units), hospital days (5.9 ± 3.2 vs 7.5 ± 5.0 d) or mortality (2% vs 2%). CONCLUSION: Pantoprozole is superior to ranitidine as an adjunct treatment to endoscopic injection therapy in high-risk bleeding ulcers. PMID:15534928

  16. Comparative effects of a contraceptive vaginal ring delivering a nonandrogenic progestin and continuous ethinyl estradiol and a combined oral contraceptive containing levonorgestrel on hemostasis variables.

    PubMed

    Rad, Mandana; Kluft, Cornelis; Ménard, Joël; Burggraaf, Jacobus; de Kam, Marieke L; Meijer, Piet; Sivin, Irving; Sitruk-Ware, Regine L

    2006-07-01

    This study aimed to compare the effects on hemostasis variables of a contraceptive vaginal ring with those of an oral contraceptive. Twenty-three and 22 healthy premenopausal women were randomized to the contraceptive vaginal ring (150 microg Nestorone and 15 microg ethinyl estradiol) or Stediril 30 during 3 cycles. Analysis of covariance was performed with baseline values as covariate. The contraceptive vaginal ring changed most hemostasis variables similarly but raised (95% confidence intervals of percent treatment differences) Factor VIIt (28% to 49%), extrinsic activated protein C resistance (14% to 65%), and sex hormone-binding globulin (117% to 210%) and lowered Protein S (-32% to -16%) and the global activated partial thromboplastin time-based activated protein C resistance (-12% to -2%) more than the oral contraceptive. The contraceptive vaginal ring affected some measured hemostasis variables and sex hormone-binding globulin differently from the oral contraceptive, most likely because of difference in androgenicity of the progestins. The results suggest that the contraindications for oral contraceptive use would also apply to the tested contraceptive vaginal ring.

  17. Involvement of human decidual cell-expressed tissue factor in uterine hemostasis and abruption.

    PubMed

    Lockwood, C J; Paidas, M; Murk, W K; Kayisli, U A; Gopinath, A; Huang, S J; Krikun, G; Schatz, F

    2009-11-01

    Vascular injury increases access and binding of plasma-derived factor VII to perivascular cell membrane-bound tissue factor (TF). The resulting TF/VIIa complex promotes hemostasis by cleaving pro-thrombin to thrombin leading to the fibrin clot. In human pregnancy, decidual cell-expressed TF prevents decidual hemorrhage (abruption). During placentation, trophoblasts remodel decidual spiral arteries into high conductance vessels. Shallow trophoblast invasion impedes decidual vascular conversion, producing an inadequate uteroplacental blood flow that elicits abruption-related placental ischemia. Thrombin induces several biological effects via cell surface protease activated receptors. In first trimester human DCs thrombin increases synthesis of sFlt-1, which elicits placental ischemia by impeding angiogenesis-related decidual vascular remodeling. During pregnacy, the fibrillar collagen-rich amnion and choriodecidua extracellular matrix (ECM) provides greater than additive tensile strength and structural integrity. Thrombin acts as an autocrine/paracrine mediator that degrades these ECMs by augmenting decidual cell expression of: 1) matrix metalloproteinases and 2) interleukin-8, a key mediator of abruption-associated decidual infiltration of neutrophils, which express several ECM degrading proteases. Among the cell types at the maternal fetal interface at term, TF expression is highest in decidual cells indicating that this TF meets the hemostatic demands of labor and delivery. TF expression in cultured term decidual cells is enhanced by progestin and thrombin suggesting that the maintenance of elevated circulating progesterone provides hemostatic protection and that abruption-generated thrombin acts in an autocrine/paracrine fashion on decidual cells to promote hemostasis via enhanced TF expression.

  18. Involvement of human decidual cell-expressed tissue factor in uterine hemostasis and abruption

    PubMed Central

    Lockwood, C.J.; Paidas, M.; Murk, W.K.; Kayisli, U.A.; Gopinath, A.; Krikun, G.; Huang, S.J.; Schatz, F.

    2009-01-01

    Vascular injury increases access and binding of plasma-derived factor VII to perivascular cell membrane-bound tissue factor (TF). The resulting TF/VIIa complex promotes hemostasis by cleaving pro-thrombin to thrombin leading to the fibrin clot. In human pregnancy, decidual cell-expressed TF prevents decidual hemorrhage (abruption). During placentation, trophoblasts remodel decidual spiral arteries into high conductance vessels. Shallow trophoblast invasion impedes decidual vascular conversion, producing an inadequate uteroplacental blood flow that elicits abruption-related placental ischemia. Thrombin induces several biological effects via cell surface protease activated receptors. In first trimester human DCs thrombin increases synthesis of sFlt-1, which elicits placental ischemia by impeding angiogenesis-related decidual vascular remodeling. During pregnacy, the fibrillar collagen-rich amnion and choriodecidua extracellular matrix (ECM) provides greater than additive tensile strength and structural integrity. Thrombin acts as an autocrine/paracrine mediator that degrades these ECMs by augmenting decidual cell expression of: 1) matrix metalloproteinases and 2) interleukin-8, a key mediator of abruption-associated decidual infiltration of neutrophils, which express several ECM degrading proteases. Our recent observations that: 1) among the cell types at the maternal fetal interface at term TF expression is highest in decidual cells indicates that this TF meets the hemostatic demands of labor and delivery; 2) TF expression in cultured term decidual cells is enhanced by progestin and thrombin suggest that maintenance of elevated circulating progesterone at term provides hemostatic protection, whereas abruption-generated thrombin can act in autocrine/paracrine fashion on DCs to promote hemostasis via enhanced TF expression. PMID:19720393

  19. The interactions between hemostasis and resistance training: a review

    PubMed Central

    Nascimento, Dahan da Cunha; Neto, Frederico Ribeiro; de Santana, Frederico Santos; da Silva, Renato André Sousa; dos Santos-Neto, Leopoldo; Balsamo, Sandor

    2012-01-01

    Physical inactivity is considered a risk factor for cardiovascular disease and is strongly associated with changes in arterial structure. Regular physical activity and exercise contributes to the prevention of coronary artery disease. Therefore, cardiovascular and resistance training improve hemostatic parameters and promote a less thrombotic blood profile. This review highlights the studies, mechanisms, and outcomes relating to the effectiveness of resistance training on the process of hemostasis. The Pubmed, Scopus, Medline, Scielo, Lilacs, Ibecs, and Cochrane databases were used to locate the original articles. Seventeen studies were found during the research process. Of these, ten articles were excluded. Those protocols using a high volume of training for young adults showed a greater fibrinolytic response, and training protocols with intensities above 80% of 1 maximum repetition showed an increased platelet activity. In subjects with coronary artery disease, just one session of resistance training resulted in improvement in the fibrinolytic system (tissue plasminogen activator) without raising potential thrombotic markers. PMID:22419885

  20. Obesity: An Independent Risk Factor for Insufficient Hemostasis Using the AngioSeal Vascular Closure Device After Antegrade Puncture

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Minko, Peter, E-mail: peterminko@yahoo.com; Katoh, Marcus; Graeber, Stefan

    Purpose: This study was designed to investigate the efficacy of the AngioSeal vascular closure device after antegrade puncture of the femoral artery. Methods: In a prospective study, 120 consecutive patients underwent lower limb vascular intervention by an antegrade access to the common femoral artery (CFA). After intervention, a 6F (n = 88) or an 8F (n = 32) AngioSeal vascular closure device was used to achieve hemostasis. The technical success or the cause of failure was documented. In addition, the coagulation status (platelets, INR, prothrombin time, atrial thromboplastin time (PTT)), hypertonus, locoregional habitus of the groin, body mass index (BMI),more » presence of calcifications, and history of previous surgical interventions of the CFA were evaluated. Results: Hemostasis was achieved in 97 patients (81%). In 12 patients (10%), persistent bleeding of the puncture site required manual compression. In another nine patients (8%) a kink of the sheath obviated the passage of the collagen plug toward the vessel, and in two patients the anchor dislodged out of the vessel, requiring manual compression. There were no significant differences between the groups of successful and unsuccessful sealing regarding the mean platelets (241 vs. 254 * 10{sup 9}/l; P = 0.86), INR (1.06 vs. 1.02; P = 0.52), prothrombin time (90% vs. 90%; P = 0.86), and PTT (30 vs. 31 s; P = 0.82). However, unsuccessful sealing was more likely in obese patients with an increased BMI (26.6 vs. 28.8 kg/m{sup 2}; P = 0.04). Conclusions: Obesity seems to be an independent risk factor for insufficient sealing using the AngioSeal vascular closure device after antegrade puncture of the CFA. In 8% of our patients, hemostasis could not be achieved due to kink of the flexible sheath.« less

  1. Trauma hemostasis and oxygenation research position paper on remote damage control resuscitation: definitions, current practice, and knowledge gaps.

    PubMed

    Jenkins, Donald H; Rappold, Joseph F; Badloe, John F; Berséus, Olle; Blackbourne, Lorne; Brohi, Karim H; Butler, Frank K; Cap, Andrew P; Cohen, Mitchell Jay; Davenport, Ross; DePasquale, Marc; Doughty, Heidi; Glassberg, Elon; Hervig, Tor; Hooper, Timothy J; Kozar, Rosemary; Maegele, Marc; Moore, Ernest E; Murdock, Alan; Ness, Paul M; Pati, Shibani; Rasmussen, Todd; Sailliol, Anne; Schreiber, Martin A; Sunde, Geir Arne; van de Watering, Leo M G; Ward, Kevin R; Weiskopf, Richard B; White, Nathan J; Strandenes, Geir; Spinella, Philip C

    2014-05-01

    The Trauma Hemostasis and Oxygenation Research Network held its third annual Remote Damage Control Resuscitation Symposium in June 2013 in Bergen, Norway. The Trauma Hemostasis and Oxygenation Research Network is a multidisciplinary group of investigators with a common interest in improving outcomes and safety in patients with severe traumatic injury. The network's mission is to reduce the risk of morbidity and mortality from traumatic hemorrhagic shock, in the prehospital phase of resuscitation through research, education, and training. The concept of remote damage control resuscitation is in its infancy, and there is a significant amount of work that needs to be done to improve outcomes for patients with life-threatening bleeding secondary to injury. The prehospital phase of resuscitation is critical in these patients. If shock and coagulopathy can be rapidly identified and minimized before hospital admission, this will very likely reduce morbidity and mortality. This position statement begins to standardize the terms used, provides an acceptable range of therapeutic options, and identifies the major knowledge gaps in the field.

  2. Commodifying animals: ethical issues in genetic engineering of animals.

    PubMed

    Almond, B

    2000-03-01

    The genetic modification of living beings raises special ethical concerns which go beyond general discussion of animal rights or welfare. Although the goals may be similar, biotechnology has accelerated the process of modification of types traditionally carried out by cross-breeding. These changes are discussed in relation to two areas: biomedicine, and animal husbandry. Alternative ethical approaches are reviewed, and it is argued that the teleological thesis underlying virtue ethics has special relevance here. The case for and the case against genetic engineering and patenting of life-forms are examined, and conclusions are drawn which favour regulation, caution and respect for animals and animal species.

  3. Circulating nucleic acids and hemostasis: biological basis behind their relationship and technical issues in assessment.

    PubMed

    Danese, Elisa; Montagnana, Martina; Fava, Cristiano; Guidi, Gian Cesare

    2014-10-01

    Nucleic acids (NAs) constitute the backbone of cellular life permitting conservation, transmission, and execution of genetic information. In the past few years, new unexpected functions for NAs, projecting them also beyond nuclear and cellular boundaries have been recognized: circulating cell-free nucleic acids (cfNAs), histones, DNA-histone complexes, microRNAs (miRs) may have a regulatory role in physiological and pathological processes. In particular, several lines of evidence suggest that they can constitute unconventional mediators of thrombus formation, intervening both in hemostasis and thrombosis. Furthermore, in the past decade, the possibility to detect and quantify these in plasma and/or in serum has led to their ancillary use as potential markers in various medical conditions. The use of these as markers within the fields of thrombosis and hemostasis looks promising: the potential implications include the possibility to assess patients' risk profiles for thrombotic events and the identification of more directed targets for pharmacologic intervention. The major impediment is that, to date, the methods by which NAs are explored, still largely differ between published studies and standardized procedures are still lacking. Future research should focus on the physiological mechanisms underlying the activities of such mediators in specific thrombotic conditions and on the definition of reliable methods for their quantification in biological fluids. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. ASVCP quality assurance guidelines: control of preanalytical and analytical factors for hematology for mammalian and nonmammalian species, hemostasis, and crossmatching in veterinary laboratories.

    PubMed

    Vap, Linda M; Harr, Kendal E; Arnold, Jill E; Freeman, Kathleen P; Getzy, Karen; Lester, Sally; Friedrichs, Kristen R

    2012-03-01

    In December 2009, the American Society for Veterinary Clinical Pathology (ASVCP) Quality Assurance and Laboratory Standards committee published the updated and peer-reviewed ASVCP Quality Assurance Guidelines on the Society's website. These guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports: (1) general analytical factors for veterinary laboratory performance and comparisons; (2) hematology, hemostasis, and crossmatching; and (3) clinical chemistry, cytology, and urinalysis. This particular report is one of 3 reports and provides recommendations for control of preanalytical and analytical factors related to hematology for mammalian and nonmammalian species, hemostasis testing, and crossmatching and is adapted from sections 1.1 and 2.3 (mammalian hematology), 1.2 and 2.4 (nonmammalian hematology), 1.5 and 2.7 (hemostasis testing), and 1.6 and 2.8 (crossmatching) of the complete guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimal guidelines for quality assurance and quality control for veterinary laboratory testing and a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts. © 2012 American Society for Veterinary Clinical Pathology.

  5. Kinetic Model Facilitates Analysis of Fibrin Generation and Its Modulation by Clotting Factors: Implications for Hemostasis-Enhancing Therapies

    DTIC Science & Technology

    2014-01-01

    facilitates analysis of fibrin generation and its modulation by clotting factors : implications for hemostasis-enhancing therapies† Alexander Y...investigate the ability of fibrinogen and a recently proposed prothrombin complex concentrate composition, PCC-AT (a combination of the clotting factors II...kinetics. Moreover, the model qualitatively predicted the impact of tissue factor and tPA/tenecteplase level variations on the fibrin output. In the

  6. TrackPlot Enhancements: Support for Multiple Animal Tracks and Gyros

    DTIC Science & Technology

    2015-09-30

    visualization and kinematic analysis of marine animal movements derived from archival tag data. Tags are supported that have sensors for pressure, acceleration...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. TrackPlot Enhancements: Support for Multiple Animal ...in combination with accelerometer and magnetometer data. 2) the extraction and frequency analysis of accelerations and rotation in animal

  7. Technical evaluation of the novel preanalytical module on instrumentation laboratory ACL TOP: advancing automation in hemostasis testing.

    PubMed

    Lippi, Giuseppe; Ippolito, Luigi; Favaloro, Emmanuel J

    2013-10-01

    Automation in hemostasis testing is entering an exciting and unprecedented phase. This study was planned to assess the performance of the new preanalytical module on the hemostasis testing system Instrumentation Laboratory ACL TOP. The evaluation included interference studies to define reliable thresholds for rejecting samples with significant concentrations of interfering substances; within-run imprecision studies of plasma indices on four different interference degrees for each index; comparison studies with reference measures of hemolysis index, bilirubin, and triglycerides on clinical chemistry analyzers; and calculation of turnaround time with and without automatic performance of preanalytical check. The upper limits for sample rejection according to our interference studies were 3.6 g/L for hemoglobin, 13.6 mg/dL for bilirubin, and 1454 mg/dL for triglycerides. We found optimal precision for all indices (0.6% to 3.1% at clinically relevant thresholds) and highly significant correlations with reference measures on clinical chemistry analyzers (from 0.985 to 0.998). The limited increase of turnaround time (i.e., +3% and +5% with or without cap-piercing), coupled with no adjunctive costs over performance of normal coagulation assays, contribute to make the automatic check of plasma indices on ACL TOP a reliable and practical approach for improving testing quality and safeguarding patient safety.

  8. Efficacy of hemostasis for epidural venous plexus and safety for neural structure using soft coagulation system in spinal surgery: a laboratory investigation using a porcine model.

    PubMed

    Nishida, Kotaro; Kakutani, Kenichiro; Maeno, Koichiro; Takada, Toru; Yurube, Takashi; Kuroda, Ryosuke; Kurosaka, Masahiro

    2013-10-01

    A laboratory investigation using porcine model. To clarify the effectiveness of the soft coagulation system for stopping bleeding from the epidural vein using different outputs and the safety in terms of tissue damage including spinal cord injury. Problems associated with coagulation using an electrosurgical device, such as carbonization of tissue or adhesion to the electrode, have been highlighted. So called "soft coagulation" has been developed to solve these problems. Its' utility as well as the safety of the neural structure in spine surgery has never been reported. A total of 3 animals and 45 spinal segments were used. Total laminectomy was performed to expose the dural tube and epidural venous plexus. Stable bleeding was induced by a 22 G needle puncture. Soft coagulation monopolar output (SCM), soft coagulation bipolar output (SCB), and conventional bipolar output (CB) were used as the coagulators. Valid hemostasis was defined as macroscopically complete bleeding stoppage by coagulation within 3 minutes. The neurological assessment was evaluated by somatosensory evoked potential. Histologic analysis was performed to determine the area of thermal damage. Valid hemostasis ratio was 75.0% of SCM group, 68.8% of SCB group, and 30.8% of CB group. Somatosensory evoked potential monitoring revealed that spinal cord injury was observed in 4 lesions (25%) of the SCM group. Neither bipolar groups (SCB and CB) showed any changes in waveform pattern. Histologic analysis revealed that severe thermal damages were observed in the epidural space of the SCM group. The usefulness of soft coagulation is revealed in terms of bleeding stoppage from epidural vessels and reduced soft-tissue damage compared with the conventional electric device. However, assessing the potential risk of severe neural tissue damage including spinal cord injury, a bipolar soft coagulation is strongly recommended for use in spine surgery.

  9. Experimental Platform for Ultra-high Dose Rate FLASH Irradiation of Small Animals Using a Clinical Linear Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schüler, Emil; Trovati, Stefania; King, Gregory

    Purpose: A key factor limiting the effectiveness of radiation therapy is normal tissue toxicity, and recent preclinical data have shown that ultra-high dose rate irradiation (>50 Gy/s, “FLASH”) potentially mitigates this effect. However, research in this field has been strongly limited by the availability of FLASH irradiators suitable for small animal experiments. We present a simple methodologic approach for FLASH electron small animal irradiation with a clinically available linear accelerator (LINAC). Methods and Materials: We investigated the FLASH irradiation potential of a Varian Clinac 21EX in both clinical mode and after tuning of the LINAC. We performed detailed FLUKA Monte Carlomore » and experimental dosimetric characterization at multiple experimental locations within the LINAC head. Results: Average dose rates of ≤74 Gy/s were achieved in clinical mode, and the dose rate after tuning exceeded 900 Gy/s. We obtained 220 Gy/s at 1-cm depth for a >4-cm field size with 90% homogeneity throughout a 2-cm-thick volume. Conclusions: We present an approach for using a clinical LINAC for FLASH irradiation. We obtained dose rates exceeding 200 Gy/s after simple tuning of the LINAC, with excellent dosimetric properties for small animal experiments. This will allow for increased availability of FLASH irradiation to the general research community.« less

  10. Radial hemostasis is facilitated with a potassium ferrate hemostatic patch: the Statseal with TR band assessment trial (STAT).

    PubMed

    Seto, Arnold H; Rollefson, William; Patel, Mitul P; Suh, William M; Tehrani, David M; Nguyen, Jacqueline A; Amador, Daniel G; Behnamfar, Omid; Garg, Vinisha; Cohen, Mauricio G

    2018-05-15

    Hemostasis is a limiting factor for discharge after uncomplicated transradial procedures. The potassium ferrate hemostatic patch (PFHP) may serve as an adjunct to the air-bladder TR band (TRB) and allow expedited deflation of the TRB. Prospective multicenter randomized controlled trial comparing radial hemostatic protocols. Deflation of the TRB was attempted at 40 minutes with PFHP and at 120 minutes without the PFHP. The primary outcome was time to full deflation of the TRB with hemostasis. At four U.S. sites, 180 patients were enrolled after receiving a minimum of 5,000 units of unfractionated heparin or bivalirudin. Interventions comprised 30% of procedures. Successful TRB deflation occurred at 43 ± 14 minutes with PFHP and 160 ± 43 minutes without PFHP (p<0.001). Minor hematomas occurred in 9 (10.3%) of TRB patients and 16 (17.2%) of PFHP patients (p=0.20). Radial artery occlusion occurred in 2% of patients in the PFHP group (p=NS). Outpatients randomized to PFHP were discharged 51 ± 83.5 minutes earlier than control. The PFHP hemostatic patch facilitated early deflation of the TRB with a nonsignificant increase in forearm hematomas. Use of the PFHP may improve patient throughput and allow for earlier discharge following transradial procedures.

  11. Comparing the Effect of 3 Kinds of Different Materials on the Hemostasis of the Central Venous Catheter

    NASA Astrophysics Data System (ADS)

    Li, Yan-Ming; Liang, Zhen-Zhen; Song, Chun-Lei

    2016-05-01

    To compare the effect of 3 kinds of different materials on the hemostasis of puncture site after central venous catheterization. Method: A selection of 120 patients with peripheral central venous catheter chemotherapy in the Affiliated Hospital of our university from January 2014 to April 2015, Randomly divided into 3 groups, using the same specification (3.5cm × 2cm) alginate gelatin sponge and gauze dressing, 3 kinds of material compression puncture point, 3 groups of patients after puncture 24 h within the puncture point of local blood and the catheter after the catheter 72 h within the catheter maintenance costs. Result: (1) The local infiltration of the puncture point in the 24 h tube: The use of alginate dressing and gelatin sponge hemostatic effect is better than that of compression gauze. The difference was statistically significant (P <0.05). Compared with gelatin sponge and alginate dressing hemostatic effect, The difference was not statistically significant. (2) Tube maintenance cost: Puncture point using gelatin sponge, The local maintenance costs of the catheter within 72 h after insertion of the tube are lowest, compared with alginate dressing and gauze was significant (P<0.05). Conclusion: The choice of compression hemostasis material for the puncture site after PICC implantation, using gelatin sponge and gauze dressing is more effective and economic.

  12. Body mass, composition, and food intake in rabbits during altered acceleration fields

    NASA Technical Reports Server (NTRS)

    Katovich, M. J.; Smith, A. H.

    1978-01-01

    Mature male Polish rabbits were subjected to varying gravitational fields in an animal centrifuge in order to evaluate the effects of acceleration and deacceleration on body mass, body composition, and food intake. The acceleration field intensity was increased by 0.25-G increments to a maximum of 2.5 G at intervals which permitted physiological adaptation at each field. Control animals of the same age were maintained at earth gravity under identical conditions of constant-light environment at a room temperature of 23 + or - 5 C. It is shown that increasing the acceleration-field intensity leads to a decrease in body mass. The regulated nature of this decreased body mass is tested by the response to an additional three-day fasting of animals adapted physiologically to 2.5 G. Ad libitum food intake per kg body mass per day tends to increase in chronically accelerated animals above 1.75 G. Increase in water content in centrifuged animals after physiological adaptation to 2.5 G is the result of decreasing body fat. Body mass and food intake returned to the precentrifuged levels of control animals within six weeks after cessation of centrifugation.

  13. Elevated Hemostasis Markers after Pneumonia Increases One-Year Risk of All-Cause and Cardiovascular Deaths

    PubMed Central

    Yende, Sachin; D'Angelo, Gina; Mayr, Florian; Kellum, John A.; Weissfeld, Lisa; Kaynar, A. Murat; Young, Tammy; Irani, Kaikobad; Angus, Derek C.

    2011-01-01

    Background Acceleration of chronic diseases, particularly cardiovascular disease, may increase long-term mortality after community-acquired pneumonia (CAP), but underlying mechanisms are unknown. Persistence of the prothrombotic state that occurs during an acute infection may increase risk of subsequent atherothrombosis in patients with pre-existing cardiovascular disease and increase subsequent risk of death. We hypothesized that circulating hemostasis markers activated during CAP persist at hospital discharge, when patients appear to have recovered clinically, and are associated with higher mortality, particularly due to cardiovascular causes. Methods In a cohort of survivors of CAP hospitalization from 28 US sites, we measured D-Dimer, thrombin-antithrombin complexes [TAT], Factor IX, antithrombin, and plasminogen activator inhibitor-1 at hospital discharge, and determined 1-year all-cause and cardiovascular mortality. Results Of 893 subjects, most did not have severe pneumonia (70.6% never developed severe sepsis) and only 13.4% required intensive care unit admission. At discharge, 88.4% of subjects had normal vital signs and appeared to have clinically recovered. D-dimer and TAT levels were elevated at discharge in 78.8% and 30.1% of all subjects, and in 51.3% and 25.3% of those without severe sepsis. Higher D-dimer and TAT levels were associated with higher risk of all-cause mortality (range of hazard ratios were 1.66-1.17, p = 0.0001 and 1.46-1.04, p = 0.001 after adjusting for demographics and comorbid illnesses) and cardiovascular mortality (p = 0.009 and 0.003 in competing risk analyses). Conclusions Elevations of TAT and D-dimer levels are common at hospital discharge in patients who appeared to have recovered clinically from pneumonia and are associated with higher risk of subsequent deaths, particularly due to cardiovascular disease. PMID:21853050

  14. Elevated hemostasis markers after pneumonia increases one-year risk of all-cause and cardiovascular deaths.

    PubMed

    Yende, Sachin; D'Angelo, Gina; Mayr, Florian; Kellum, John A; Weissfeld, Lisa; Kaynar, A Murat; Young, Tammy; Irani, Kaikobad; Angus, Derek C

    2011-01-01

    Acceleration of chronic diseases, particularly cardiovascular disease, may increase long-term mortality after community-acquired pneumonia (CAP), but underlying mechanisms are unknown. Persistence of the prothrombotic state that occurs during an acute infection may increase risk of subsequent atherothrombosis in patients with pre-existing cardiovascular disease and increase subsequent risk of death. We hypothesized that circulating hemostasis markers activated during CAP persist at hospital discharge, when patients appear to have recovered clinically, and are associated with higher mortality, particularly due to cardiovascular causes. In a cohort of survivors of CAP hospitalization from 28 US sites, we measured D-Dimer, thrombin-antithrombin complexes [TAT], Factor IX, antithrombin, and plasminogen activator inhibitor-1 at hospital discharge, and determined 1-year all-cause and cardiovascular mortality. Of 893 subjects, most did not have severe pneumonia (70.6% never developed severe sepsis) and only 13.4% required intensive care unit admission. At discharge, 88.4% of subjects had normal vital signs and appeared to have clinically recovered. D-dimer and TAT levels were elevated at discharge in 78.8% and 30.1% of all subjects, and in 51.3% and 25.3% of those without severe sepsis. Higher D-dimer and TAT levels were associated with higher risk of all-cause mortality (range of hazard ratios were 1.66-1.17, p = 0.0001 and 1.46-1.04, p = 0.001 after adjusting for demographics and comorbid illnesses) and cardiovascular mortality (p = 0.009 and 0.003 in competing risk analyses). Elevations of TAT and D-dimer levels are common at hospital discharge in patients who appeared to have recovered clinically from pneumonia and are associated with higher risk of subsequent deaths, particularly due to cardiovascular disease.

  15. Upper non-variceal gastrointestinal bleeding - review the effectiveness of endoscopic hemostasis methods

    PubMed Central

    Szura, Mirosław; Pasternak, Artur

    2015-01-01

    Upper non-variceal gastrointestinal bleeding is a condition that requires immediate medical intervention and has a high associated mortality rate (exceeding 10%). The vast majority of upper gastrointestinal bleeding cases are due to peptic ulcers. Helicobacter pylori infection, non-steroidal anti-inflammatory drugs and aspirin are the main risk factors for peptic ulcer disease. Endoscopic therapy has generally been recommended as the first-line treatment for upper gastrointestinal bleeding as it has been shown to reduce recurrent bleeding, the need for surgery and mortality. Early endoscopy (within 24 h of hospital admission) has a greater impact than delayed endoscopy on the length of hospital stay and requirement for blood transfusion. This paper aims to review and compare the efficacy of the types of endoscopic hemostasis most commonly used to control non-variceal gastrointestinal bleeding by pooling data from the literature. PMID:26421105

  16. Wound healing after craniotomy: a randomized trial comparing scalp clips to artery forceps for scalp hemostasis.

    PubMed

    Langford, Peter; Wolfe, Rory; Danks, R Andrew

    2009-12-01

    In this prospective randomized clinical trial, investigators looked at wound healing after craniotomy. The hypothesis was that the self-closing plastic scalp clips used for hemostasis on the skin edge might lead to localized microscopic tissue damage and subsequent delayed wound healing. The trial consisted of 2 arms in which different methods were used to secure scalp hemostasis: 1) the routinely used plastic clips (Scalpfix, Aesculap); and 2) the older method of artery forceps placed on the galea. Participants were restricted to those > 16 years of age undergoing craniotomies expected to last > 2 hours. Repeat operations were not included. One hundred fifty patients were enrolled. They were visited at 3 and 6 weeks postoperatively by an observer blinded to the method used, and the wounds were assessed for macroscopic epithelial closure, signs of infection, and hair regrowth by using a predefined assessment scale. The results showed no significant difference in wound healing between the 2 groups at either 3 weeks (OR 0.55, 95% CI 0.27-1.11; p = 0.09) or 6 weeks (OR 0.79, 95% CI 0.39-1.58; p = 0.50). The length of operation was found to be a significant factor affecting wound healing at 6 weeks (OR/hour 0.68, 95% CI 0.51-0.92; p = 0.01). The use of Aesculap Scalpfix self-retaining plastic scalp clips on the skin edge during craniotomy surgery does not appear to affect wound healing significantly to the postoperative 6-week mark.

  17. Decidualized Human Endometrial Stromal Cells Mediate Hemostasis, Angiogenesis, and Abnormal Uterine Bleeding

    PubMed Central

    Lockwood, Charles J.; Krikun, Graciela; Hickey, Martha; Huang, S. Joseph; Schatz, Frederick

    2011-01-01

    Factor VII binds trans-membrane tissue factor to initiate hemostasis by forming thrombin. Tissue factor expression is enhanced in decidualized human endometrial stromal cells during the luteal phase. Long-term progestin only contraceptives elicit: 1) abnormal uterine bleeding from fragile vessels at focal bleeding sites, 2) paradoxically high tissue factor expression at bleeding sites; 3) reduced endometrial blood flow promoting local hypoxia and enhancing reactive oxygen species levels; and 4) aberrant angiogenesis reflecting increased stromal cell-expressed vascular endothelial growth factor, decreased Angiopoietin-1 and increased endothelial cell-expressed Angiopoietin-2. Aberrantly high local vascular permeability enhances circulating factor VII to decidualized stromal cell-expressed tissue factor to generate excess thrombin. Hypoxia-thrombin interactions augment expression of vascular endothelial growth factor and interleukin-8 by stromal cells. Thrombin, vascular endothelial growth factor and interlerukin-8 synergis-tically augment angiogenesis in a milieu of reactive oxygen species-induced endothelial cell activation. The resulting enhanced vessel fragility promotes abnormal uterine bleeding. PMID:19208784

  18. Topical Erythropoietin Treatment Accelerates the Healing of Cutaneous Burn Wounds in Diabetic Pigs Through an Aquaporin-3-Dependent Mechanism.

    PubMed

    Hamed, Saher; Ullmann, Yehuda; Egozi, Dana; Keren, Aviad; Daod, Essam; Anis, Omer; Kabha, Hoda; Belokopytov, Mark; Ashkar, Manal; Shofti, Rona; Zaretsky, Asaph; Schlesinger, Michal; Teot, Luc; Liu, Paul Y

    2017-08-01

    We have previously reported that the topical application of erythropoietin (EPO) to cutaneous wounds in rats and mice with experimentally induced diabetes accelerates their healing by stimulating angiogenesis, reepithelialization, and collagen deposition, and by suppressing the inflammatory response and apoptosis. Aquaporins (AQPs) are integral membrane proteins whose function is to regulate intracellular fluid hemostasis by enabling the transport of water and glycerol. AQP3 is the AQP that is expressed in the skin where it facilitates cell migration and proliferation and re-epithelialization during wound healing. In this report, we provide the results of an investigation that examined the contribution of AQP3 to the mechanism of EPO action on the healing of burn wounds in the skin of pigs with experimentally induced type 1 diabetes. We found that topical EPO treatment of the burns accelerated their healing through an AQP3-dependent mechanism that activates angiogenesis, triggers collagen and hyaluronic acid synthesis and the formation of the extracellular matrix (ECM), and stimulates reepithelialization by keratinocytes. We also found that incorporating fibronectin, a crucial constituent of the ECM, into the topical EPO-containing gel, can potentiate the accelerating action of EPO on the healing of the burn injury. © 2017 by the American Diabetes Association.

  19. Validation of GPU-accelerated superposition-convolution dose computations for the Small Animal Radiation Research Platform.

    PubMed

    Cho, Nathan; Tsiamas, Panagiotis; Velarde, Esteban; Tryggestad, Erik; Jacques, Robert; Berbeco, Ross; McNutt, Todd; Kazanzides, Peter; Wong, John

    2018-05-01

    The Small Animal Radiation Research Platform (SARRP) has been developed for conformal microirradiation with on-board cone beam CT (CBCT) guidance. The graphics processing unit (GPU)-accelerated Superposition-Convolution (SC) method for dose computation has been integrated into the treatment planning system (TPS) for SARRP. This paper describes the validation of the SC method for the kilovoltage energy by comparing with EBT2 film measurements and Monte Carlo (MC) simulations. MC data were simulated by EGSnrc code with 3 × 10 8 -1.5 × 10 9 histories, while 21 photon energy bins were used to model the 220 kVp x-rays in the SC method. Various types of phantoms including plastic water, cork, graphite, and aluminum were used to encompass the range of densities of mouse organs. For the comparison, percentage depth dose (PDD) of SC, MC, and film measurements were analyzed. Cross beam (x,y) dosimetric profiles of SC and film measurements are also presented. Correction factors (CFz) to convert SC to MC dose-to-medium are derived from the SC and MC simulations in homogeneous phantoms of aluminum and graphite to improve the estimation. The SC method produces dose values that are within 5% of film measurements and MC simulations in the flat regions of the profile. The dose is less accurate at the edges, due to factors such as geometric uncertainties of film placement and difference in dose calculation grids. The GPU-accelerated Superposition-Convolution dose computation method was successfully validated with EBT2 film measurements and MC calculations. The SC method offers much faster computation speed than MC and provides calculations of both dose-to-water in medium and dose-to-medium in medium. © 2018 American Association of Physicists in Medicine.

  20. Respiratory syncytial virus infection accelerates lung fibrosis through the unfolded protein response in a bleomycin-induced pulmonary fibrosis animal model.

    PubMed

    Wang, Lina; Cheng, Wei; Zhang, Zhimin

    2017-07-01

    Emerging evidence has demonstrated that endoplasmic reticulum stress (ER) is involved in the pathogenesis of idiopathic pulmonary fibrosis, however, the underlying mechanism remains unclear. Viral infection often triggers a hyperinflammatory response by an expansion of the ER. The present study was designed to observe the role of respiratory syncytial virus infection (RSV)‑induced ER stress on lung fibrosis. In order to determine the role of ER stress on the onset and progression of pulmonary fibrosis, mice received an intratracheal combined injection of RSV and bleomycin on day 0. At day 7, 14 and 21 following combined injection, RSV in the lung tissues was assayed by immunohistochemistry, cellular classification was assayed by direct microscopic observation after Wright staining and the secretion of cytokines in the broncho‑alveolar lavage fluid (BALF) was assayed by ELISA. The expression of collagen type I was assayed by immunofluorescence and western blot analysis. The expression of ER stress related proteins was analyzed by western blot. In addition, the correlations of ER‑stress related proteins with collagen type‑1 were examined. RSV administration resulted in increased inflammation, as demonstrated by increased levels of leukocytes and pro‑inflammatory cytokines in the BALF, and increased collagen type‑1 deposition in the lung tissues of bleomycin-induced pulmonary fibrosis animal model at 7, 14 and 21 days. RSV promoted the expression of phosphorylated protein kinase R‑like endoplasmic reticulum kinase (p‑PERK), 78 kDa glucose‑regulated protein (GRP78) and activating transcription factor 6α (ATF6α), which accelerated the severity and process of fibrosis in bleomycin‑induced animal models. The present study provides evidence that RSV infection accelerated the unfolded protein response and bleomycin‑induced lung fibrosis, which may improve our understanding of the pathogenesis of pulmonary fibrosis.

  1. Effects of preoperative administration of carprofen on renal function and hemostasis in dogs undergoing surgery for fracture repair.

    PubMed

    Bergmann, Hannes M L; Nolte, Ingo J A; Kramer, Sabine

    2005-08-01

    To evaluate effects of preoperative administration of carprofen on renal function and hemostasis in dogs undergoing general anesthesia for fracture repair. 26 client-owned dogs. Anesthesia was induced with levomethadone, diazepam, and propofol and maintained by administration of isoflurane in oxygen-nitrous oxide. Carprofen (4 mg/kg, SC) was administered 1 hour before induction to 13 dogs (group 1) and after extubation to the other 13 dogs (group 2). All dogs also received carprofen (4 mg/kg, SC, q 24 h) for the first 4 days after surgery. Renal function (glomerular filtration rate [GFR], urinary protein-to-urinary creatinine ratio [UP:UC], and results of urinalysis and biochemical analysis of plasma), hemostatic variables (bleeding time, platelet aggregation, prothrombin time [PT], activated partial thromboplastin time [APTT], and platelet count), and Hct were assessed before and at various time points after surgery. Analysis of results for renal function tests, most of the hemostatic and plasma biochemical variables, and Hct did not reveal significant differences between treatment groups. Values for GFR, UP:UC, PT, APTT, and platelet aggregation were outside reference ranges in many dogs before surgery and during the first 6 hours after surgery. In most dogs, these trauma-induced pathologic changes returned to within reference ranges during the 4-day period after surgery. Carprofen did not cause clinically relevant adverse effects in dogs anesthetized for fracture repair after 5 days of treatment, even when it was administered before surgery or given to patients with trauma-induced alterations in renal function or hemostasis.

  2. Left Atrial 4D Blood Flow Dynamics and Hemostasis following Electrical Cardioversion of Atrial Fibrillation.

    PubMed

    Cibis, Merih; Lindahl, Tomas L; Ebbers, Tino; Karlsson, Lars O; Carlhäll, Carl-Johan

    2017-01-01

    Background: Electrical cardioversion in patients with atrial fibrillation is followed by a transiently impaired atrial mechanical function, termed atrial stunning. During atrial stunning, a retained risk of left atrial thrombus formation exists, which may be attributed to abnormal left atrial blood flow patterns. 4D Flow cardiovascular magnetic resonance (CMR) enables blood flow assessment from the entire three-dimensional atrial volume throughout the cardiac cycle. We sought to investigate left atrial 4D blood flow patterns and hemostasis during left atrial stunning and after left atrial mechanical function was restored. Methods: 4D Flow and morphological CMR data as well as blood samples were collected in fourteen patients at two time-points: 2-3 h (Time-1) and 4 weeks (Time-2) following cardioversion. The volume of blood stasis and duration of blood stasis were calculated. In addition, hemostasis markers were analyzed. Results: From Time-1 to Time-2: Heart rate decreased (61 ± 7 vs. 56 ± 8 bpm, p = 0.01); Maximum change in left atrial volume increased (8 ± 4 vs. 22 ± 15%, p = 0.009); The duration of stasis (68 ± 11 vs. 57 ± 8%, p = 0.002) and the volume of stasis (14 ± 9 vs. 9 ± 7%, p = 0.04) decreased; Thrombin-antithrombin complex (TAT) decreased (5.2 ± 3.3 vs. 3.3 ± 2.2 μg/L, p = 0.008). A significant correlation was found between TAT and the volume of stasis ( r 2 = 0.69, p < 0.001) at Time-1 and between TAT and the duration of stasis ( r 2 = 0.34, p = 0.04) at Time-2. Conclusion: In this longitudinal study, left atrial multidimensional blood flow was altered and blood stasis was elevated during left atrial stunning compared to the restored left atrial mechanical function. The coagulability of blood was also elevated during atrial stunning. The association between blood stasis and hypercoagulability proposes that assessment of left atrial 4D flow can add to the pathophysiological understanding of thrombus formation during atrial fibrillation

  3. Histologic findings following use of hydrophilic polymer with potassium ferrate for hemostasis.

    PubMed

    Barlev, Danny; Spicknall, Kerith E

    2014-12-01

    Hydrophilic polymer with potassium salt is a hemostatic agent marketed for use by healthcare professionals and as an over-the-counter product available to healthcare consumers. In particular, dermatologic surgeons may use hydrophilic polymer for hemostasis in wounds left to heal by secondary intention. Foreign body reaction to hydrophilic polymer was recently reported. The microscopic findings in four additional patients treated with hydrophilic polymer are presented. The wounds of three patients were treated with hydrophilic polymer following a dermatologic surgical procedure while one patient used over-the-counter hydrophilic polymer on an abrasion. Three patients developed a foreign body reaction. Histopathologic examination revealed angulated fragments of deep purple material representing hydrophilic polymer admixed with round orange-red bodies and yellow-brown granules representing potassium ferrate. The components were found both free in the dermis and within multinucleated giant cells. Hydrophilic polymer must be differentiated from other materials observed in re-excision specimens, including ferric subsulfate, aluminum chloride and Gelfoam(®) (Pharmacia and Upjohn Co., New York, NY, USA). © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Macrophage Differentiation in Normal and Accelerated Wound Healing.

    PubMed

    Kotwal, Girish J; Chien, Sufan

    2017-01-01

    Chronic wounds pose considerable public health challenges and burden. Wound healing is known to require the participation of macrophages, but mechanisms remain unclear. The M1 phenotype macrophages have a known scavenger function, but they also play multiple roles in tissue repair and regeneration when they transition to an M2 phenotype. Macrophage precursors (mononuclear cells/monocytes) follow the influx of PMN neutrophils into a wound during the natural wound-healing process, to become the major cells in the wound. Natural wound-healing process is a four-phase progression consisting of hemostasis, inflammation, proliferation, and remodeling. A lag phase of 3-6 days precedes the remodeling phase, which is characterized by fibroblast activation and finally collagen production. This normal wound-healing process can be accelerated by the intracellular delivery of ATP to wound tissue. This novel ATP-mediated acceleration arises due to an alternative activation of the M1 to M2 transition (macrophage polarization), a central and critical feature of the wound-healing process. This response is also characterized by an early increased release of pro-inflammatory cytokines (TNF, IL-1 beta, IL-6), a chemokine (MCP-1), an activation of purinergic receptors (a family of plasma membrane receptors found in almost all mammalian cells), and an increased production of platelets and platelet microparticles. These factors trigger a massive influx of macrophages, as well as in situ proliferation of the resident macrophages and increased synthesis of VEGFs. These responses are followed, in turn, by rapid neovascularization and collagen production by the macrophages, resulting in wound covering with granulation tissue within 24 h.

  5. Animal virus discovery: improving animal health, understanding zoonoses, and opportunities for vaccine development

    PubMed Central

    Delwart, Eric

    2012-01-01

    The characterization of viral genomes has accelerated due to improvement in DNA sequencing technology. Sources of animal samples and molecular methods for the identification of novel viral pathogens and steps to determine their pathogenicity are listed. The difficulties for predicting future cross-species transmissions are highlighted by the wide diversity of known viral zoonoses. Recent surveys of viruses in wild and domesticated animals have characterized numerous viruses including some closely related to those infecting humans. The detection of multiple genetic lineages within viral families infecting a single host species, phylogenetically interspersed with viruses found in other host species, reflects frequent past cross-species transmissions. Numerous opportunities for the generation of novel vaccines will arise from a better understanding of animal viromes. PMID:22463981

  6. A key enzyme of animal steroidogenesis can function in plants enhancing their immunity and accelerating the processes of growth and development.

    PubMed

    Shpakovski, George V; Spivak, Svetlana G; Berdichevets, Irina N; Babak, Olga G; Kubrak, Svetlana V; Kilchevsky, Alexander V; Aralov, Andrey V; Slovokhotov, Ivan Yu; Shpakovski, Dmitry G; Baranova, Ekaterina N; Khaliluev, Marat R; Shematorova, Elena K

    2017-11-14

    The initial stage of the biosynthesis of steroid hormones in animals occurs in the mitochondria of steroidogenic tissues, where cytochrome P450 SCC (CYP11A1) encoded by the CYP11A1 gene catalyzes the conversion of cholesterol into pregnenolone - the general precursor of all the steroid hormones, starting with progesterone. This stage is missing in plants where mitochondrial cytochromes P450 (the mito CYP clan) have not been found. Generating transgenic plants with a mitochondrial type P450 from animals would offer an interesting option to verify whether plant mitochondria could serve as another site of P450 monooxygenase reaction for the steroid hormones biosynthesis. For a more detailed comparison of steroidogenic systems of Plantae and Animalia, we have created and studied transgenic tobacco and tomato plants efficiently expressing mammalian CYP11A1 cDNA. The detailed phenotypic characterization of plants obtained has shown that through four generations studied, the transgenic tobacco plants have reduced a period of vegetative development (early flowering and maturation of bolls), enlarged biomass and increased productivity (quantity and quality of seeds) as compared to the only empty-vector containing or wild type plants. Moreover, the CYP11A1 transgenic plants show resistance to such fungal pathogen as Botrytis cinerea. Similar valuable phenotypes (the accelerated course of ontogenesis and/or stress resistance) are also visible in two clearly distinct transgenic tomato lines expressing CYP11A1 cDNA: one line (No. 4) has an accelerated rate of vegetative development, while the other (No. 7) has enhanced immunity to abiotic and biotic stresses. The progesterone level in transgenic tobacco and tomato leaves is 3-5 times higher than in the control plants of the wild type. For the first time, we could show the compatibility in vivo of even the most specific components of the systems of biosynthesis of steroid hormones in Plantae and Animalia. The hypothesis is

  7. Emergency endoscopy for acute gastrointestinal bleeding: prognostic value of endoscopic hemostasis and the AIMS65 score in Japanese patients.

    PubMed

    Nakamura, Shotaro; Matsumoto, Takayuki; Sugimori, Hiroshi; Esaki, Motohiro; Kitazono, Takanari; Hashizume, Makoto

    2014-05-01

    To evaluate the prognostic factors, including risk scores (Glasgow-Blatchford score and AIMS65) in patients with acute upper or lower gastrointestinal bleeding. The medical records of patients who had undergone emergency gastrointestinal endoscopy for suspected gastrointestinal bleeding during the past 5 years were retrospectively analyzed. A total of 232 endoscopies (130 esophagogastroduodenoscopies, 102 colonoscopies) for 192 patients met the inclusion criteria. Median age was 66 years, and 64% of patients were males. Endoscopy identified causes for bleeding in 173 patients (post-endoscopic interventions for neoplastic lesions in 36 cases, colonic diverticula in 34, gastroduodenal ulcers in 29, gastric erosions in 15, vascular ectasia in 14, post-biopsy bleeding in 13, malignant tumors in 10, inflammatory conditions in nine, esophagogastric varices in five, Mallory-Weiss tears in four, nasalbleeding in three, and injury by swallowed blister pack in one), whereas the source of bleeding remained obscure in 19 patients. Blood transfusion was given in 97 patients (51%), and 97 (51%) underwent endoscopic hemostasis. During the follow-up period, 49 patients (26%) experienced rebleeding, seven of whom were treated by interventional radiology. Thirty-nine patients (20%) died as a result of various diseases. The probabilities of overall survival (OS) after 3 and 5 years were 71% and 67%, respectively. Cox multivariate analysis revealed blood transfusion, co-existing malignancy, absence of endoscopic hemostasis, and high AIMS65 score to be independent prognostic factors for poor OS. The AIMS65 score is useful for predicting the prognosis of patients with acute gastrointestinal bleeding. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

  8. Hemostasis and Post-operative Care of Oral Surgical Wounds by Hemcon Dental Dressing in Patients on Oral Anticoagulant Therapy: A Split Mouth Randomized Controlled Clinical Trial.

    PubMed

    Kumar, K R Ashok; Kumar, Jambukeshwar; Sarvagna, Jagadesh; Gadde, Praveen; Chikkaboriah, Shwetha

    2016-09-01

    Hemostasis is a fundamental management issue post-operatively in minor oral surgical procedures. To ensure safety and therapeutic efficacy in patients, under oral anti coagulant therapy, is complicated by necessity for frequent determination of prothrombin time or international normalised ratio. The aim of the study was to determine whether early hemostasis achieved by using Hemcon Dental Dressing (HDD) will affect post-operative care and surgical healing outcome in minor oral surgical procedures. A total of 30 patients, aged 18 years to 90 years, except those allergic to seafood, who consented to participate, were enrolled into this study. Patients were required to have two or more surgical sites so that they would have both surgical and control sites. All patients taking Oral Anticoagulation Therapy (OAT) were included for treatment in the study without altering the anticoagulant regimens. Institutional Review Board approval was obtained for the same. The collected data was subjected to statistical analysis using unpaired t-test. All HDD surgically treated sites achieved hemostasis in 1.49 minutes and control wounds in 4.06 minutes (p < 0.001). Post-operative pain at HDD treated sites (1.87,1.27 on 1 st and 3 rd day respectively) was significantly lower than the control sites (4.0,1.87 on 1 st and 3 rd day respectively) p-value (0.001, 0.001 respectively). HDD treated oral surgery wounds achieved statistically significant improved healing both at 1 st and 3 rd post-operative days (p <0.0001). The HDD has been proven to be a clinically effective hemostatic dressing material that significantly shortens bleeding time following minor oral surgical procedures under local anaesthesia, including those patients taking OAT. Patients receiving the HDD had improved surgical wound healing as compared to controls.

  9. Benefits of applying low-temperature plasma treatment to wound care and hemostasis from the viewpoints of physics and pathology

    NASA Astrophysics Data System (ADS)

    Shimizu, Tetsuji; Ikehara, Yuzuru

    2017-12-01

    Over the last decade, low-temperature plasma (LTP) technology has reached the life sciences and introduced the benefits of using such technology at atmospheric pressure for medical applications. The active elements from LTP, such as reactive molecular species, charged particles and photons, appear to react with biomolecules on wounds and at bleeding points. This action by LTP might be analogous with semiconductor fabrication techniques such as etching and surface modification. From this perspective, we discuss the general aspects and principles of LTP devices used at atmospheric pressure in wound care and hemostasis as an interdisciplinary fusion of applied physics and pathology.

  10. Potassium-titanyl-phosphate laser assisted robotic partial nephrectomy in a porcine model: can robotic assistance optimize the power needed for effective cutting and hemostasis?

    PubMed

    Boris, Ronald S; Eun, Daniel; Bhandari, Akshay; Lyall, Kathryn; Bhandari, Mahendra; Rogers, Craig; Alassi, Osama; Menon, Mani

    2007-01-01

    A potassium-titanyl-phosphate (KTP) laser through robotic endo-wrist instrument has been evaluated as an ablative and hemostatic tool in robotic assisted laparoscopic partial nephrectomy (RALPN). Ten RALPN were performed in five domestic female pigs. The partial nephrectomies were performed with bulldog clamping of the pedicle. Flexible glass fiber carrying 532-nm green light laser was used through a robotic endowrist instrument in two cases. Power usage from 4 to 10 W was tested. The laser probe was explored both as a cutting knife and for hemostasis. The pelvicalyceal system was closed with a running suture. Partial nephrectomies using KTP laser were performed without complications. Mean operative times and warm ischemia times for laser cases were 96 and 18 min, respectively. Mean estimated blood loss was 60 ml compared with 50 ml for non-laser cases. Complete hemostasis with the laser alone could be achieved with a power of 4 W and was found to be effective. In our hands the laser fiber powered up to 10 W was not effective as a quick cutting agent. Histopathologic analysis of the renal remnant revealed a cauterized surface effect with average laser penetration depth less than 1 mm and minimal surrounding cellular injury. The new robotic endowrist instrument carrying flexible glass fiber transmitting 532-nm green light laser is a useful addition to the armamentarium of the robotic urologic setup. Its control by the console surgeon enables quicker and more complete hemostasis of the cut surface in renal sparing surgery using a porcine model. Histologically proven lased depth of less than 1 mm suggests minimal parenchyma damage in an acute setting. Laser application as a cutting agent, however, requires further investigation with interval power settings beyond the limits of this preliminary study. We estimate that effective cutting should be possible with a setting lower than traditionally recommended for solid organs.

  11. Functionalization of single-walled carbon nanotubes regulates their effect on hemostasis

    NASA Astrophysics Data System (ADS)

    Sokolov, A. V.; Aseychev, A. V.; Kostevich, V. A.; Gusev, A. A.; Gusev, S. A.; Vlasova, I. I.

    2011-04-01

    Applications of single-walled carbon nanotubes (SWNTs) in medical field imply the use of drug-coupled carbon nanotubes as well as carbon nanotubes functionalized with different chemical groups that change nanotube surface properties and interactions between nanotubes and cells. Covalent attachment of polyethylene glycol (PEG) to carboxylated single-walled carbon nanotubes (c-SWNT) is known to prevent the nanotubes from interaction with macrophages. Here we characterized nanotube's ability to stimulate coagulation processes in platelet-poor plasma (PPP), and evaluated the effect of SWNTs on platelet aggregation in platelet-rich plasma (PRP). Our study showed that PEG-SWNT did not affect the rate of clotting in PPP, while c-SWNT shortened the clot formation time five times compared to the control PPP. Since c-SWNT failed to accelerate coagulation in plasma lacking coagulation factor XI, it may be suggested that c-SWNT affects the contact activation pathway. In PRP, platelets responded to both SWNT types with irreversible aggregation, as evidenced by changes in the aggregate mean radius. However, the rate of aggregation induced by c-SWNT was two times higher than it was with PEG-SWNT. Cytological analysis also showed that c-SWNT was two times more efficient when compared to PEG-SWNT in aggregating platelets in PRP. Taken together, our results show that functionalization of nanoparticles can diminish their negative influence on blood cells. As seen from our data, modification of c-SWNT with PEG, when only a one percent of carbon atoms is bound to polymer (70 wt %), decreased the nanotube-induced coagulation in PRP and repelled the accelerating effect on the coagulation in PPP. Thus, when functionalized SWNTs are used for administration into bloodstream of laboratory animals, their possible pro-coagulant and pro-aggregating properties must be taken into account.

  12. Harmonic versus LigaSure hemostasis technique in thyroid surgery: A meta-analysis

    PubMed Central

    Upadhyaya, Arun; Hu, Tianpeng; Meng, Zhaowei; Li, Xue; He, Xianghui; Tian, Weijun; Jia, Qiang; Tan, Jian

    2016-01-01

    Harmonic scalpel and LigaSure vessel sealing systems have been suggested as options for saving surgical time and reducing postoperative complications. The aim of the present meta-analysis was to compare surgical time, postoperative complications and other parameters between them in for the open thyroidectomy procedure. Studies were retrieved from MEDLINE, Cochrane Library, EMBASE and ISI Web of Science until December 2015. All the randomized controlled trials (RCTs) comparing Harmonic scalpel and LigaSure during open thyroidectomy were selected. Following data extraction, statistical analyses were performed. Among the 24 studies that were evaluated for eligibility, 7 RCTs with 981 patients were included. The Harmonic scalpel significantly reduced surgical time compared with LigaSure techniques (8.79 min; 95% confidence interval, −15.91 to −1.67; P=0.02). However, no significant difference was observed for the intraoperative blood loss, postoperative blood loss, duration of hospital stay, thyroid weight and serum calcium level postoperatively in either group. The present meta-analysis indicated superiority of Harmonic Scalpel only in terms of surgical time compared with LigaSure hemostasis techniques in open thyroid surgery. PMID:27446546

  13. Exploring the mechanical basis for acceleration: pelvic limb locomotor function during accelerations in racing greyhounds (Canis familiaris)

    PubMed Central

    Williams, S. B.; Usherwood, J. R.; Jespers, K.; Channon, A. J.; Wilson, A. M.

    2009-01-01

    Summary Animals in their natural environments are confronted with a regular need to perform rapid accelerations (for example when escaping from predators or chasing prey). Such acceleration requires net positive mechanical work to be performed on the centre of mass by skeletal muscle. Here we determined how pelvic limb joints contribute to the mechanical work and power that are required for acceleration in galloping quadrupeds. In addition, we considered what, if any, biomechanical strategies exist to enable effective acceleration to be achieved. Simultaneous kinematic and kinetic data were collected for racing greyhounds undergoing a range of low to high accelerations. From these data, joint moments and joint powers were calculated for individual hindlimb joints. In addition, the mean effective mechanical advantage (EMA) of the limb and the `gear ratio' of each joint throughout stance were calculated. Greatest increases in joint work and power with acceleration appeared at the hip and hock joints, particularly in the lead limb. Largest increases in absolute positive joint work occurred at the hip, consistent with the hypothesis that quadrupeds power locomotion by torque about the hip. In addition, hindlimb EMA decreased substantially with increased acceleration – a potential strategy to increase stance time and thus ground impulses for a given peak force. This mechanism may also increase the mechanical advantage for applying the horizontal forces necessary for acceleration. PMID:19181903

  14. A comparison between tourniquet application and epinephrine injection for hemostasis during hypospadias surgery: The effect on bleeding and postoperative outcome.

    PubMed

    Alizadeh, F; Fakoor, A; Haghdani, S

    2016-06-01

    To compare tourniquet application and epinephrine injection for hemostasis during hypospadias surgery in terms of bleeding and complications. Between April 2013 and September 2014, patients who were admitted for hypospadias repair were divided by random allocation into either a diluted epinephrine injection (DE) group or tourniquet application (T) group for hemostasis during the procedure. In the T group, a rubber band was applied at the base of the penis after skin dissection, and in the DE group, epinephrine 1/100,000 was injected along the incision lines. The patients' ages, urethral defect lengths, pre-operative, intraoperative and postoperative variables were compared between the two groups. A total of 70 patients (35 in each group) were enrolled into the study. The mean ages and preoperative variables were not significantly different. Average blood loss was 23.51 ± 15.36 cc in the tourniquet group and 15.99 ± 10.00 cc in the epinephrine group, and was significantly higher in tourniquet group (P = 0.022); however, the mean operative time was not significantly different. Postoperative complications, described as Clavian classification, were reported in eight patients (23%) in the T group and 10 patients (30%) in the DE group, which was not significantly different. Epinephrine injections minimize operative bleeding without significant harmful effects on postoperative outcomes; therefore, it could be considered to be a safe and effective method for preparation of a bloodless field during hypospadias surgery. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  15. Caffeine accelerates recovery from general anesthesia

    PubMed Central

    Wang, Qiang; Fong, Robert; Mason, Peggy; Fox, Aaron P.

    2013-01-01

    General anesthetics inhibit neurotransmitter release from both neurons and secretory cells. If inhibition of neurotransmitter release is part of an anesthetic mechanism of action, then drugs that facilitate neurotransmitter release may aid in reversing general anesthesia. Drugs that elevate intracellular cAMP levels are known to facilitate neurotransmitter release. Three cAMP elevating drugs (forskolin, theophylline, and caffeine) were tested; all three drugs reversed the inhibition of neurotransmitter release produced by isoflurane in PC12 cells in vitro. The drugs were tested in isoflurane-anesthetized rats. Animals were injected with either saline or saline containing drug. All three drugs dramatically accelerated recovery from isoflurane anesthesia, but caffeine was most effective. None of the drugs, at the concentrations tested, had significant effects on breathing rates, O2 saturation, heart rate, or blood pressure in anesthetized animals. Caffeine alone was tested on propofol-anesthetized rats where it dramatically accelerated recovery from anesthesia. The ability of caffeine to accelerate recovery from anesthesia for different chemical classes of anesthetics, isoflurane and propofol, opens the possibility that it will do so for all commonly used general anesthetics, although additional studies will be required to determine whether this is in fact the case. Because anesthesia in rodents is thought to be similar to that in humans, these results suggest that caffeine might allow for rapid and uniform emergence from general anesthesia in human patients. PMID:24375022

  16. X-ray Laser Animated Fly-Through

    ScienceCinema

    None

    2018-01-16

    Take a tour with an electron's-eye-view through SLAC's revolutionary new X-ray laser facility with this 5 1/2 minute animation. See how the X-ray pulses are generated using the world's longest linear accelerator along with unique arrays of machinery specially designed for this one-of-a-kind tool. For more than 40 years, SLAC's two-mile-long linear accelerator (or linac) linac has produced high-energy electrons for cutting-edge physics experiments. Now, SLAC's linac has entered a new phase of its career with the creation of the Linac Coherent Light Source (LCLS).

  17. The hemostatic efficacy of chitosan-pads in hemodialysis patients with significant bleeding tendency.

    PubMed

    Misgav, Mudi; Lubetszki, Ahron; Brutman-Barazani, Tami; Martinowitz, Uri; Kenet, Gili

    2017-05-15

    Patients on chronic hemodialysis often have acquired coagulopathy that can aggravate bleeding from puncture site after needle extraction. Chitosan-based pads have been reported to accelerate hemostasis even in the presence of coagulopathy. The aim of this study was to evaluate the hemostatic efficacy of the chitosan pads compared to gauze pads, applied for local hemostasis. A crossover study in a cohort of patients on hemodialysis with extended time to hemostasis after needle extraction. At the end of each dialysis, either gauze or chitosan pad was applied on both access points (arterial and venous). The type of pad was changed in the next dialysis all together 5 times in each patient (10 applications per patient for every pad). A total of 288 applications, 144 for each type of pad, were performed in 15 patients. The average time to hemostasis for the entire group was significantly shorter with the chitosan pads compared to the regular gauze pads ("arterial" point 3 vs. 18.5 min, p<0.001 "venous" access 2.8 vs. 13.2 min, p<0.001, respectively). Chitosan pads significantly reduce time to hemostasis and should be considered for the treatment of accessible bleeds in patients with coagulopathy.

  18. Thrombin generation by activated factor VII on platelet activated by different agonists. Extending the cell-based model of hemostasis

    PubMed Central

    Altman, Raul; Scazziota, Alejandra Silvia; Herrera, Maria de Lourdes; Gonzalez, Claudio

    2006-01-01

    Background Platelet activation is crucial in normal hemostasis. Using a clotting system free of external tissue factor, we investigated whether activated Factor VII in combination with platelet agonists increased thrombin generation (TG) in vitro. Methods and results TG was quantified by time parameters: lag time (LT) and time to peak (TTP), and by amount of TG: peak of TG (PTG) and area under thrombin formation curve after 35 minutes (AUC→35min) in plasma from 29 healthy volunteers using the calibrated automated thrombography (CAT) technique. TG parameters were measured at basal conditions and after platelet stimulation by sodium arachidonate (AA), ADP, and collagen (Col). In addition, the effects of recombinant activated FVII (rFVIIa) alone or combined with the other platelet agonists on TG parameters were investigated. We found that LT and TTP were significantly decreased (p < 0.05) and PTG and AUC→35min were significantly increased (p < 0.05) in platelet rich plasma activated with AA, ADP, Col, and rFVIIa compared to non-activated platelet rich plasma from normal subjects (p = 0.01). Furthermore platelet rich plasma activated by the combined effects of rFVIIa plus AA, ADP or Col had significantly reduced LT and TTP and increased AUC→35min (but not PTG) when compared to platelet rich plasma activated with agonists in the absence of rFVIIa. Conclusion Platelets activated by AA, ADP, Col or rFVIIa triggered TG. This effect was increased by combining rFVIIa with other agonists. Our intrinsic coagulation system produced a burst in TG independent of external tissue factor activity an apparent hemostatic effect with little thrombotic capacity. Thus we suggest a modification in the cell-based model of hemostasis. PMID:16630353

  19. First Selective 12-LOX Inhibitor, ML355, Impairs Thrombus Formation and Vessel Occlusion In Vivo With Minimal Effects on Hemostasis.

    PubMed

    Adili, Reheman; Tourdot, Benjamin E; Mast, Katherine; Yeung, Jennifer; Freedman, John C; Green, Abigail; Luci, Diane K; Jadhav, Ajit; Simeonov, Anton; Maloney, David J; Holman, Theodore R; Holinstat, Michael

    2017-10-01

    Adequate platelet reactivity is required for maintaining hemostasis. However, excessive platelet reactivity can also lead to the formation of occlusive thrombi. Platelet 12(S)-lipoxygenase (12-LOX), an oxygenase highly expressed in the platelet, has been demonstrated to regulate platelet function and thrombosis ex vivo, supporting a key role for 12-LOX in the regulation of in vivo thrombosis. However, the ability to pharmacologically target 12-LOX in vivo has not been established to date. Here, we studied the effect of the first highly selective 12-LOX inhibitor, ML355, on in vivo thrombosis and hemostasis. ML355 dose-dependently inhibited human platelet aggregation and 12-LOX oxylipin production, as confirmed by mass spectrometry. Interestingly, the antiplatelet effects of ML355 were reversed after exposure to high concentrations of thrombin in vitro. Ex vivo flow chamber assays confirmed that human platelet adhesion and thrombus formation at arterial shear over collagen were attenuated in whole blood treated with ML355 comparable to aspirin. Oral administration of ML355 in mice showed reasonable plasma drug levels by pharmacokinetic assessment. ML355 treatment impaired thrombus growth and vessel occlusion in FeCl 3 -induced mesenteric and laser-induced cremaster arteriole thrombosis models in mice. Importantly, hemostatic plug formation and bleeding after treatment with ML355 was minimal in mice in response to laser ablation on the saphenous vein or in a cremaster microvasculature laser-induced rupture model. Our data strongly support 12-LOX as a key determinant of platelet reactivity in vivo, and inhibition of platelet 12-LOX with ML355 may represent a new class of antiplatelet therapy. © 2017 American Heart Association, Inc.

  20. Direct Injection of Blood Products Versus Gelatin Sponge as a Technique for Local Hemostasis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haaga, John; Rahim, Shiraz, E-mail: Shiraz.rahim@uhhospitals.org

    PurposeTo provide a method of reducing risk of minimally invasive procedures on patients with abnormal hemostasis and evaluate efficacy of direct fresh frozen plasma injection through a procedure needle tract compared to Gelfoam (gelatin sponge) administration.Materials and MethodsEighty patients with elevated international standardized ratio (INR) undergoing minimally invasive procedures using imaging guidance were selected retrospectively. Forty patients had received Gelfoam as a means of tract embolization during the procedure. The other 40 received local fresh frozen plasma (FFP) through the needle tract. The number of complications and clinically significant bleeding events were recorded. A threshold of 30 cc of blood lossmore » after a procedure was used to identify excess bleeding.ResultsNo patients experienced clinically significant bleeding after administration of FFP. Five patients experienced postoperative drops in hemoglobin or hematomas after administration of Gelfoam.ConclusionLocal injection of blood products can reduce postprocedure bleeding in patients undergoing minimally invasive procedures and provides a safe alternative to the use of synthetic fibrin plugs.« less

  1. Hemostasis biomarkers and incident cognitive impairment: the REGARDS study.

    PubMed

    Gillett, S R; McClure, L A; Callas, P W; Thacker, E L; Unverzagt, F W; Wadley, V G; Letter, A J; Cushman, M

    2018-05-07

    Vascular risk factors are associated with cognitive impairment, a condition with substantial public health burden. We hypothesized that hemostasis biomarkers related to vascular disease would be associated with risk of incident cognitive impairment. We performed a nested case control study including 1,082 participants with 3.5 years of follow-up in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a longitudinal cohort study of 30,239 black and white Americans ≥45 years old. Participants were free of stroke or cognitive impairment at baseline. Baseline D-dimer, fibrinogen, factor VIII, and protein C were measured in 495 cases who developed cognitive impairment during follow-up (based on abnormal scores on ≥2 of 3 cognitive tests) and 587 controls. Unadjusted ORs for incident cognitive impairment were 1.32 (95% CI 1.02, 1.70) for D-dimer >0.50 μg/mL, 1.83 (CI 1.24, 2.71) for fibrinogen >90 th percentile, 1.63 (CI 1.11, 2.38) for factor VIII >90 th percentile and 1.10 (CI 0.73, 1.65) for protein C < 10 th percentile. There were no differences in associations by race or region. Adjustment for demographic, vascular and health behavior risk factors attenuated these associations. However, having at least 2 elevated biomarkers was associated with incident cognitive impairment, with an adjusted OR 1.73 (CI 1.10, 2.69). Elevated D-dimer, fibrinogen, and factor VIII were not associated with occurrence of cognitive impairment after multivariable adjustment; however, having at least 2 abnormal biomarkers was associated, suggesting the burden of these biomarkers is relevant. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Gravity as a factor in the animal environment.

    NASA Technical Reports Server (NTRS)

    Smith, A. H.

    1972-01-01

    Review of current knowledge, research, and research planning on the influence of gravity upon living organisms. Discussed factors affecting the adaptability of animals to increased acceleration fields include age, sex, posture, and body size. Affected functions and aspects reviewed cover growth and mature body size, body composition, maintenance feed requirements, and feed utilization efficiency. It is expected that research involving the exposure of animals to altered gravity states will lead to new biological concepts of very broad importance.

  3. Fos-defined activity in rat brainstem following centripetal acceleration.

    PubMed

    Kaufman, G D; Anderson, J H; Beitz, A J

    1992-11-01

    To identify rat brainstem nuclei involved in the initial, short-term response to a change in gravito-inertial force, adult Long-Evans rats were rotated in the horizontal plane for 90 min in complete darkness after they were eccentrically positioned off the axis of rotation (off-axis) causing a centripetal acceleration of 2 g. Neural activation was defined by the brainstem distribution of the c-fos primary response gene protein, Fos, using immunohistochemistry. The Fos labeling in off-axis animals was compared with that of control animals who were rotated on the axis of rotation (on-axis) with no centripetal acceleration, or who were restrained but not rotated. In the off-axis animals there was a significant labeling of neurons: in the inferior, medial, and y-group subnuclei of the vestibular complex; in subnuclei of the inferior olive, especially the dorsomedial cell column; in midbrain nuclei, including the interstitial nucleus of Cajal, nucleus of Darkschewitsch, Edinger-Westphal nucleus, and dorsolateral periaqueductal gray; in autonomic centers including the solitary nucleus, area postrema, and locus coeruleus; and in reticular nuclei including the lateral reticular nucleus and the lateral parabrachial nucleus. Also, there was greater Fos expression in the dorsomedial cell column, the principal inferior olive subnuclei, inferior vestibular nucleus, the dorsolateral central gray, and the locus coeruleus in animals who had their heads restrained compared to animals whose heads were not restrained. As one control, the vestibular neuroepithelium was destroyed by injecting sodium arsanilate into the middle ear, bilaterally. This resulted in a complete lack of Fos labeling in the vestibular nuclei and the inferior olive, and a significant reduction in labeling in other nuclei in the off-axis condition, indicating that these nuclei have a significant labyrinth-sensitive component to their Fos labeling. The data indicate that several novel brainstem regions, including

  4. Evoked Potential Studies of the Effects of Impact Acceleration on the Motor Nervous System,

    DTIC Science & Technology

    1983-01-01

    experimental animals subjected to -Y ampere) were applied sufficient to obtain good (lateral impact) acceleration and animals sub- afferent evoked...NBDL -Y impact experiments were processed at the EP recorded from these animals before and after Texas Research Institute of Mental Sciences impact were...adjustments were made to playback discriminators and cord in a lateral (-Y) collision. Each and the sampling interval. The final digit. -e d, J animal was

  5. Accelerating Drug Development: Antiviral Therapies for Emerging Viruses as a Model.

    PubMed

    Everts, Maaike; Cihlar, Tomas; Bostwick, J Robert; Whitley, Richard J

    2017-01-06

    Drug discovery and development is a lengthy and expensive process. Although no one, simple, single solution can significantly accelerate this process, steps can be taken to avoid unnecessary delays. Using the development of antiviral therapies as a model, we describe options for acceleration that cover target selection, assay development and high-throughput screening, hit confirmation, lead identification and development, animal model evaluations, toxicity studies, regulatory issues, and the general drug discovery and development infrastructure. Together, these steps could result in accelerated timelines for bringing antiviral therapies to market so they can treat emerging infections and reduce human suffering.

  6. The role of platelet and endothelial GARP in thrombosis and hemostasis.

    PubMed

    Vermeersch, Elien; Denorme, Frederik; Maes, Wim; De Meyer, Simon F; Vanhoorelbeke, Karen; Edwards, Justin; Shevach, Ethan M; Unutmaz, Derya; Fujii, Hodaka; Deckmyn, Hans; Tersteeg, Claudia

    2017-01-01

    Glycoprotein-A Repetitions Predominant protein (GARP or LRRC32) is present on among others human platelets and endothelial cells. Evidence for its involvement in thrombus formation was suggested by full knockout of GARP in zebrafish. To evaluate the role of GARP in platelet physiology and in thrombus formation using platelet and endothelial conditional GARP knock out mice. Platelet and endothelial specific GARP knockout mice were generated using the Cre-loxP recombination system. The function of platelets without GARP was measured by flow cytometry, spreading analysis and aggregometry using PAR4-activating peptide and collagen related peptide. Additionally, clot retraction and collagen-induced platelet adhesion and aggregation under flow were analyzed. Finally, in vivo tail bleeding time, occlusion time of the mesenteric and carotid artery after FeCl3-induced thrombosis were determined in platelet and endothelial specific GARP knock out mice. Platelet specific GARP knockout mice had normal surface GPIb, GPVI and integrin αIIb glycoprotein expression. Although GARP expression was increased upon platelet activation, platelets without GARP displayed normal agonist induced activation, spreading on fibrinogen and aggregation responses. Furthermore, absence of GARP on platelets did not influence clot retraction and had no impact on thrombus formation on collagen-coated surfaces under flow. In line with this, neither the tail bleeding time nor the occlusion time in the carotid- and mesenteric artery after FeCl3-induced thrombus formation in platelet or endothelial specific GARP knock out mice were affected. Evidence is provided that platelet and endothelial GARP are not important in hemostasis and thrombosis in mice.

  7. Biological evaluation of the effect of sugammadex on hemostasis and bleeding

    PubMed Central

    Guerci, Philippe; Harter, Valentin; Fuchs-Buder, Thomas; Meistelman, Claude

    2015-01-01

    Background Notification of sugammadex has been supplemented with a section on hemostasis, including a longer clotting time in the first minutes following injection, without any documented clinical consequences. The objective of this observational study was to analyze the effects of sugammadex administration on routine coagulation tests and bleeding in the clinical setting. Methods After Institutional Review Board approval, a prospective observational study was conducted between January and December 2011. Adult patients scheduled for laparotomies were analyzed in groups according to the type of reversal (without sugammadex versus 2 or 4 mg/kg sugammadex). There were no changes in our current clinical practice. Blood samples drawn from these patients were standardized at the same time and tested using the same daily calibrated machine. The endpoint was a comparison of the activated partial thromboplastin time (aPTT), prothrombin time (PT), hemoglobin (Hb) level and hematocrit (Ht), immediately before sugammadex administration (H0) and 1 h after neuromuscular block reversal (H1). Results One hundred and forty-two patients in three groups were included as follows: 11 in the "without sugammadex" group, 64 in the "2 mg/kg sugammadex" group and 67 in the "4 mg/kg sugammadex" group. Results did not differ significantly among the groups. Conclusions In this prospective observational study, the use of 2 and 4 mg/kg sugammadex was not associated with a longer clotting time or decreased hemoglobin concentrations. Future prospective investigations should study patients receiving 16 mg/kg sugammadex and/or with abnormal coagulation tests. PMID:25664150

  8. [The morphology, typical combinations of polymorphic genes of hemostasis, and specific features of the pathogenesis of retrochorial hematoma in missed abortion].

    PubMed

    Milovanov, A P; Kuznetsova, N B; Bushtyreva, I O

    to identify mutations and hemostatic gene polymorphisms typical for retrochorial hematoma (RCH) and to study its pathogenesis in missed abortion. A PCR assay was used to detect the genetic forms of thrombophilia in 270 patients with ultrasonographically verified RCH. Logistic regression analysis revealed that with the F7 (proconvertin, coagulation factor (CF) VII G10976A polymorphism or with the F13 (fibrinase, CF XIII) G>T, or FGB (fibrinogen β-chain) G455A polymorphism, the risk of RCH was 2.72, 2.16, and 1.92 times higher, respectively. First trimester missed abortion was found in 42 (15.5%) cases; among them there were 24 (8.8%) women with different polymorphism combinations: F7 (G10976A), F13 (fibrinase, G>T), FGB (G455A). A total of 18 cases of missed abortion due to morphologically verified endometritis, endocrinopathies, and antiphospholipid syndrome were excluded from the sample. Compared to the morphology of medical abortions of the same period (16 women), patients with polymorphic genes of hemostasis were found to have statistically significant incomplete endometrial decidualization, thinning or absence of a Rohr's fibrinoid layer, a smaller number and shortening of syncytiotrophoblast microvilli, and the maximum amount of dissecting hemorrhage and RCH in the utero-chorionic region. The stages of RCH pathogenesis were determined; these included penetration of maternal erythrocytes deep into the decidua ~ dissociation of a layer of decidual cells with impairment of a «hemostatic envelope» ~ formation of RCH with a dense network of fibrin threads ~ final necrosis of surrounding cells and tissues. The investigators identified for the first time the typical combinations of polymorphic genes of predisposition to a high risk for RCH; its complete formation requires additional changes in maternal and placental components that provide local hemostasis.

  9. Changes in hemostasis caused by different replacement fluids and outcome in therapeutic plasma exchange in pediatric patients in a retrospective single center study.

    PubMed

    Witt, Volker; Pichler, Herbert; Beiglboeck, Elisabeth; Kursten, Friedrich; Weidner, Lisa

    2017-02-01

    Therapeutic plasma exchange (TPE) is a generally accepted and frequently performed procedure for numerous therapeutic indications in adults. Slowly, TPE is also becoming more and more popular in the treatment of pediatric patients. Although, we know that TPE is safe in pediatric patients, the outcome of children treated with TPE is rarely reported. Furthermore, there are only general recommendations regarding the plasma replacement fluid for children and these are adopted from adults. Data concerning outcome and the influence of different types of replacement fluids on hemostasis in children are scarce. We retrospectively evaluated 324 TPE treatments performed in 35 patients between 2008 and 2013 in our level 4 institution for pediatric hematology and oncology. The plasmapheresis procedures were categorized into three groups based on the replacement fluid used. The first group received solvent/detergent-treated (S/D) plasma (70.0% of patients), the second group was administered 5% human albumin (7.7% of patients) and the third group was treated with a combination of human albumin 5% and S/D plasma (22.3% of patients). To assess hemostasis, data on INR, aPTT, fibrinogen and ATIII were collected before and after plasmapheresis from the patients' charts. A modified Multi Organ Dysfunction Syndrome (MODS) Index was used to classify organ failure. Patient outcome, survival rate and adverse events were evaluated. We found a significant increase in the INR by 35.83% and of the aPTT by 18.53% within the human albumin group. The INR and aPTT of patients allocated to the S/D plasma group decreased by 1.58% and 15.77% on average, respectively. The combination group revealed a mild increase of the INR (9.47%), accompanied by a reduction of aPTT (5.97%). Furthermore we found that the survival rate was significantly associated with a MODS Index of <2 (p<0.001). Overall, the number of adverse events was low (1.2%) and none of these were considered life-threatening. Hemostasis

  10. Acute Management of Hemostasis in Patients With Neurological Injury.

    PubMed

    Baharoglu, M Irem; Brand, Anneke; Koopman, Maria M; Vermeulen, Marinus; Roos, Yvo B W E M

    2017-10-01

    Neurological injuries can be divided into those with traumatic and nontraumatic causes. The largest groups are traumatic brain injury (TBI) and nontraumatic stroke. TBI patients may present with intracranial hemorrhages (contusions, or subdural or epidural hematomas). Strokes are ischemic or hemorrhagic. In all these disorders, thrombosis and hemostasis play a major role. Treatment aims to either cease bleeding and/or restore perfusion. We reviewed hemostatic and thrombolytic therapies in patients with neurological injuries by MEDLINE and EMBASE search using various key words for neurological disorders and hemostatic therapies restricted to English language and human adults. Review of articles fulfilling inclusion criteria and relevant references revealed that, in patients with ischemic stroke, intravenous thrombolytic therapy with recombinant tissue plasminogen activator within 4.5-5 hours after onset of symptoms improves clinical outcome. In contrast, there are no hemostatic therapies that are proven to improve clinical outcome of patients with hemorrhagic stroke or TBI. In patients with hemorrhagic stroke who use vitamin K antagonist or direct oral anticoagulants, there is evidence that specific reversal therapies improve hemostatic laboratory parameters but without an effect on clinical recovery. In patients with hemorrhagic stroke or TBI who use concomitant antiplatelet therapy, there is evidence for harm of platelet transfusion. In patients with aneurysmal subarachnoid hemorrhage, tranexamic acid was shown to reduce rebleeding rate without improving clinical outcome. The effects of tranexamic acid in patients with TBI are still under investigation. We conclude that, in patients with ischemic stroke, thrombolytic therapy improves outcome when given within 4.5-5 hours. In hemorrhagic stroke and TBI, most hemostatic therapies improved or corrected laboratory parameters but not clinical outcome. Currently, in several trials, the effects of tranexamic acid are

  11. [The method of accelerating osteanagenesis and revascularization of tissue engineered bone in big animal in vivo].

    PubMed

    Chen, Bin; Pei, Guo-xian; Wang, Ke; Jin, Dan; Wei, Kuan-hai; Ren, Gao-hong

    2003-02-01

    To study whether tissue engineered bone can repair the large segment bone defect of large animal or not. To observe what character the fascia flap played during the osteanagenesis and revascularization process of tissue engineered bone. 9 Chinese goats were made 2 cm left tibia diaphyseal defect. The repairing effect of the defects was evaluated by ECT, X-ray and histology. 27 goats were divided into three groups: group of CHAP, the defect was filled with coral hydroxyapatite (CHAP); group of tissue engineered bone, the defect was filled with CHAP + bone marrow stroma cells (BMSc); group of fascia flap, the defect was filled with CHAP + BMSc + fascia flap. After finished culturing and inducing the BMSc, CHAP of group of tissue engineered bone and of fascia flap was combined with it. Making fascia flap, different materials as described above were then implanted separately into the defects. Radionuclide bone imaging was used to monitor the revascularization of the implants at 2, 4, 8 weeks after operation. X-ray examination, optical density index of X-ray film, V-G staining of tissue slice of the implants were used at 4, 8, 12 weeks after operation, and the biomechanical character of the specimens were tested at 12 weeks post operation. In the first study, the defect showed no bone regeneration phenomenon. 2 cm tibia defect was an ideal animal model. In the second study, group of CHAP manifested a little trace of bone regeneration, as to group of tissue engineered bone, the defect was almost repaired totally. In group of fascia flap, with the assistance of fascia flap which gave more chance to making implants to get more nutrient, the repair was quite complete. The model of 2 cm caprine tibia diaphyseal defect cannot be repaired by goat itself and can satisfy the tissue engineering's demands. Tissue engineered bone had good ability to repair large segment tibia defect of goat. Fascia flap can accelerate the revascularization process of tissue engineered bone. And by

  12. Acceleration performance of individual European sea bass Dicentrarchus labrax measured with a sprint performance chamber: comparison with high-speed cinematography and correlates with ecological performance.

    PubMed

    Vandamm, Joshua P; Marras, Stefano; Claireaux, Guy; Handelsman, Corey A; Nelson, Jay A

    2012-01-01

    Locomotor performance can influence the ecological and evolutionary success of a species. For fish, favorable outcomes of predator-prey encounters are often presumably due to robust acceleration ability. Although escape-response or "fast-start" studies utilizing high-speed cinematography are prevalent, little is known about the contribution of relative acceleration performance to ecological or evolutionary success in a species. This dearth of knowledge may be due to the time-consuming nature of analyzing film, which imposes a practical limit on sample sizes. Herein, we present a high-throughput potential alternative for measuring fish acceleration performance using a sprint performance chamber (SPC). The acceleration performance of a large number of juvenile European sea bass (Dicentrarchus labrax) from two populations was analyzed. Animals from both hatchery and natural ontogenies were assessed, and animals of known acceleration ability had their ecological performance measured in a mesocosm environment. Individuals from one population also had their acceleration performance assessed by both high-speed cinematography and an SPC. Acceleration performance measured in an SPC was lower than that measured by classical high-speed video techniques. However, short-term repeatability and interindividual variation of acceleration performance were similar between the two techniques, and the SPC recorded higher sprint swimming velocities. Wild fish were quicker to accelerate in an SPC and had significantly greater accelerations than all groups of hatchery-raised fish. Acceleration performance had no significant effect on ecological performance (as assessed through animal growth and survival in the mesocosms). However, it is worth noting that wild animals did survive predation in the mesocosm better than farmed ones. Moreover, the hatchery-originated fish that survived the mesocosm experiment, when no predators were present, displayed significantly increased acceleration

  13. A Rare Case of Pancreas Divisum Accompanied by Acute Pancreatitis Following Endoscopic Hemostasis for Duodenal Ulcer Bleeding.

    PubMed

    Choi, Yong Hyeok; Yoon, Soon Man; Kim, Eun Bee; Oh, Youngmin; Kim, Keunmo; Lee, Jisun; Park, Seon Mee; Youn, Sei Jin

    2017-04-25

    Peptic ulcer bleeding is treated using endoscopic hemostasis using clips or bands. Pancreas divisum (PD), a congenital anomaly of the pancreas, usually has no clinical symptoms; however, pancreatitis may occur if there are disturbances in the drainage of pancreatic secretions. We report an unusual case of PD accompanied by acute pancreatitis, following endoscopic band ligation for duodenal ulcer bleeding. A 48-year-old woman was admitted to our hospital due to melena. An upper endoscopy revealed a small ulcer with oozing adjacent minor papilla. An endoscopic band ligation was performed on this lesion. Acute pancreatitis developed suddenly 6 hours after the band ligation and improved dramatically after removal of the band. Magnetic resonance cholangiopancreatography was performed, revealing complete PD. Endoscopic band ligation is known as the effective method for peptic ulcer bleeding; however, it should be used carefully in duodenal ulcer bleeding near the minor duodenal papilla due to the possibility of PD.

  14. Animal models for osteoporosis

    NASA Technical Reports Server (NTRS)

    Turner, R. T.; Maran, A.; Lotinun, S.; Hefferan, T.; Evans, G. L.; Zhang, M.; Sibonga, J. D.

    2001-01-01

    Animal models will continue to be important tools in the quest to understand the contribution of specific genes to establishment of peak bone mass and optimal bone architecture, as well as the genetic basis for a predisposition toward accelerated bone loss in the presence of co-morbidity factors such as estrogen deficiency. Existing animal models will continue to be useful for modeling changes in bone metabolism and architecture induced by well-defined local and systemic factors. However, there is a critical unfulfilled need to develop and validate better animal models to allow fruitful investigation of the interaction of the multitude of factors which precipitate senile osteoporosis. Well characterized and validated animal models that can be recommended for investigation of the etiology, prevention and treatment of several forms of osteoporosis have been listed in Table 1. Also listed are models which are provisionally recommended. These latter models have potential but are inadequately characterized, deviate significantly from the human response, require careful choice of strain or age, or are not practical for most investigators to adopt. It cannot be stressed strongly enough that the enormous potential of laboratory animals as models for osteoporosis can only be realized if great care is taken in the choice of an appropriate species, age, experimental design, and measurements. Poor choices will results in misinterpretation of results which ultimately can bring harm to patients who suffer from osteoporosis by delaying advancement of knowledge.

  15. Effect of artificial gravity on thermoregulation, respiratory metabolism and intermediary metabolism of animals

    NASA Technical Reports Server (NTRS)

    Oyama, J.

    1973-01-01

    Metabolic alterations in animals exposed to radial acceleration are reported. Temperatures in acutely stressed animals dropped profoundly in correlation with decreased food consumption. Repeated exposure of the acutely stressed animal caused a decrease in hypothermic response whereas deceleration or reduction of G load did not significantly change body temperatures. Adrenal corticosteroids affected significantly the animal's recovery rate. No changes occured in body temperature patterns of chronically centrifuged animals after full adaptation; their respiratory rate increased very significantly in terms of CO2 output as did their glucose uptake by muscle tissues and their insulin responsiveness or sensitivity.

  16. Acceleration modules in linear induction accelerators

    NASA Astrophysics Data System (ADS)

    Wang, Shao-Heng; Deng, Jian-Jun

    2014-05-01

    The Linear Induction Accelerator (LIA) is a unique type of accelerator that is capable of accelerating kilo-Ampere charged particle current to tens of MeV energy. The present development of LIA in MHz bursting mode and the successful application into a synchrotron have broadened LIA's usage scope. Although the transformer model is widely used to explain the acceleration mechanism of LIAs, it is not appropriate to consider the induction electric field as the field which accelerates charged particles for many modern LIAs. We have examined the transition of the magnetic cores' functions during the LIA acceleration modules' evolution, distinguished transformer type and transmission line type LIA acceleration modules, and re-considered several related issues based on transmission line type LIA acceleration module. This clarified understanding should help in the further development and design of LIA acceleration modules.

  17. Companion animals: Translational scientist’s new best friends

    PubMed Central

    Kol, Amir; Arzi, Boaz; Athanasiou, Kyriacos A.; Farmer, Diana L.; Nolta, Jan A.; Rebhun, Robert B.; Chen, Xinbin; Griffiths, Leigh G.; Verstraete, Frank J. M.; Murphy, Christopher J.; Borjesson, Dori L.

    2016-01-01

    Knowledge and resources derived from veterinary medicine represent an underused resource that could serve as a bridge between data obtained from diseases models in laboratory animals and human clinical trials. Naturally occurring disease in companion animals that display the defining attributes of similar, if not identical, diseases in humans hold promise for providing predictive proof of concept in the evaluation of new therapeutics and devices. Here we outline comparative aspects of naturally occurring diseases in companion animals and discuss their current uses in translational medicine, benefits, and shortcomings. Last, we envision how these natural models of disease might ultimately decrease the failure rate in human clinical trials and accelerate the delivery of effective treatments to the human clinical market. PMID:26446953

  18. The role of platelet and endothelial GARP in thrombosis and hemostasis

    PubMed Central

    Vermeersch, Elien; Denorme, Frederik; Maes, Wim; De Meyer, Simon F.; Vanhoorelbeke, Karen; Edwards, Justin; Shevach, Ethan M.; Unutmaz, Derya; Fujii, Hodaka; Deckmyn, Hans; Tersteeg, Claudia

    2017-01-01

    Background Glycoprotein-A Repetitions Predominant protein (GARP or LRRC32) is present on among others human platelets and endothelial cells. Evidence for its involvement in thrombus formation was suggested by full knockout of GARP in zebrafish. Objectives To evaluate the role of GARP in platelet physiology and in thrombus formation using platelet and endothelial conditional GARP knock out mice. Methods Platelet and endothelial specific GARP knockout mice were generated using the Cre-loxP recombination system. The function of platelets without GARP was measured by flow cytometry, spreading analysis and aggregometry using PAR4-activating peptide and collagen related peptide. Additionally, clot retraction and collagen-induced platelet adhesion and aggregation under flow were analyzed. Finally, in vivo tail bleeding time, occlusion time of the mesenteric and carotid artery after FeCl3-induced thrombosis were determined in platelet and endothelial specific GARP knock out mice. Results Platelet specific GARP knockout mice had normal surface GPIb, GPVI and integrin αIIb glycoprotein expression. Although GARP expression was increased upon platelet activation, platelets without GARP displayed normal agonist induced activation, spreading on fibrinogen and aggregation responses. Furthermore, absence of GARP on platelets did not influence clot retraction and had no impact on thrombus formation on collagen-coated surfaces under flow. In line with this, neither the tail bleeding time nor the occlusion time in the carotid- and mesenteric artery after FeCl3-induced thrombus formation in platelet or endothelial specific GARP knock out mice were affected. Conclusions Evidence is provided that platelet and endothelial GARP are not important in hemostasis and thrombosis in mice. PMID:28278197

  19. Lack of grading agreement among international hemostasis external quality assessment programs

    PubMed Central

    Olson, John D.; Jennings, Ian; Meijer, Piet; Bon, Chantal; Bonar, Roslyn; Favaloro, Emmanuel J.; Higgins, Russell A.; Keeney, Michael; Mammen, Joy; Marlar, Richard A.; Meley, Roland; Nair, Sukesh C.; Nichols, William L.; Raby, Anne; Reverter, Joan C.; Srivastava, Alok; Walker, Isobel

    2018-01-01

    Laboratory quality programs rely on internal quality control and external quality assessment (EQA). EQA programs provide unknown specimens for the laboratory to test. The laboratory's result is compared with other (peer) laboratories performing the same test. EQA programs assign target values using a variety of methods statistical tools and performance assessment of ‘pass’ or ‘fail’ is made. EQA provider members of the international organization, external quality assurance in thrombosis and hemostasis, took part in a study to compare outcome of performance analysis using the same data set of laboratory results. Eleven EQA organizations using eight different analytical approaches participated. Data for a normal and prolonged activated partial thromboplastin time (aPTT) and a normal and reduced factor VIII (FVIII) from 218 laboratories were sent to the EQA providers who analyzed the data set using their method of evaluation for aPTT and FVIII, determining the performance for each laboratory record in the data set. Providers also summarized their statistical approach to assignment of target values and laboratory performance. Each laboratory record in the data set was graded pass/fail by all EQA providers for each of the four analytes. There was a lack of agreement of pass/fail grading among EQA programs. Discordance in the grading was 17.9 and 11% of normal and prolonged aPTT results, respectively, and 20.2 and 17.4% of normal and reduced FVIII results, respectively. All EQA programs in this study employed statistical methods compliant with the International Standardization Organization (ISO), ISO 13528, yet the evaluation of laboratory results for all four analytes showed remarkable grading discordance. PMID:29232255

  20. Comparative evaluation of two techniques of hemostasis in neonatal circumcision using the Plastibell device.

    PubMed

    Kazem, Moslemi Mohammad; Mehdi, Abedin Zadeh; Golrasteh, Kholaseh Zadeh; Behzad, Feis Zadeh

    2010-06-01

    To evaluate the safety of the Plastibell neonatal circumcision technique and the incidence of complications in Iranian neonates. In this study, 7510 term neonates born between 2001 and 2006 in Rafsanjan medical centers, with age range of 3-36h, were randomized into two groups. In group A (3760 cases), an incision was made in the dorsal surface of the prepuce and then 3min frenular manual compression was performed with a sponge. In group B (3750 cases), frenular hemostasis was achieved using ophthalmologic thermal cautery. The two groups were compared in terms of complications of hemorrhage, wound infection, urine retention and delayed wound healing. In group A, bleeding occurred in 15 cases (0.4%), and in group B in two cases (0.05%). The bleeding rate in group A was significantly higher (P=0.002). In group A, urinary retention was seen in 12 cases (0.03%), in comparison to 35 cases (0.9%) in group B. This complication rate was significantly higher in group B (P=0.001). Local or systemic infection was not seen in either group. Although using thermal cautery we have less bleeding, the total complication rate is increased significantly. Copyright (c) 2010 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  1. Outcomes in Patients Treated with a Novel, Simple Method for Hemostasis of Dermal Avulsion Injuries.

    PubMed

    Dowling, Sean Taylor; Lin, Brian Wai

    2017-10-01

    A recently described technique proposes a simple method to achieve permanent hemostasis of distal fingertip dermal avulsion injuries. It is simple to learn and easy to perform with readily available materials found in most emergency departments. However, long-term outcomes for patients treated with this technique have not yet been evaluated. A primary objective of the current article is to provide safety data for the technique using an off-label product indication. Emergency department of Kaiser Permanente Medical Center, San Francisco, California. Six patients were treated in the emergency department for fingertip dermal avulsion injuries using a tourniquet and tissue adhesive glue (Dermabond by Ethicon, Somerville, New Jersey). Patients were subsequently contacted to assess healing and satisfaction with cosmetic outcome through interview and photographs of their wounds at 9 months following the date of injury. All 6 patients were satisfied with the cosmetic outcome of treatment, and none received a diagnosis of serious complications. This series demonstrates cosmetic outcomes for injuries treated with the technique, highlights potential problems that may be perceived by patients during their clinical course, and creates the groundwork for a larger clinical study examining the use of the technique.

  2. Changes in mesenteric, renal, and aortic flows with +Gx acceleration

    NASA Technical Reports Server (NTRS)

    Stone, H. L.; Erickson, H. H.; Sandler, H.

    1974-01-01

    Previous studies in man and dogs have indicated that the splanchnic bed might contribute to the maintenance of arterial pressure during +Gx acceleration. Eight mongrel dogs were chronically instrumented with Doppler flow probes around the superior mesenteric (SMA) and renal arteries (RA) as well as the terminal aorta (TA). A solid-state pressure transducer was placed in the aorta distal to the flow probe. Using alpha-chloralose anesthesia following a 2-4 week recovery period, the animals were subjected to 120 sec at levels of 5, 10 and 15 +Gx acceleration on a 7.6-m radius centrifuge. The results indicate that both an active component and a mechanical component contribute to the maintenance of arterial pressure during +Gx acceleration.

  3. A prospective study on the effects on hemostasis of two oral contraceptives containing drospirenone in combination with either 30 or 20 microg ethinyl estradiol and a reference containing desogestrel and 30 microg ethinyl estradiol.

    PubMed

    Kluft, Cornelis; Endrikat, Jan; Mulder, Simone M; Gerlinger, Christoph; Heithecker, Renate

    2006-04-01

    In this open-label, randomized study, we assessed the effects on hemostasis of two combined oral contraceptives containing drospirenone (DRSP) as progestogen component. Three milligrams of DRSP, a progestogen with antimineralocorticoid activity, was combined with either 30 or 20 microg ethinyl estradiol (EE) (DRSP/30EE; DRSP/20EE) and compared with a preparation containing 150 microg desogestrel (DSG) and 30 microg ethinyl estradiol (DSG/30EE). A total of 75 healthy female volunteers aged 18-35 years were enrolled. The hemostasis variables were measured in the medication-free precycle (baseline); in the first, third and sixth treatment cycle; and in the follow-up phase. The target variables for comparison were the relative changes from baseline to Cycle 6. Data of 25 volunteers in each group were valid for the per-protocol evaluation. Most changes in hemostasis variables were similar in the three treatment groups. All procoagulatory variables and the anticoagulatory variable protein C antigen increased slightly, while protein S antigen and activity decreased. For fibrinogen and protein S activity, the changes were statistically significant: less pronounced with DRSP/20EE compared to DSG/30EE at Cycle 6. There were no statistically significant differences in the changes of antifibrinolytic variables, the global clotting tests and D-dimer. All pairwise comparisons of DRSP/30EE vs. DSG/30EE yielded nonsignificant results; however, there was a trend of a lower impact of DRSP/20EE on nearly all hemostatic parameters compared to the 30EE products. All three study treatments were safe and well tolerated by the volunteers and provided adequate contraceptive reliability. The changes in the hemostatic variables for DRSP/20EE were less pronounced compared to DSG/30EE and DRSP/30EE. The results were in accordance with previous reports on effects of similar OCs.

  4. A review of three stand-alone topical thrombins for surgical hemostasis.

    PubMed

    Cheng, Christine M; Meyer-Massetti, Carla; Kayser, Steven R

    2009-01-01

    bovine thrombin, the percentages of patients who achieved hemostasis within 10 minutes of topical thrombin application were 95.4% and 95.1%, respectively (95% CI, -3.7 to 5.0). The incidence of hemostasis within 10 minutes was also similar in a Phase III comparison of human plasma-derived thrombin and bovine thrombin (both, 97.4% [95% CI, 0.96 to 1.05]). In the study that compared human recombinant and bovine thrombin, the incidence of antiproduct antibody formation was 21.5% (43/200) in the bovine thrombin group and 1.5% (3/198) in the human recombinant thrombin group (P < 0.001); patients with antibodies to bovine thrombin had numerically higher incidences of bleeding or thromboembolic events than did patients without these antibodies (19% vs 13%; P value not reported). Human plasma-derived thrombin is available as a frozen sterile solution that must be thawed before application, whereas the human recombinant and bovine plasma-derived products are supplied as unrefrigerated sterile powders that must be reconstituted before use. The human thrombins are more costly than bovine thrombin on a per-vial basis. The average wholesale prices (US $, 2008) for 5000-IU vials of bovine thrombin and human recombinant thrombin were $87.85 and $103.20, respectively; the average wholesale price for a 4000- to 6000-IU vial of human plasma-derived thrombin was $96.00. Topical thrombins vary in the ways in which they are manufactured and their safety profiles, storage requirements, and costs. Human recombinant thrombin and human plasma-derived thrombin have each been shown to have hemostatic efficacy comparable to that of bovine thrombin. Bovine thrombin carries the risk of formation of cross-reactive antibodies to bovine thrombin, factor V, and other impurities that may be present in these formulations. Immunogenicity data for the currently marketed, highly purified bovine thrombin relative to older formulations of bovine thrombin could not be found. Whether the potential safety

  5. From sensor data to animal behaviour: an oystercatcher example.

    PubMed

    Shamoun-Baranes, Judy; Bom, Roeland; van Loon, E Emiel; Ens, Bruno J; Oosterbeek, Kees; Bouten, Willem

    2012-01-01

    Animal-borne sensors enable researchers to remotely track animals, their physiological state and body movements. Accelerometers, for example, have been used in several studies to measure body movement, posture, and energy expenditure, although predominantly in marine animals. In many studies, behaviour is often inferred from expert interpretation of sensor data and not validated with direct observations of the animal. The aim of this study was to derive models that could be used to classify oystercatcher (Haematopus ostralegus) behaviour based on sensor data. We measured the location, speed, and tri-axial acceleration of three oystercatchers using a flexible GPS tracking system and conducted simultaneous visual observations of the behaviour of these birds in their natural environment. We then used these data to develop three supervised classification trees of behaviour and finally applied one of the models to calculate time-activity budgets. The model based on accelerometer data developed to classify three behaviours (fly, terrestrial locomotion, and no movement) was much more accurate (cross-validation error = 0.14) than the model based on GPS-speed alone (cross-validation error = 0.35). The most parsimonious acceleration model designed to classify eight behaviours could distinguish five: fly, forage, body care, stand, and sit (cross-validation error = 0.28); other behaviours that were observed, such as aggression or handling of prey, could not be distinguished. Model limitations and potential improvements are discussed. The workflow design presented in this study can facilitate model development, be adapted to a wide range of species, and together with the appropriate measurements, can foster the study of behaviour and habitat use of free living animals throughout their annual routine.

  6. [Effects of phytoecdysteroids and bemithyl on functional, metabolic, and immunobiological parameters of working capacity in experimental animals].

    PubMed

    Syrov, V N; Shakhmurova, G A; Khushbaktova, Z A

    2008-01-01

    Influence of phytoecdysteroids (isolated from Ajuga turkestanica) and bemithyl on the duration of swimming of laboratory animals (mice, rats) under various experimental conditions was studied. Turkesteron and cyasteron increased duration of dynamic work carried out by animals, decreased fatigue, and accelerated recovery processes to a greater extent that did bemithyl. The positive influence of phytoecdysteroids on the working capacity is based on the activation of metabolic processes in skeletal muscles, directed to support the homeostasis of energy production. Phytoecdysteroids also accelerate recovery of immune reactions which are decreased due to the exhausting physical work.

  7. Gravitational considerations with animal rhythms

    NASA Technical Reports Server (NTRS)

    Wunder, C. C.

    1974-01-01

    As established in the laboratory and largely confirmed by others, simulated high-g environments influence growth and development of animals as small as or smaller than baby turtles, sometimes accelerating and sometimes decelerating these processes. High-g environments result in many functional changes or adjustments in feeding, metabolism, circulation, fluid balances, and structures for support, and influence life expectancy. An assembly of equipment suitable for measuring oxygen consumption of small mammals as influenced by chronic centrifugation and/or by day-night rhythms is discussed.

  8. Computer animation challenges for computational fluid dynamics

    NASA Astrophysics Data System (ADS)

    Vines, Mauricio; Lee, Won-Sook; Mavriplis, Catherine

    2012-07-01

    Computer animation requirements differ from those of traditional computational fluid dynamics (CFD) investigations in that visual plausibility and rapid frame update rates trump physical accuracy. We present an overview of the main techniques for fluid simulation in computer animation, starting with Eulerian grid approaches, the Lattice Boltzmann method, Fourier transform techniques and Lagrangian particle introduction. Adaptive grid methods, precomputation of results for model reduction, parallelisation and computation on graphical processing units (GPUs) are reviewed in the context of accelerating simulation computations for animation. A survey of current specific approaches for the application of these techniques to the simulation of smoke, fire, water, bubbles, mixing, phase change and solid-fluid coupling is also included. Adding plausibility to results through particle introduction, turbulence detail and concentration on regions of interest by level set techniques has elevated the degree of accuracy and realism of recent animations. Basic approaches are described here. Techniques to control the simulation to produce a desired visual effect are also discussed. Finally, some references to rendering techniques and haptic applications are mentioned to provide the reader with a complete picture of the challenges of simulating fluids in computer animation.

  9. Toward a theory of energetically optimal body size in growing animals.

    PubMed

    Hannon, B M; Murphy, M R

    2016-06-01

    Our objective was to formulate a general and useful model of the energy economy of the growing animal. We developed a theory that the respiratory energy per unit of size reaches a minimum at a particular point, when the marginal respiratory heat production rate is equal to the average rate. This occurs at what we defined as the energetically optimal size for the animal. The relationship between heat production rate and size was found to be well described by a cubic function in which heat production rate accelerates as the animal approaches and then exceeds its optimal size. Reanalysis of energetics data from the literature often detected cubic curvature in the relationship between heat production rate and body size of fish, rats, chickens, goats, sheep, swine, cattle, and horses. This finding was consistent with the theory for 13 of 17 data sets. The bias-corrected Akaike information criterion indicated that the cubic equation modeled the influence of the size of a growing animal on its heat production rate better than a power function for 11 of 17 data sets. Changes in the sizes and specific heat production rates of metabolically active internal organs, and body composition and tissue turnover rates were found to explain notable portions of the expected increase in heat production rate as animals approached and then exceeded their energetically optimum size. Accelerating maintenance costs in this region decrease net energy available for productive functions. Energetically and economically optimum size criteria were also compared.

  10. Accelerator system and method of accelerating particles

    NASA Technical Reports Server (NTRS)

    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.

  11. Handedness helps homing in swimming and flying animals.

    PubMed

    Bandyopadhyay, Promode R; Leinhos, Henry A; Hellum, Aren M

    2013-01-01

    Swimming and flying animals rely on their ability to home on mobile targets. In some fish, physiological handedness and homing correlate, and dolphins exhibit handedness in their listening response. Here, we explore theoretically whether the actuators, sensors, and controllers in these animals follow similar laws of self-regulation, and how handedness affects homing. We find that the acoustic sensor (combined hydrophone-accelerometer) response maps are similar to fin force maps-modeled by Stuart-Landau oscillators-allowing localization by transitional vortex-propelled animals. The planar trajectories of bats in a room filled with obstacles are approximately reproduced by the states of a pair of strong and weak olivo-cerebellar oscillators. The stereoscopy of handedness reduces ambiguity near a mobile target, resulting in accelerated homing compared to even-handedness. Our results demonstrate how vortex-propelled animals may be localizing each other and circumventing obstacles in changing environments. Handedness could be useful in time-critical robot-assisted rescues in hazardous environments.

  12. Handedness helps homing in swimming and flying animals

    PubMed Central

    Bandyopadhyay, Promode R.; Leinhos, Henry A.; Hellum, Aren M.

    2013-01-01

    Swimming and flying animals rely on their ability to home on mobile targets. In some fish, physiological handedness and homing correlate, and dolphins exhibit handedness in their listening response. Here, we explore theoretically whether the actuators, sensors, and controllers in these animals follow similar laws of self-regulation, and how handedness affects homing. We find that the acoustic sensor (combined hydrophone-accelerometer) response maps are similar to fin force maps—modeled by Stuart-Landau oscillators—allowing localization by transitional vortex-propelled animals. The planar trajectories of bats in a room filled with obstacles are approximately reproduced by the states of a pair of strong and weak olivo-cerebellar oscillators. The stereoscopy of handedness reduces ambiguity near a mobile target, resulting in accelerated homing compared to even-handedness. Our results demonstrate how vortex-propelled animals may be localizing each other and circumventing obstacles in changing environments. Handedness could be useful in time-critical robot-assisted rescues in hazardous environments. PMID:23350035

  13. Reversal of Apixaban Induced Alterations in Hemostasis by Different Coagulation Factor Concentrates: Significance of Studies In Vitro with Circulating Human Blood

    PubMed Central

    Arellano-Rodrigo, Eduardo; Roquer, Jaume; Reverter, Joan Carles; Sanz, Victoria Veronica; Molina, Patricia; Lopez-Vilchez, Irene; Diaz-Ricart, Maribel; Galan, Ana Maria

    2013-01-01

    Apixaban is a new oral anticoagulant with a specific inhibitory action on FXa. No information is available on the reversal of the antihemostatic action of apixaban in experimental or clinical settings. We have evaluated the effectiveness of different factor concentrates at reversing modifications of hemostatic mechanisms induced by moderately elevated concentrations of apixaban (200 ng/ml) added in vitro to blood from healthy donors (n = 10). Effects on thrombin generation (TG) and thromboelastometry (TEM) parameters were assessed. Modifications in platelet adhesive, aggregating and procoagulant activities were evaluated in studies with blood circulating through damaged vascular surfaces, at a shear rate of 600 s−1. The potential of prothrombin complex concentrates (PCCs; 50 IU/kg), activated prothrombin complex concentrates (aPCCs; 75 IU/kg), or activated recombinant factor VII (rFVIIa; 270 μg/kg), at reversing the antihemostatic actions of apixaban, were investigated. Apixaban interfered with TG kinetics. Delayed lag phase, prolonged time to peak and reduced peak values, were improved by the different concentrates, though modifications in TG patterns were diversely affected depending on the activating reagents. Apixaban significantly prolonged clotting times (CTs) in TEM studies. Prolongations in CTs were corrected by the different concentrates with variable efficacies (rFVIIa≥aPCC>PCC). Apixaban significantly reduced fibrin and platelet interactions with damaged vascular surfaces in perfusion studies (p<0.05 and p<0.01, respectively). Impairments in fibrin formation were normalized by the different concentrates. Only rFVIIa significantly restored levels of platelet deposition. Alterations in hemostasis induced by apixaban were variably compensated by the different factor concentrates investigated. However, effects of these concentrates were not homogeneous in all the tests, with PCCs showing more efficacy in TG, and rFVIIa being more effective on TEM

  14. The role of animal seed dispersal in accelerating native forest regeneration on degraded tropical lands.

    Treesearch

    J.M. Wunderle Jr.

    1997-01-01

    this paper reviews the characteristicas of animal seed dispersal. relevant to tropical forest restoration efforts and discusses their managment implication. In many tropical regions seed dispersal by animals is the predominant form of dissemination of propagules and has a potential to facilitate recolonization of native vegetation on degraded sites.

  15. Collagen fibril surface displays a constellation of sites capable of promoting fibril assembly, stability, and hemostasis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Orgel, J.P.; Antipova, O.; Sagi, I.

    Fibrillar collagens form the structural basis of organs and tissues including the vasculature, bone, and tendon. They are also dynamic, organizational scaffolds that present binding and recognition sites for ligands, cells, and platelets. We interpret recently published X-ray diffraction findings and use atomic force microscopy data to illustrate the significance of new insights into the functional organization of the collagen fibril. These data indicate that collagen's most crucial functional domains localize primarily to the overlap region, comprising a constellation of sites we call the 'master control region.' Moreover, the collagen's most exposed aspect contains its most stable part - themore » C-terminal region that controls collagen assembly, cross-linking, and blood clotting. Hidden beneath the fibril surface exists a constellation of 'cryptic' sequences poised to promote hemostasis and cell - collagen interactions in tissue injury and regeneration. These findings begin to address several important, and previously unresolved, questions: How functional domains are organized in the fibril, which domains are accessible, and which require proteolysis or structural trauma to become exposed? Here we speculate as to how collagen fibrillar organization impacts molecular processes relating to tissue growth, development, and repair.« less

  16. Is Intraoperative Use of QuikClot Combat Gauze Effective for Hemostasis after Total Knee Arthroplasty?

    PubMed Central

    Lee, Jae Woo; Nam, Young Joon; Choi, Ki Yong

    2017-01-01

    Background To assess the hemostatic effect of QuikClot Combat Gauze (QCG) compared to that of standard gauze during cruciate-retaining total knee arthroplasty (TKA). Methods Sixty knees underwent TKA using a pneumatic tourniquet in this prospective randomized study. After implantation of the femoral and tibial components and hardening of the bone cement, the tourniquet was deflated and QCG (group 1) or standard gauze (group 2) was packed into the joint cavity for 5 minutes for hemostasis. Perioperative bleeding volume and blood transfusion volume were compared between two groups. Results The mean intraoperative bleeding volume was 64.7 ± 12.7 mL in group 1 and 63.9 ± 9.2 mL in group 2 (p = 0.808). The mean postoperative blood drainage was 349.0 ± 170.6 mL in group 1 and 270.1 ± 136.3 mL in group 2 (p = 0.057). The average postoperative blood transfusion volume was 323.7 ± 325.9 mL in group 1 and 403.6 ± 274.8 mL in group 2 (p = 0.314). Conclusions QCG was not significantly effective for reducing perioperative bleeding volume or the blood transfusion rate compared with standard gauze during TKA. PMID:28261426

  17. Pathogenesis of Pancreatic Cancer: Lessons from Animal Models

    PubMed Central

    Murtaugh, L. Charles

    2014-01-01

    The past several decades have seen great effort devoted to mimicking the key features of pancreatic ductal adenocarcinoma (PDAC) in animals, and have produced two robust models of this deadly cancer. Carcinogen-treated Syrian hamsters develop PDAC with genetic lesions that reproduce those of human, including activation of the Kras oncogene, and early studies in this species validated non-genetic risk factors for PDAC including pancreatitis, obesity and diabetes. More recently, PDAC research has been invigorated by the development of genetically-engineered mouse models based on tissue-specific Kras activation and deletion of tumor suppressor genes. Surprisingly, mouse PDAC appears to arise from exocrine acinar rather than ductal cells, via a process of phenotypic reprogramming that is accelerated by inflammation. Studies in both models have uncovered molecular mechanisms by which inflammation promotes and sustains PDAC, and identified targets for chemoprevention to suppress PDAC in high-risk individuals. The mouse model, in particular, has also been instrumental in developing new approaches to early detection as well as treatment of advanced disease. Together, animal models enable diverse approaches to basic and preclinical research on pancreatic cancer, the results of which will accelerate progress against this currently intractable cancer. PMID:24178582

  18. Harmonisation of animal testing alternatives in China.

    PubMed

    Cheng, Shujun; Qu, Xiaoting; Qin, Yao

    2017-12-01

    More and more countries are lining up to follow the EU's approach and implement a full ban on the sale of cosmetics that have been tested on animals, which has been the case in the EU since 2013. Besides animal welfare considerations, the need for mutual acceptance of data (MAD) and harmonisation of the global market have made the move toward non-animal testing a desirable general trend for countries worldwide. Over the last 10 years, the concept of alternative methods has been gradually developing in China. This has seen the harmonisation of relevant legislation, the organisation of various theoretical and hands-on training sessions, the exploration of method validation, the adoption of internationally recognised methods, the propagation of alternative testing standards, and an in-depth investigation into the potential use of in vitro methods in the biosciences. There are barriers to this progress, including the demand for a completely new infrastructure, the need to build technology capability, the requirement for a national standardisation system formed through international co-operation, and the lack of technical assistance to facilitate self-innovation. China is now increasing speed in harmonising its approach to the use of non-animal alternatives, accelerating technological development and attempting to incorporate non-animal, in vitro, testing methods into the national regulatory system.

  19. The Intrinsic Pathway of Coagulation as a Target for Antithrombotic Therapy

    PubMed Central

    Wheeler, Allison P.; Gailani, David

    2016-01-01

    Plasma coagulation in the activated partial thromboplastin time assay is initiated by sequential activation of coagulation factors XII, XI and IX – the classical intrinsic pathway of coagulation. It is well recognized that this series of proteolytic reactions is not an accurate model for hemostasis in vivo, as factor XII deficiency does not cause abnormal bleeding, and fXI deficiency causes a relatively mild propensity to bleed excessively with injury. Despite their limited roles in hemostasis, there is mounting evidence that fXI and fXII contribute to thrombosis, and that inhibiting them can produce an antithrombotic effect with a relatively small effect on hemostasis. In this chapter the contributions of components of the intrinsic pathway to thrombosis in animal models and humans are discussed, and results of early clinical trials of drugs targeting factors IX, XI and XII are presented. PMID:27637310

  20. Imputation approaches for animal movement modeling

    USGS Publications Warehouse

    Scharf, Henry; Hooten, Mevin B.; Johnson, Devin S.

    2017-01-01

    The analysis of telemetry data is common in animal ecological studies. While the collection of telemetry data for individual animals has improved dramatically, the methods to properly account for inherent uncertainties (e.g., measurement error, dependence, barriers to movement) have lagged behind. Still, many new statistical approaches have been developed to infer unknown quantities affecting animal movement or predict movement based on telemetry data. Hierarchical statistical models are useful to account for some of the aforementioned uncertainties, as well as provide population-level inference, but they often come with an increased computational burden. For certain types of statistical models, it is straightforward to provide inference if the latent true animal trajectory is known, but challenging otherwise. In these cases, approaches related to multiple imputation have been employed to account for the uncertainty associated with our knowledge of the latent trajectory. Despite the increasing use of imputation approaches for modeling animal movement, the general sensitivity and accuracy of these methods have not been explored in detail. We provide an introduction to animal movement modeling and describe how imputation approaches may be helpful for certain types of models. We also assess the performance of imputation approaches in two simulation studies. Our simulation studies suggests that inference for model parameters directly related to the location of an individual may be more accurate than inference for parameters associated with higher-order processes such as velocity or acceleration. Finally, we apply these methods to analyze a telemetry data set involving northern fur seals (Callorhinus ursinus) in the Bering Sea. Supplementary materials accompanying this paper appear online.

  1. GPU-Accelerated Molecular Modeling Coming Of Age

    PubMed Central

    Stone, John E.; Hardy, David J.; Ufimtsev, Ivan S.

    2010-01-01

    Graphics processing units (GPUs) have traditionally been used in molecular modeling solely for visualization of molecular structures and animation of trajectories resulting from molecular dynamics simulations. Modern GPUs have evolved into fully programmable, massively parallel co-processors that can now be exploited to accelerate many scientific computations, typically providing about one order of magnitude speedup over CPU code and in special cases providing speedups of two orders of magnitude. This paper surveys the development of molecular modeling algorithms that leverage GPU computing, the advances already made and remaining issues to be resolved, and the continuing evolution of GPU technology that promises to become even more useful to molecular modeling. Hardware acceleration with commodity GPUs is expected to benefit the overall computational biology community by bringing teraflops performance to desktop workstations and in some cases potentially changing what were formerly batch-mode computational jobs into interactive tasks. PMID:20675161

  2. VENOM VARIATION IN HEMOSTASIS OF THE SOUTHERN PACIFIC RATTLESNAKE (Crotalus oreganus helleri): ISOLATION OF HELLERASE

    PubMed Central

    Salazar, Ana Maria; Guerrero, Belsy; Cantu, Bruno; Cantu, Esteban; Rodríguez-Acosta, Alexis; Pérez, John C.; Galán, Jacob A.; Tao, Andy; Sánchez, Elda E.

    2009-01-01

    Envenomations by the Southern Pacific Rattlesnake (Crotalus oreganus helleri) are the most common snakebite accidents in southern California. Intraspecies venom variation may lead to unresponsiveness of antivenom therapy. Even in a known species, venom toxins are recognized as diverse in conformity with interpopulational, seasonal, ontogenetic and individual factors. Five venoms of individual C. o. helleri located in Riverside and San Bernardino counties of southern California were studied for their variation in their hemostasis activity. The results demonstrated that Riverside 2 and San Bernardino 1 venoms presented the highest lethal activity without hemorrhagic activity. In contrast, San Bernardino 2 and 3 venoms had the highest hemorrhagic and fibrinolytic activities with low lethal and coagulant activities. Riverside 1, Riverside 2 and San Bernardino 1 venoms presented a significant thrombin-like activity. San Bernardino 2 and 3 venoms presented an insignificant thrombin-like activity. In relation to the fibrinolytic activity, San Bernardino 3 venom was the most active on fibrin plates, which was in turn neutralized by metal chelating inhibitors. These results demonstrate the differences amongst C. o helleri venoms from close localities. A metalloproteinase, hellerase, was purified by anionic and cationic exchange chromatography from San Bernardino 3 venom. Hellerase exhibited the ability to break fibrin clots in vitro, which can be of biomedically importance in the treatment of heart attacks and strokes. PMID:18804187

  3. Quantitative proteomics analysis highlights the role of redox hemostasis and energy metabolism in human embryonic stem cell differentiation to neural cells.

    PubMed

    Fathi, Ali; Hatami, Maryam; Vakilian, Haghighat; Han, Chia-Li; Chen, Yu-Ju; Baharvand, Hossein; Salekdeh, Ghasem Hosseini

    2014-04-14

    Neural differentiation of human embryonic stem cells (hESCs) is a unique opportunity for in vitro analyses of neurogenesis in humans. Extrinsic cues through neural plate formation are well described in the hESCs although intracellular mechanisms underlying neural development are largely unknown. Proteome analysis of hESC differentiation to neural cells will help to further define molecular mechanisms involved in neurogenesis in humans. Using a two-dimensional differential gel electrophoresis (2D-DIGE) system, we analyzed the proteome of hESC differentiation to neurons at three stages, early neural differentiation, neural ectoderm and mature neurons. Out of 137 differentially accumulated protein spots, 118 spots were identified using MALDI-TOF/TOF and LC MS/MS. We observed that proteins involved in redox hemostasis, vitamin and energy metabolism and ubiquitin dependent proteolysis were more abundant in differentiated cells, whereas the abundance of proteins associated with RNA processing and protein folding was higher in hESCs. Higher abundance of proteins involved in maintaining cellular redox state suggests the importance of redox hemostasis in neural differentiation. Furthermore, our results support the concept of a coupling mechanism between neuronal activity and glucose utilization. The protein network analysis showed that the majority of the interacting proteins were associated with the cell cycle and cellular proliferation. These results enhanced our understanding of the molecular dynamics that underlie neural commitment and differentiation. In highlighting the role of redox and unique metabolic properties of neuronal cells, the present findings add insight to our understanding of hESC differentiation to neurons. The abundance of fourteen proteins involved in maintaining cellular redox state, including 10 members of peroxiredoxin (Prdx) family, mainly increased during differentiation, thus highlighting a link of neural differentiation to redox. Our results

  4. First muon acceleration using a radio-frequency accelerator

    NASA Astrophysics Data System (ADS)

    Bae, S.; Choi, H.; Choi, S.; Fukao, Y.; Futatsukawa, K.; Hasegawa, K.; Iijima, T.; Iinuma, H.; Ishida, K.; Kawamura, N.; Kim, B.; Kitamura, R.; Ko, H. S.; Kondo, Y.; Li, S.; Mibe, T.; Miyake, Y.; Morishita, T.; Nakazawa, Y.; Otani, M.; Razuvaev, G. P.; Saito, N.; Shimomura, K.; Sue, Y.; Won, E.; Yamazaki, T.

    2018-05-01

    Muons have been accelerated by using a radio-frequency accelerator for the first time. Negative muonium atoms (Mu- ), which are bound states of positive muons (μ+) and two electrons, are generated from μ+'s through the electron capture process in an aluminum degrader. The generated Mu- 's are initially electrostatically accelerated and injected into a radio-frequency quadrupole linac (RFQ). In the RFQ, the Mu- 's are accelerated to 89 keV. The accelerated Mu- 's are identified by momentum measurement and time of flight. This compact muon linac opens the door to various muon accelerator applications including particle physics measurements and the construction of a transmission muon microscope.

  5. A Prospective, Randomized, Multicenter Clinical Trial on the Safety and Efficacy of a Ready-to-Use Fibrin Sealant as an Adjunct to Hemostasis during Vascular Surgery.

    PubMed

    Chetter, Ian; Stansby, Gerard; Sarralde, José Aurelio; Riambau, Vicente; Giménez-Gaibar, Antonio; MacKenzie, Kent; Acín, Francisco; Navarro-Puerto, Jordi

    2017-11-01

    Anastomotic or "stitch hole" bleeding is common during vascular surgery with synthetic material such as Dacron or polytetrafluoroethylene. Hemostatic adjuncts such as fibrin sealant (FS) may reduce blood loss and operating time in such circumstances. We evaluated the safety and the hemostatic effectiveness of a ready-to-use human plasma-derived FS in vascular surgery. Patients with mild/moderate suture line bleeding during elective, open, vascular surgery using synthetic grafts or patches were studied. In an initial Exploratory Study, all patients were treated with FS Grifols, and in a subsequent Primary Study were randomized in a 2:1 ratio to FS Grifols or manual compression (MC). The primary efficacy end point was time to hemostasis (TTH), assessed at defined intervals from the start of treatment application, during a 10-min observational period. Safety end points (in Exploratory + Primary Studies) included adverse events (AEs), vital signs, physical assessments, common clinical laboratory tests (coagulation, complete blood count, serum clinical chemistry parameters, microscopic urinalysis), viral markers, and immunogenicity. In the Primary Study, the proportion of patients who achieved hemostasis at the 3-min time point was higher in the FS Grifols group (46.4%, n = 51/110) than in the MC group (26.3%, n = 15/57) (P < 0.05). The benefit was maintained at successive time intervals: 69 FS Grifols patients (62.7%) and 18 MC patients (31.6%) at 4 min; 82 FS Grifols patients (74.5%) and 28 MC patients (49.1%) at 5 min. The differences between the groups persisted for TTH ≤ 7 min and TTH ≤ 10 min. Treatment failure was reported for 13 FS Grifols patients (11.8%) and 16 MC patients (28.1%). TTH was shorter after FS Grifols application than after MC application. Differences were statistically significant in favor of FS Grifols for each TTH category and for the overall comparison (P < 0.001) as well as for each TTH category (cumulative) and for

  6. Chronic acceleration and egg production in domestic fowl

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Besch, E. L.; Burton, R. R.

    1985-01-01

    A study of the influence of chronic acceleration on egg production of commercially raised hens placed on a large animal centrifuge at 90 days of age, was performed. S8 generation hens were stepped up from 1.25 G to 2 G, which was maintained for 30 days. Fifty percent ceased to be in the laying condition at 1.5 G, and 10.8 percent suffered oviduct prolapse above 1.8 G. S21 generation hens had no incidents of oviduct prolapse despite 170-day retention at 2 G, and, assuming a 30 percent population not in the laying condition, approximated the commercial production rate. Chronic acceleration did not appear to affect the relative sizes of albumen or yolk, but it did appear to reduce the relative shell size, consistent with a decrease in plasma calcium. Dry matter content was not affected.

  7. PARTICLE ACCELERATOR

    DOEpatents

    Teng, L.C.

    1960-01-19

    ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the cyclotron, a magnetic shield between the ring accelerator and the cyclotron, and a magnetic inflector within the ring accelerator.

  8. Accelerating cocaine metabolism as an approach to the treatment of cocaine abuse and toxicity

    PubMed Central

    Schindler, Charles W; Goldberg, Steven R

    2012-01-01

    One pharmacokinetic approach to the treatment of cocaine abuse and toxicity involves the development of compounds that can be safely administered to humans and that accelerate the metabolism of cocaine to inactive components. Catalytic antibodies have been developed and shown to accelerate cocaine metabolism, but their catalytic efficiency for cocaine is relatively low. Mutations of human butyrylcholinesterase and a bacterial cocaine esterase found in the soil of coca plants have also been developed. These compounds accelerate cocaine metabolism and antagonize the behavioral and toxic effects of cocaine in animal models. Of these two approaches, the human butyrylcholinesterase mutants show the most immediate promise as they would not be expected to evoke an immune response in humans. PMID:22300096

  9. Acceleration Modes and Transitions in Pulsed Plasma Accelerators

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Greve, Christine M.

    2018-01-01

    Pulsed plasma accelerators typically operate by storing energy in a capacitor bank and then discharging this energy through a gas, ionizing and accelerating it through the Lorentz body force. Two plasma accelerator types employing this general scheme have typically been studied: the gas-fed pulsed plasma thruster and the quasi-steady magnetoplasmadynamic (MPD) accelerator. The gas-fed pulsed plasma accelerator is generally represented as a completely transient device discharging in approximately 1-10 microseconds. When the capacitor bank is discharged through the gas, a current sheet forms at the breech of the thruster and propagates forward under a j (current density) by B (magnetic field) body force, entraining propellant it encounters. This process is sometimes referred to as detonation-mode acceleration because the current sheet representation approximates that of a strong shock propagating through the gas. Acceleration of the initial current sheet ceases when either the current sheet reaches the end of the device and is ejected or when the current in the circuit reverses, striking a new current sheet at the breech and depriving the initial sheet of additional acceleration. In the quasi-steady MPD accelerator, the pulse is lengthened to approximately 1 millisecond or longer and maintained at an approximately constant level during discharge. The time over which the transient phenomena experienced during startup typically occur is short relative to the overall discharge time, which is now long enough for the plasma to assume a relatively steady-state configuration. The ionized gas flows through a stationary current channel in a manner that is sometimes referred to as the deflagration-mode of operation. The plasma experiences electromagnetic acceleration as it flows through the current channel towards the exit of the device. A device that had a short pulse length but appeared to operate in a plasma acceleration regime different from the gas-fed pulsed plasma

  10. Concussion in professional football: animal model of brain injury--part 15.

    PubMed

    Viano, David C; Hamberger, Anders; Bolouri, Hayde; Säljö, Annette

    2009-06-01

    A concussion model was developed to study injury mechanisms, functional effects, treatment, and recovery. Concussions in National Football League football involve high-impact velocity (7.4-11.2 m/s) and rapid change in head velocity (DeltaV) (5.4-9.0 m/s). Current animal models do not simulate these head impact conditions. One hundred eight adult male Wistar rats weighing 280 to 350 g were used in ballistic impacts simulating 3 collision severities causing National Football League-type concussion. Pneumatic pressure accelerated a 50 g impactor to velocities of 7.4, 9.3, and 11.2 m/s at the left side of the helmet-protected head. A thin layer of padding on the helmet controlled head acceleration, which was measured on the opposite side of the head, in line with the impact. Peak head acceleration, DeltaV, impact duration, and energy transfer were determined. Fifty-four animals were exposed to single impact, with 18 each having 1, 4, or 10 days of survival. Similar tests were conducted on another 54 animals, which received 3 impacts at 6-hour intervals. An additional 72 animals were tested with a 100g impactor to study more serious brain injuries. Brains were perfused, and surface injuries were identified. The 50 g impactor matches concussion conditions scaled to the rat. Impact velocity and head DeltaV were within 1% and 3% of targets on average. Head acceleration reached 450 g to 1750 g without skull fracture. The test is repeatable and robust. Gross pathology was observed in 11%, 28%, and 33% of animals in the 7.4-, 9.3-, and 11.2-m/s single impacts, respectively. At 7.4 m/s, a single diameter area of less than 0.5 mm of fine petechial hemorrhage occurred on the brain surface in the parenchyma and meninges nearest the point of impact. At higher velocities, there were larger areas of bleeding, sometimes with subdural hemorrhage. When the 50 g impactor tests were examined by logistic regression, greater energy transfer increased the probability of injury (odds ratio

  11. Coordinated international action to accelerate genome-to-phenome with FAANG, The Functional Annotation of Animal Genomes project

    USDA-ARS?s Scientific Manuscript database

    We describe the organization of a nascent international effort - the "Functional Annotation of ANimal Genomes" project - whose aim is to produce comprehensive maps of functional elements in the genomes of domesticated animal species....

  12. GPU-accelerated molecular modeling coming of age.

    PubMed

    Stone, John E; Hardy, David J; Ufimtsev, Ivan S; Schulten, Klaus

    2010-09-01

    Graphics processing units (GPUs) have traditionally been used in molecular modeling solely for visualization of molecular structures and animation of trajectories resulting from molecular dynamics simulations. Modern GPUs have evolved into fully programmable, massively parallel co-processors that can now be exploited to accelerate many scientific computations, typically providing about one order of magnitude speedup over CPU code and in special cases providing speedups of two orders of magnitude. This paper surveys the development of molecular modeling algorithms that leverage GPU computing, the advances already made and remaining issues to be resolved, and the continuing evolution of GPU technology that promises to become even more useful to molecular modeling. Hardware acceleration with commodity GPUs is expected to benefit the overall computational biology community by bringing teraflops performance to desktop workstations and in some cases potentially changing what were formerly batch-mode computational jobs into interactive tasks. (c) 2010 Elsevier Inc. All rights reserved.

  13. Coordinated international action to accelerate genome-to-phenome with FAANG, the Functional Annotation of Animal Genomes project.

    PubMed

    Andersson, Leif; Archibald, Alan L; Bottema, Cynthia D; Brauning, Rudiger; Burgess, Shane C; Burt, Dave W; Casas, Eduardo; Cheng, Hans H; Clarke, Laura; Couldrey, Christine; Dalrymple, Brian P; Elsik, Christine G; Foissac, Sylvain; Giuffra, Elisabetta; Groenen, Martien A; Hayes, Ben J; Huang, LuSheng S; Khatib, Hassan; Kijas, James W; Kim, Heebal; Lunney, Joan K; McCarthy, Fiona M; McEwan, John C; Moore, Stephen; Nanduri, Bindu; Notredame, Cedric; Palti, Yniv; Plastow, Graham S; Reecy, James M; Rohrer, Gary A; Sarropoulou, Elena; Schmidt, Carl J; Silverstein, Jeffrey; Tellam, Ross L; Tixier-Boichard, Michele; Tosser-Klopp, Gwenola; Tuggle, Christopher K; Vilkki, Johanna; White, Stephen N; Zhao, Shuhong; Zhou, Huaijun

    2015-03-25

    We describe the organization of a nascent international effort, the Functional Annotation of Animal Genomes (FAANG) project, whose aim is to produce comprehensive maps of functional elements in the genomes of domesticated animal species.

  14. Averaged Propulsive Body Acceleration (APBA) Can Be Calculated from Biologging Tags That Incorporate Gyroscopes and Accelerometers to Estimate Swimming Speed, Hydrodynamic Drag and Energy Expenditure for Steller Sea Lions

    PubMed Central

    Trites, Andrew W.; Rosen, David A. S.; Potvin, Jean

    2016-01-01

    Forces due to propulsion should approximate forces due to hydrodynamic drag for animals horizontally swimming at a constant speed with negligible buoyancy forces. Propulsive forces should also correlate with energy expenditures associated with locomotion—an important cost of foraging. As such, biologging tags containing accelerometers are being used to generate proxies for animal energy expenditures despite being unable to distinguish rotational movements from linear movements. However, recent miniaturizations of gyroscopes offer the possibility of resolving this shortcoming and obtaining better estimates of body accelerations of swimming animals. We derived accelerations using gyroscope data for swimming Steller sea lions (Eumetopias jubatus), and determined how well the measured accelerations correlated with actual swimming speeds and with theoretical drag. We also compared dive averaged dynamic body acceleration estimates that incorporate gyroscope data, with the widely used Overall Dynamic Body Acceleration (ODBA) metric, which does not use gyroscope data. Four Steller sea lions equipped with biologging tags were trained to swim alongside a boat cruising at steady speeds in the range of 4 to 10 kph. At each speed, and for each dive, we computed a measure called Gyro-Informed Dynamic Acceleration (GIDA) using a method incorporating gyroscope data with accelerometer data. We derived a new metric—Averaged Propulsive Body Acceleration (APBA), which is the average gain in speed per flipper stroke divided by mean stroke cycle duration. Our results show that the gyro-based measure (APBA) is a better predictor of speed than ODBA. We also found that APBA can estimate average thrust production during a single stroke-glide cycle, and can be used to estimate energy expended during swimming. The gyroscope-derived methods we describe should be generally applicable in swimming animals where propulsive accelerations can be clearly identified in the signal—and they should

  15. Rotational accelerations stabilize leading edge vortices on revolving fly wings.

    PubMed

    Lentink, David; Dickinson, Michael H

    2009-08-01

    The aerodynamic performance of hovering insects is largely explained by the presence of a stably attached leading edge vortex (LEV) on top of their wings. Although LEVs have been visualized on real, physically modeled, and simulated insects, the physical mechanisms responsible for their stability are poorly understood. To gain fundamental insight into LEV stability on flapping fly wings we expressed the Navier-Stokes equations in a rotating frame of reference attached to the wing's surface. Using these equations we show that LEV dynamics on flapping wings are governed by three terms: angular, centripetal and Coriolis acceleration. Our analysis for hovering conditions shows that angular acceleration is proportional to the inverse of dimensionless stroke amplitude, whereas Coriolis and centripetal acceleration are proportional to the inverse of the Rossby number. Using a dynamically scaled robot model of a flapping fruit fly wing to systematically vary these dimensionless numbers, we determined which of the three accelerations mediate LEV stability. Our force measurements and flow visualizations indicate that the LEV is stabilized by the ;quasi-steady' centripetal and Coriolis accelerations that are present at low Rossby number and result from the propeller-like sweep of the wing. In contrast, the unsteady angular acceleration that results from the back and forth motion of a flapping wing does not appear to play a role in the stable attachment of the LEV. Angular acceleration is, however, critical for LEV integrity as we found it can mediate LEV spiral bursting, a high Reynolds number effect. Our analysis and experiments further suggest that the mechanism responsible for LEV stability is not dependent on Reynolds number, at least over the range most relevant for insect flight (100

  16. Non-Transfusional Hemocomponents: From Biology to the Clinic-A Literature Review.

    PubMed

    Gasparro, Roberta; Qorri, Erda; Valletta, Alessandra; Masucci, Michele; Sammartino, Pasquale; Amato, Alessandra; Marenzi, Gaetano

    2018-03-31

    Non-transfusional hemocomponents for surgical use are autogenous products prepared through the centrifugation of a blood sample from a patient. Their potential beneficial outcomes include hard and soft tissue regeneration, local hemostasis, and the acceleration of wound healing. Therefore, they are suitable for application in different medical fields as therapeutic options and in surgical practices that require tissue regeneration.

  17. Covariant Uniform Acceleration

    NASA Astrophysics Data System (ADS)

    Friedman, Yaakov; Scarr, Tzvi

    2013-04-01

    We derive a 4D covariant Relativistic Dynamics Equation. This equation canonically extends the 3D relativistic dynamics equation , where F is the 3D force and p = m0γv is the 3D relativistic momentum. The standard 4D equation is only partially covariant. To achieve full Lorentz covariance, we replace the four-force F by a rank 2 antisymmetric tensor acting on the four-velocity. By taking this tensor to be constant, we obtain a covariant definition of uniformly accelerated motion. This solves a problem of Einstein and Planck. We compute explicit solutions for uniformly accelerated motion. The solutions are divided into four Lorentz-invariant types: null, linear, rotational, and general. For null acceleration, the worldline is cubic in the time. Linear acceleration covariantly extends 1D hyperbolic motion, while rotational acceleration covariantly extends pure rotational motion. We use Generalized Fermi-Walker transport to construct a uniformly accelerated family of inertial frames which are instantaneously comoving to a uniformly accelerated observer. We explain the connection between our approach and that of Mashhoon. We show that our solutions of uniformly accelerated motion have constant acceleration in the comoving frame. Assuming the Weak Hypothesis of Locality, we obtain local spacetime transformations from a uniformly accelerated frame K' to an inertial frame K. The spacetime transformations between two uniformly accelerated frames with the same acceleration are Lorentz. We compute the metric at an arbitrary point of a uniformly accelerated frame. We obtain velocity and acceleration transformations from a uniformly accelerated system K' to an inertial frame K. We introduce the 4D velocity, an adaptation of Horwitz and Piron s notion of "off-shell." We derive the general formula for the time dilation between accelerated clocks. We obtain a formula for the angular velocity of a uniformly accelerated object. Every rest point of K' is uniformly accelerated, and

  18. [First experience of a polyurethane foam composition "Locus" use to stop intra-abdominal hemorrhage as a result of liver damage of V degree. (An experimental study)].

    PubMed

    Reva, V A; Litinskii, M A; Denisov, A V; Sokhranov, M V; Telitskii, S Yu; Samokhvalov, I M

    2015-04-01

    Today self-expanding polymers are considered as the most promising as means for intracavitary hemostasis in case of continuing bleeding after trauma. Testing of domestic open-cell polyurethane foam composition "Locus" was carried out on the developed experimental model simulating liver trauma of V degree. After damaging 6 experimental rabbits were injected intraperitoneally with 80 ml of the composition. 5 experimental rabbits were included into to control group (haemostatic agent was not given). Estimated blood loss was 111-124 ml. The two-hour survival rate didn't differ significantly: 3 animals survived in the experimental group; 2 animal survived in the control. Despite the 3-4-fold widening of the foam, due to open cells it absorbed 72.6 +/- 8.3 g of blood. Thus, open-cell polyurethane foam intraperitoneal administration of the composition didn't provide a temporary intra-abdominal hemostasis in liver. In order to enhance the hemostatic effect it requires changing the formulation of the polyurethane composition. For a more accurate assessment of the results it is neccessary to perform additional researches on larger animals.

  19. Analyzing radial acceleration with a smartphone acceleration sensor

    NASA Astrophysics Data System (ADS)

    Vogt, Patrik; Kuhn, Jochen

    2013-03-01

    This paper continues the sequence of experiments using the acceleration sensor of smartphones (for description of the function and the use of the acceleration sensor, see Ref. 1) within this column, in this case for analyzing the radial acceleration.

  20. [Experimental investigations of coagulation possibilities of noncoherent optico-electronic systems in operations on parenchymatous organs].

    PubMed

    Sukhin, I A; Furmanov, Iu O; Kozhukhar, O T; Savits'ka, I M; Kachan, S H; Bililovets', O M; Savits'kiĭ, O V

    2012-03-01

    Results of experimental investigation on elaboration and trial of surgical hemostasis method, using the quartz heating optic noncoherent irradiators of light, are adduced. Basing on analysis of the results obtained, the apparatus for photooptic coagulation was elaborated and trialed on experimental animals.

  1. A general scaling law reveals why the largest animals are not the fastest.

    PubMed

    Hirt, Myriam R; Jetz, Walter; Rall, Björn C; Brose, Ulrich

    2017-08-01

    Speed is the fundamental constraint on animal movement, yet there is no general consensus on the determinants of maximum speed itself. Here, we provide a general scaling model of maximum speed with body mass, which holds across locomotion modes, ecosystem types and taxonomic groups. In contrast to traditional power-law scaling, we predict a hump-shaped relationship resulting from a finite acceleration time for animals, which explains why the largest animals are not the fastest. This model is strongly supported by extensive empirical data (474 species, with body masses ranging from 30 μg to 100 tonnes) from terrestrial as well as aquatic ecosystems. Our approach unravels a fundamental constraint on the upper limit of animal movement, thus enabling a better understanding of realized movement patterns in nature and their multifold ecological consequences.

  2. Radiolabeled Microsphere Technique in Conscious Subjects during Acceleration Exposures on the USAFSAM Centrifuge.

    DTIC Science & Technology

    1980-03-01

    function even though the pump is pumping air into the blood manifold. R-2 is secured to the plate with two thumb screws, and when the syringes are...the scapula . The animals were allowed 2-4 weeks of surgical recovery before the acceleration studies were performed. Experimental Protocol--On the day

  3. Simple animal models for amyotrophic lateral sclerosis drug discovery.

    PubMed

    Patten, Shunmoogum A; Parker, J Alex; Wen, Xiao-Yan; Drapeau, Pierre

    2016-08-01

    Simple animal models have enabled great progress in uncovering the disease mechanisms of amyotrophic lateral sclerosis (ALS) and are helping in the selection of therapeutic compounds through chemical genetic approaches. Within this article, the authors provide a concise overview of simple model organisms, C. elegans, Drosophila and zebrafish, which have been employed to study ALS and discuss their value to ALS drug discovery. In particular, the authors focus on innovative chemical screens that have established simple organisms as important models for ALS drug discovery. There are several advantages of using simple animal model organisms to accelerate drug discovery for ALS. It is the authors' particular belief that the amenability of simple animal models to various genetic manipulations, the availability of a wide range of transgenic strains for labelling motoneurons and other cell types, combined with live imaging and chemical screens should allow for new detailed studies elucidating early pathological processes in ALS and subsequent drug and target discovery.

  4. Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Spentzouris, P.; /Fermilab; Cary, J.

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessarymore » accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors. ComPASS is in the first year of executing its plan to develop the next-generation HPC accelerator modeling tools. ComPASS aims to develop an integrated simulation environment that will utilize existing and new accelerator physics modules with petascale capabilities, by employing modern computing and solver technologies. The ComPASS vision is to deliver to accelerator scientists a virtual accelerator and virtual prototyping modeling environment, with the necessary multiphysics, multiscale capabilities. The plan for this development includes delivering accelerator modeling applications appropriate for each stage of the ComPASS software evolution. Such applications are already being used to address challenging problems in accelerator design and optimization. The Com

  5. Hemostasis and Lipoprotein Indices Signify Exacerbated Lung Injury in TB With Diabetes Comorbidity.

    PubMed

    Dong, Zhengwei; Shi, Jingyun; Dorhoi, Anca; Zhang, Jie; Soodeen-Lalloo, Adiilah K; Tan, WenLing; Yin, Hongyun; Sha, Wei; Li, Weitong; Zheng, Ruijuan; Liu, Zhonghua; Yang, Hua; Qin, Lianhua; Wang, Jie; Huang, Xiaochen; Wu, Chunyan; Kaufmann, Stefan H E; Feng, Yonghong

    2018-05-01

    Exacerbated immunopathology is a frequent consequence of TB that is complicated by diabetes mellitus (DM); however, the underlying mechanisms are still poorly defined. In the two groups of age- and sex-matched patients with TB and DM (DM-TB) and with TB and without DM, we microscopically evaluated the areas of caseous necrosis and graded the extent of perinecrotic fibrosis in lung biopsies from the sputum smear-negative (SN) patients. We scored acid-fast bacilli in sputum smear-positive (SP) patients and compiled CT scan data from both the SN and SP patients. We compared inflammatory biomarkers and routine hematologic and biochemical parameters. Binary logistic regression analyses were applied to define the indices associated with the extent of lung injury. Enlarged caseous necrotic areas with exacerbated fibrotic encapsulations were found in SN patients with DM-TB, consistent with the higher ratio of thick-walled cavities and more bacilli in the sputum from SP patients with DM-TB. Larger necrotic foci were detected in men compared with women within the SN TB groups. Significantly higher fibrinogen and lower high-density lipoprotein cholesterol (HDL-C) were observed in SN patients with DM-TB. Regression analyses revealed that diabetes, activation of the coagulation pathway (shown by increased platelet distribution width, decreased mean platelet volume, and shortened prothrombin time), and dyslipidemia (shown by decreased low-density lipoprotein cholesterol, HDL-C, and apolipoprotein A) are risk factors for severe lung lesions in both SN and SP patients with TB. Hemostasis and dyslipidemia are associated with granuloma necrosis and fibroplasia leading to exacerbated lung damage in TB, especially in patients with DM-TB. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  6. Effects of Geometry and Kinematics on Animals Leaping Out of Water

    NASA Astrophysics Data System (ADS)

    Chang, Brian; Myeong, Jihye; Virot, Emmanuel; Kim, Ho-Young; Jung, Sunghwan

    2017-11-01

    Leaping out of water is a phenomenon exhibited by a variety of aquatic and semi-aquatic animals, such as frogs and whales. In this study, we aim to elucidate the effects of geometric and kinematic conditions on the propulsive and drag force required for an animal to jump through the water interface. A simple mechanism was designed to measure the propulsive thrust produced by a flapping appendage. In a separate experiment to measure the opposing drag, simplified models of animals are 3D printed and fitted with pressure sensors. The model is accelerated from rest and covers a range of Re from 103 to 105. Using a high-speed camera and pressure sensors, we observed a deformation of the free surface prior to water exit, and correlated this to the drag force. Finally, we discuss a scaling law to describe the general physics which allow animals to leap out of water. NSF EAPSI.

  7. Experimental comparative study on morphological effects of different lasers on the liver.

    PubMed

    Godlewski, G; Miro, L; Chevalier, J M; Bureau, J P

    1982-01-01

    Three types of laser radiation were compared as to their capabilities in hepatic surgery using 17 New Zealand rabbits. In four animals, subtotal scalpel lobectomy was performed, the hepatic pedicle being clamped. Hemostasis is obtained by means of argon or Nd YAG laser as long as the internal diameter of the vessels encountered is less than 4.5 mm. Nd YAG laser requires a power output four times higher than argon laser to obtain hemostasis. In six animals limited resection was performed by means of Nd YAG and CO2 lasers. CO2 radiation supplied insufficient hemostasis whenever the vessel diameter was more than 1 mm despite an excellent cutting power. Nd YAG radiation created an important necrosis zone due to thermal diffusion. In seven animals various focal hepatic lesions produced by the three types of laser were compared. Argon laser induced superficial and regularly round lesion, Nd YAG laser deeper, cauliflower-like lesions with thermal diffusion following especially vessels. Veins presented thrombosis of their blood content and coagulation necrosis of their wall. The amount of glycogenic granulation decreased. The CO2 laser induced very sharp punctual lesion without necrosis. Electron-microscopic sections revealed faint shadowy liver cells closet to the thermal source and bubbled mitochondria containing disrupted critea around the lesion. In later lesions Nd YAG laser produced more extensive fibrosis than argon or CO2 laser. After first clinical trials we believe that laser irradiation is actually an adjuvant safety factor in current hepatic surgery, whereas the Nd YAG laser could be of real interest in metastatic carcinoma destruction in liver.

  8. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Siemann, R.H.; /SLAC

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  9. Commnity Petascale Project for Accelerator Science And Simulation: Advancing Computational Science for Future Accelerators And Accelerator Technologies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Spentzouris, Panagiotis; /Fermilab; Cary, John

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessarymore » accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.« less

  10. Fermilab | Tevatron | Accelerator

    Science.gov Websites

    Leading accelerator technology Accelerator complex Illinois Accelerator Research Center Fermilab temperature. They were used to transfer particles from one part of the Fermilab accelerator complex to another center ring of Fermilab's accelerator complex. Before the Tevatron shut down, it had three primary

  11. Post-procedural/pre-hemostasis intra-arterial nitroglycerin after transradial catheterization: A gender based analysis.

    PubMed

    Dharma, Surya; Kedev, Sasko; Patel, Tejas; Sukmawan, Renan; Gilchrist, Ian C; Rao, Sunil V

    2016-01-01

    We analyzed the effect of nitroglycerin on radial artery occlusion (RAO) in women undergoing transradial catheterization. A total of 1706 patients undergoing transradial catheterization were randomized to receive either 500μg intra-arterial nitroglycerin or placebo at the end of the radial procedure. We explored the gender-based analysis between women (n=539) and men (n=1167). The primary outcome was the incidence of RAO as confirmed by absence of antegrade flow at one day after the transradial procedure evaluated by duplex ultrasound of the radial artery. The use of nitroglycerin, as compared with placebo, did not significantly reduce the risk of RAO in women patients [odds ratio, 0.69; 95% confidence interval (CI), 0.38 to 1.26; P=0.147]. The risk of RAO was higher in women age <60years as compared with women age ≥60years [5.6% vs. 3.5%; odds ratio, 2.16; 95% CI, 1.18 to 3.94; P=0.008]. In women age <60years (n=237), both counter puncture technique and a duration of hemostasis ≥4h were associated with a similar enhanced risk of developing RAO (odds ratio, 3.51; 95% CI, 1.59 to 7.72; P<0.001). The administration of nitroglycerin at the end of a transradial catheterization in women did not reduce the risk of RAO as determined by ultrasound one day after the radial procedure. Age <60years was associated with a higher risk of RAO compared with age ≥60years in women. Further strategies to reduce RAO in women are needed. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Linking animal-borne video to accelerometers reveals prey capture variability.

    PubMed

    Watanabe, Yuuki Y; Takahashi, Akinori

    2013-02-05

    Understanding foraging is important in ecology, as it determines the energy gains and, ultimately, the fitness of animals. However, monitoring prey captures of individual animals is difficult. Direct observations using animal-borne videos have short recording periods, and indirect signals (e.g., stomach temperature) are never validated in the field. We took an integrated approach to monitor prey captures by a predator by deploying a video camera (lasting for 85 min) and two accelerometers (on the head and back, lasting for 50 h) on free-swimming Adélie penguins. The movies showed that penguins moved the heads rapidly to capture krill in midwater and fish (Pagothenia borchgrevinki) underneath the sea ice. Captures were remarkably fast (two krill per second in swarms) and efficient (244 krill or 33 P. borchgrevinki in 78-89 min). Prey captures were detected by the signal of head acceleration relative to body acceleration with high sensitivity and specificity (0.83-0.90), as shown by receiver-operating characteristic analysis. Extension of signal analysis to the entire behavioral records showed that krill captures were spatially and temporally more variable than P. borchgrevinki captures. Notably, the frequency distribution of krill capture rate closely followed a power-law model, indicating that the foraging success of penguins depends on a small number of very successful dives. The three steps illustrated here (i.e., video observations, linking video to behavioral signals, and extension of signal analysis) are unique approaches to understanding the spatial and temporal variability of ecologically important events such as foraging.

  13. Linking animal-borne video to accelerometers reveals prey capture variability

    PubMed Central

    Watanabe, Yuuki Y.; Takahashi, Akinori

    2013-01-01

    Understanding foraging is important in ecology, as it determines the energy gains and, ultimately, the fitness of animals. However, monitoring prey captures of individual animals is difficult. Direct observations using animal-borne videos have short recording periods, and indirect signals (e.g., stomach temperature) are never validated in the field. We took an integrated approach to monitor prey captures by a predator by deploying a video camera (lasting for 85 min) and two accelerometers (on the head and back, lasting for 50 h) on free-swimming Adélie penguins. The movies showed that penguins moved the heads rapidly to capture krill in midwater and fish (Pagothenia borchgrevinki) underneath the sea ice. Captures were remarkably fast (two krill per second in swarms) and efficient (244 krill or 33 P. borchgrevinki in 78–89 min). Prey captures were detected by the signal of head acceleration relative to body acceleration with high sensitivity and specificity (0.83–0.90), as shown by receiver-operating characteristic analysis. Extension of signal analysis to the entire behavioral records showed that krill captures were spatially and temporally more variable than P. borchgrevinki captures. Notably, the frequency distribution of krill capture rate closely followed a power-law model, indicating that the foraging success of penguins depends on a small number of very successful dives. The three steps illustrated here (i.e., video observations, linking video to behavioral signals, and extension of signal analysis) are unique approaches to understanding the spatial and temporal variability of ecologically important events such as foraging. PMID:23341596

  14. Piezoelectric particle accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kemp, Mark A.; Jongewaard, Erik N.; Haase, Andrew A.

    2017-08-29

    A particle accelerator is provided that includes a piezoelectric accelerator element, where the piezoelectric accelerator element includes a hollow cylindrical shape, and an input transducer, where the input transducer is disposed to provide an input signal to the piezoelectric accelerator element, where the input signal induces a mechanical excitation of the piezoelectric accelerator element, where the mechanical excitation is capable of generating a piezoelectric electric field proximal to an axis of the cylindrical shape, where the piezoelectric accelerator is configured to accelerate a charged particle longitudinally along the axis of the cylindrical shape according to the piezoelectric electric field.

  15. EDITORIAL: Laser and plasma accelerators Laser and plasma accelerators

    NASA Astrophysics Data System (ADS)

    Bingham, Robert

    2009-02-01

    This special issue on laser and plasma accelerators illustrates the rapid advancement and diverse applications of laser and plasma accelerators. Plasma is an attractive medium for particle acceleration because of the high electric field it can sustain, with studies of acceleration processes remaining one of the most important areas of research in both laboratory and astrophysical plasmas. The rapid advance in laser and accelerator technology has led to the development of terawatt and petawatt laser systems with ultra-high intensities and short sub-picosecond pulses, which are used to generate wakefields in plasma. Recent successes include the demonstration by several groups in 2004 of quasi-monoenergetic electron beams by wakefields in the bubble regime with the GeV energy barrier being reached in 2006, and the energy doubling of the SLAC high-energy electron beam from 42 to 85 GeV. The electron beams generated by the laser plasma driven wakefields have good spatial quality with energies ranging from MeV to GeV. A unique feature is that they are ultra-short bunches with simulations showing that they can be as short as a few femtoseconds with low-energy spread, making these beams ideal for a variety of applications ranging from novel high-brightness radiation sources for medicine, material science and ultrafast time-resolved radiobiology or chemistry. Laser driven ion acceleration experiments have also made significant advances over the last few years with applications in laser fusion, nuclear physics and medicine. Attention is focused on the possibility of producing quasi-mono-energetic ions with energies ranging from hundreds of MeV to GeV per nucleon. New acceleration mechanisms are being studied, including ion acceleration from ultra-thin foils and direct laser acceleration. The application of wakefields or beat waves in other areas of science such as astrophysics and particle physics is beginning to take off, such as the study of cosmic accelerators considered

  16. Understanding projectile acceleration.

    PubMed

    Hecht, H; Bertamini, M

    2000-04-01

    Throwing and catching balls or other objects is a generally highly practiced skill; however, conceptual as well as perceptual understanding of the mechanics that underlie this skill is surprisingly poor. In 5 experiments, we investigated conceptual and perceptual understanding of simple ballistic motion. Paper-and-pencil tests revealed that up to half of all participants mistakenly believed that a ball would continue to accelerate after it left the thrower's hand. Observers also showed a remarkable tolerance for anomalous trajectory shapes. Perceptual judgments based on graphics animations replicated these erroneous beliefs for shallow release angles. Observers' tolerance for anomalies tended to decrease with their distance from the actor. The findings are at odds with claims of the naive physics literature that liken intuitive understanding to Aristotelian or medieval physics theories. Instead, observers seem to project their intentions to the ball itself (externalization) or even feel that they have power over the ball when it is still close.

  17. Effect of animal products and extracts on wound healing promotion in topical applications: a review.

    PubMed

    Napavichayanun, Supamas; Aramwit, Pornanong

    2017-06-01

    Wound healing is a natural process of body reaction to repair itself after injury. Nonetheless, many internal and external factors such as aging, comorbidity, stress, smoking, alcohol drinking, infections, malnutrition, or wound environment significantly affect the quality and speed of wound healing. The unsuitable conditions may delay wound healing process and cause chronic wound or scar formation. Therefore, many researches have attempted to search for agents that can accelerate wound healing with safety and biocompatibility to human body. Widely studied wound healing agents are those derived from either natural sources including plants and animals or chemical synthesis. The natural products seem to be safer and more biocompatible to human tissue. This review paper demonstrated various kinds of the animal-derived products including chitosan, collagen, honey, anabolic steroids, silk sericin, peptides, and proteoglycan in term of mechanisms of action, advantages, and disadvantages when applied as wound healing accelerator. The benefits of these animal-derived products are wound healing promotion, anti-inflammatory, antimicrobial activity, moisturizing effect, biocompatibility, and safety. However, the drawbacks such as allergy, low stability, batch-to-batch variability, and high extraction and purification costs could not be avoided in some products.

  18. Aging accelerates memory extinction and impairs memory restoration in Drosophila.

    PubMed

    Chen, Nannan; Guo, Aike; Li, Yan

    2015-05-15

    Age-related memory impairment (AMI) is a phenomenon observed from invertebrates to human. Memory extinction is proposed to be an active inhibitory modification of memory, however, whether extinction is affected in aging animals remains to be elucidated. Employing a modified paradigm for studying memory extinction in fruit flies, we found that only the stable, but not the labile memory component was suppressed by extinction, thus effectively resulting in higher memory loss in aging flies. Strikingly, young flies were able to fully restore the stable memory component 3 h post extinction, while aging flies failed to do so. In conclusion, our findings reveal that both accelerated extinction and impaired restoration contribute to memory impairment in aging animals. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Engineering to support wellbeing of dairy animals.

    PubMed

    Caja, Gerardo; Castro-Costa, Andreia; Knight, Christopher H

    2016-05-01

    Current trends in the global milk market and the recent abolition of milk quotas have accelerated the trend of the European dairy industry towards larger farm sizes and higher-yielding animals. Dairy cows remain in focus, but there is a growing interest in other dairy species, whose milk is often directed to traditional and protected designation of origin and gourmet dairy products. The challenge for dairy farms in general is to achieve the best possible standards of animal health and welfare, together with high lactational performance and minimal environmental impact. For larger farms, this may need to be done with a much lower ratio of husbandry staff to animals. Recent engineering advances and the decreasing cost of electronic technologies has allowed the development of 'sensing solutions' that automatically collect data, such as physiological parameters, production measures and behavioural traits. Such data can potentially help the decision making process, enabling early detection of health or wellbeing problems in individual animals and hence the application of appropriate corrective husbandry practices. This review focuses on new knowledge and emerging developments in welfare biomarkers (e.g. stress and metabolic diseases), activity-based welfare assessment (e.g. oestrus and lameness detection) and sensors of temperature and pH (e.g. calving alert and rumen function) and their combination and integration into 'smart' husbandry support systems that will ensure optimum wellbeing for dairy animals and thereby maximise farm profitability. Use of novel sensors combined with new technologies for information handling and communication are expected to produce dramatic changes in traditional dairy farming systems.

  20. Principles for developing animal models of military PTSD

    PubMed Central

    Daskalakis, Nikolaos P.; Yehuda, Rachel

    2014-01-01

    The extent to which animal studies can be relevant to military posttraumatic stress disorder (PTSD) continues to be a matter of discussion. Some features of the clinical syndrome are more easily modeled than others. In the animal literature, a great deal of attention is focused on modeling the characteristics of military exposures and their impact on measurable behaviors and biological parameters. There are many issues to consider regarding the ecological validity of predator, social defeat or immobilization stress to combat-related experience. In contrast, less attention has been paid to individual variation following these exposures. Such variation is critical to understand how individual differences in the response to military trauma exposure may result to PTSD or resilience. It is important to consider potential differences in biological findings when comparing extremely exposed to non-exposed animals, versus those that result from examining individual differences. Animal models of military PTSD are also critical in advancing efforts in clinical treatment. In an ideal translational approach to study deployment related outcomes, information from humans and animals, blood and brain, should be carefully considered in tandem, possibly even computed simultaneously, to identify molecules, pathways and networks that are likely to be the key drivers of military PTSD symptoms. With the use novel biological methodologies (e.g., optogenetics) in the animal models, critical genes and pathways can be tuned up or down (rather than over-expressed or ablated completely) in discrete brain regions. Such techniques together with pre-and post-deployment human imaging will accelerate the identification of novel pharmacological and non-pharmacological intervention strategies. PMID:25206946

  1. Response of semicircular canal dependent units in vestibular nuclei to rotation of a linear acceleration vector without angular acceleration

    PubMed Central

    Benson, A. J.; Guedry, F. E.; Jones, G. Melvill

    1970-01-01

    1. Recent experiments have shown that rotation of a linear acceleration vector round the head can generate involuntary ocular nystagmus in the absence of angular acceleration. The present experiments examine the suggestion that adequate stimulation of the semicircular canals may contribute to this response. 2. Decerebrate cats were located in a stereotaxic device on a platform, slung from four parallel cables, which could be driven smoothly round a circular orbit without inducing significant angular movement of the platform. This Parallel Swing Rotation (PSR) generated a centripetal acceleration of 4·4 m/sec2 which rotated round the head at 0·52 rev/sec. 3. The discharge frequency of specifically lateral canal-dependent neural units in the vestibular nuclei of cats was recorded during PSR to right and left, and in the absence of motion. The dynamic responses to purely angular motion were also examined on a servo-driven turntable. 4. Without exception all proven canal-dependent cells examined (twenty-nine cells in nine cats) were more active during PSR in the direction of endolymph circulation assessed to be excitatory to the unit, than during PSR in the opposite direction. 5. The observed changes in discharge frequency are assessed to have been of a magnitude appropriate for the generation of the involuntary oculomotor response induced by the same stimulus in the intact animal. 6. The findings suggest that a linear acceleration vector which rotates in the plane of the lateral semicircular canals can be an adequate stimulus to ampullary receptors, though an explanation which invokes the modulation of canal cells by a signal dependent upon the sequential activation of macular receptors cannot be positively excluded. PMID:5501270

  2. Source-to-accelerator quadrupole matching section for a compact linear accelerator

    NASA Astrophysics Data System (ADS)

    Seidl, P. A.; Persaud, A.; Ghiorso, W.; Ji, Q.; Waldron, W. L.; Lal, A.; Vinayakumar, K. B.; Schenkel, T.

    2018-05-01

    Recently, we presented a new approach for a compact radio-frequency (RF) accelerator structure and demonstrated the functionality of the individual components: acceleration units and focusing elements. In this paper, we combine these units to form a working accelerator structure: a matching section between the ion source extraction grids and the RF-acceleration unit and electrostatic focusing quadrupoles between successive acceleration units. The matching section consists of six electrostatic quadrupoles (ESQs) fabricated using 3D-printing techniques. The matching section enables us to capture more beam current and to match the beam envelope to conditions for stable transport in an acceleration lattice. We present data from an integrated accelerator consisting of the source, matching section, and an ESQ doublet sandwiched between two RF-acceleration units.

  3. Endoscopic hemostasis for peptic ulcer bleeding: systematic review and meta-analyses of randomized controlled trials.

    PubMed

    Baracat, Felipe; Moura, Eduardo; Bernardo, Wanderley; Pu, Leonardo Zorron; Mendonça, Ernesto; Moura, Diogo; Baracat, Renato; Ide, Edson

    2016-06-01

    Peptic ulcer represents the most common cause of upper gastrointestinal bleeding. Endoscopic therapy can reduce the risks of rebleeding, continued bleeding, need for surgery, and mortality. The objective of this review is to compare the different modalities of endoscopic therapy. Studies were identified by searching electronic databases MEDLINE, Embase, Cochrane, LILACS, DARE, and CINAHL. We selected randomized clinical trials that assessed contemporary endoscopic hemostatic techniques. The outcomes evaluated were: initial hemostasis, rebleeding rate, need for surgery, and mortality. The possibility of publication bias was evaluated by funnel plots. An additional analysis was made, including only the higher-quality trials. Twenty-eight trials involving 2988 patients were evaluated. Injection therapy alone was inferior to injection therapy with hemoclip and with thermal coagulation when evaluating rebleeding and the need for emergency surgery. Hemoclip was superior to injection therapy in terms of rebleeding; there were no statistically significant differences between hemoclip alone and hemoclip with injection therapy. There was considerable heterogeneity in the comparisons between hemoclip and thermal coagulation. There were no statistically significant differences between thermal coagulation and injection therapy, though their combination was superior, in terms of rebleeding, to thermal coagulation alone. Injection therapy should not be used alone. Hemoclip is superior to injection therapy, and combining hemoclip with an injectate does not improve hemostatic efficacy above hemoclip alone. Thermal coagulation has similar efficacy as injection therapy; combining these appears to be superior to thermal coagulation alone. Therefore, we recommend the application of hemoclips or the combined use of injection therapy with thermal coagulation for the treatment of peptic ulcer bleeding.

  4. Animal welfare: an animal science approach.

    PubMed

    Koknaroglu, H; Akunal, T

    2013-12-01

    Increasing world population and demand for animal-derived protein puts pressure on animal production to meet this demand. For this purpose animal breeding efforts were conducted to obtain the maximum yield that the genetic makeup of the animals permits. Under the influence of economics which is the driving force behind animal production, animal farming became more concentrated and controlled which resulted in rearing animals under confinement. Since more attention was given on economics and yield per animal, animal welfare and behavior were neglected. Animal welfare which can be defined as providing environmental conditions in which animals can display all their natural behaviors in nature started gaining importance in recent years. This does not necessarily mean that animals provided with good management practices would have better welfare conditions as some animals may be distressed even though they are in good environmental conditions. Consumers are willing to pay more for welfare-friendly products (e.g.: free range vs caged egg) and this will change the animal production practices in the future. Thus animal scientists will have to adapt themselves for the changing animal welfare rules and regulations that differ for farm animal species and countries. In this review paper, animal welfare is discussed from an animal science standpoint. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  5. [Effects of hypophyseal Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly synthetic peptides on immunity, hemostasis, morphology and functions of the thyroid gland in neonatally hypophysectomized chicken and one-year-old birds].

    PubMed

    Kuznik, B I; Pateiuk, A V; Rusaeva, N S; Baranchugova, L M; Obydenko, V I

    2010-01-01

    Neonatal hypophysectomy in chicken produces enlarged follicles of the thyroid gland, accumulation of colloids, impressed follicular epithelium, increased nucleus-cytoplasm ratio in thyrocytes, atrophied inter-follicular epithelium, depressed immunity, development of hypercoagulation and depressed fibrinolysis. When hypophysectomy is performed in one-year-old birds the impairments developing in thyroid morphology, immunity and hemostasis are less pronounced. Peptides of the anterior (Lys-Glu-Asp-Gly) and posterior (Ala-Glu-Asp-Gly) thyroid lobes injected to hypophysectomized birds prevent atrophic changes of the thyroid gland, normalize immune and hemostatic parameters.

  6. Can Accelerators Accelerate Learning?

    NASA Astrophysics Data System (ADS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    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.

  7. Molecular evolution of cyclin proteins in animals and fungi

    PubMed Central

    2011-01-01

    Background The passage through the cell cycle is controlled by complexes of cyclins, the regulatory units, with cyclin-dependent kinases, the catalytic units. It is also known that cyclins form several families, which differ considerably in primary structure from one eukaryotic organism to another. Despite these lines of evidence, the relationship between the evolution of cyclins and their function is an open issue. Here we present the results of our study on the molecular evolution of A-, B-, D-, E-type cyclin proteins in animals and fungi. Results We constructed phylogenetic trees for these proteins, their ancestral sequences and analyzed patterns of amino acid replacements. The analysis of infrequently fixed atypical amino acid replacements in cyclins evidenced that accelerated evolution proceeded predominantly during paralog duplication or after it in animals and fungi and that it was related to aromorphic changes in animals. It was shown also that evolutionary flexibility of cyclin function may be provided by consequential reorganization of regions on protein surface remote from CDK binding sites in animal and fungal cyclins and by functional differentiation of paralogous cyclins formed in animal evolution. Conclusions The results suggested that changes in the number and/or nature of cyclin-binding proteins may underlie the evolutionary role of the alterations in the molecular structure of cyclins and their involvement in diverse molecular-genetic events. PMID:21798004

  8. Accelerations in Flight

    NASA Technical Reports Server (NTRS)

    Doolittle, J H

    1925-01-01

    This work on accelerometry was done at McCook Field for the purpose of continuing the work done by other investigators and obtaining the accelerations which occur when a high-speed pursuit airplane is subjected to the more common maneuvers. The accelerations obtained in suddenly pulling out of a dive with well-balanced elevators are shown to be within 3 or 4 per cent of the theoretically possible accelerations. The maximum acceleration which a pilot can withstand depends upon the length of time the acceleration is continued. It is shown that he experiences no difficulty under the instantaneous accelerations as high as 7.8 G., but when under accelerations in excess of 4.5 G., continued for several seconds, he quickly loses his faculties.

  9. Ultrahigh resolution and brilliance laser wakefield accelerator betatron x-ray source for rapid in vivo tomographic microvasculature imaging in small animal models

    NASA Astrophysics Data System (ADS)

    Fourmaux, Sylvain; Kieffer, Jean-Claude; Krol, Andrzej

    2017-03-01

    We are developing ultrahigh spatial resolution (FWHM < 2 μm) high-brilliance x-ray source for rapid in vivo tomographic microvasculature imaging micro-CT angiography (μCTA) in small animal models using optimized contrast agent. It exploits Laser Wakefield Accelerator (LWFA) betatron x-ray emission phenomenon. Ultrashort high-intensity laser pulse interacting with a supersonic gas jet produces an ion cavity ("bubble") in the plasma in the wake of the laser pulse. Electrons that are injected into this bubble gain energy, perform wiggler-like oscillations and generate burst of incoherent x-rays with characteristic duration time comparable to the laser pulse duration, continuous synchrotron-like spectral distribution that might extend to hundreds keV, very high brilliance, very small focal spot and highly directional emission in the cone-beam geometry. Such LWFA betatron x-ray source created in our lab produced 1021 -1023 photonsṡ shot-1ṡmrad-2ṡmm-2/0.1%bw with mean critical energy in the12-30 keV range. X-ray source size for a single laser shot was FWHM=1.7 μm x-ray beam divergence 20-30 mrad, and effective focal spot size for multiple shots FWHM= 2 μm. Projection images of simple phantoms and complex biological objects including insects and mice were obtained in single laser shots. We conclude that ultrahigh spatial resolution μCTA (FWHM 2 μm) requiring thousands of projection images could be accomplished using LWFA betatron x-ray radiation in approximately 40 s with our existing 220 TW laser and sub seconds with next generation of ultrafast lasers and x-ray detectors, as opposed to several hours required using conventional microfocal x-ray tubes. Thus, sub second ultrahigh resolution in vivo microtomographic microvasculature imaging (in both absorption and phase contrast mode) in small animal models of cancer and vascular diseases will be feasible with LWFA betatron x-ray source.

  10. Are Anxiety Disorders Associated with Accelerated Aging? A Focus on Neuroprogression

    PubMed Central

    Perna, Giampaolo; Iannone, Giuseppe; Alciati, Alessandra; Caldirola, Daniela

    2016-01-01

    Anxiety disorders (AnxDs) are highly prevalent throughout the lifespan, with detrimental effects on daily-life functioning, somatic health, and quality of life. An emerging perspective suggested that AnxDs may be associated with accelerated aging. In this paper, we explored the association between AnxDs and hallmarks of accelerated aging, with a specific focus on neuroprogression. We reviewed animal and human findings that suggest an overlap between processes of impaired neurogenesis, neurodegeneration, structural, functional, molecular, and cellular modifications in AnxDs, and aging. Although this research is at an early stage, our review suggests a link between anxiety and accelerated aging across multiple processes involved in neuroprogression. Brain structural and functional changes that accompany normal aging were more pronounced in subjects with AnxDs than in coevals without AnxDs, including reduced grey matter density, white matter alterations, impaired functional connectivity of large-scale brain networks, and poorer cognitive performance. Similarly, molecular correlates of brain aging, including telomere shortening, Aβ accumulation, and immune-inflammatory and oxidative/nitrosative stress, were overrepresented in anxious subjects. No conclusions about causality or directionality between anxiety and accelerated aging can be drawn. Potential mechanisms of this association, limitations of the current research, and implications for treatments and future studies are discussed. PMID:26881136

  11. Maternal intake of cashew nuts accelerates reflex maturation and facilitates memory in the offspring.

    PubMed

    de Melo, Marília Ferreira Frazão Tavares; Pereira, Diego Elias; Sousa, Morgana Moura; Medeiros, Dilian Maise Ferreira; Lemos, Leanderson Tulio Marques; Madruga, Marta Suely; Santos, Nayane Medeiros; de Oliveira, Maria Elieidy Gomes; de Menezes, Camila Carolina; Soares, Juliana Késsia Barbosa

    2017-10-01

    Essential fatty acids, being indispensable during the stages of pregnancy, lactation and infancy influence the transmission of nerve impulses and brain function, and cashew nuts are a good source of these fatty acids. The objective of this study was to evaluate the effects of cashew nut consumption on reflex development, memory and profile of fatty acids of rat offspring treated during pregnancy and lactation. The animals were divided into three groups: Control (CONT), treated with 7% lipid derived from soybean oil; Normolipidic (NL) treated with 7% lipids derived from cashew nuts; and Hyperlipidic (HL) treated with 20% lipids derived from cashew nuts. Reflex ontogeny, Open-field habituation test and the Object Recognition Test (ORT) were assessed. The profile of fatty acids in the brain was carried out when the animals were zero, 21 and 60days old. Accelerated reflex maturation was observed in animals treated with cashew nuts (p<0.05). NL presented better memory in the Open-field habituation test; the NL and HL showed improvement of short-term memory in the ORT, but long term damage in HL (p<0.05). The results of the lipid profile of the brain at the end of the experiment showed an increase in levels of saturated fatty acids and less Docosahexaenoic acid (DHA) in animals of the HL. The data showed that maternal consumption of cashew nuts can accelerate reflex maturation and facilitate memory in offspring when offered in adequate quantities. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

  12. A budesonide prodrug accelerates treatment of colitis in rats.

    PubMed Central

    Cui, N; Friend, D R; Fedorak, R N

    1994-01-01

    Although oral glucocorticoids are the treatment of choice for moderate to severe ulcerative pancolitis, their systemic side effects and adrenal suppression account for considerable morbidity. An oral glucocorticoid-conjugate (prodrug), budesonide-beta-D-glucuronide, which is not absorbed in the small intestine but is hydrolysed by colonic bacterial and mucosal beta-glucuronidase to release free budesonide into the colon was synthesised. The objective of this study was to compare treatment with budesonide-beta-D-glucuronide with treatment with free budesonide by examining: (1) the healing of experimental colitis and (2) the extent of adrenal suppression. Pancolitis was induced with 4% acetic acid. Animals were then randomised to receive oral therapy for 72 hours with (1) budesonide-beta-D-glucuronide, (2) free budesonide, or (3) vehicle. Drug efficacy and colitic healing was determined by measuring gross colonic ulceration, myeloperoxidase activity, and in vivo colonic fluid absorption. Adrenal suppression was determined by measuring plasma adrenocorticotrophic hormone and serum corticosterone. Vehicle-treated colitis animals had gross ulceration, increased myeloperoxidase activity, and net colonic fluid secretion. Treatment with oral budesonide-beta-D-glucuronide accelerated all measures of colitis healing at a fourfold lower dose than did free budesonide. Furthermore, treatment with budesonide-beta-D-glucuronide did not result in adrenal suppression whereas free budesonide treatment did. A newly synthesised orally administered glucocorticoid-conjugate accelerates colitis healing with limited adrenal suppression. Development of an orally administered colon-specific steroid delivery system represents a novel approach to inflammatory bowel disease treatment. PMID:7959202

  13. Compact Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2004-01-01

    A plasma accelerator has been conceived for both material-processing and spacecraft-propulsion applications. This accelerator generates and accelerates ions within a very small volume. Because of its compactness, this accelerator could be nearly ideal for primary or station-keeping propulsion for spacecraft having masses between 1 and 20 kg. Because this accelerator is designed to generate beams of ions having energies between 50 and 200 eV, it could also be used for surface modification or activation of thin films.

  14. Microelectromechanical acceleration-sensing apparatus

    DOEpatents

    Lee, Robb M [Albuquerque, NM; Shul, Randy J [Albuquerque, NM; Polosky, Marc A [Albuquerque, NM; Hoke, Darren A [Albuquerque, NM; Vernon, George E [Rio Rancho, NM

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  15. SHORT ACCELERATION TIMES FROM SUPERDIFFUSIVE SHOCK ACCELERATION IN THE HELIOSPHERE

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Perri, S.; Zimbardo, G., E-mail: silvia.perri@fis.unical.it

    2015-12-10

    The analysis of time profiles of particles accelerated at interplanetary shocks allows particle transport properties to be inferred. The frequently observed power-law decay upstream, indeed, implies a superdiffusive particle transport when the level of magnetic field variance does not change as the time interval from the shock front increases. In this context, a superdiffusive shock acceleration (SSA) theory has been developed, allowing us to make predictions of the acceleration times. In this work we estimate for a number of interplanetary shocks, including the solar wind termination shock, the acceleration times for energetic protons in the framework of SSA and wemore » compare the results with the acceleration times predicted by standard diffusive shock acceleration. The acceleration times due to SSA are found to be much shorter than in the classical model, and also shorter than the interplanetary shock lifetimes. This decrease of the acceleration times is due to the scale-free nature of the particle displacements in the framework of superdiffusion. Indeed, very long displacements are possible, increasing the probability for particles far from the front of the shock to return, and short displacements have a high probability of occurrence, increasing the chances for particles close to the front to cross the shock many times.« less

  16. MABE multibeam accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hasti, D.E.; Ramirez, J.J.; Coleman, P.D.

    1985-01-01

    The Megamp Accelerator and Beam Experiment (MABE) was the technology development testbed for the multiple beam, linear induction accelerator approach for Hermes III, a new 20 MeV, 0.8 MA, 40 ns accelerator being developed at Sandia for gamma-ray simulation. Experimental studies of a high-current, single-beam accelerator (8 MeV, 80 kA), and a nine-beam injector (1.4 MeV, 25 kA/beam) have been completed, and experiments on a nine-beam linear induction accelerator are in progress. A two-beam linear induction accelerator is designed and will be built as a gamma-ray simulator to be used in parallel with Hermes III. The MABE pulsed power systemmore » and accelerator for the multiple beam experiments is described. Results from these experiments and the two-beam design are discussed. 11 refs., 6 figs.« less

  17. Ex-vivo and live animal models are equally effective training for the management of a penetrating cardiac injury.

    PubMed

    Izawa, Yoshimitsu; Hishikawa, Shuji; Muronoi, Tomohiro; Yamashita, Keisuke; Maruyama, Hiroyuki; Suzukawa, Masayuki; Lefor, Alan Kawarai

    2016-01-01

    Live tissue models are considered the most useful simulation for training in the management for hemostasis of penetrating injuries. However, these models are expensive, with limited opportunities for repetitive training. Ex-vivo models using tissue and a fluid pump are less expensive, allow repetitive training and respect ethical principles in animal research. The purpose of this study is to objectively evaluate the effectiveness of ex-vivo training with a pump, compared to live animal model training. Staff surgeons and residents were divided into live tissue training and ex-vivo training groups. Training in the management of a penetrating cardiac injury was conducted for each group, separately. One week later, all participants were formally evaluated in the management of a penetrating cardiac injury in a live animal. There are no differences between the two groups regarding average years of experience or previous trauma surgery experience. All participants achieved hemostasis, with no difference between the two groups in the Global Rating Scale score (ex-vivo: 25.2 ± 6.3, live: 24.7 ± 6.3, p = 0.646), blood loss (1.6 ± 0.7, 2.0 ± 0.6, p = 0.051), checklist score (3.7 ± 0.6, 3.6 ± 0.9, p = 0.189), or time required for repair (101 s ± 31, 107 s ± 15, p = 0.163), except overall evaluation (3.8 ± 0.9, 3.4 ± 0.9, p = 0.037). The internal consistency reliability and inter-rater reliability in the Global Rating Scale were excellent (0.966 and 0.953 / 0.719 and 0.784, respectively), and for the checklist were moderate (0.570 and 0.636 / 0.651 and 0.607, respectively). The validity is rated good for both the Global Rating Scale (Residents: 21.7 ± 5.6, Staff: 28.9 ± 4.7, p = 0.000) and checklist (Residents: 3.4 ± 0.9, Staff Surgeons: 3.9 ± 0.3, p = 0.003). The results of self-assessment questionnaires were similarly high (4.2-4.9) with scores in self-efficacy increased after

  18. Probing electron acceleration and x-ray emission in laser-plasma accelerators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thaury, C.; Ta Phuoc, K.; Corde, S.

    2013-06-15

    While laser-plasma accelerators have demonstrated a strong potential in the acceleration of electrons up to giga-electronvolt energies, few experimental tools for studying the acceleration physics have been developed. In this paper, we demonstrate a method for probing the acceleration process. A second laser beam, propagating perpendicular to the main beam, is focused on the gas jet few nanosecond before the main beam creates the accelerating plasma wave. This second beam is intense enough to ionize the gas and form a density depletion, which will locally inhibit the acceleration. The position of the density depletion is scanned along the interaction lengthmore » to probe the electron injection and acceleration, and the betatron X-ray emission. To illustrate the potential of the method, the variation of the injection position with the plasma density is studied.« less

  19. Human Tolerance to Rapidly Applied Accelerations: A Summary of the Literature

    NASA Technical Reports Server (NTRS)

    Eiband, A. Martin

    1959-01-01

    The literature is surveyed to determine human tolerance to rapidly applied accelerations. Pertinent human and animal experiments applicable to space flight and to crash impact forces are analyzed and discussed. These data are compared and presented on the basis of a trapezoidal pulse. The effects of body restraint and of acceleration direction, onset rate, and plateau duration on the maximum tolerable and survivable rapidly applied accelerations are shown. Results of the survey indicate that adequate torso and extremity restraint is the primary variable in tolerance to rapidly applied accelerations. The harness, or restraint system, must be arranged to transmit the major portion of the accelerating force directly to the pelvic structure and not via the vertebral column. When the conditions of adequate restraint have been met, then the other variables, direction, magnitude, and onset rate of rapidly applied accelerations, govern maximum tolerance and injury limits. The results also indicate that adequately stressed aft-faced passenger seats offer maximum complete body support with minimum objectionable harnessing. Such a seat, whether designed for 20-, 30-, or 40-G dynamic loading, would include lap strap, chest (axillary) strap, and winged-back seat to increase headward and lateral G protection, full-height integral head rest, arm rests (load-bearing) with recessed hand-holds and provisions to prevent arms from slipping either laterally or beyond the seat back, and leg support to keep the legs from being wedged under the seat. For crew members and others whose duties require forward-facing seats, maximum complete body support requires lap, shoulder, and thigh straps, lap-belt tie-down strap, and full-height seat back with integral head support.

  20. Bioethical Problems: Animal Welfare, Animal Rights.

    ERIC Educational Resources Information Center

    March, B. E.

    1984-01-01

    Discusses various bioethical issues and problems related to animal welfare and animal rights. Areas examined include: Aristotelian views; animal welfare legislation; Darwin and evolutionary theory; animal and human behavior; and vegetarianism. A 14-point universal declaration of the rights of animals is included. (JN)

  1. Social-emotional characteristics of gifted accelerated and non-accelerated students in the Netherlands.

    PubMed

    Hoogeveen, Lianne; van Hell, Janet G; Verhoeven, Ludo

    2012-12-01

    In the studies of acceleration conducted so far a multidimensional perspective has largely been neglected. No attempt has been made to relate social-emotional characteristics of accelerated versus non-accelerated students in perspective of environmental factors. In this study, social-emotional characteristics of accelerated gifted students in the Netherlands were examined in relation to personal and environmental factors. Self-concept and social contacts of accelerated (n = 148) and non-accelerated (n = 55) gifted students, aged 4 to 27 (M = 11.22, SD = 4.27) were measured. Self-concept and social contacts of accelerated and non-accelerated gifted students were measured using a questionnaire and a diary, and parents of these students evaluated their behavioural characteristics. Gender and birth order were studied as personal factors and grade, classroom, teachers' gender, teaching experience, and the quality of parent-school contact as environmental factors. The results showed minimal differences in the social-emotional characteristics of accelerated and non-accelerated gifted students. The few differences we found favoured the accelerated students. We also found that multiple grade skipping does not have negative effects on social-emotional characteristics, and that long-term effects of acceleration tend to be positive. As regards the possible modulation of personal and environmental factors, we merely found an impact of such factors in the non-accelerated group. The results of this study strongly suggest that social-emotional characteristics of accelerated gifted students and non-accelerated gifted students are largely similar. These results thus do not support worries expressed by teachers about the acceleration of gifted students. Our findings parallel the outcomes of earlier studies in the United States and Germany in that we observed that acceleration does not harm gifted students, not even in the case of multiple grade skipping. On the contrary, there is a

  2. Compact Superconducting Radio-frequency Accelerators and Innovative RF Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kephart, Robert; Chattopadhyay, Swaapan; Milton, Stephen

    2015-04-10

    We will present several new technical and design breakthroughs that enable the creation of a new class of compact linear electron accelerators for industrial purposes. Use of Superconducting Radio-Frequency (SRF) cavities allow accelerators less than 1.5 M in length to create electron beams beyond 10 MeV and with average beam powers measured in 10’s of KW. These machines can have the capability to vary the output energy dynamically to produce brehmstrahlung x-rays of varying spectral coverage for applications such as rapid scanning of moving cargo for security purposes. Such compact accelerators will also be cost effective for many existing andmore » new industrial applications. Examples include radiation crosslinking of plastics and rubbers, creation of pure materials with surface properties radically altered from the bulk, modification of bulk or surface optical properties of materials, sterilization of medical instruments animal solid or liquid waste, and destruction of organic compounds in industrial waste water effluents. Small enough to be located on a mobile platform, such accelerators will enable new remediation methods for chemical and biological spills and/or in-situ crosslinking of materials. We will describe one current design under development at Fermilab including plans for prototype and value-engineering to reduce costs. We will also describe development of new nano-structured field-emitter arrays as sources of electrons, new methods for fabricating and cooling superconducting RF cavities, and a new novel RF power source based on magnetrons with full phase and amplitude control.« less

  3. Diet-induced obesity accelerates acute lymphoblastic leukemia progression in two murine models.

    PubMed

    Yun, Jason P; Behan, James W; Heisterkamp, Nora; Butturini, Anna; Klemm, Lars; Ji, Lingyun; Groffen, John; Müschen, Markus; Mittelman, Steven D

    2010-10-01

    Obesity is associated with an increased incidence of many cancers, including leukemia, although it is unknown whether leukemia incidence is increased directly by obesity or rather by associated genetic, lifestyle, health, or socioeconomic factors. We developed animal models of obesity and leukemia to test whether obesity could directly accelerate acute lymphoblastic leukemia (ALL) using BCR/ABL transgenic and AKR/J mice weaned onto a high-fat diet. Mice were observed until development of progressive ALL. Although obese and control BCR/ABL mice had similar median survival, older obese mice had accelerated ALL onset, implying a time-dependent effect of obesity on ALL. Obese AKR mice developed ALL significantly earlier than controls. The effect of obesity was not explained by WBC count, thymus/spleen weight, or ALL phenotype. However, obese AKR mice had higher leptin, insulin, and interleukin-6 levels than controls, and these obesity-related hormones all have potential roles in leukemia pathogenesis. In conclusion, obesity directly accelerates presentation of ALL, likely by increasing the risk of an early event in leukemogenesis. This is the first study to show that obesity can directly accelerate the progression of ALL. Thus, the observed associations between obesity and leukemia incidence are likely to be directly related to biological effects of obesity. ©2010 AACR.

  4. Continuing use of antithrombotic medications for patients with bleeding gastroduodenal ulcer requiring endoscopic hemostasis: a case-control study.

    PubMed

    Kawasaki, Keisuke; Nakamura, Shotaro; Kurahara, Koichi; Nagasue, Tomohiro; Yanai, Shunichi; Harada, Akira; Yaita, Hiroki; Fuchigami, Tadahiko; Matsumoto, Takayuki

    2017-09-01

    The aim of this study was to compare clinical characteristics and outcomes of bleeding gastroduodenal ulcer between patients taking antithrombotic medications and those not taking antithrombotic medications. We performed a case-control study of 346 patients with endoscopically verified bleeding gastroduodenal ulcer, which included 173 cases taking antithrombotic medications throughout peri-bleeding period and 173 age- and sex-matched controls not taking antithrombotic medications. The cases showed less frequent Helicobacter pylori (H. pylori) infections (45.1% versus 60.7%, p = .005), more frequent duodenal location (31.8% versus 19.1%, p = .009), and more frequent rebleeding (13.9% versus 5.8%, p = .02) than the controls. Multivariate analysis revealed that duodenal location (odds ratio [OR] 3.01, 95% confidence interval [CI] 1.37-6.65) and use of antithrombotic medications (OR 2.47, 95% CI 1.13-5.77) were independent factors for rebleeding. However, there were no differences in clinical outcomes, including final successful endoscopic hemostasis, need for surgical intervention, and mortality between cases and controls. Thromboembolic events did not occur in any cases and controls during the periendoscopic period. Low prevalence of H. pylori infection, frequent duodenal location, and high rebleeding rate are characteristics of patients with bleeding gastroduodenal ulcer under antithrombotic medications. Continuation of antithrombotic medications can be accepted for bleeding gastroduodenal ulcer.

  5. SRS Computer Animation and Drive Train System

    NASA Technical Reports Server (NTRS)

    Arthun, Daniel; Schachner, Christian

    2001-01-01

    The spinning rocket simulator (SRS) is an ongoing project at Oral Roberts University. The goal of the SRS is to gather crucial data concerning a spinning rocket under thrust for the purpose of analysis and correction of the coning motion experienced by this type of spacecraft maneuver. The computer animation simulates a virtual, scale model of the component of the SRS that represents the spacecraft itself. This component is known as the (VSM), or virtual spacecraft model. During actual physical simulation, this component of the SRS will experience a coning. The goal of the animation is to cone the VSM within that range to accurately represent the motion of the actual simulator. The drive system of the SRS is the apparatus that turns the actual simulator. It consists of a drive motor, motor mount and chain to power the simulator into motion. The motor mount is adjustable and rigid for high torque application. A digital stepper motor controller actuates the main drive motor for linear acceleration. The chain transfers power from the motor to the simulator via sprockets on both ends.

  6. A simple hemostasis model for the quantitative evaluation of hydrogel-based local hemostatic biomaterials on tissue surface.

    PubMed

    Murakami, Yoshihiko; Yokoyama, Masayuki; Nishida, Hiroshi; Tomizawa, Yasuko; Kurosawa, Hiromi

    2008-09-01

    Several hemostat hydrogels are clinically used, and some other agents are studied for safer, more facile, and more efficient hemostasis. In the present paper, we proposed a novel method to evaluate local hemostat hydrogel on tissue surface. The procedure consisted of the following steps: (step 1) a mouse was fixed on a cork board, and its abdomen was incised; (step 2) serous fluid was carefully removed because it affected the estimation of the weight gained by the filter paper, and parafilm and preweighted filter paper were placed beneath the liver (parafilm prevented the filter paper's absorption of gradually oozing serous fluid); (step 3) the cork board was tilted and maintained at an angle of about 45 degrees so that the bleeding would more easily flow from the liver toward the filter paper; and (step 4) the bleeding lasted for 3 min. In this step, a hemostat was applied to the liver wound immediately after the liver was pricked with a needle. We found that (1) a careful removal of serous fluid prior to a bleeding and (2) a quantitative determination of the amount of excess aqueous solution that oozed out from a hemostat were important to a rigorous evaluation of hemostat efficacy. We successfully evaluated the efficacy of a fibrin-based hemostat hydrogel by using our method. The method proposed in the present study enabled the quantitative, accurate, and easy evaluation of the efficacy of local hemostatic hydrogel which acts as tissue-adhesive agent on biointerfaces.

  7. Vibration acceleration promotes bone formation in rodent models

    PubMed Central

    Uchida, Ryohei; Nakata, Ken; Kawano, Fuminori; Yonetani, Yasukazu; Ogasawara, Issei; Nakai, Naoya; Mae, Tatsuo; Matsuo, Tomohiko; Tachibana, Yuta; Yokoi, Hiroyuki; Yoshikawa, Hideki

    2017-01-01

    All living tissues and cells on Earth are subject to gravitational acceleration, but no reports have verified whether acceleration mode influences bone formation and healing. Therefore, this study was to compare the effects of two acceleration modes, vibration and constant (centrifugal) accelerations, on bone formation and healing in the trunk using BMP 2-induced ectopic bone formation (EBF) mouse model and a rib fracture healing (RFH) rat model. Additionally, we tried to verify the difference in mechanism of effect on bone formation by accelerations between these two models. Three groups (low- and high-magnitude vibration and control-VA groups) were evaluated in the vibration acceleration study, and two groups (centrifuge acceleration and control-CA groups) were used in the constant acceleration study. In each model, the intervention was applied for ten minutes per day from three days after surgery for eleven days (EBF model) or nine days (RFH model). All animals were sacrificed the day after the intervention ended. In the EBF model, ectopic bone was evaluated by macroscopic and histological observations, wet weight, radiography and microfocus computed tomography (micro-CT). In the RFH model, whole fracture-repaired ribs were excised with removal of soft tissue, and evaluated radiologically and histologically. Ectopic bones in the low-magnitude group (EBF model) had significantly greater wet weight and were significantly larger (macroscopically and radiographically) than those in the other two groups, whereas the size and wet weight of ectopic bones in the centrifuge acceleration group showed no significant difference compared those in control-CA group. All ectopic bones showed calcified trabeculae and maturated bone marrow. Micro-CT showed that bone volume (BV) in the low-magnitude group of EBF model was significantly higher than those in the other two groups (3.1±1.2mm3 v.s. 1.8±1.2mm3 in high-magnitude group and 1.3±0.9mm3 in control-VA group), but BV in the

  8. Vibration acceleration promotes bone formation in rodent models.

    PubMed

    Uchida, Ryohei; Nakata, Ken; Kawano, Fuminori; Yonetani, Yasukazu; Ogasawara, Issei; Nakai, Naoya; Mae, Tatsuo; Matsuo, Tomohiko; Tachibana, Yuta; Yokoi, Hiroyuki; Yoshikawa, Hideki

    2017-01-01

    All living tissues and cells on Earth are subject to gravitational acceleration, but no reports have verified whether acceleration mode influences bone formation and healing. Therefore, this study was to compare the effects of two acceleration modes, vibration and constant (centrifugal) accelerations, on bone formation and healing in the trunk using BMP 2-induced ectopic bone formation (EBF) mouse model and a rib fracture healing (RFH) rat model. Additionally, we tried to verify the difference in mechanism of effect on bone formation by accelerations between these two models. Three groups (low- and high-magnitude vibration and control-VA groups) were evaluated in the vibration acceleration study, and two groups (centrifuge acceleration and control-CA groups) were used in the constant acceleration study. In each model, the intervention was applied for ten minutes per day from three days after surgery for eleven days (EBF model) or nine days (RFH model). All animals were sacrificed the day after the intervention ended. In the EBF model, ectopic bone was evaluated by macroscopic and histological observations, wet weight, radiography and microfocus computed tomography (micro-CT). In the RFH model, whole fracture-repaired ribs were excised with removal of soft tissue, and evaluated radiologically and histologically. Ectopic bones in the low-magnitude group (EBF model) had significantly greater wet weight and were significantly larger (macroscopically and radiographically) than those in the other two groups, whereas the size and wet weight of ectopic bones in the centrifuge acceleration group showed no significant difference compared those in control-CA group. All ectopic bones showed calcified trabeculae and maturated bone marrow. Micro-CT showed that bone volume (BV) in the low-magnitude group of EBF model was significantly higher than those in the other two groups (3.1±1.2mm3 v.s. 1.8±1.2mm3 in high-magnitude group and 1.3±0.9mm3 in control-VA group), but BV in the

  9. Semiconductor acceleration sensor

    NASA Astrophysics Data System (ADS)

    Ueyanagi, Katsumichi; Kobayashi, Mitsuo; Goto, Tomoaki

    1996-09-01

    This paper reports a practical semiconductor acceleration sensor especially suited for automotive air bag systems. The acceleration sensor includes four beams arranged in a swastika structure. Two piezoresistors are formed on each beam. These eight piezoresistors constitute a Wheatstone bridge. The swastika structure of the sensing elements, an upper glass plate and a lower glass plate exhibit the squeeze film effect which enhances air dumping, by which the constituent silicon is prevented from breakdown. The present acceleration sensor has the following features. The acceleration force component perpendicular to the sensing direction can be cancelled. The cross-axis sensitivity is less than 3 percent. And, the erroneous offset caused by the differences between the thermal expansion coefficients of the constituent materials can be canceled. The high aspect ratio configuration realized by plasma etching facilitates reducing the dimensions and improving the sensitivity of the acceleration sensor. The present acceleration sensor is 3.9 mm by 3.9 mm in area and 1.2 mm in thickness. The present acceleration sensor can measure from -50 to +50 G with sensitivity of 0.275 mV/G and with non-linearity of less than 1 percent. The acceleration sensor withstands shock of 3000 G.

  10. SketchBio: a scientist's 3D interface for molecular modeling and animation.

    PubMed

    Waldon, Shawn M; Thompson, Peter M; Hahn, Patrick J; Taylor, Russell M

    2014-10-30

    Because of the difficulties involved in learning and using 3D modeling and rendering software, many scientists hire programmers or animators to create models and animations. This both slows the discovery process and provides opportunities for miscommunication. Working with multiple collaborators, a tool was developed (based on a set of design goals) to enable them to directly construct models and animations. SketchBio is presented, a tool that incorporates state-of-the-art bimanual interaction and drop shadows to enable rapid construction of molecular structures and animations. It includes three novel features: crystal-by-example, pose-mode physics, and spring-based layout that accelerate operations common in the formation of molecular models. Design decisions and their consequences are presented, including cases where iterative design was required to produce effective approaches. The design decisions, novel features, and inclusion of state-of-the-art techniques enabled SketchBio to meet all of its design goals. These features and decisions can be incorporated into existing and new tools to improve their effectiveness.

  11. Signature energetic analysis of accelerate electron beam after first acceleration station by accelerating stand of Joint Institute for Nuclear Research

    NASA Astrophysics Data System (ADS)

    Sledneva, A. S.; Kobets, V. V.

    2017-06-01

    The linear electron accelerator based on the LINAC - 800 accelerator imported from the Netherland is created at Joint Institute for Nuclear Research in the framework of the project on creation of the Testbed with an electron beam of a linear accelerator with an energy up to 250 MV. Currently two accelerator stations with a 60 MV energy of a beam are put in operation and the work is to put the beam through accelerating section of the third accelerator station. The electron beam with an energy of 23 MeV is used for testing the crystals (BaF2, CsI (native), and LYSO) in order to explore the opportunity to use them in particle detectors in experiments: Muon g-2, Mu2e, Comet, whose preparation requires a detailed study of the detectors properties such as their irradiation by the accelerator beams.

  12. FERMILAB ACCELERATOR R&D PROGRAM TOWARDS INTENSITY FRONTIER ACCELERATORS : STATUS AND PROGRESS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shiltsev, Vladimir

    2016-11-15

    The 2014 P5 report indicated the accelerator-based neutrino and rare decay physics research as a centrepiece of the US domestic HEP program at Fermilab. Operation, upgrade and development of the accelerators for the near- term and longer-term particle physics program at the Intensity Frontier face formidable challenges. Here we discuss key elements of the accelerator physics and technology R&D program toward future multi-MW proton accelerators and present its status and progress. INTENSITY FRONTIER ACCELERATORS

  13. Clinical use of a 15-W diode laser in small animal surgery: results in 30 varied procedures

    NASA Astrophysics Data System (ADS)

    Crowe, Dennis T.; Swalander, David; Hittenmiller, Donald; Newton, Jenifer

    1999-06-01

    The use of a 15-watt diode laser (CeramOptec)in 30 surgical procedures in dogs and cats was reviewed. Ease of use, operator safety, hemostasis control, wound healing, surgical time, complication rate, and pain control were observed and recorded. Procedures performed were partial pancreatectomy, nasal carcinoma ablation, medial meniscus channeling, perianal and anorectal mass removal (5), hemangioma and hemangiopericytoma removal from two legs, benign skin mass removal (7), liver lobectomy, partial prostatectomy, soft palate resection, partial arytenoidectomy, partial ablation of a thyroid carcinoma, photo-vaporization of the tumor bed following malignant tumor resection (4), neurosheath tumor removal from the tongue, tail sebaceous cyst resection, malignant mammary tumor and mast cell tumor removal. The laser was found to be very simple and safe to use. Hemostasis was excellent in all but the liver and prostate surgeries. The laser was particularly effective in preventing hemorrhage during perianal, anal, and tongue mass removal. It is estimated that a time and blood loss savings of 50% over that of conventional surgery occurred with the use of the laser. All external wounds made by laser appeared to heal faster and with less inflammation than those made with a conventional or electrosurgical scalpel.

  14. Larval crowding accelerates C. elegans development and reduces lifespan.

    PubMed

    Ludewig, Andreas H; Gimond, Clotilde; Judkins, Joshua C; Thornton, Staci; Pulido, Dania C; Micikas, Robert J; Döring, Frank; Antebi, Adam; Braendle, Christian; Schroeder, Frank C

    2017-04-01

    Environmental conditions experienced during animal development are thought to have sustained impact on maturation and adult lifespan. Here we show that in the model organism C. elegans developmental rate and adult lifespan depend on larval population density, and that this effect is mediated by excreted small molecules. By using the time point of first egg laying as a marker for full maturity, we found that wildtype hermaphrodites raised under high density conditions developed significantly faster than animals raised in isolation. Population density-dependent acceleration of development (Pdda) was dramatically enhanced in fatty acid β-oxidation mutants that are defective in the biosynthesis of ascarosides, small-molecule signals that induce developmental diapause. In contrast, Pdda is abolished by synthetic ascarosides and steroidal ligands of the nuclear hormone receptor DAF-12. We show that neither ascarosides nor any known steroid hormones are required for Pdda and that another chemical signal mediates this phenotype, in part via the nuclear hormone receptor NHR-8. Our results demonstrate that C. elegans development is regulated by a push-pull mechanism, based on two antagonistic chemical signals: chemosensation of ascarosides slows down development, whereas population-density dependent accumulation of a different chemical signal accelerates development. We further show that the effects of high larval population density persist through adulthood, as C. elegans larvae raised at high densities exhibit significantly reduced adult lifespan and respond differently to exogenous chemical signals compared to larvae raised at low densities, independent of density during adulthood. Our results demonstrate how inter-organismal signaling during development regulates reproductive maturation and longevity.

  15. Larval crowding accelerates C. elegans development and reduces lifespan

    PubMed Central

    Ludewig, Andreas H.; Gimond, Clotilde; Judkins, Joshua C.; Thornton, Staci; Pulido, Dania C.; Micikas, Robert J.; Döring, Frank; Antebi, Adam; Braendle, Christian; Schroeder, Frank C.

    2017-01-01

    Environmental conditions experienced during animal development are thought to have sustained impact on maturation and adult lifespan. Here we show that in the model organism C. elegans developmental rate and adult lifespan depend on larval population density, and that this effect is mediated by excreted small molecules. By using the time point of first egg laying as a marker for full maturity, we found that wildtype hermaphrodites raised under high density conditions developed significantly faster than animals raised in isolation. Population density-dependent acceleration of development (Pdda) was dramatically enhanced in fatty acid β-oxidation mutants that are defective in the biosynthesis of ascarosides, small-molecule signals that induce developmental diapause. In contrast, Pdda is abolished by synthetic ascarosides and steroidal ligands of the nuclear hormone receptor DAF-12. We show that neither ascarosides nor any known steroid hormones are required for Pdda and that another chemical signal mediates this phenotype, in part via the nuclear hormone receptor NHR-8. Our results demonstrate that C. elegans development is regulated by a push-pull mechanism, based on two antagonistic chemical signals: chemosensation of ascarosides slows down development, whereas population-density dependent accumulation of a different chemical signal accelerates development. We further show that the effects of high larval population density persist through adulthood, as C. elegans larvae raised at high densities exhibit significantly reduced adult lifespan and respond differently to exogenous chemical signals compared to larvae raised at low densities, independent of density during adulthood. Our results demonstrate how inter-organismal signaling during development regulates reproductive maturation and longevity. PMID:28394895

  16. Influence of angular acceleration-deceleration pulse shapes on regional brain strains.

    PubMed

    Yoganandan, Narayan; Li, Jianrong; Zhang, Jiangyue; Pintar, Frank A; Gennarelli, Thomas A

    2008-07-19

    Recognizing the association of angular loading with brain injuries and inconsistency in previous studies in the application of the biphasic loads to animal, physical, and experimental models, the present study examined the role of the acceleration-deceleration pulse shapes on region-specific strains. An experimentally validated two-dimensional finite element model representing the adult male human head was used. The model simulated the skull and falx as a linear elastic material, cerebrospinal fluid as a hydrodynamic material, and cerebrum as a linear viscoelastic material. The angular loading matrix consisted coronal plane rotation about a center of rotation that was acceleration-only (4.5 ms duration, 7.8 krad/s/s peak), deceleration-only (20 ms, 1.4 krad/s/s peak), acceleration-deceleration, and deceleration-acceleration pulses. Both biphasic pulses had peaks separated by intervals ranging from 0 to 25 ms. Principal strains were determined at the corpus callosum, base of the postcentral sulcus, and cerebral cortex of the parietal lobe. The cerebrum was divided into 17 regions and peak values of average maximum principal strains were determined. In all simulations, the corpus callosum responded with the highest strains. Strains were the least under all simulations in the lower parietal lobes. In all regions peak strains were the same for both monophase pulses suggesting that the angular velocity may be a better metric than peak acceleration or deceleration. In contrast, for the biphasic pulse, peak strains were region- and pulse-shape specific. Peak values were lower in both biphasic pulses when there was no time separation between the pulses than the corresponding monophase pulse. Increasing separation time intervals increased strains, albeit non-uniformly. Acceleration followed by deceleration pulse produced greater strains in all regions than the other form of biphasic pulse. Thus, pulse shape appears to have an effect on regional strains in the brain.

  17. Trialability, observability and risk reduction accelerating individual innovation adoption decisions.

    PubMed

    Hayes, Kathryn J; Eljiz, Kathy; Dadich, Ann; Fitzgerald, Janna-Anneke; Sloan, Terry

    2015-01-01

    The purpose of this paper is to provide a retrospective analysis of computer simulation's role in accelerating individual innovation adoption decisions. The process innovation examined is Lean Systems Thinking, and the organizational context is the imaging department of an Australian public hospital. Intrinsic case study methods including observation, interviews with radiology and emergency personnel about scheduling procedures, mapping patient appointment processes and document analysis were used over three years and then complemented with retrospective interviews with key hospital staff. The multiple data sources and methods were combined in a pragmatic and reflexive manner to explore an extreme case that provides potential to act as an instructive template for effective change. Computer simulation of process change ideas offered by staff to improve patient-flow accelerated the adoption of the process changes, largely because animated computer simulation permitted experimentation (trialability), provided observable predictions of change results (observability) and minimized perceived risk. The difficulty of making accurate comparisons between time periods in a health care setting is acknowledged. This work has implications for policy, practice and theory, particularly for inducing the rapid diffusion of process innovations to address challenges facing health service organizations and national health systems. Originality/value - The research demonstrates the value of animated computer simulation in presenting the need for change, identifying options, and predicting change outcomes and is the first work to indicate the importance of trialability, observability and risk reduction in individual adoption decisions in health services.

  18. Behavioural responses to infrasonic particle acceleration in cuttlefish.

    PubMed

    Wilson, Maria; Haga, Jens Ådne Rekkedal; Karlsen, Hans Erik

    2018-01-11

    Attacks by aquatic predators generate frontal water disturbances characterised by low-frequency gradients in pressure and particle motion. Low-frequency hearing is highly developed in cephalopods. Thus, we examined behavioural responses in juvenile cuttlefish to infrasonic accelerations mimicking main aspects of the hydrodynamic signals created by predators. In the experimental set-up, animals and their surrounding water moved as a unit to minimise lateral line activation and to allow examination of the contribution by the inner ear. Behavioural responses were tested in light versus darkness and after food deprivation following a 'simulated' hunting opportunity. At low acceleration levels, colour change threshold at 3, 5 and 9 Hz was 0.028, 0.038 and 0.035 m s -2 , respectively. At higher stimulus levels, jet-propulsed escape responses thresholds in daylight were 0.043, 0.065 and 0.069 m s -2 at 3, 5 and 9 Hz, respectively, and not significantly different from the corresponding darkness thresholds of 0.043, 0.071 and 0.064 m s -2 In a simulated hunting mode, escape thresholds were significantly higher at 3 Hz (0.118 m s -2 ) but not at 9 Hz (0.134 m s -2 ). Escape responses were directional, and overall followed the direction of the initial particle acceleration, with mean escape angles from 313 to 33 deg for all three experiments. Thus, in the wild, particle acceleration might cause escape responses directed away from striking predators but towards suction-feeding predators. We suggest that cuttlefish jet-propulsed escape behaviour has evolved to be elicited by the early hydrodynamic disturbances generated during predator encounters, and that the inner ear plays an essential role in the acoustic escape responses. © 2018. Published by The Company of Biologists Ltd.

  19. Illinois Accelerator Research Center

    DOE PAGES

    Kroc, Thomas K.; Cooper, Charlie A.

    2017-10-26

    The Illinois Accelerator Research Center (IARC) hosts a new accelerator development program at Fermi National Accelerator Laboratory. IARC provides access to Fermi's state-of-the-art facilities and technologies for research, development and industrialization of particle accelerator technology. In addition to facilitating access to available existing Fermi infrastructure, the IARC Campus has a dedicated 36,000 ft2 heavy assembly building (HAB) with all the infrastructure needed to develop, commission and operate new accelerators. Connected to the HAB is a 47,000 ft Office, Technology and Engineering (OTE) building, paid for by the state, that has office, meeting, and light technical space. The OTE building, whichmore » contains the Accelerator Physics Center, and nearby Accelerator and Technical divisions provide IARC collaborators with unique access to world class expertise in a wide array of accelerator technologies. Finally, at IARC scientists and engineers from Fermilab and academia work side by side with industrial partners to develop breakthroughs in accelerator science and translate them into applications for the nation's health, wealth and security.« less

  20. Illinois Accelerator Research Center

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kroc, Thomas K.; Cooper, Charlie A.

    The Illinois Accelerator Research Center (IARC) hosts a new accelerator development program at Fermi National Accelerator Laboratory. IARC provides access to Fermi's state-of-the-art facilities and technologies for research, development and industrialization of particle accelerator technology. In addition to facilitating access to available existing Fermi infrastructure, the IARC Campus has a dedicated 36,000 ft2 heavy assembly building (HAB) with all the infrastructure needed to develop, commission and operate new accelerators. Connected to the HAB is a 47,000 ft Office, Technology and Engineering (OTE) building, paid for by the state, that has office, meeting, and light technical space. The OTE building, whichmore » contains the Accelerator Physics Center, and nearby Accelerator and Technical divisions provide IARC collaborators with unique access to world class expertise in a wide array of accelerator technologies. Finally, at IARC scientists and engineers from Fermilab and academia work side by side with industrial partners to develop breakthroughs in accelerator science and translate them into applications for the nation's health, wealth and security.« less

  1. Illinois Accelerator Research Center

    NASA Astrophysics Data System (ADS)

    Kroc, Thomas K.; Cooper, Charlie A.

    The Illinois Accelerator Research Center (IARC) hosts a new accelerator development program at Fermi National Accelerator Laboratory. IARC provides access to Fermi's state-of-the-art facilities and technologies for research, development and industrialization of particle accelerator technology. In addition to facilitating access to available existing Fermi infrastructure, the IARC Campus has a dedicated 36,000 ft2 Heavy Assembly Building (HAB) with all the infrastructure needed to develop, commission and operate new accelerators. Connected to the HAB is a 47,000 ft2 Office, Technology and Engineering (OTE) building, paid for by the state, that has office, meeting, and light technical space. The OTE building, which contains the Accelerator Physics Center, and nearby Accelerator and Technical divisions provide IARC collaborators with unique access to world class expertise in a wide array of accelerator technologies. At IARC scientists and engineers from Fermilab and academia work side by side with industrial partners to develop breakthroughs in accelerator science and translate them into applications for the nation's health, wealth and security.

  2. Accelerated test design

    NASA Technical Reports Server (NTRS)

    Mcdermott, P. P.

    1980-01-01

    The design of an accelerated life test program for electric batteries is discussed. A number of observations and suggestions on the procedures and objectives for conducting an accelerated life test program are presented. Equations based on nonlinear regression analysis for predicting the accelerated life test parameters are discussed.

  3. Plasma inverse transition acceleration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xie, Ming

    It can be proved fundamentally from the reciprocity theorem with which the electromagnetism is endowed that corresponding to each spontaneous process of radiation by a charged particle there is an inverse process which defines a unique acceleration mechanism, from Cherenkov radiation to inverse Cherenkov acceleration (ICA) [1], from Smith-Purcell radiation to inverse Smith-Purcell acceleration (ISPA) [2], and from undulator radiation to inverse undulator acceleration (IUA) [3]. There is no exception. Yet, for nearly 30 years after each of the aforementioned inverse processes has been clarified for laser acceleration, inverse transition acceleration (ITA), despite speculation [4], has remained the least understood,more » and above all, no practical implementation of ITA has been found, until now. Unlike all its counterparts in which phase synchronism is established one way or the other such that a particle can continuously gain energy from an acceleration wave, the ITA to be discussed here, termed plasma inverse transition acceleration (PITA), operates under fundamentally different principle. As a result, the discovery of PITA has been delayed for decades, waiting for a conceptual breakthrough in accelerator physics: the principle of alternating gradient acceleration [5, 6, 7, 8, 9, 10]. In fact, PITA was invented [7, 8] as one of several realizations of the new principle.« less

  4. Minimally Invasive Techniques to Accelerate the Orthodontic Tooth Movement: A Systematic Review of Animal Studies

    PubMed Central

    Qamruddin, Irfan; Alam, Mohammad Khursheed; Khamis, Mohd Fadhli; Husein, Adam

    2015-01-01

    Objective. To evaluate various noninvasive and minimally invasive procedures for the enhancement of orthodontic tooth movement in animals. Materials and Methods. Literature was searched using NCBI (PubMed, PubMed Central, and PubMed Health), MedPilot (Medline, Catalogue ZB MED, Catalogue Medicine Health, and Excerpta Medica Database (EMBASE)), and Google Scholar from January 2009 till 31 December 2014. We included original articles related to noninvasive and minimally invasive procedures to enhance orthodontic tooth movement in animals. Extraction of data and quality assessments were carried out by two observers independently. Results. The total number of hits was 9195 out of which just 11 fulfilled the inclusion criteria. Nine articles were good and 5 articles were moderate in quality. Low level laser therapy (LLLT) was among the most common noninvasive techniques whereas flapless corticision using various instruments was among the commonest minimally invasive procedures to enhance velocity of tooth movement. Conclusions. LLLT, low intensity pulsed ultrasound (LIPUS), mechanical vibration, and flapless corticision are emerging noninvasive and minimally invasive techniques which need further researches to establish protocols to use them clinically with conviction. PMID:26881201

  5. Multipactor Physics, Acceleration, and Breakdown in Dielectric-Loaded Accelerating Structures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fischer, Richard P.; Gold, Steven H.

    2016-07-01

    The objective of this 3-year program is to study the physics issues associated with rf acceleration in dielectric-loaded accelerating (DLA) structures, with a focus on the key issue of multipactor loading, which has been found to cause very significant rf power loss in DLA structures whenever the rf pulsewidth exceeds the multipactor risetime (~10 ns). The experiments are carried out in the X-band magnicon laboratory at the Naval Research Laboratory (NRL) in collaboration with Argonne National Laboratory (ANL) and Euclid Techlabs LLC, who develop the test structures with support from the DoE SBIR program. There are two main elements inmore » the research program: (1) high-power tests of DLA structures using the magnicon output (20 MW @11.4 GHz), and (2) tests of electron acceleration in DLA structures using relativistic electrons from a compact X-band accelerator. The work during this period has focused on a study of the use of an axial magnetic field to suppress multipactor in DLA structures, with several new high power tests carried out at NRL, and on preparation of the accelerator for the electron acceleration experiments.« less

  6. Induction linear accelerators

    NASA Astrophysics Data System (ADS)

    Birx, Daniel

    1992-03-01

    Among the family of particle accelerators, the Induction Linear Accelerator is the best suited for the acceleration of high current electron beams. Because the electromagnetic radiation used to accelerate the electron beam is not stored in the cavities but is supplied by transmission lines during the beam pulse it is possible to utilize very low Q (typically<10) structures and very large beam pipes. This combination increases the beam breakup limited maximum currents to of order kiloamperes. The micropulse lengths of these machines are measured in 10's of nanoseconds and duty factors as high as 10-4 have been achieved. Until recently the major problem with these machines has been associated with the pulse power drive. Beam currents of kiloamperes and accelerating potentials of megavolts require peak power drives of gigawatts since no energy is stored in the structure. The marriage of liner accelerator technology and nonlinear magnetic compressors has produced some unique capabilities. It now appears possible to produce electron beams with average currents measured in amperes, peak currents in kiloamperes and gradients exceeding 1 MeV/meter, with power efficiencies approaching 50%. The nonlinear magnetic compression technology has replaced the spark gap drivers used on earlier accelerators with state-of-the-art all-solid-state SCR commutated compression chains. The reliability of these machines is now approaching 1010 shot MTBF. In the following paper we will briefly review the historical development of induction linear accelerators and then discuss the design considerations.

  7. Acceleration of vascularized bone tissue-engineered constructs in a large animal model combining intrinsic and extrinsic vascularization.

    PubMed

    Weigand, Annika; Beier, Justus P; Hess, Andreas; Gerber, Thomas; Arkudas, Andreas; Horch, Raymund E; Boos, Anja M

    2015-05-01

    During the last decades, a range of excellent and promising strategies in Bone Tissue Engineering have been developed. However, the remaining major problem is the lack of vascularization. In this study, extrinsic and intrinsic vascularization strategies were combined for acceleration of vascularization. For optimal biomechanical stability of the defect site and simplifying future transition into clinical application, a primary stable and approved nanostructured bone substitute in clinically relevant size was used. An arteriovenous (AV) loop was microsurgically created in sheep and implanted, together with the bone substitute, in either perforated titanium chambers (intrinsic/extrinsic) for different time intervals of up to 18 weeks or isolated Teflon(®) chambers (intrinsic) for 18 weeks. Over time, magnetic resonance imaging and micro-computed tomography (CT) analyses illustrate the dense vascularization arising from the AV loop. The bone substitute was completely interspersed with newly formed tissue after 12 weeks of intrinsic/extrinsic vascularization and after 18 weeks of intrinsic/extrinsic and intrinsic vascularization. Successful matrix change from an inorganic to an organic scaffold could be demonstrated in vascularized areas with scanning electron microscopy and energy dispersive X-ray spectroscopy. Using the intrinsic vascularization method only, the degradation of the scaffold and osteoclastic activity was significantly lower after 18 weeks, compared with 12 and 18 weeks in the combined intrinsic-extrinsic model. Immunohistochemical staining revealed an increase in bone tissue formation over time, without a difference between intrinsic/extrinsic and intrinsic vascularization after 18 weeks. This study presents the combination of extrinsic and intrinsic vascularization strategies for the generation of an axially vascularized bone substitute in clinically relevant size using a large animal model. The additional extrinsic vascularization promotes tissue

  8. ION ACCELERATOR

    DOEpatents

    Bell, J.S.

    1959-09-15

    An arrangement for the drift tubes in a linear accelerator is described whereby each drift tube acts to shield the particles from the influence of the accelerating field and focuses the particles passing through the tube. In one embodiment the drift tube is splii longitudinally into quadrants supported along the axis of the accelerator by webs from a yoke, the quadrants. webs, and yoke being of magnetic material. A magnetic focusing action is produced by energizing a winding on each web to set up a magnetic field between adjacent quadrants. In the other embodiment the quadrants are electrically insulated from each other and have opposite polarity voltages on adjacent quadrants to provide an electric focusing fleld for the particles, with the quadrants spaced sufficienily close enough to shield the particles within the tube from the accelerating electric field.

  9. Schooling in Times of Acceleration

    ERIC Educational Resources Information Center

    Buddeberg, Magdalena; Hornberg, Sabine

    2017-01-01

    Modern societies are characterised by forms of acceleration, which influence social processes. Sociologist Hartmut Rosa has systematised temporal structures by focusing on three categories of social acceleration: technical acceleration, acceleration of social change, and acceleration of the pace of life. All three processes of acceleration are…

  10. Animal models to improve our understanding and treatment of suicidal behavior.

    PubMed

    Gould, T D; Georgiou, P; Brenner, L A; Brundin, L; Can, A; Courtet, P; Donaldson, Z R; Dwivedi, Y; Guillaume, S; Gottesman, I I; Kanekar, S; Lowry, C A; Renshaw, P F; Rujescu, D; Smith, E G; Turecki, G; Zanos, P; Zarate, C A; Zunszain, P A; Postolache, T T

    2017-04-11

    Worldwide, suicide is a leading cause of death. Although a sizable proportion of deaths by suicide may be preventable, it is well documented that despite major governmental and international investments in research, education and clinical practice suicide rates have not diminished and are even increasing among several at-risk populations. Although nonhuman animals do not engage in suicidal behavior amenable to translational studies, we argue that animal model systems are necessary to investigate candidate endophenotypes of suicidal behavior and the neurobiology underlying these endophenotypes. Animal models are similarly a critical resource to help delineate treatment targets and pharmacological means to improve our ability to manage the risk of suicide. In particular, certain pathophysiological pathways to suicidal behavior, including stress and hypothalamic-pituitary-adrenal axis dysfunction, neurotransmitter system abnormalities, endocrine and neuroimmune changes, aggression, impulsivity and decision-making deficits, as well as the role of critical interactions between genetic and epigenetic factors, development and environmental risk factors can be modeled in laboratory animals. We broadly describe human biological findings, as well as protective effects of medications such as lithium, clozapine, and ketamine associated with modifying risk of engaging in suicidal behavior that are readily translatable to animal models. Endophenotypes of suicidal behavior, studied in animal models, are further useful for moving observed associations with harmful environmental factors (for example, childhood adversity, mechanical trauma aeroallergens, pathogens, inflammation triggers) from association to causation, and developing preventative strategies. Further study in animals will contribute to a more informed, comprehensive, accelerated and ultimately impactful suicide research portfolio.

  11. Recent advancement in biosensors technology for animal and livestock health management.

    PubMed

    Neethirajan, Suresh; Tuteja, Satish K; Huang, Sheng-Tung; Kelton, David

    2017-12-15

    The term biosensors encompasses devices that have the potential to quantify physiological, immunological and behavioural responses of livestock and multiple animal species. Novel biosensing methodologies offer highly specialised monitoring devices for the specific measurement of individual and multiple parameters covering an animal's physiology as well as monitoring of an animal's environment. These devices are not only highly specific and sensitive for the parameters being analysed, but they are also reliable and easy to use, and can accelerate the monitoring process. Novel biosensors in livestock management provide significant benefits and applications in disease detection and isolation, health monitoring and detection of reproductive cycles, as well as monitoring physiological wellbeing of the animal via analysis of the animal's environment. With the development of integrated systems and the Internet of Things, the continuously monitoring devices are expected to become affordable. The data generated from integrated livestock monitoring is anticipated to assist farmers and the agricultural industry to improve animal productivity in the future. The data is expected to reduce the impact of the livestock industry on the environment, while at the same time driving the new wave towards the improvements of viable farming techniques. This review focusses on the emerging technological advancements in monitoring of livestock health for detailed, precise information on productivity, as well as physiology and well-being. Biosensors will contribute to the 4th revolution in agriculture by incorporating innovative technologies into cost-effective diagnostic methods that can mitigate the potentially catastrophic effects of infectious outbreaks in farmed animals. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Animal models to improve our understanding and treatment of suicidal behavior

    PubMed Central

    Gould, T D; Georgiou, P; Brenner, L A; Brundin, L; Can, A; Courtet, P; Donaldson, Z R; Dwivedi, Y; Guillaume, S; Gottesman, I I; Kanekar, S; Lowry, C A; Renshaw, P F; Rujescu, D; Smith, E G; Turecki, G; Zanos, P; Zarate, C A; Zunszain, P A; Postolache, T T

    2017-01-01

    Worldwide, suicide is a leading cause of death. Although a sizable proportion of deaths by suicide may be preventable, it is well documented that despite major governmental and international investments in research, education and clinical practice suicide rates have not diminished and are even increasing among several at-risk populations. Although nonhuman animals do not engage in suicidal behavior amenable to translational studies, we argue that animal model systems are necessary to investigate candidate endophenotypes of suicidal behavior and the neurobiology underlying these endophenotypes. Animal models are similarly a critical resource to help delineate treatment targets and pharmacological means to improve our ability to manage the risk of suicide. In particular, certain pathophysiological pathways to suicidal behavior, including stress and hypothalamic–pituitary–adrenal axis dysfunction, neurotransmitter system abnormalities, endocrine and neuroimmune changes, aggression, impulsivity and decision-making deficits, as well as the role of critical interactions between genetic and epigenetic factors, development and environmental risk factors can be modeled in laboratory animals. We broadly describe human biological findings, as well as protective effects of medications such as lithium, clozapine, and ketamine associated with modifying risk of engaging in suicidal behavior that are readily translatable to animal models. Endophenotypes of suicidal behavior, studied in animal models, are further useful for moving observed associations with harmful environmental factors (for example, childhood adversity, mechanical trauma aeroallergens, pathogens, inflammation triggers) from association to causation, and developing preventative strategies. Further study in animals will contribute to a more informed, comprehensive, accelerated and ultimately impactful suicide research portfolio. PMID:28398339

  13. SU-E-T-457: Design and Characterization of An Economical 192Ir Hemi-Brain Small Animal Irradiator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grams, M; Wilson, Z; Sio, T

    Purpose: To describe the design and dosimetric characterization of a simple and economical small animal irradiator. Methods: A high dose rate 192Ir brachytherapy source from a commercially available afterloader was used with a 1.3 centimeter thick tungsten collimator to provide sharp beam penumbra suitable for hemi-brain irradiation of mice. The unit is equipped with continuous gas anesthesia to allow robust animal immobilization. Dosimetric characterization of the device was performed with Gafchromic film. The penumbra from the small animal irradiator was compared under similar collimating conditions to the penumbra from 6 MV photons, 6 MeV electrons, and 20 MeV electrons frommore » a linear accelerator as well as 300 kVp photons from an orthovoltage unit and Monte Carlo simulated 90 MeV protons. Results: The tungsten collimator provides a sharp penumbra suitable for hemi-brain irradiation, and dose rates on the order of 200 cGy/minute were achieved. The sharpness of the penumbra attainable with this device compares favorably to those measured experimentally for 6 MV photons, and 6 and 20 MeV electron beams from a linear accelerator. Additionally, the penumbra was comparable to those measured for a 300 kVp orthovoltage beam and a Monte Carlo simulated 90 MeV proton beam. Conclusions: The small animal irradiator described here can be built for under $1,000 and used in conjunction with any commercial brachytherapy afterloader to provide a convenient and cost-effective option for small animal irradiation experiments. The unit offers high dose rate delivery and sharp penumbra, which is ideal for hemi-brain irradiation of mice. With slight modifications to the design, irradiation of sites other than the brain could be accomplished easily. Due to its simplicity and low cost, the apparatus described is an attractive alternative for small animal irradiation experiments requiring a sharp penumbra.« less

  14. ACCELERATION AND THE GIFTED.

    ERIC Educational Resources Information Center

    GIBSON, ARTHUR R.; STEPHANS, THOMAS M.

    ACCELERATION OF PUPILS AND SUBJECTS IS CONSIDERED A MEANS OF EDUCATING THE ACADEMICALLY GIFTED STUDENT. FIVE INTRODUCTORY ARTICLES PROVIDE A FRAMEWORK FOR THINKING ABOUT ACCELERATION. FIVE PROJECT REPORTS OF ACCELERATED PROGRAMS IN OHIO ARE INCLUDED. ACCELERATION IS NOW BEING REGARDED MORE FAVORABLY THAN FORMERLY, BECAUSE METHODS HAVE BEEN…

  15. [Animal experimentation, animal welfare and scientific research].

    PubMed

    Tal, H

    2013-10-01

    Hundreds of thousands of laboratory animals are being used every year for scientific experiments held in Israel, mostly mice, rats, rabbits, guinea pigs, and a few sheep, cattle, pigs, cats, dogs, and even a few dozen monkeys. In addition to the animals sacrificed to promote scientific research, millions of animals slain every year for other purposes such as meat and fine leather fashion industries. While opening a front against all is an impossible and perhaps an unjustified task, the state of Israel enacted the Animal Welfare (Animal Experimentation) Law (1994). The law aims to regulate scientific animal experiments and to find the appropriate balance between the need to continue to perform animal experiments for the advancement of research and medicine, and at the same time to avoid unnecessary trials and minimize animal suffering. Among other issues the law deals with the phylogenetic scale according to which experimental animals should be selected, experiments for teaching and practicing, and experiments for the cosmetic industry. This article discusses bioethics considerations in animal experiments as well as the criticism on the scientific validity of such experiments. It further deals with the vitality of animal studies and the moral and legal obligation to prevent suffering from laboratory animals.

  16. Magnetic resonance imaging for precise radiotherapy of small laboratory animals.

    PubMed

    Frenzel, Thorsten; Kaul, Michael Gerhard; Ernst, Thomas Michael; Salamon, Johannes; Jäckel, Maria; Schumacher, Udo; Krüll, Andreas

    2017-03-01

    Radiotherapy of small laboratory animals (SLA) is often not as precisely applied as in humans. Here we describe the use of a dedicated SLA magnetic resonance imaging (MRI) scanner for precise tumor volumetry, radiotherapy treatment planning, and diagnostic imaging in order to make the experiments more accurate. Different human cancer cells were injected at the lower trunk of pfp/rag2 and SCID mice to allow for local tumor growth. Data from cross sectional MRI scans were transferred to a clinical treatment planning system (TPS) for humans. Manual palpation of the tumor size was compared with calculated tumor size of the TPS and with tumor weight at necropsy. As a feasibility study MRI based treatment plans were calculated for a clinical 6MV linear accelerator using a micro multileaf collimator (μMLC). In addition, diagnostic MRI scans were used to investigate animals which did clinical poorly during the study. MRI is superior in precise tumor volume definition whereas manual palpation underestimates their size. Cross sectional MRI allow for treatment planning so that conformal irradiation of mice with a clinical linear accelerator using a μMLC is in principle feasible. Several internal pathologies were detected during the experiment using the dedicated scanner. MRI is a key technology for precise radiotherapy of SLA. The scanning protocols provided are suited for tumor volumetry, treatment planning, and diagnostic imaging. Copyright © 2016. Published by Elsevier GmbH.

  17. Development of Acceleration Sensor and Acceleration Evaluation System for Super-Low-Range Frequencies

    NASA Astrophysics Data System (ADS)

    Asano, Shogo; Matsumoto, Hideki

    2001-05-01

    This paper describes the development process for acceleration sensors used on automobiles and an acceleration evaluation system designed specifically for acceleration at super-low-range frequencies. The features of the newly developed sensor are as follows. 1) Original piezo-bimorph design based on a disc-center-fixed structure achieves pyroeffect cancelling and stabilization of sensor characteristics and enables the detection of the acceleration of 0.0009 G at the super-low-range-frequency of 0.03 Hz. 2) The addition of a self-diagnostic function utilizing the characteristics of piezoceramics enables constant monitoring of sensor failure. The frequency range of acceleration for accurate vehicle motion control is considered to be from DC to about 50 Hz. However, the measurement of acceleration in the super-low-range frequency near DC has been difficult because of mechanical and electrical noise interruption. This has delayed the development of the acceleration sensor for automotive use. We have succeeded in the development of an acceleration evaluation system for super-low-range frequencies from 0.015 Hz to 2 Hz with detection of the acceleration range from 0.0002 G (0.2 gal) to 1 G, as well as the development of a piezoelectric-type acceleration sensor for automotive use.

  18. Do ungulates accelerate or decelerate nitrogen cycling?

    USGS Publications Warehouse

    Singer, F.J.; Schoenecker, K.A.

    2003-01-01

    Nitrogen (N) is an essential nutrient for plants and animals, and N may be limiting in many western US grassland and shrubland ungulate winter ranges. Ungulates may influence N pools and they may alter N inputs and outputs (losses) to the ecosystem in a number of ways. In this paper we compare the ecosystem effects of ungulate herbivory in two western national parks, Rocky Mountain National Park (RMNP), Colorado, and Yellowstone National Park (YNP), Wyoming. We compare ungulate herbivory effects on N pools, N fluxes, N yields, and plant productivity in the context of the accelerating and decelerating nutrient cycling scenarios [Ecology 79 (1998) 165]. We concluded that the YNP grasslands fit the accelerating nutrient cycling scenario for ungulate herbivory: in response to grazing, grassland plant species abundance was largely unaltered, net annual aboveground primary productivity (NAPP) was stimulated (except during drought), consumption of key N-rich forages by ungulates was moderate and their abundance was sustained, soil N mineralization rates doubled, N pools increased, aboveground N yield increased, and N concentrations increased in most grassland plant species. Grazing in grasslands in RMNP resulted in no consistent detectable acceleration or deceleration of nutrient cycling. Grazing effects in short willow and aspen vegetation types in RMNP fit the decelerating nutrient cycling scenario of Ritchie et al. [Ecology 79 (1998) 165]. Key N-rich forages declined due to herbivory (willows, aspen, herbaceous vegetation). Aboveground production declined, soil N mineralization rates declined, N pools declined (NO3− pools were 30% that of ungrazed controls), and aboveground N yield declined. We believe that the higher ungulate densities and rates of plant consumption in RMNP, large declines in N-rich forage plants, and possibly a tendency of ungulates to move N from willow and aspen vegetation types to other types in RMNP, contributed to deceleration of nutrient

  19. Gel point and fractal microstructure of incipient blood clots are significant new markers of hemostasis for healthy and anticoagulated blood.

    PubMed

    Evans, Phillip A; Hawkins, Karl; Morris, Roger H K; Thirumalai, Naresh; Munro, Roger; Wakeman, Lisa; Lawrence, Matthew J; Williams, P Rhodri

    2010-10-28

    Here we report the first application of a fractal analysis of the viscoelastic properties of incipient blood clots. We sought to ascertain whether the incipient clot's fractal dimension, D(f,) could be used as a functional biomarker of hemostasis. The incipient clot is formed at the gel point (GP) of coagulating blood, the GP demarcating a functional change from viscoelastic liquid to a viscoelastic solid. Incipient clots formed in whole healthy blood show a clearly defined value of D(f) within a narrow range that represents an index of clotting in health, where D(f) = 1.74 (± 0.07). A significant relationship is found between the incipient clot formation time, T(GP), and the activated partial thromboplastin time, whereas the association of D(f) with the microstructural characteristics of the incipient clot is supported by its significant correlation with fibrinogen. Our study reveals that unfractionated heparin not only prolongs the onset of clot formation but has a significant effect on its fractal microstructure. A progressive increase in unfractionated heparin concentration results in a linear decrease in D(f) and a corresponding prolongation in T(GP). The results represent a new, quantitative measure of clot quality derived from measurements on whole blood samples.

  20. Acceleration: It's Elementary

    ERIC Educational Resources Information Center

    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…

  1. Terahertz-driven linear electron acceleration

    PubMed Central

    Nanni, Emilio A.; Huang, Wenqian R.; Hong, Kyung-Han; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Dwayne Miller, R. J.; Kärtner, Franz X.

    2015-01-01

    The cost, size and availability of electron accelerators are dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency accelerating structures operate with 30–50 MeV m−1 gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional radio-frequency structures. However, laser-driven wakefield accelerators require intense femtosecond sources and direct laser-driven accelerators suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here we demonstrate linear acceleration of electrons with keV energy gain using optically generated terahertz pulses. Terahertz-driven accelerating structures enable high-gradient electron/proton accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. These ultra-compact terahertz accelerators with extremely short electron bunches hold great potential to have a transformative impact for free electron lasers, linear colliders, ultrafast electron diffraction, X-ray science and medical therapy with X-rays and electron beams. PMID:26439410

  2. Terahertz-driven linear electron acceleration

    DOE PAGES

    Nanni, Emilio A.; Huang, Wenqian R.; Hong, Kyung-Han; ...

    2015-10-06

    The cost, size and availability of electron accelerators are dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency accelerating structures operate with 30–50 MeVm -1 gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional radio-frequency structures. However, laser-driven wakefield accelerators require intense femtosecond sources and direct laser-driven accelerators suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here we demonstrate linear acceleration of electrons with keV energy gain using optically generated terahertz pulses. Terahertz-driven accelerating structures enable high-gradient electron/protonmore » accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. As a result, these ultra-compact terahertz accelerators with extremely short electron bunches hold great potential to have a transformative impact for free electron lasers, linear colliders, ultrafast electron diffraction, X-ray science and medical therapy with X-rays and electron beams.« less

  3. A Porcine Model of Traumatic Brain Injury via Head Rotational Acceleration

    PubMed Central

    Cullen, D. Kacy; Harris, James P.; Browne, Kevin D.; Wolf, John A; Duda, John E.; Meaney, David F.; Margulies, Susan S.; Smith, Douglas H.

    2017-01-01

    Unique from other brain disorders, traumatic brain injury (TBI) generally results from a discrete biomechanical event that induces rapid head movement. The large size and high organization of the human brain makes it particularly vulnerable to traumatic injury from rotational accelerations that can cause dynamic deformation of the brain tissue. Therefore, replicating the injury biomechanics of human TBI in animal models presents a substantial challenge, particularly with regard to addressing brain size and injury parameters. Here we present the historical development and use of a porcine model of head rotational acceleration. By scaling up the rotational forces to account for difference in brain mass between swine and humans, this model has been shown to produce the same tissue deformations and identical neuropathologies found in human TBI. The parameters of scaled rapid angular accelerations applied for the model reproduce inertial forces generated when the human head suddenly accelerates or decelerates in falls, collisions, or blunt impacts. The model uses custom-built linkage assemblies and a powerful linear actuator designed to produce purely impulsive nonimpact head rotation in different angular planes at controlled rotational acceleration levels. Through a range of head rotational kinematics, this model can produce functional and neuropathological changes across the spectrum from concussion to severe TBI. Notably, however, the model is very difficult to employ, requiring a highly skilled team for medical management, biomechanics, neurological recovery, and specialized outcome measures including neuromonitoring, neurophysiology, neuroimaging, and neuropathology. Nonetheless, while challenging, this clinically relevant model has proven valuable for identifying mechanisms of acute and progressive neuropathologies as well as for the evaluation of noninvasive diagnostic techniques and potential neuroprotective treatments following TBI. PMID:27604725

  4. Laser driven ion accelerator

    DOEpatents

    Tajima, Toshiki

    2006-04-18

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  5. High brightness electron accelerator

    DOEpatents

    Sheffield, Richard L.; Carlsten, Bruce E.; Young, Lloyd M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  6. Acceleration of a trailing positron bunch in a plasma wakefield accelerator

    DOE PAGES

    Doche, A.; Beekman, C.; Corde, S.; ...

    2017-10-27

    High gradients of energy gain and high energy efficiency are necessary parameters for compact, cost-efficient and high-energy particle colliders. Plasma Wakefield Accelerators (PWFA) offer both, making them attractive candidates for next-generation colliders. Here in these devices, a charge-density plasma wave is excited by an ultra-relativistic bunch of charged particles (the drive bunch). The energy in the wave can be extracted by a second bunch (the trailing bunch), as this bunch propagates in the wake of the drive bunch. While a trailing electron bunch was accelerated in a plasma with more than a gigaelectronvolt of energy gain, accelerating a trailing positronmore » bunch in a plasma is much more challenging as the plasma response can be asymmetric for positrons and electrons. We report the demonstration of the energy gain by a distinct trailing positron bunch in a plasma wakefield accelerator, spanning nonlinear to quasi-linear regimes, and unveil the beam loading process underlying the accelerator energy efficiency. A positron bunch is used to drive the plasma wake in the experiment, though the quasi-linear wake structure could as easily be formed by an electron bunch or a laser driver. Finally, the results thus mark the first acceleration of a distinct positron bunch in plasma-based particle accelerators.« less

  7. Acceleration of a trailing positron bunch in a plasma wakefield accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Doche, A.; Beekman, C.; Corde, S.

    High gradients of energy gain and high energy efficiency are necessary parameters for compact, cost-efficient and high-energy particle colliders. Plasma Wakefield Accelerators (PWFA) offer both, making them attractive candidates for next-generation colliders. Here in these devices, a charge-density plasma wave is excited by an ultra-relativistic bunch of charged particles (the drive bunch). The energy in the wave can be extracted by a second bunch (the trailing bunch), as this bunch propagates in the wake of the drive bunch. While a trailing electron bunch was accelerated in a plasma with more than a gigaelectronvolt of energy gain, accelerating a trailing positronmore » bunch in a plasma is much more challenging as the plasma response can be asymmetric for positrons and electrons. We report the demonstration of the energy gain by a distinct trailing positron bunch in a plasma wakefield accelerator, spanning nonlinear to quasi-linear regimes, and unveil the beam loading process underlying the accelerator energy efficiency. A positron bunch is used to drive the plasma wake in the experiment, though the quasi-linear wake structure could as easily be formed by an electron bunch or a laser driver. Finally, the results thus mark the first acceleration of a distinct positron bunch in plasma-based particle accelerators.« less

  8. Accelerator-based BNCT.

    PubMed

    Kreiner, A J; Baldo, M; Bergueiro, J R; Cartelli, D; Castell, W; Thatar Vento, V; Gomez Asoia, J; Mercuri, D; Padulo, J; Suarez Sandin, J C; Erhardt, J; Kesque, J M; Valda, A A; Debray, M E; Somacal, H R; Igarzabal, M; Minsky, D M; Herrera, M S; Capoulat, M E; Gonzalez, S J; del Grosso, M F; Gagetti, L; Suarez Anzorena, M; Gun, M; Carranza, O

    2014-06-01

    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 (9)Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases. © 2013 Elsevier Ltd. All rights reserved.

  9. The Accelerated Schools Movement: Expansion and Support through Accelerated Schools Centers.

    ERIC Educational Resources Information Center

    Brunner, Ilse; And Others

    From 1987 to 1995, the Accelerated Schools Project moved from a two-school pilot project to a national movement of over 700 schools in 35 states. This paper examines how the Accelerated Schools Centers have helped the expansion of the accelerated schools movement by recruiting and supporting schools in their regions, and how their institutional…

  10. Whole-body kinematics of a fruit bat reveal the influence of wing inertia on body accelerations.

    PubMed

    Iriarte-Díaz, José; Riskin, Daniel K; Willis, David J; Breuer, Kenneth S; Swartz, Sharon M

    2011-05-01

    The center of mass (COM) of a flying animal accelerates through space because of aerodynamic and gravitational forces. For vertebrates, changes in the position of a landmark on the body have been widely used to estimate net aerodynamic forces. The flapping of relatively massive wings, however, might induce inertial forces that cause markers on the body to move independently of the COM, thus making them unreliable indicators of aerodynamic force. We used high-speed three-dimensional kinematics from wind tunnel flights of four lesser dog-faced fruit bats, Cynopterus brachyotis, at speeds ranging from 2.4 to 7.8 m s(-1) to construct a time-varying model of the mass distribution of the bats and to estimate changes in the position of their COM through time. We compared accelerations calculated by markers on the trunk with accelerations calculated from the estimated COM and we found significant inertial effects on both horizontal and vertical accelerations. We discuss the effect of these inertial accelerations on the long-held idea that, during slow flights, bats accelerate their COM forward during 'tip-reversal upstrokes', whereby the distal portion of the wing moves upward and backward with respect to still air. This idea has been supported by the observation that markers placed on the body accelerate forward during tip-reversal upstrokes. As in previously published studies, we observed that markers on the trunk accelerated forward during the tip-reversal upstrokes. When removing inertial effects, however, we found that the COM accelerated forward primarily during the downstroke. These results highlight the crucial importance of the incorporation of inertial effects of wing motion in the analysis of flapping flight.

  11. Fast animation of lightning using an adaptive mesh.

    PubMed

    Kim, Theodore; Lin, Ming C

    2007-01-01

    We present a fast method for simulating, animating, and rendering lightning using adaptive grids. The "dielectric breakdown model" is an elegant algorithm for electrical pattern formation that we extend to enable animation of lightning. The simulation can be slow, particularly in 3D, because it involves solving a large Poisson problem. Losasso et al. recently proposed an octree data structure for simulating water and smoke, and we show that this discretization can be applied to the problem of lightning simulation as well. However, implementing the incomplete Cholesky conjugate gradient (ICCG) solver for this problem can be daunting, so we provide an extensive discussion of implementation issues. ICCG solvers can usually be accelerated using "Eisenstat's trick," but the trick cannot be directly applied to the adaptive case. Fortunately, we show that an "almost incomplete Cholesky" factorization can be computed so that Eisenstat's trick can still be used. We then present a fast rendering method based on convolution that is competitive with Monte Carlo ray tracing but orders of magnitude faster, and we also show how to further improve the visual results using jittering.

  12. Systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators

    DOEpatents

    Grisham, Larry R

    2013-12-17

    The present invention provides systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators. Advantageously, the systems and methods of the present invention improve the practically obtainable performance of these electrostatic accelerators by addressing, among other things, voltage holding problems and conditioning issues. The problems and issues are addressed by flowing electric currents along these accelerator electrodes to produce magnetic fields that envelope the accelerator electrodes and their support structures, so as to prevent very low energy electrons from leaving the surfaces of the accelerator electrodes and subsequently picking up energy from the surrounding electric field. In various applications, this magnetic insulation must only produce modest gains in voltage holding capability to represent a significant achievement.

  13. A TE-mode accelerator

    NASA Astrophysics Data System (ADS)

    Takeuchi, S.; Sakai, K.; Matsumoto, M.; Sugihara, R.

    1987-04-01

    An accelerator is proposed in which a TE-mode wave is used to drive charged particles in contrast to the usual linear accelerators in which longitudinal electric fields or TM-mode waves are supposed to be utilized. The principle of the acceleration is based on the V(p) x B acceleration of a dynamo force acceleration, in which a charged particle trapped in a transverse wave feels a constant electric field (Faraday induction field) and subsequently is accelerated when an appropriate magnetic field is externally applied in the direction perpendicular to the wave propagation. A pair of dielectric plates is used to produce a slow TE mode. The conditions of the particle trapping the stabilization of the particle orbit are discussed.

  14. Uniformly accelerated black holes

    NASA Astrophysics Data System (ADS)

    Letelier, Patricio S.; Oliveira, Samuel R.

    2001-09-01

    The static and stationary C metric are examined in a generic framework and their interpretations studied in some detail, especially those with two event horizons, one for the black hole and another for the acceleration. We find that (i) the spacetime of an accelerated static black hole is plagued by either conical singularities or a lack of smoothness and compactness of the black hole horizon, (ii) by using standard black hole thermodynamics we show that accelerated black holes have a higher Hawking temperature than Unruh temperature of the accelerated frame, and (iii) the usual upper bound on the product of the mass and acceleration parameters (<1/27) is just a coordinate artifact. The main results are extended to accelerated rotating black holes with no significant changes.

  15. Accelerated Reader.

    ERIC Educational Resources Information Center

    Education Commission of the States, Denver, CO.

    This paper provides an overview of Accelerated Reader, a system of computerized testing and record-keeping that supplements the regular classroom reading program. Accelerated Reader's primary goal is to increase literature-based reading practice. The program offers a computer-aided reading comprehension and management program intended to motivate…

  16. Animal rights and animal experimentation. Implications for physicians.

    PubMed Central

    Gelpi, A. P.

    1991-01-01

    Practicing physicians are just becoming aware of the animal rights movement, which during the 1980s spawned numerous acts of violence against research facilities throughout the United States. The animal rightists are challenging physicians to show moral justification for the human exploitation of nature and the world of subhuman species. They have aroused public interest in animal welfare, sparked protective legislation for experimental animals, and indirectly encouraged the creation of committees to oversee the conduct of animal experimentation and the conditions of animal confinement. This controversy has necessitated a closer look at the questions of animal experimentation and animal rights against the backdrop of human experimentation and human rights. Physicians and specialists in animal care seek to alleviate suffering and anxiety, and, as moderates, they may be able to bring both sides of the animal rights controversy together in a spirit of mutual tolerance and in the common cause of promoting both human and animal welfare. PMID:1949772

  17. Hemostatic efficacy of local chitosan linear polymer granule in an experimental sheep model with severe bleeding of arteria and vena femoralis.

    PubMed

    Ersoy, Gürkan; Rodoplu, Ülkümen; Yılmaz, Osman; Gökmen, Necati; Doğan, Alper; Dikme, Özgür; Aydınoğlu, Aslı; Orhon, Okyanus

    2016-05-01

    The aim of the present study was to evaluate the hemostatic effect of chitosan linear polymer in a sheep model with femoral bleeding. Following induction of anesthesia and intubation of sheep, groin injury was induced to initiate hemorrhage. Animals were randomly assigned to study and control groups. In the control group, absorbent pads were packed on the wound, and pressure was supplied by a weight placed over the dressing. In the study group, chitosan linear polymer was poured onto the bleeding site; absorbent pads and pressure were applied in the same manner. At 5-min intervals, bleeding was evaluated. Primary endpoint was time to hemostasis. Bleeding had stopped by the 1st interval in 5 members of the study group, and by the 2nd interval in 1 member. One sheep was excluded. The bleeding stopped after the 1st interval in 1 member of the control group and after the 2nd interval in 4 members. Bleeding stopped in 2 cases following ligation of the bleeding vessel. Hemostasis was achieved earlier in the study group, compared to the control group, and the difference was statistically significant. Hemostasis was achieved earlier following application of chitosan linear polymer.

  18. Sutureless laparoscopic heminephrectomy using laser tissue soldering.

    PubMed

    Ogan, Kenneth; Jacomides, Lucas; Saboorian, Hossein; Koeneman, Kenneth; Li, Yingming; Napper, Cheryl; Hoopman, John; Pearle, Margaret S; Cadeddu, Jeffrey A

    2003-06-01

    Widespread application of laparoscopic partial nephrectomy has been limited by the lack of a reliable means of attaining hemostasis. We describe laser tissue welding using human albumin as a solder to control bleeding and seal the collecting system during laparoscopic heminephrectomy in a porcine model. Laparoscopic left lower-pole heminephrectomy was performed in five female domestic pigs after occluding the hilar vessels. Using an 810-nm pulsed diode laser (20 W), a 50% liquid albumin-indocyanine green solder was welded to the cut edge of the renal parenchyma to seal the collecting system and achieve hemostasis. Two weeks later, an identical procedure was performed on the right kidney, after which, the animals were sacrificed and both kidneys were harvested for ex vivo retrograde pyelograms and histopathologic analysis. All 10 heminephrectomies were performed without complication. The mean operative time was 82 minutes, with an average blood loss of 43.5 mL per procedure. The mean warm ischemia time was 11.7 minutes. For each heminephrectomy, a mean of 4.2 mL of solder was welded to the cut parenchymal surface. In three of the five acute kidneys and all five 2-week kidneys, ex vivo retrograde pyelograms demonstrated no extravasation. In addition, no animal had clinical evidence of urinoma or delayed hemorrhage. Histopathologic analysis showed preservation of the renal parenchyma immediately beneath the solder. Laser tissue welding provided reliable hemostasis and closure of the collecting system while protecting the underlying parenchyma from the deleterious effect of the laser during porcine laparoscopic heminephrectomy.

  19. Amps particle accelerator definition study

    NASA Technical Reports Server (NTRS)

    Sellen, J. M., Jr.

    1975-01-01

    The Particle Accelerator System of the AMPS (Atmospheric, Magnetospheric, and Plasmas in Space) payload is a series of charged particle accelerators to be flown with the Space Transportation System Shuttle on Spacelab missions. In the configuration presented, the total particle accelerator system consists of an energetic electron beam, an energetic ion accelerator, and both low voltage and high voltage plasma acceleration devices. The Orbiter is illustrated with such a particle accelerator system.

  20. Penicillin treatment accelerates middle ear inflammation in experimental pneumococcal otitis media.

    PubMed Central

    Kawana, M; Kawana, C; Giebink, G S

    1992-01-01

    Most Streptococcus pneumoniae strains are killed by very low concentrations of penicillin and other beta-lactam antibiotics, yet middle ear inflammation and effusion persist for days to weeks after treatment in most cases of pneumococcal otitis media. To study the effect of beta-lactam antibiotic treatment on pneumococci and the middle ear inflammatory response during pneumococcal otitis media, we measured concentrations of pneumococci, inflammatory cells, and lysozyme in middle ear fluid (MEF) by using the chinchilla model. Procaine penicillin G given intramuscularly 12 and 36 h after inoculation of pneumococci into the middle ear caused a significant acceleration in the MEF inflammatory cell concentration compared with that in untreated controls, with a significant peak in the inflammatory cell concentration 24 h after pneumococcal inoculation. The lysozyme concentration in MEF also increased more rapidly in treated than in control animals. Viable pneumococci were not detected in MEF after the second dose of penicillin, but the total pneumococcal cell concentration remained unchanged for at least 45 days. Therefore, penicillin treatment accelerated middle ear inflammation while killing pneumococci, but treatment did not accelerate clearance of the nonviable pneumococcal cells from MEF. Further studies will need to define the contribution of these responses to acute and chronic tissue injury. PMID:1563782

  1. Vestibular afferent responses to linear accelerations in the alert squirrel monkey

    NASA Technical Reports Server (NTRS)

    Somps, Christopher J.; Schor, Robert H.; Tomko, David L.

    1994-01-01

    The spontaneous activity of 40 otolith afferents and 44 canal afferents was recorded in 4 alert, intact squirrel monkeys. Polarization vectors and response properties of otolith afferents were determined during static re-orientations relative to gravity and during Earth-horizontal, sinusoidal, linear oscillations. Canal afferents were tested for sensitivity to linear accelerations. For regular otolith afferents, a significant correlation between upright discharge rate and sensitivity to dynamic acceleration in the horizontal plane was observed. This correlation was not present in irregular units. The sensitivity of otolith afferents to both static tilts and dynamic linear acceleration was much greater in irregularly discharging units than in regularly discharging units. The spontaneous activity and static and dynamic response properties of regularly discharging otolith afferents were similar to those reported in barbiturate-anesthetized squirrel monkeys. Irregular afferents also had similar dynamic response properties when compared to anesthetized monkeys. However, this sample of irregular afferents in alert animals had higher resting discharge rates and greater sensitivity to static tilts. The majority of otolith polarization vectors were oriented near the horizontal in the plane of the utricular maculae; however, directions of maximum sensitivity were different during dynamic and static testing. Canal afferents were not sensitive to static tilts or linear oscillations of the head.

  2. Radical Acceleration

    ERIC Educational Resources Information Center

    Gross, Miraca U. M.; Van Vliet, Helen E.

    2005-01-01

    Research has found that teachers' objections to accelerating gifted students are mainly based on a fear that acceleration will lead to social or emotional damage. Ironically, it is the academic and emotional maturity which characterizes intellectually gifted students, coupled with their high levels of academic achievement, which makes them such…

  3. [Simultaneous determination of arsanilic, nitarsone and roxarsone residues in foods of animal origin by ASE-LC-AFS].

    PubMed

    Xiao, Ya-Bing; Zhang, Man; Wen, Hua-Wei

    2014-04-01

    A method for simultaneous determination of arsanilic, nitarsone and roxarsone (ROX) residues in foods of animal origin was developed by accelerated solvent extraction-liquid chromatography-atomic fluorescence spectrometry (ASE-LC-AFS). The ultrasound centrifugation extraction and accelerated solvent extraction were compared, and the accelerated solvent extraction conditions, namely the proportion of the extraction solvent, the extraction temperature, extraction time and extraction times, were optimized. The operating conditions of LC-AFS and the mobile phase were optimized. Under the optimal conditions, the calibration curves for ASA , NIT and ROX were linear over the concentration range of 0-2.0 mg x L(-1) and their correlation coefficients were 0.999 2-0.999 8. The detection limits of ASA, NIT and ROX were 2.4, 7.4 and 4.1 microg x L(-1) respectively. The average recoveries of ASA, NIT and ROX from two samples spiked at three levels of 0.5, 2, 5 mg x kg(-1) were in the ranges of 87.1%-93.2%, 85.2%-93.9%, and 84.2%-93.7% with RSDs of 1.4%-4.6%, 1.2%-4.2%, and 1.1%-4.5%, respectively. This method possesses the merits of convenience and good repeatability, and is a feasible method for analysis of ASA, NIT and ROX in foods of animal origin.

  4. Observation of acceleration and deceleration in gigaelectron-volt-per-metre gradient dielectric wakefield accelerators

    DOE PAGES

    O’Shea, B. D.; Andonian, G.; Barber, S. K.; ...

    2016-09-14

    There is urgent need to develop new acceleration techniques capable of exceeding gigaelectron-volt-per-metre (GeV m –1) gradients in order to enable future generations of both light sources and high-energy physics experiments. To address this need, short wavelength accelerators based on wakefields, where an intense relativistic electron beam radiates the demanded fields directly into the accelerator structure or medium, are currently under intense investigation. One such wakefield based accelerator, the dielectric wakefield accelerator, uses a dielectric lined-waveguide to support a wakefield used for acceleration. Here we show gradients of 1.347±0.020 GeV m –1 using a dielectric wakefield accelerator of 15 cmmore » length, with sub-millimetre transverse aperture, by measuring changes of the kinetic state of relativistic electron beams. We follow this measurement by demonstrating accelerating gradients of 320±17 MeV m –1. As a result, both measurements improve on previous measurements by and order of magnitude and show promise for dielectric wakefield accelerators as sources of high-energy electrons.« less

  5. Observation of acceleration and deceleration in gigaelectron-volt-per-metre gradient dielectric wakefield accelerators

    PubMed Central

    O'Shea, B. D.; Andonian, G.; Barber, S. K.; Fitzmorris, K. L.; Hakimi, S.; Harrison, J.; Hoang, P. D.; Hogan, M. J.; Naranjo, B.; Williams, O. B.; Yakimenko, V.; Rosenzweig, J. B.

    2016-01-01

    There is urgent need to develop new acceleration techniques capable of exceeding gigaelectron-volt-per-metre (GeV m−1) gradients in order to enable future generations of both light sources and high-energy physics experiments. To address this need, short wavelength accelerators based on wakefields, where an intense relativistic electron beam radiates the demanded fields directly into the accelerator structure or medium, are currently under intense investigation. One such wakefield based accelerator, the dielectric wakefield accelerator, uses a dielectric lined-waveguide to support a wakefield used for acceleration. Here we show gradients of 1.347±0.020 GeV m−1 using a dielectric wakefield accelerator of 15 cm length, with sub-millimetre transverse aperture, by measuring changes of the kinetic state of relativistic electron beams. We follow this measurement by demonstrating accelerating gradients of 320±17 MeV m−1. Both measurements improve on previous measurements by and order of magnitude and show promise for dielectric wakefield accelerators as sources of high-energy electrons. PMID:27624348

  6. Staging of RF-accelerating Units in a MEMS-based Ion Accelerator

    NASA Astrophysics Data System (ADS)

    Persaud, A.; Seidl, P. A.; Ji, Q.; Feinberg, E.; Waldron, W. L.; Schenkel, T.; Ardanuc, S.; Vinayakumar, K. B.; Lal, A.

    Multiple Electrostatic Quadrupole Array Linear Accelerators (MEQALACs) provide an opportunity to realize compact radio- frequency (RF) accelerator structures that can deliver very high beam currents. MEQALACs have been previously realized with acceleration gap distances and beam aperture sizes of the order of centimeters. Through advances in Micro-Electro-Mechanical Systems (MEMS) fabrication, MEQALACs can now be scaled down to the sub-millimeter regime and batch processed on wafer substrates. In this paper we show first results from using three RF stages in a compact MEMS-based ion accelerator. The results presented show proof-of-concept with accelerator structures formed from printed circuit boards using a 3 × 3 beamlet arrangement and noble gas ions at 10 keV. We present a simple model to describe the measured results. We also discuss some of the scaling behaviour of a compact MEQALAC. The MEMS-based approach enables a low-cost, highly versatile accelerator covering a wide range of currents (10 μA to 100 mA) and beam energies (100 keV to several MeV). Applications include ion-beam analysis, mass spectrometry, materials processing, and at very high beam powers, plasma heating.

  7. Staging of RF-accelerating Units in a MEMS-based Ion Accelerator

    DOE PAGES

    Persaud, A.; Seidl, P. A.; Ji, Q.; ...

    2017-10-26

    Multiple Electrostatic Quadrupole Array Linear Accelerators (MEQALACs) provide an opportunity to realize compact radio- frequency (RF) accelerator structures that can deliver very high beam currents. MEQALACs have been previously realized with acceleration gap distances and beam aperture sizes of the order of centimeters. Through advances in Micro-Electro-Mechanical Systems (MEMS) fabrication, MEQALACs can now be scaled down to the sub-millimeter regime and batch processed on wafer substrates. In this paper we show first results from using three RF stages in a compact MEMS-based ion accelerator. The results presented show proof-of-concept with accelerator structures formed from printed circuit boards using a 3more » × 3 beamlet arrangement and noble gas ions at 10 keV. We present a simple model to describe the measured results. We also discuss some of the scaling behaviour of a compact MEQALAC. The MEMS-based approach enables a low-cost, highly versatile accelerator covering a wide range of currents (10 μA to 100 mA) and beam energies (100 keV to several MeV). Applications include ion-beam analysis, mass spectrometry, materials processing, and at very high beam powers, plasma heating.« less

  8. Staging of RF-accelerating Units in a MEMS-based Ion Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Persaud, A.; Seidl, P. A.; Ji, Q.

    Multiple Electrostatic Quadrupole Array Linear Accelerators (MEQALACs) provide an opportunity to realize compact radio- frequency (RF) accelerator structures that can deliver very high beam currents. MEQALACs have been previously realized with acceleration gap distances and beam aperture sizes of the order of centimeters. Through advances in Micro-Electro-Mechanical Systems (MEMS) fabrication, MEQALACs can now be scaled down to the sub-millimeter regime and batch processed on wafer substrates. In this paper we show first results from using three RF stages in a compact MEMS-based ion accelerator. The results presented show proof-of-concept with accelerator structures formed from printed circuit boards using a 3more » × 3 beamlet arrangement and noble gas ions at 10 keV. We present a simple model to describe the measured results. We also discuss some of the scaling behaviour of a compact MEQALAC. The MEMS-based approach enables a low-cost, highly versatile accelerator covering a wide range of currents (10 μA to 100 mA) and beam energies (100 keV to several MeV). Applications include ion-beam analysis, mass spectrometry, materials processing, and at very high beam powers, plasma heating.« less

  9. Proposal for an Accelerator R&D User Facility at Fermilab's Advanced Superconducting Test Accelerator (ASTA)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Church, M.; Edwards, H.; Harms, E.

    2013-10-01

    Fermilab is the nation’s particle physics laboratory, supported by the DOE Office of High Energy Physics (OHEP). Fermilab is a world leader in accelerators, with a demonstrated track-record— spanning four decades—of excellence in accelerator science and technology. We describe the significant opportunity to complete, in a highly leveraged manner, a unique accelerator research facility that supports the broad strategic goals in accelerator science and technology within the OHEP. While the US accelerator-based HEP program is oriented toward the Intensity Frontier, which requires modern superconducting linear accelerators and advanced highintensity storage rings, there are no accelerator test facilities that support themore » accelerator science of the Intensity Frontier. Further, nearly all proposed future accelerators for Discovery Science will rely on superconducting radiofrequency (SRF) acceleration, yet there are no dedicated test facilities to study SRF capabilities for beam acceleration and manipulation in prototypic conditions. Finally, there are a wide range of experiments and research programs beyond particle physics that require the unique beam parameters that will only be available at Fermilab’s Advanced Superconducting Test Accelerator (ASTA). To address these needs we submit this proposal for an Accelerator R&D User Facility at ASTA. The ASTA program is based on the capability provided by an SRF linac (which provides electron beams from 50 MeV to nearly 1 GeV) and a small storage ring (with the ability to store either electrons or protons) to enable a broad range of beam-based experiments to study fundamental limitations to beam intensity and to develop transformative approaches to particle-beam generation, acceleration and manipulation which cannot be done elsewhere. It will also establish a unique resource for R&D towards Energy Frontier facilities and a test-bed for SRF accelerators and high brightness beam applications in support of the

  10. Diffusive shock acceleration - Acceleration rate, magnetic-field direction and the diffusion limit

    NASA Technical Reports Server (NTRS)

    Jokipii, J. R.

    1992-01-01

    This paper reviews the concept of diffusive shock acceleration, showing that the acceleration of charged particles at a collisionless shock is a straightforward consequence of the standard cosmic-ray transport equation, provided that one treats the discontinuity at the shock correctly. This is true for arbitrary direction of the upstream magnetic field. Within this framework, it is shown that acceleration at perpendicular or quasi-perpendicular shocks is generally much faster than for parallel shocks. Paradoxically, it follows also that, for a simple scattering law, the acceleration is faster for less scattering or larger mean free path. Obviously, the mean free path can not become too large or the diffusion limit becomes inapplicable. Gradient and curvature drifts caused by the magnetic-field change at the shock play a major role in the acceleration process in most cases. Recent observations of the charge state of the anomalous component are shown to require the faster acceleration at the quasi-perpendicular solar-wind termination shock.

  11. 9 CFR 79.4 - Designation of scrapie-positive animals, high-risk animals, exposed animals, suspect animals...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... designated scrapie epidemiologist may conduct testing of animals if he or she determines such testing is... epidemiologist will select animals for testing in a manner that will provide a 95 percent confidence of detecting... lambed in the flock are available for testing, may limit the testing to all exposed and suspect animals...

  12. 9 CFR 79.4 - Designation of scrapie-positive animals, high-risk animals, exposed animals, suspect animals...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... designated scrapie epidemiologist may conduct testing of animals if he or she determines such testing is... epidemiologist will select animals for testing in a manner that will provide a 95 percent confidence of detecting... lambed in the flock are available for testing, may limit the testing to all exposed and suspect animals...

  13. 9 CFR 79.4 - Designation of scrapie-positive animals, high-risk animals, exposed animals, suspect animals...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... designated scrapie epidemiologist may conduct testing of animals if he or she determines such testing is... epidemiologist will select animals for testing in a manner that will provide a 95 percent confidence of detecting... lambed in the flock are available for testing, may limit the testing to all exposed and suspect animals...

  14. ADVANCES IN ANIMAL WELFARE FOR FREE-LIVING ANIMALS.

    PubMed

    2016-04-01

    Over several decades, animal welfare has grown into its own free-standing field of scientific study, from its early beginnings in laboratory animal research to eventually include exhibited animals and farm animals. While it has always been present to some degree, consideration of animal welfare for free-ranging animals has lagged behind, developing as a field of study in the last 20 yr or so. Part of that increase was that animal welfare legislation was finally applied to studies being done on free-ranging animals. But it is the appreciation by the biologists and veterinarians working on wild animals, in which the quality of their results is largely controlled by the quality of the animals they use in their studies, which has resulted in increased attention to the well-being or welfare of the animals that they use. Other important influences driving the recognition of wildlife welfare have been changes in the public's expectations of how wild animals are dealt with, a shift in focus of wildlife professionals from managing animals that can be hunted or angled to include nongame species, the decrease in participation in hunting and fishing by members of the public, and the entry of large numbers of women into fish and wildlife agencies and departments and into veterinary medicine. Technical improvements have allowed the safe capture and handling of large or dangerous animals as immobilization drugs and equipment have been developed. The increasing use of sedating drugs allows for handling of animals with reduced stress and other impacts. A number of topics, such as toe-clipping, branding, defining which taxa can or cannot feel pain, catch-and-release fishing, and more, remain controversial within wildlife science. How we treat the wild animals that we deal with defines who we are as wildlife professionals, and animal welfare concerns and techniques for free-ranging animals will continue to develop and evolve.

  15. Plasma Wakefield Acceleration and FACET - Facilities for Accelerator Science and Experimental Test Beams at SLAC

    ScienceCinema

    Seryi, Andrei

    2017-12-22

    Plasma wakefield acceleration is one of the most promising approaches to advancing accelerator technology. This approach offers a potential 1,000-fold or more increase in acceleration over a given distance, compared to existing accelerators.  FACET, enabled by the Recovery Act funds, will study plasma acceleration, using short, intense pulses of electrons and positrons. In this lecture, the physics of plasma acceleration and features of FACET will be presented.  

  16. Horizontal vestibuloocular reflex evoked by high-acceleration rotations in the squirrel monkey. III. Responses after labyrinthectomy

    NASA Technical Reports Server (NTRS)

    Lasker, D. M.; Hullar, T. E.; Minor, L. B.; Shelhamer, M. J. (Principal Investigator)

    2000-01-01

    The horizontal angular vestibuloocular reflex (VOR) evoked by high-frequency, high-acceleration rotations was studied in four squirrel monkeys after unilateral labyrinthectomy. Spontaneous nystagmus was measured at the beginning and end of each testing session. During the period that animals were kept in darkness (4 days), the nystagmus at each of these times measured approximately 20 degrees /s. Within 18-24 h after return to the light, the nystagmus (measured in darkness) decreased to 2.8 +/- 1.5 degrees /s (mean +/- SD) when recorded at the beginning but was 20.3 +/- 3.9 degrees /s at the end of the testing session. The latency of the VOR measured from responses to steps of acceleration (3,000 degrees /s(2) reaching a velocity of 150 degrees /s) was 8.4 +/- 0.3 ms for responses to ipsilesional rotations and 7.7 +/- 0.4 ms for contralesional rotations. During the period that animals were kept in darkness after the labyrinthectomy, the gain of the VOR measured during the steps of acceleration was 0.67 +/- 0.12 for contralesional rotations and 0.39 +/- 0.04 for ipsilesional rotations. Within 18-24 h after return to light, the VOR gain for contralesional rotations increased to 0.87 +/- 0.08, whereas there was only a slight increase for ipsilesional rotations to 0.41 +/- 0. 06. A symmetrical increase in the gain measured at the plateau of head velocity was noted after the animals were returned to light. The VOR evoked by sinusoidal rotations of 2-15 Hz, +/-20 degrees /s, showed a better recovery of gain at lower (2-4 Hz) than at higher (6-15 Hz) frequencies. At 0.5 Hz, gain decreased symmetrically when the peak amplitude was increased from 20 to 100 degrees /s. At 10 Hz, gain was decreased for ipsilesional half-cycles and increased for contralesional half-cycles when velocity was raised from 20 to 50 degrees /s. A model incorporating linear and nonlinear pathways was used to simulate the data. Selective increases in the gain for the linear pathway accounted for the

  17. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOEpatents

    Birx, Daniel L.; Reginato, Louis L.

    1988-01-01

    An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .gtoreq.0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

  18. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOEpatents

    Birx, Daniel L.; Reginato, Louis L.

    1987-01-01

    An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially 0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

  19. Particle acceleration

    NASA Technical Reports Server (NTRS)

    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.

  20. ACCELERATION INTEGRATOR

    DOEpatents

    Pope, K.E.

    1958-01-01

    This patent relates to an improved acceleration integrator and more particularly to apparatus of this nature which is gyrostabilized. The device may be used to sense the attainment by an airborne vehicle of a predetermined velocitv or distance along a given vector path. In its broad aspects, the acceleration integrator utilizes a magnetized element rotatable driven by a synchronous motor and having a cylin drical flux gap and a restrained eddy- current drag cap deposed to move into the gap. The angular velocity imparted to the rotatable cap shaft is transmitted in a positive manner to the magnetized element through a servo feedback loop. The resultant angular velocity of tae cap is proportional to the acceleration of the housing in this manner and means may be used to measure the velocity and operate switches at a pre-set magnitude. To make the above-described dcvice sensitive to acceleration in only one direction the magnetized element forms the spinning inertia element of a free gyroscope, and the outer housing functions as a gimbal of a gyroscope.

  1. Joint kinematics and kinetics of overground accelerated running versus running on an accelerated treadmill

    PubMed Central

    Van Caekenberghe, Ine; Segers, Veerle; Aerts, Peter; Willems, Patrick; De Clercq, Dirk

    2013-01-01

    Literature shows that running on an accelerated motorized treadmill is mechanically different from accelerated running overground. Overground, the subject has to enlarge the net anterior–posterior force impulse proportional to acceleration in order to overcome linear whole body inertia, whereas on a treadmill, this force impulse remains zero, regardless of belt acceleration. Therefore, it can be expected that changes in kinematics and joint kinetics of the human body also are proportional to acceleration overground, whereas no changes according to belt acceleration are expected on a treadmill. This study documents kinematics and joint kinetics of accelerated running overground and running on an accelerated motorized treadmill belt for 10 young healthy subjects. When accelerating overground, ground reaction forces are characterized by less braking and more propulsion, generating a more forward-oriented ground reaction force vector and a more forwardly inclined body compared with steady-state running. This change in body orientation as such is partly responsible for the changed force direction. Besides this, more pronounced hip and knee flexion at initial contact, a larger hip extension velocity, smaller knee flexion velocity and smaller initial plantarflexion velocity are associated with less braking. A larger knee extension and plantarflexion velocity result in larger propulsion. Altogether, during stance, joint moments are not significantly influenced by acceleration overground. Therefore, we suggest that the overall behaviour of the musculoskeletal system (in terms of kinematics and joint moments) during acceleration at a certain speed remains essentially identical to steady-state running at the same speed, yet acting in a different orientation. However, because acceleration implies extra mechanical work to increase the running speed, muscular effort done (in terms of power output) must be larger. This is confirmed by larger joint power generation at the level

  2. Locus coeruleus activation accelerates perceptual learning.

    PubMed

    Glennon, Erin; Carcea, Ioana; Martins, Ana Raquel O; Multani, Jasmin; Shehu, Ina; Svirsky, Mario A; Froemke, Robert C

    2018-05-31

    Neural representations of the external world are constructed and updated in a manner that depends on behavioral context. For neocortical networks, this contextual information is relayed by a diverse range of neuromodulatory systems, which govern attention and signal the value of internal state variables such as arousal, motivation, and stress. Neuromodulators enable cortical circuits to differentially process specific stimuli and modify synaptic strengths in order to maintain short- or long-term memory traces of significant perceptual events and behavioral episodes. One of the most important subcortical neuromodulatory systems for attention and arousal is the noradrenergic locus coeruleus. Here we report that the noradrenergic system can enhance behavior in rats performing a self-initiated auditory recognition task, and optogenetic stimulation of noradrenergic locus coeruleus neurons accelerated the rate at which trained rats began correctly responding to a change in reward contingency. Animals successively progressed through distinct behavioral epochs, including periods of perseverance and exploration that occurred much more rapidly when animals received locus coeruleus stimulation. In parallel, we made recordings from primary auditory cortex and found that pairing tones with locus coeruleus stimulation led to a similar set of changes to cortical tuning profiles. Thus both behavioral and neural responses go through phases of adjustment for exploring and exploiting environmental reward contingencies. Furthermore, behavioral engagement does not necessarily recruit optimal locus coeruleus activity. Copyright © 2018. Published by Elsevier B.V.

  3. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOEpatents

    Birx, D.L.; Reginato, L.L.

    1984-03-22

    An electron beam accelerator is described comprising an electron beam generator-injector to produce a focused beam of greater than or equal to .1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electron by about .1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .1-1 MeV maximum energy over a time duration of less than or equal to 1 ..mu..sec.

  4. Traveling wave linear accelerator with RF power flow outside of accelerating cavities

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dolgashev, Valery A.

    A high power RF traveling wave accelerator structure includes a symmetric RF feed, an input matching cell coupled to the symmetric RF feed, a sequence of regular accelerating cavities coupled to the input matching cell at an input beam pipe end of the sequence, one or more waveguides parallel to and coupled to the sequence of regular accelerating cavities, an output matching cell coupled to the sequence of regular accelerating cavities at an output beam pipe end of the sequence, and output waveguide circuit or RF loads coupled to the output matching cell. Each of the regular accelerating cavities hasmore » a nose cone that cuts off field propagating into the beam pipe and therefore all power flows in a traveling wave along the structure in the waveguide.« less

  5. Development of bipolar-pulse accelerator for intense pulsed ion beam acceleration

    NASA Astrophysics Data System (ADS)

    Masugata, Katsumi; Shimizu, Yuichro; Fujioka, Yuhki; Kitamura, Iwao; Tanoue, Hisao; Arai, Kazuo

    2004-12-01

    To improve the purity of intense pulsed ion beams, a new type of pulsed ion beam accelerator named "bipolar pulse accelerator" was proposed. To confirm the principle of the accelerator a prototype of the experimental system was developed. The system utilizes By type magnetically insulated acceleration gap and operated with single polar negative pulse. A coaxial gas puff plasma gun was used as an ion source, which was placed inside the grounded anode. Source plasma (nitrogen) of current density ≈25 A/cm2, duration ≈1.5 μs was injected into the acceleration gap by the plasma gun. The ions were successfully accelerated from the grounded anode to the drift tube by applying negative pulse of voltage 240 kV, duration 100 ns to the drift tube. Pulsed ion beam of current density ≈40 A/cm2, duration ≈50 ns was obtained at 41 mm downstream from the anode surface. To evaluate the irradiation effect of the ion beam to solid material, an amorphous silicon thin film of thickness ≈500 nm was used as the target, which was deposited on the glass substrate. The film was found to be poly-crystallized after 4-shots of the pulsed nitrogen ion beam irradiation.

  6. Compact particle accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Elizondo-Decanini, Juan M.

    2017-08-29

    A compact particle accelerator having an input portion configured to receive power to produce particles for acceleration, where the input portion includes a switch, is provided. In a general embodiment, a vacuum tube receives particles produced from the input portion at a first end, and a plurality of wafer stacks are positioned serially along the vacuum tube. Each of the plurality of wafer stacks include a dielectric and metal-oxide pair, wherein each of the plurality of wafer stacks further accelerate the particles in the vacuum tube. A beam shaper coupled to a second end of the vacuum tube shapes themore » particles accelerated by the plurality of wafer stacks into a beam and an output portion outputs the beam.« less

  7. Accelerating gradient improvement using shape-tailor laser front in radiation pressure acceleration progress

    NASA Astrophysics Data System (ADS)

    Wang, W. P.; Shen, B. F.; Xu, Z. Z.

    2017-05-01

    The accelerating gradient of a proton beam is crucial for stable radiation pressure acceleration (RPA) because the multi-dimensional instabilities increase γ times slower in the relativistic region. In this paper, a shape-tailored laser is proposed to significantly accelerate the ions in a controllable high accelerating gradient. In this method, the fastest ions initially rest in the middle of the foil are controlled to catch the compressed electron layer at the end of the hole-boring stage, thus the light-sail stage can start as soon as possible. Then the compressed electron layer is accelerated tightly together with the fastest ions by the shaped laser intensity, which further increases the accelerating gradient in the light-sail stage. Such tailored pulse may be beneficial for the RPA driven by the 10-fs 10 petawatt laser in the future.

  8. ACCELERATION RESPONSIVE SWITCH

    DOEpatents

    Chabrek, A.F.; Maxwell, R.L.

    1963-07-01

    An acceleration-responsive device with dual channel capabilities whereby a first circuit is actuated upon attainment of a predetermined maximum acceleration level and when the acceleration drops to a predetermined minimum acceleriltion level another circuit is actuated is described. A fluid-damped sensing mass slidably mounted in a relatively frictionless manner on a shaft through the intermediation of a ball bushing and biased by an adjustable compression spring provides inertially operated means for actuating the circuits. (AEC)

  9. Knowledge of the animal welfare act and animal welfare regulations influences attitudes toward animal research.

    PubMed

    Metzger, Mitchell M

    2015-01-01

    Recent public-opinion polls indicate that Americans have shown a decline in support for animal experimentation, and several reports suggest a relationship between people's knowledge of animal welfare regulations and their attitudes toward animal research. Therefore, this study was designed to assess respondent's knowledge of several provisions in the Animal Welfare Act (AWA) and Animal Welfare Regulations (AWR), and determine whether exposure to elements of this legislation would influence an individual's attitudes toward the use of animals in research. A survey was used to assess knowledge of animal research regulations and attitudes toward animal research from a sample of individuals recruited through Amazon's Mechanical Turk crowdsourcing marketplace. Results from study 1 confirmed the hypothesis that respondents had little knowledge of various federal regulations that govern animal research activities. Data from study 2 revealed that exposure to elements of the AWA and AWR influenced participants' attitudes toward the use of animals in research. These results suggest that providing information to the general public about the AWA and AWR that protect laboratory animals from abuse and neglect may help alleviate concerns about using animals in research settings.

  10. Knowledge of the Animal Welfare Act and Animal Welfare Regulations Influences Attitudes toward Animal Research

    PubMed Central

    2015-01-01

    Recent public-opinion polls indicate that Americans have shown a decline in support for animal experimentation, and several reports suggest a relationship between people's knowledge of animal welfare regulations and their attitudes toward animal research. Therefore, this study was designed to assess respondent's knowledge of several provisions in the Animal Welfare Act (AWA) and Animal Welfare Regulations (AWR), and determine whether exposure to elements of this legislation would influence an individual's attitudes toward the use of animals in research. A survey was used to assess knowledge of animal research regulations and attitudes toward animal research from a sample of individuals recruited through Amazon's Mechanical Turk crowdsourcing marketplace. Results from study 1 confirmed the hypothesis that respondents had little knowledge of various federal regulations that govern animal research activities. Data from study 2 revealed that exposure to elements of the AWA and AWR influenced participants’ attitudes toward the use of animals in research. These results suggest that providing information to the general public about the AWA and AWR that protect laboratory animals from abuse and neglect may help alleviate concerns about using animals in research settings. PMID:25651094

  11. High Gradient Accelerator Research

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Temkin, Richard

    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 coldmore » 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.« less

  12. Horizontal vestibuloocular reflex evoked by high-acceleration rotations in the squirrel monkey. II. Responses after canal plugging

    NASA Technical Reports Server (NTRS)

    Lasker, D. M.; Backous, D. D.; Lysakowski, A.; Davis, G. L.; Minor, L. B.

    1999-01-01

    The horizontal angular vestibuloocular reflex (VOR) evoked by high-frequency, high-acceleration rotations was studied in four squirrel monkeys after unilateral plugging of the three semicircular canals. During the period (1-4 days) that animals were kept in darkness after plugging, the gain during steps of acceleration (3, 000 degrees /s(2), peak velocity = 150 degrees /s) was 0.61 +/- 0.14 (mean +/- SD) for contralesional rotations and 0.33 +/- 0.03 for ipsilesional rotations. Within 18-24 h after animals were returned to light, the VOR gain for contralesional rotations increased to 0. 88 +/- 0.05, whereas there was only a slight increase in the gain for ipsilesional rotations to 0.37 +/- 0.07. A symmetrical increase in the gain measured at the plateau of head velocity was noted after animals were returned to light. The latency of the VOR was 8.2 +/- 0. 4 ms for ipsilesional and 7.1 +/- 0.3 ms for contralesional rotations. The VOR evoked by sinusoidal rotations of 0.5-15 Hz, +/-20 degrees /s had no significant half-cycle asymmetries. The recovery of gain for these responses after plugging was greater at lower than at higher frequencies. Responses to rotations at higher velocities for frequencies >/=4 Hz showed an increase in contralesional half-cycle gain, whereas ipsilesional half-cycle gain was unchanged. A residual response that appeared to be canal and not otolith mediated was noted after plugging of all six semicircular canals. This response increased with frequency to reach a gain of 0.23 +/- 0.03 at 15 Hz, resembling that predicted based on a reduction of the dominant time constant of the canal to 32 ms after plugging. A model incorporating linear and nonlinear pathways was used to simulate the data. The coefficients of this model were determined from data in animals with intact vestibular function. Selective increases in the gain for the linear and nonlinear pathways predicted the changes in recovery observed after canal plugging. An increase in gain of

  13. The hydrodynamic principle for the caudal fin shape of small aquatic animals

    NASA Astrophysics Data System (ADS)

    Lee, Jeongsu; Park, Yong-Jai; Cho, Kyu-Jin; Kim, Ho-Young

    2014-11-01

    The shape of caudal fins of small aquatic animals is completely different from that of large cruising animals like dolphin and tuna which have high aspect-ratio lunate tail. To unveil the physical principle behind natural selection of caudal fins of small aquatic animals, here we investigate the hydrodynamics of an angularly reciprocating plate as a model for the caudal fin oscillation. We find that the thrust production of a reciprocating plate at high Strouhal numbers is dominated by generation of two distinct vortical structures associated with the acceleration and deceleration of the plate regardless of their shape. Based on our observations, we construct a scaling law to predict the thrust of the flapping plate, which agrees well with the experimental data. We then seek the optimal aspect ratio to maximize thrust and efficiency of a flapping plate for fixed flapping frequency and amplitude. Thrust is maximized for the aspect ratio of approximately 0.7. We also theoretically explain the power law behaviors of the thrust and efficiency as a function of the aspect ratio.

  14. [Assessment of prophylaxis and treatment of blood loss in patients with pre-eclampsia].

    PubMed

    Timokhova, S Iu; Golubtsov, V V; Zabolotskikh, I B

    2014-01-01

    To improve treatment results of women with massive obstetrical blood loss. Subjects and methods: 96 female patients with average and heavy degree preeclampsia worsened massive blood developing were involved into the investigation. The women were divided into two groups: main (n=55) (basic) - it's patients were treated with complex of offered wiays control (n=41) - it's patients were evaluated retrospectively. During the investigation the parameters of hemostasis system and periphery blood values were performed as dynamic evaluations, acidity-basic state and water-electrolyte balance parameters, medical history were monitored. As a result of the investigation it was found out that these offered actions complex application about reducing massive obstetric blood accelerates restoration of clinic, bio-chemical paramnleters during the early post-operating period The application of the offered methods has reduced both inltraoperative blood loss in women with preeclamsia and use of blood components and the time spent on the hemostasis system correction for all the women of the base group.

  15. Convection-Enhanced Delivery (CED) in an Animal Model of Malignant Peripheral Nerve Sheath Tumors and Plexiform Neurofibromas

    DTIC Science & Technology

    2011-09-01

    with an accelerated schedule Convection-Enhanced Delivery ( CED ), Malignant Peripheral Nerve Sheath ( MPNST ), Plexiform Neurofibromas (PN...the distribution of macromolecules delivered to intraneural PNs and MPNST via CED . Design: Orthotopic xenograft models of sciatic intraneural NF1...determine the efficacy CED of the epidermal growth factor receptor (EGFR) inhibitor erlotinib in animal models of intraneural PNs and MPNST

  16. Linear Accelerator (LINAC)

    MedlinePlus

    ... equipment? How is safety ensured? What is this equipment used for? A linear accelerator (LINAC) is the ... Therapy (SBRT) . top of page How does the equipment work? The linear accelerator uses microwave technology (similar ...

  17. Accelerated Hydrolysis of Aspirin Using Alternating Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Reinscheid, Uwe M.

    2009-08-01

    The major problem of current drug-based therapy is selectivity. As in other areas of science, a combined approach might improve the situation decisively. The idea is to use the pro-drug principle together with an alternating magnetic field as physical stimulus, which can be applied in a spatially and temporarily controlled manner. As a proof of principle, the neutral hydrolysis of aspirin in physiological phosphate buffer of pH 7.5 at 40 °C was chosen. The sensor and actuator system is a commercially available gold nanoparticle (NP) suspension which is approved for animal usage, stable in high concentrations and reproducibly available. Applying the alternating magnetic field of a conventional NMR magnet system accelerated the hydrolysis of aspirin in solution.

  18. The compact Erlangen Active Simulator for Interventional Endoscopy: a prospective comparison in structured team-training courses on "endoscopic hemostasis" for doctors and nurses to the "Endo-Trainer" model.

    PubMed

    Hochberger, J; Euler, K; Naegel, A; Hahn, E G; Maiss, J

    2004-09-01

    In 1997 Hochberger and Neumann presented the "Erlangen Biosimulation Model" (commercialized as the "Erlangen Endo-Trainer") at various national and international meetings. The new compactEASIE is a simplified version of the original "Biosimulation Model" (Endo-Trainer) and is specially designed for easy handling. CompactEASIE is reduced in its features, focusing exclusively on flexible endoscopy training. The acceptance of training in endoscopic hemostasis is accepted by workshop participants, as evaluated by a questionnaire on both models. Eleven structured courses on endoscopic hemostasis for doctors and nurses organized by the same endoscopists from 3/1998 to 5/1999 were evaluated using one of both models. The questionnaires were filled in by 207/291 trainees (71%). The Endo-Trainer was used in 4 (n = 103) and the compactEASIE in 7 courses (n = 104). Both simulators were equipped with identical types of specially prepared pig-organ packages consisting of esophagus, stomach and duodenum, including artificial sewn-in vessels, polyps and varices. Blood perfusion was done with a roller pump connected to the sewn-in vessels and blood surrogate. All workshops were identical concerning the course structure: a 30-min theoretical introduction on ulcer bleeding was followed by 2 h of practical training in injection techniques and hemoclip application. The second part of variceal therapy consisted of a 30-min theoretical introduction prior to 2 h of practical training on sclerotherapy, band ligation and cyanoacrylate application. Finally, a questionnaire on the trainees' pre-experience and their rating of the different workshop sections was handed out to each participant. Previous endoscopic experience was comparable in both groups. The training in both simulators was highly accepted by the trainees (compactEASIE 95% excellent and good versus EASIE (Endo-Trainer) 97%) and did not show any significant difference (P = 0.493). Even in the assessment of the single techniques

  19. USPAS | U.S. Particle Accelerator School

    Science.gov Websites

    U.S. Particle Accelerator School U.S. Particle Accelerator School U.S. Particle Accelerator School U.S. Particle Accelerator School Education in Beam Physics and Accelerator Technology Home About About University Credits Joint International Accelerator School University-Style Programs Symposium-Style Programs

  20. Dosimetry of a Small-Animal Irradiation Model using a 6 MV Linear Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fitch, F. Moran; Martinez-Davalos, A.; Garcia-Garduno, O. A.

    2010-12-07

    A custom made rat-like phantom was used to measure dose distributions using a 6 MV linear accelerator. The phantom has air cavities that simulate the lungs and cylindrical inserts that simulate the backbone. The calculated dose distributions were obtained with the BrainScan v.5.31 TPS software. For the irradiation two cases were considered: (a) near the region where the phantom has two air cavities that simulate the lungs, and (b) with an entirely uniform phantom. The treatment plan consisted of two circular cone arcs that imparted a 500 cGy dose to a simulated lesion in the backbone. We measured dose distributionsmore » using EBT2 GafChromic film and an Epson Perfection V750 scanner working in transmission mode. Vertical and horizontal profiles, isodose curves from 50 to 450 cGy, dose and distance to agreement (DTA) histograms and Gamma index were obtained to compare the dose distributions using DoseLab v4.11. As a result, these calculations show very good agreement between calculated and measured dose distribution in both cases. With a 2% 2 mm criteria 100% of the points pass the Gamma test for the uniform case, while 98.9% of the points do it for the lungs case.« less

  1. The spinning disc: studying radial acceleration and its damping process with smartphone acceleration sensors

    NASA Astrophysics Data System (ADS)

    Hochberg, K.; Gröber, S.; Kuhn, J.; Müller, A.

    2014-03-01

    Here, we show the possibility of analysing circular motion and acceleration using the acceleration sensors of smartphones. For instance, the known linear dependence of the radial acceleration on the distance to the centre (a constant angular frequency) can be shown using multiple smartphones attached to a revolving disc. As a second example, the decrease of the radial acceleration and the rotation frequency due to friction can be measured and fitted with a quadratic function, in accordance with theory. Finally, because the disc is not set up exactly horizontal, each smartphone measures a component of the gravitational acceleration that adds to the radial acceleration during one half of the period and subtracts from the radial acceleration during the other half. Hence, every graph shows a small modulation, which can be used to determine the rotation frequency, thus converting a ‘nuisance effect’ into a source of useful information, making additional measurements with stopwatches or the like unnecessary.

  2. Social-Emotional Characteristics of Gifted Accelerated and Non-Accelerated Students in the Netherlands

    ERIC Educational Resources Information Center

    Hoogeveen, Lianne; van Hell, Janet G.; Verhoeven, Ludo

    2012-01-01

    Background: In the studies of acceleration conducted so far a multidimensional perspective has largely been neglected. No attempt has been made to relate social-emotional characteristics of accelerated versus non-accelerated students in perspective of environmental factors. Aims: In this study, social-emotional characteristics of accelerated…

  3. Anomalous acceleration of ions in a plasma accelerator with an anodic layer

    NASA Astrophysics Data System (ADS)

    V, M. BARDAKOV; S, D. IVANOV; A, V. KAZANTSEV; N, A. STROKIN; A, N. STUPIN; Binhao, JIANG; Zhenyu, WANG

    2018-03-01

    In a plasma accelerator with an anodic layer (PAAL), we discovered experimentally the effect of ‘super-acceleration’ of the bulk of the ions to energies W exceeding the energy equivalent to the discharge voltage V d. The E × B discharge was ignited in an environment of atomic argon and helium and molecular nitrogen. Singly charged argon ions were accelerated most effectively in the case of the largest discharge currents and pressure P of the working gas. Helium ions with W > eV d (e being the electron charge) were only recorded at maximum pressures. Molecular nitrogen was not accelerated to energies W > eV d. Anomalous acceleration is realized in the range of radial magnetic fields on the anode 2.8 × 10 -2 ≤ B rA ≤ 4 × 10 -2 T. It was also found analytically that the cathode of the accelerator can receive anomalously accelerated ions. In this case, the value of the potential in the anodic layer becomes higher than the anode potential, and the anode current exceeds some critical value. Numerical modeling in terms of the developed theory showed qualitative agreement between modeling data and measurements.

  4. Animal rights, animal minds, and human mindreading.

    PubMed

    Mameli, M; Bortolotti, L

    2006-02-01

    Do non-human animals have rights? The answer to this question depends on whether animals have morally relevant mental properties. Mindreading is the human activity of ascribing mental states to other organisms. Current knowledge about the evolution and cognitive structure of mindreading indicates that human ascriptions of mental states to non-human animals are very inaccurate. The accuracy of human mindreading can be improved with the help of scientific studies of animal minds. However, the scientific studies do not by themselves solve the problem of how to map psychological similarities (and differences) between humans and animals onto a distinction between morally relevant and morally irrelevant mental properties. The current limitations of human mindreading-whether scientifically aided or not-have practical consequences for the rational justification of claims about which rights (if any) non-human animals should be accorded.

  5. Cumulative stress in research animals: Telomere attrition as a biomarker in a welfare context?

    PubMed

    Bateson, Melissa

    2016-02-01

    Progress in improving animal welfare is currently limited by the lack of objective methods for assessing lifetime experience. I propose that telomere attrition, a cellular biomarker of biological age, provides a molecular measure of cumulative experience that could be used to assess the welfare impact of husbandry regimes and/or experimental procedures on non-human animals. I review evidence from humans that telomere attrition is accelerated by negative experiences in a cumulative and dose-dependent manner, but that this attrition can be mitigated or even reversed by positive life-style interventions. Evidence from non-human animals suggests that despite some specific differences in telomere biology, stress-induced telomere attrition is a robust phenomenon, occurring in a range of species including mice and chickens. I conclude that telomere attrition apparently integrates positive and negative experience in an accessible common currency that translates readily to novel species--the Holy Grail of a cumulative welfare indicator. © 2015 The Author. BioEssays published by WILEY Periodicals, Inc.

  6. Cumulative stress in research animals: Telomere attrition as a biomarker in a welfare context?

    PubMed Central

    2015-01-01

    Progress in improving animal welfare is currently limited by the lack of objective methods for assessing lifetime experience. I propose that telomere attrition, a cellular biomarker of biological age, provides a molecular measure of cumulative experience that could be used to assess the welfare impact of husbandry regimes and/or experimental procedures on non‐human animals. I review evidence from humans that telomere attrition is accelerated by negative experiences in a cumulative and dose‐dependent manner, but that this attrition can be mitigated or even reversed by positive life‐style interventions. Evidence from non‐human animals suggests that despite some specific differences in telomere biology, stress‐induced telomere attrition is a robust phenomenon, occurring in a range of species including mice and chickens. I conclude that telomere attrition apparently integrates positive and negative experience in an accessible common currency that translates readily to novel species – the Holy Grail of a cumulative welfare indicator. PMID:26645576

  7. Using Acceleration Data to Automatically Detect the Onset of Farrowing in Sows.

    PubMed

    Traulsen, Imke; Scheel, Christoph; Auer, Wolfgang; Burfeind, Onno; Krieter, Joachim

    2018-01-10

    The aim of the present study was to automatically predict the onset of farrowing in crate-confined sows. (1) Background: Automatic tools are appropriate to support animal surveillance under practical farming conditions. (2) Methods: In three batches, sows in one farrowing compartment of the Futterkamp research farm were equipped with an ear sensor to sample acceleration. As a reference video, recordings of the sows were used. A classical CUSUM chart using different acceleration indices of various distribution characteristics with several scenarios were compared. (3) Results: The increase of activity mainly due to nest building behavior before the onset of farrowing could be detected with the sow individual CUSUM chart. The best performance required a statistical distribution characteristic that represented fluctuations in the signal (for example, 1st variation) combined with a transformation of this parameter by cumulating differences in the signal within certain time periods from one day to another. With this transformed signal, farrowing sows could reliably be detected. For 100% or 85% of the sows, an alarm was given within 48 or 12 h before the onset of farrowing. (4) Conclusions: Acceleration measurements in the ear of a sow are suitable for detecting the onset of farrowing in individually housed sows in commercial farrowing crates.

  8. Accelerating proof of concept for small molecule drugs using solid-state chemistry.

    PubMed

    Byrn, Stephen R; Zografi, George; Chen, Xiaoming Sean

    2010-09-01

    In this perspective we have shown that the process of "proof of concept" (POC) in the early part of drug development can be greatly accelerated by close attention to the underlying solid-state chemistry (SSC) of a new chemical entity. POC seeks data that provide confidence in the therapeutic activity and safety of a new chemical entity, which can rapidly lead to a key "GO/NO-GO" decision point for further development. Due to the high cost of the development of new chemical entities and the current low overall productivity of obtaining successful candidates, the pharmaceutical industry is being required to develop accelerated POC strategies. The success of accelerated approaches to POC depends on a full understanding of the SSC of drugs in relation to solubility and stability. Dissolution-limited absorption due to poor solubility of drug substances is particularly important because it can lead to low exposure in animals and undesired bioavailability in humans. Choosing a desirable solid form with sufficient solubility and acceptable stability is essential in developing formulations for POC with superior quality. In this perspective we present an approach that utilizes SSC as part of a novel 2-year development strategy for reaching the pivotal clinical trial stage of development.

  9. MOM3D/EM-ANIMATE - MOM3D WITH ANIMATION CODE

    NASA Technical Reports Server (NTRS)

    Shaeffer, J. F.

    1994-01-01

    compare surface-current distribution due to various initial excitation directions or electric field orientations. The program can accept up to 50 planes of field data consisting of a grid of 100 by 100 field points. These planes of data are user selectable and can be viewed individually or concurrently. With these preset limits, the program requires 55 megabytes of core memory to run. These limits can be changed in the header files to accommodate the available core memory of an individual workstation. An estimate of memory required can be made as follows: approximate memory in bytes equals (number of nodes times number of surfaces times 14 variables times bytes per word, typically 4 bytes per floating point) plus (number of field planes times number of nodes per plane times 21 variables times bytes per word). This gives the approximate memory size required to store the field and surface-current data. The total memory size is approximately 400,000 bytes plus the data memory size. The animation calculations are performed in real time at any user set time step. For Silicon Graphics Workstations that have multiple processors, this program has been optimized to perform these calculations on multiple processors to increase animation rates. The optimized program uses the SGI PFA (Power FORTRAN Accelerator) library. On single processor machines, the parallelization directives are seen as comments to the program and will have no effect on compilation or execution. MOM3D and EM-ANIMATE are written in FORTRAN 77 for interactive or batch execution on SGI series computers running IRIX 3.0 or later. The RAM requirements for these programs vary with the size of the problem being solved. A minimum of 30Mb of RAM is required for execution of EM-ANIMATE; however, the code may be modified to accommodate the available memory of an individual workstation. For EM-ANIMATE, twenty-four bit, double-buffered color capability is suggested, but not required. Sample executables and sample input and

  10. Acceleration characteristics of human ocular accommodation.

    PubMed

    Bharadwaj, Shrikant R; Schor, Clifton M

    2005-01-01

    Position and velocity of accommodation are known to increase with stimulus magnitude, however, little is known about acceleration properties. We investigated three acceleration properties: peak acceleration, time-to-peak acceleration and total duration of acceleration to step changes in defocus. Peak velocity and total duration of acceleration increased with response magnitude. Peak acceleration and time-to-peak acceleration remained independent of response magnitude. Independent first-order and second-order dynamic components of accommodation demonstrate that neural control of accommodation has an initial open-loop component that is independent of response magnitude and a closed-loop component that increases with response magnitude.

  11. Evolution of transcriptional enhancers and animal diversity

    PubMed Central

    Rubinstein, Marcelo; de Souza, Flávio S. J.

    2013-01-01

    Deciphering the genetic bases that drive animal diversity is one of the major challenges of modern biology. Although four decades ago it was proposed that animal evolution was mainly driven by changes in cis-regulatory DNA elements controlling gene expression rather than in protein-coding sequences, only now are powerful bioinformatics and experimental approaches available to accelerate studies into how the evolution of transcriptional enhancers contributes to novel forms and functions. In the introduction to this Theme Issue, we start by defining the general properties of transcriptional enhancers, such as modularity and the coexistence of tight sequence conservation with transcription factor-binding site shuffling as different mechanisms that maintain the enhancer grammar over evolutionary time. We discuss past and current methods used to identify cell-type-specific enhancers and provide examples of how enhancers originate de novo, change and are lost in particular lineages. We then focus in the central part of this Theme Issue on analysing examples of how the molecular evolution of enhancers may change form and function. Throughout this introduction, we present the main findings of the articles, reviews and perspectives contributed to this Theme Issue that together illustrate some of the great advances and current frontiers in the field. PMID:24218630

  12. Angular Acceleration without Torque?

    ERIC Educational Resources Information Center

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

  13. 1985 Particle Accelerator Conference: Accelerator Engineering and Technology, 11th, Vancouver, Canada, May 13-16, 1985, Proceedings

    NASA Astrophysics Data System (ADS)

    Strathdee, A.

    1985-10-01

    The topics discussed are related to high-energy accelerators and colliders, particle sources and electrostatic accelerators, controls, instrumentation and feedback, beam dynamics, low- and intermediate-energy circular accelerators and rings, RF and other acceleration systems, beam injection, extraction and transport, operations and safety, linear accelerators, applications of accelerators, radiation sources, superconducting supercolliders, new acceleration techniques, superconducting components, cryogenics, and vacuum. Accelerator and storage ring control systems are considered along with linear and nonlinear orbit theory, transverse and longitudinal instabilities and cures, beam cooling, injection and extraction orbit theory, high current dynamics, general beam dynamics, and medical and radioisotope applications. Attention is given to superconducting RF structures, magnet technology, superconducting magnets, and physics opportunities with relativistic heavy ion accelerators.

  14. Accelerators for America's Future

    NASA Astrophysics Data System (ADS)

    Bai, Mei

    2016-03-01

    Particle accelerator, a powerful tool to energize beams of charged particles to a desired speed and energy, has been the working horse for investigating the fundamental structure of matter and fundermental laws of nature. Most known examples are the 2-mile long Stanford Linear Accelerator at SLAC, the high energy proton and anti-proton collider Tevatron at FermiLab, and Large Hadron Collider that is currently under operation at CERN. During the less than a century development of accelerator science and technology that led to a dazzling list of discoveries, particle accelerators have also found various applications beyond particle and nuclear physics research, and become an indispensible part of the economy. Today, one can find a particle accelerator at almost every corner of our lives, ranging from the x-ray machine at the airport security to radiation diagnostic and therapy in hospitals. This presentation will give a brief introduction of the applications of this powerful tool in fundermental research as well as in industry. Challenges in accelerator science and technology will also be briefly presented

  15. Improved plasma accelerator

    NASA Technical Reports Server (NTRS)

    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.

  16. Beam acceleration through proton radio frequency quadrupole accelerator in BARC

    NASA Astrophysics Data System (ADS)

    Bhagwat, P. V.; Krishnagopal, S.; Mathew, J. V.; Singh, S. K.; Jain, P.; Rao, S. V. L. S.; Pande, M.; Kumar, R.; Roychowdhury, P.; Kelwani, H.; Rama Rao, B. V.; Gupta, S. K.; Agarwal, A.; Kukreti, B. M.; Singh, P.

    2016-05-01

    A 3 MeV proton Radio Frequency Quadrupole (RFQ) accelerator has been designed at the Bhabha Atomic Research Centre, Mumbai, India, for the Low Energy High Intensity Proton Accelerator (LEHIPA) programme. The 352 MHz RFQ is built in 4 segments and in the first phase two segments of the LEHIPA RFQ were commissioned, accelerating a 50 keV, 1 mA pulsed proton beam from the ion source, to an energy of 1.24 MeV. The successful operation of the RFQ gave confidence in the physics understanding and technology development that have been achieved, and indicate that the road forward can now be traversed rather more quickly.

  17. Coupling and decoupling of the accelerating units for pulsed synchronous linear accelerator

    NASA Astrophysics Data System (ADS)

    Shen, Yi; Liu, Yi; Ye, Mao; Zhang, Huang; Wang, Wei; Xia, Liansheng; Wang, Zhiwen; Yang, Chao; Shi, Jinshui; Zhang, Linwen; Deng, Jianjun

    2017-12-01

    A pulsed synchronous linear accelerator (PSLA), based on the solid-state pulse forming line, photoconductive semiconductor switch, and high gradient insulator technologies, is a novel linear accelerator. During the prototype PSLA commissioning, the energy gain of proton beams was found to be much lower than expected. In this paper, the degradation of the energy gain is explained by the circuit and cavity coupling effect of the accelerating units. The coupling effects of accelerating units are studied, and the circuit topologies of these two kinds of coupling effects are presented. Two methods utilizing inductance and membrane isolations, respectively, are proposed to reduce the circuit coupling effects. The effectiveness of the membrane isolation method is also supported by simulations. The decoupling efficiency of the metal drift tube is also researched. We carried out the experiments on circuit decoupling of the multiple accelerating cavity. The result shows that both circuit decoupling methods could increase the normalized voltage.

  18. Amazing Animals

    ERIC Educational Resources Information Center

    Al-Kuwari, Najat Saad

    2007-01-01

    "Animals" is a three-part lesson plan for young learners with a zoo animal theme. The first lesson is full of activities to describe animals, with Simon Says, guessing games, and learning stations. The second lesson is about desert animals, but other types of animals could be chosen depending on student interest. This lesson teaches…

  19. Testing relativistic electron acceleration mechanisms

    NASA Astrophysics Data System (ADS)

    Green, Janet Carol

    2002-09-01

    This dissertation tests models of relativistic electron acceleration in the earth's outer radiation belt. The models fall into two categories: external and internal. External acceleration models transport and accelerate electrons from a source region in the outer magnetosphere to the inner magnetosphere. Internal acceleration models accelerate a population of electrons already present in the inner magnetosphere. In this dissertation, we test one specific external acceleration mechanism, perform a general test that differentiates between internal and external acceleration models, and test one promising internal acceleration model. We test the models using Polar-HIST data that we transform into electron phase space density (PSD) as a function of adiabatic invariants. We test the ultra low frequency (ULF) wave enhanced radial diffusion external acceleration mechanism by looking for a causal relationship between increased wave power and increased electron PSD at three L* values. One event with increased wave power at two L* values and no subsequent PSD increase does not support the model suggesting that ULF wave power alone is not sufficient to cause an electron response. Excessive loss of electrons and the duration of wave power do not explain the lack of a PSD enhancement at low L*. We differentiate between internal and external acceleration mechanisms by examining the radial profile of electron PSD. We observe PSD profiles that depend on local time. Nightside profiles are highly dependent on the magnetic field model used to calculate PSD as a function of adiabatic invariants and are not reliable. Dayside PSD profiles are more robust and consistent with internal acceleration of electrons. We test one internal acceleration model, the whistler/electromagnetic ion cyclotron wave model, by comparing observed pitch angle distributions to those predicted by the model using a superposed epoch analysis. The observations show pitch angle distributions corresponding to

  20. Using the Animal Model to Accelerate Response to Selection in a Self-Pollinating Crop

    PubMed Central

    Cowling, Wallace A.; Stefanova, Katia T.; Beeck, Cameron P.; Nelson, Matthew N.; Hargreaves, Bonnie L. W.; Sass, Olaf; Gilmour, Arthur R.; Siddique, Kadambot H. M.

    2015-01-01

    We used the animal model in S0 (F1) recurrent selection in a self-pollinating crop including, for the first time, phenotypic and relationship records from self progeny, in addition to cross progeny, in the pedigree. We tested the model in Pisum sativum, the autogamous annual species used by Mendel to demonstrate the particulate nature of inheritance. Resistance to ascochyta blight (Didymella pinodes complex) in segregating S0 cross progeny was assessed by best linear unbiased prediction over two cycles of selection. Genotypic concurrence across cycles was provided by pure-line ancestors. From cycle 1, 102/959 S0 plants were selected, and their S1 self progeny were intercrossed and selfed to produce 430 S0 and 575 S2 individuals that were evaluated in cycle 2. The analysis was improved by including all genetic relationships (with crossing and selfing in the pedigree), additive and nonadditive genetic covariances between cycles, fixed effects (cycles and spatial linear trends), and other random effects. Narrow-sense heritability for ascochyta blight resistance was 0.305 and 0.352 in cycles 1 and 2, respectively, calculated from variance components in the full model. The fitted correlation of predicted breeding values across cycles was 0.82. Average accuracy of predicted breeding values was 0.851 for S2 progeny of S1 parent plants and 0.805 for S0 progeny tested in cycle 2, and 0.878 for S1 parent plants for which no records were available. The forecasted response to selection was 11.2% in the next cycle with 20% S0 selection proportion. This is the first application of the animal model to cyclic selection in heterozygous populations of selfing plants. The method can be used in genomic selection, and for traits measured on S0-derived bulks such as grain yield. PMID:25943522

  1. Improved animal models for testing gene therapy for atherosclerosis.

    PubMed

    Du, Liang; Zhang, Jingwan; De Meyer, Guido R Y; Flynn, Rowan; Dichek, David A

    2014-04-01

    Gene therapy delivered to the blood vessel wall could augment current therapies for atherosclerosis, including systemic drug therapy and stenting. However, identification of clinically useful vectors and effective therapeutic transgenes remains at the preclinical stage. Identification of effective vectors and transgenes would be accelerated by availability of animal models that allow practical and expeditious testing of vessel-wall-directed gene therapy. Such models would include humanlike lesions that develop rapidly in vessels that are amenable to efficient gene delivery. Moreover, because human atherosclerosis develops in normal vessels, gene therapy that prevents atherosclerosis is most logically tested in relatively normal arteries. Similarly, gene therapy that causes atherosclerosis regression requires gene delivery to an existing lesion. Here we report development of three new rabbit models for testing vessel-wall-directed gene therapy that either prevents or reverses atherosclerosis. Carotid artery intimal lesions in these new models develop within 2-7 months after initiation of a high-fat diet and are 20-80 times larger than lesions in a model we described previously. Individual models allow generation of lesions that are relatively rich in either macrophages or smooth muscle cells, permitting testing of gene therapy strategies targeted at either cell type. Two of the models include gene delivery to essentially normal arteries and will be useful for identifying strategies that prevent lesion development. The third model generates lesions rapidly in vector-naïve animals and can be used for testing gene therapy that promotes lesion regression. These models are optimized for testing helper-dependent adenovirus (HDAd)-mediated gene therapy; however, they could be easily adapted for testing of other vectors or of different types of molecular therapies, delivered directly to the blood vessel wall. Our data also supports the promise of HDAd to deliver long

  2. Animal

    ERIC Educational Resources Information Center

    Jaeger, Cora

    2018-01-01

    Tracking the depictions of animals in children's literature through history reveals not only what authors think about animals, but also what they think about the human experience and of childhood itself. As the word "animal" can be used both to mark the similarities and the differences between beasts and men, it makes sense then that…

  3. Multi-beam linear accelerator EVT

    NASA Astrophysics Data System (ADS)

    Teryaev, Vladimir E.; Kazakov, Sergey Yu.; Hirshfield, Jay L.

    2016-09-01

    A novel electron multi-beam accelerator is presented. The accelerator, short-named EVT (Electron Voltage Transformer) belongs to the class of two-beam accelerators. It combines an RF generator and essentially an accelerator within the same vacuum envelope. Drive beam-lets and an accelerated beam are modulated in RF modulators and then bunches pass into an accelerating structure, comprising uncoupled with each other and inductive tuned cavities, where the energy transfer from the drive beams to the accelerated beam occurs. A phasing of bunches is solved by choice correspond distances between gaps of the adjacent cavities. Preliminary results of numerical simulations and the initial specification of EVT operating in S-band, with a 60 kV gun and generating a 2.7 A, 1.1 MV beam at its output is presented. A relatively high efficiency of 67% and high design average power suggest that EVT can find its use in industrial applications.

  4. Multi-beam linear accelerator EVT

    DOE PAGES

    Teryaev, Vladimir E.; Kazakov, Sergey Yu.; Hirshfield, Jay L.

    2016-03-29

    A novel electron multi-beam accelerator is presented. The accelerator, short-named EVT (Electron Voltage Transformer) belongs to the class of two-beam accelerators. It combines an RF generator and essentially an accelerator within the same vacuum envelope. Drive beam-lets and an accelerated beam are modulated in RF modulators and then bunches pass into an accelerating structure, comprising uncoupled with each other and inductive tuned cavities, where the energy transfer from the drive beams to the accelerated beam occurs. A phasing of bunches is solved by choice correspond distances between gaps of the adjacent cavities. Preliminary results of numerical simulations and the initialmore » specification of EVT operating in S-band, with a 60 kV gun and generating a 2.7 A, 1.1 MV beam at its output is presented. Furthermore, a relatively high efficiency of 67% and high design average power suggest that EVT can find its use in industrial applications.« less

  5. Accelerated lymphocyte reconstitution and long-term recovery after transplantation of lentiviral-transduced rhesus CD34+ cells mobilized by G-CSF and plerixafor.

    PubMed

    Uchida, Naoya; Bonifacino, Aylin; Krouse, Allen E; Metzger, Mark E; Csako, Gyorgy; Lee-Stroka, Agnes; Fasano, Ross M; Leitman, Susan F; Mattapallil, Joseph J; Hsieh, Matthew M; Tisdale, John F; Donahue, Robert E

    2011-07-01

    Granulocyte colony-stimulating factor (G-CSF) in combination with plerixafor produces significant mobilization of CD34(+) cells in rhesus macaques. We sought to evaluate whether these CD34(+) cells can stably reconstitute blood cells with lentiviral gene marking. We performed hematopoietic stem cell transplantation using G-CSF and plerixafor-mobilized rhesus CD34(+) cells transduced with a lentiviral vector, and these data were compared with those of G-CSF and stem cell factor mobilization. G-CSF and plerixafor mobilization resulted in CD34(+) cell yields that were twofold higher than yields with G-CSF and stem cell factor. CD123 (interleukin-3 receptor) expression was greater in G-CSF and plerixafor-mobilized CD34(+) cells when compared to G-CSF alone. Animals transplanted with G-CSF and plerixafor-mobilized cells showed engraftment of all lineages, similar to animals who received G-CSF and stem cell factor-mobilized grafts. Lymphocyte engraftment was accelerated in animals receiving the G-CSF and plerixafor-mobilized CD34(+) cells. One animal in the G-CSF and plerixafor group developed cold agglutinin-associated skin rash during the first 3 months of rapid lymphocyte recovery. One year after transplantation, all animals had 2% to 10% transgene expression in all blood cell lineages. G-CSF and plerixafor-mobilized CD34(+) cells accelerate lymphocyte engraftment and contain hematopoietic stem cell capable of reconstituting multilineage blood cells. These findings indicate important differences to consider in plerixafor-based hematopoietic stem cell mobilization protocols in rhesus macaques. Published by Elsevier Inc.

  6. Treatment of Severe Aortic Bleeding Using Hemopatch in Swine on Dual Antiplatelet Therapy.

    PubMed

    Baumgartner, Bernhard; Draxler, Wolfgang; Lewis, Kevin M

    2016-12-01

    The perioperative management of patients on antithrombotic therapy is currently an unresolved problem as these therapies pose a considerable risk for perioperative hemorrhagic complications. The presented studies investigated the efficacy of a new collagen technology to achieve hemostasis. A polyethylene glycol-coated collagen pad (PCC) was compared to a marketed fibrinogen-thrombin coated collagen pad (FTC) for the treatment of an aortotomy incision in heparinized swine on dual antiplatelet therapy. Twenty-eight 3-mm aortotomy incisions were created in nine heparinized pigs without antiplatelet therapy and treated with PCC. Sixty-eight aortotomy incisions were created in ten heparinized pigs that received clopidogrel (10-11 mg/kg) and acetylsalicylic acid (8-11 mg/kg) orally for 5 days, and treated with either PCC or FTC (N = 34/group). Dual antiplatelet therapy resulted in significantly reduced platelet function. Aortotomy incisions resulted in life-threatening bleeding of 35-292 ml/min. In animals without antiplatelet treatment, PCC provided 96% immediate hemostatic success. In animals with antiplatelet treatment, FTC provided 18% immediate hemostatic success increasing to 74% after 10 min. Strikingly, PCC provided 94% immediate success increasing to 100% after 10 min. Controlling for differences in pretreatment bleeding rates, statistical model-estimated time to hemostasis was 12 times shorter in PCC-treated lesions (p < .02). The combination of a procoagulant collagen pad with a synthetic sealing component provides excellent hemostatic properties under a worst-case scenario. PCC rapidly and firmly adheres to tissue, thereby controlling severe arterial bleeding, even when platelet function is significantly reduced. Treatment with PCC provided superior time to hemostasis compared to FTC.

  7. Laser Accelerator

    DTIC Science & Technology

    2014-09-01

    hollow metal sphere. Voltages of over 10 MV can be reached if used with an insulating gas. Corona discharge limits all electrostatic accelerators to...laser field. Lasers can have strong electric fields with frequencies high enough to avoid corona formation and break- down. The key is to couple the...leading to a spark discharge in the accelerator and thus a breakdown of the electrostatic field [6], [7]. Figure 1.1: Cockroft-Walton cascade generator

  8. Does size matter? Animal units and animal unit months

    Treesearch

    Lamar Smith; Joe Hicks; Scott Lusk; Mike Hemmovich; Shane Green; Sarah McCord; Mike Pellant; John Mitchell; Judith Dyess; Jim Sprinkle; Amanda Gearhart; Sherm Karl; Mike Hannemann; Ken Spaeth; Jason Karl; Matt Reeves; Dave Pyke; Jordan Spaak; Andrew Brischke; Del Despain; Matt Phillippi; Dave Weixelmann; Alan Bass; Jessie Page; Lori Metz; David Toledo; Emily Kachergis

    2017-01-01

    The concepts of animal units, animal unit months, and animal unit equivalents have long been used as standards for range management planning, estimating stocking rates, reporting actual use, assessing grazing fees, ranch appraisal, and other purposes. Increasing size of cattle on rangelands has led some to suggest that the definition of animal units and animal unit...

  9. Ultra-high vacuum photoelectron linear accelerator

    DOEpatents

    Yu, David U.L.; Luo, Yan

    2013-07-16

    An rf linear accelerator for producing an electron beam. The outer wall of the rf cavity of said linear accelerator being perforated to allow gas inside said rf cavity to flow to a pressure chamber surrounding said rf cavity and having means of ultra high vacuum pumping of the cathode of said rf linear accelerator. Said rf linear accelerator is used to accelerate polarized or unpolarized electrons produced by a photocathode, or to accelerate thermally heated electrons produced by a thermionic cathode, or to accelerate rf heated field emission electrons produced by a field emission cathode.

  10. Space Acceleration Measurement System (SAMS)/Orbital Acceleration Research Experiment (OARE)

    NASA Technical Reports Server (NTRS)

    Hakimzadeh, Roshanak

    1998-01-01

    The Life and Microgravity Spacelab (LMS) payload flew on the Orbiter Columbia on mission STS-78 from June 20th to July 7th, 1996. The LMS payload on STS-78 was dedicated to life sciences and microgravity experiments. Two accelerometer systems managed by the NASA Lewis Research Center (LERC) flew to support these experiments, namely the Orbital Acceleration Research Experiment (OARE) and the Space Acceleration Measurements System (SAMS). In addition, the Microgravity Measurement Assembly (NOAA), managed by the European Space Research and Technology Center (ESA/ESTEC), and sponsored by NASA, collected acceleration data in support of the experiments on-board the LMS mission. OARE downlinked real-time quasi-steady acceleration data, which was provided to the investigators. The SAMS recorded higher frequency data on-board for post-mission analysis. The MMA downlinked real-time quasi-steady as well as higher frequency acceleration data, which was provided to the investigators. The Principal Investigator Microgravity Services (PIMS) project at NASA LERC supports principal investigators of microgravity experiments as they evaluate the effects of varying acceleration levels on their experiments. A summary report was prepared by PIMS to furnish interested experiment investigators with a guide to evaluate the acceleration environment during STS-78, and as a means of identifying areas which require further study. The summary report provides an overview of the STS-78 mission, describes the accelerometer systems flown on this mission, discusses some specific analyses of the accelerometer data in relation to the various activities which occurred during the mission, and presents plots resulting from these analyses as a snapshot of the environment during the mission. Numerous activities occurred during the STS-78 mission that are of interest to the low-gravity community. Specific activities of interest during this mission were crew exercise, radiator deployment, Vernier Reaction

  11. Advanced Accelerators for Medical Applications

    NASA Astrophysics Data System (ADS)

    Uesaka, Mitsuru; Koyama, Kazuyoshi

    We review advanced accelerators for medical applications with respect to the following key technologies: (i) higher RF electron linear accelerator (hereafter “linac”); (ii) optimization of alignment for the proton linac, cyclotron and synchrotron; (iii) superconducting magnet; (iv) laser technology. Advanced accelerators for medical applications are categorized into two groups. The first group consists of compact medical linacs with high RF, cyclotrons and synchrotrons downsized by optimization of alignment and superconducting magnets. The second group comprises laser-based acceleration systems aimed of medical applications in the future. Laser plasma electron/ion accelerating systems for cancer therapy and laser dielectric accelerating systems for radiation biology are mentioned. Since the second group has important potential for a compact system, the current status of the established energy and intensity and of the required stability are given.

  12. Advanced Accelerators for Medical Applications

    NASA Astrophysics Data System (ADS)

    Uesaka, Mitsuru; Koyama, Kazuyoshi

    We review advanced accelerators for medical applications with respect to the following key technologies: (i) higher RF electron linear accelerator (hereafter "linac"); (ii) optimization of alignment for the proton linac, cyclotron and synchrotron; (iii) superconducting magnet; (iv) laser technology. Advanced accelerators for medical applications are categorized into two groups. The first group consists of compact medical linacs with high RF, cyclotrons and synchrotrons downsized by optimization of alignment and superconducting magnets. The second group comprises laserbased acceleration systems aimed of medical applications in the future. Laser plasma electron/ion accelerating systems for cancer therapy and laser dielectric accelerating systems for radiation biology are mentioned. Since the second group has important potential for a compact system, the current status of the established energy and intensity and of the required stability are given.

  13. LINEAR ACCELERATOR

    DOEpatents

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  14. Accelerators (4/5)

    ScienceCinema

    Metral, Elias

    2017-12-09

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  15. Accelerators (5/5)

    ScienceCinema

    None

    2018-05-16

    1a) Introduction and motivation; 1b) History and accelerator types; 2) Transverse beam dynamics; 3a) Longitudinal beam dynamics; 3b) Figure of merit of a synchrotron/collider; 3c) Beam control; 4) Main limiting factors; 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  16. Brief electrical stimulation after facial nerve transection and neurorrhaphy: a randomized prospective animal study.

    PubMed

    Mendez, Adrian; Seikaly, Hadi; Biron, Vincent L; Zhu, Lin Fu; Côté, David W J

    2016-02-01

    Recent studies have examined the effects of brief electrical stimulation (BES) on nerve regeneration, with some suggesting that BES accelerates facial nerve recovery. However, the facial nerve outcome measurement in these studies has not been precise or accurate. The objective of this study is to assess the effect of BES on accelerating facial nerve functional recovery from a transection injury in the rat model. A prospective randomized animal study using a rat model was performed. Two groups of 9 rats underwent facial nerve surgery. Both group 1 and 2 underwent facial nerve transection and repair at the main trunk of the nerve, with group 2 additionally receiving BES on post-operative day 0 for 1 h using an implantable stimulation device. Primary outcome was measured using a laser curtain model, which measured amplitude of whisking at 2, 4, and 6 weeks post-operatively. At week 2, the average amplitude observed for group 1 was 4.4°. Showing a statistically significant improvement over group 1, the group 2 mean was 14.0° at 2 weeks post-operatively (p = 0.0004). At week 4, group 1 showed improvement having an average of 9.7°, while group 2 remained relatively unchanged with an average of 12.8°. Group 1 had an average amplitude of 13.63° at 6-weeks from surgery. Group 2 had a similar increase in amplitude with an average of 15.8°. There was no statistically significant difference between the two groups at 4 and 6 weeks after facial nerve surgery. This is the first study to use an implantable stimulator for serial BES following neurorrhaphy in a validated animal model. Results suggest performing BES after facial nerve transection and neurorrhaphy at the main trunk of the facial nerve is associated with accelerated whisker movement in a rat model compared with a control group.

  17. Influence of the ambient acceleration field upon acute acceleration tolerance in chickens

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Spangler, W. L.; Rhode, E. A.; Burton, R. R.

    1979-01-01

    The paper measured the acceleration tolerance of domestic fowl (Rhode Island Red cocks), acutely exposed to a 6 Gz field, as the time over which a normal heart rate can be maintained. This period of circulatory adjustment ends abruptly with pronounced bradycardia. For chickens which previously have been physiologically adapted to 2.5 -G field, the acute acceleration tolerance is greatly increased. The influence of the ambient acceleration field on the adjustment of the circulatory system appears to be a general phenomenon.

  18. Particle acceleration in pulsar magnetospheres

    NASA Technical Reports Server (NTRS)

    Baker, K. B.

    1978-01-01

    The structure of pulsar magnetospheres and the acceleration mechanism for charged particles in the magnetosphere was studied using a pulsar model which required large acceleration of the particles near the surface of the star. A theorem was developed which showed that particle acceleration cannot be expected when the angle between the magnetic field lines and the rotation axis is constant (e.g. radial field lines). If this angle is not constant, however, acceleration must occur. The more realistic model of an axisymmetric neutron star with a strong dipole magnetic field aligned with the rotation axis was investigated. In this case, acceleration occurred at large distances from the surface of the star. The magnitude of the current can be determined using the model presented. In the case of nonaxisymmetric systems, the acceleration is expected to occur nearer to the surface of the star.

  19. A traveling-wave forward coupler design for a new accelerating mode in a silicon woodpile accelerator

    DOE PAGES

    Wu, Ziran; Lee, Chunghun H.; Wootton, Kent P.; ...

    2016-03-01

    Silicon woodpile photonic crystals provide a base structure that can be used to build a three-dimensional dielectric waveguide system for high-gradient laser driven acceleration. A new woodpile waveguide design that hosts a phase synchronous, centrally confined accelerating mode is proposed. Comparing with previously discovered silicon woodpile accelerating modes, this mode shows advantages in terms of better electron beam loading and higher achievable acceleration gradient. Several traveling-wave coupler design schemes developed for multi-cell RF cavity accelerators are adapted to the woodpile power coupler design for this new accelerating mode. Design of a forward coupled, highly efficient silicon woodpile accelerator is achieved.more » Simulation shows high efficiency of over 75% of the drive laser power coupled to this fundamental accelerating mode, with less than 15% backward wave scattering. The estimated acceleration gradient, when the coupler structure is driven at the damage threshold fluence of silicon at its operating 1.506 μm wavelength, can reach 185 MV/m. Lastly, a 17-layer woodpile waveguide structure was successfully fabricated, and the measured bandgap is in excellent agreement with simulation.« less

  20. A traveling-wave forward coupler design for a new accelerating mode in a silicon woodpile accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Ziran; Lee, Chunghun H.; Wootton, Kent P.

    Silicon woodpile photonic crystals provide a base structure that can be used to build a three-dimensional dielectric waveguide system for high-gradient laser driven acceleration. A new woodpile waveguide design that hosts a phase synchronous, centrally confined accelerating mode is proposed. Comparing with previously discovered silicon woodpile accelerating modes, this mode shows advantages in terms of better electron beam loading and higher achievable acceleration gradient. Several traveling-wave coupler design schemes developed for multi-cell RF cavity accelerators are adapted to the woodpile power coupler design for this new accelerating mode. Design of a forward coupled, highly efficient silicon woodpile accelerator is achieved.more » Simulation shows high efficiency of over 75% of the drive laser power coupled to this fundamental accelerating mode, with less than 15% backward wave scattering. The estimated acceleration gradient, when the coupler structure is driven at the damage threshold fluence of silicon at its operating 1.506 μm wavelength, can reach 185 MV/m. Lastly, a 17-layer woodpile waveguide structure was successfully fabricated, and the measured bandgap is in excellent agreement with simulation.« less

  1. ACE/DD genotype is associated with hemostasis balance disturbances reflecting hypercoagulability and endothelial dysfunction in patients with untreated hypertension.

    PubMed

    Makris, T K; Stavroulakis, G A; Dafni, U G; Gialeraki, A E; Krespi, P G; Hatzizacharias, A N; Tsoukala, C G; Vythoulkas, J S; Kyriakidis, M K

    2000-11-01

    Angiotensin-converting enzyme (ACE) gene polymorphism has been associated with an increased incidence of myocardial infarction. Recent studies have investigated a potential influence of ACE gene polymorphism on fibrinolysis or endothelial function. It has been previously established that essential hypertension is accompanied by endothelial dysfunction and fibrinolytic balance disorders. The aim of our study was to study the relation between ACE gene polymorphism and fibrinolytic/hemostatic factors as well as endothelial cell damage markers in patients with hypertension. The following parameters were evaluated in 104 patients with previously untreated hypertension: plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA) antigen, fibrinogen, D-dimer, and von Willebrand factor (vWF). The genotype of the ACE gene was also determined (by the polymerase chain reaction method), and patients were characterized according to the observed alleles as deletion/deletion (DD), insertion/insertion (II), or insertion/deletion (ID). Those with DD genotype (n = 42) had significantly higher plasma levels of PAI-1 antigen (P =. 012), tPA antigen (P =.0001), fibrinogen (P =.0002), D-dimer (P =. 0001) and vWF (P =.0004) compared with ID (n = 30) or II (n = 32) genotypes. The ACE gene genotypes appeared to be significant predictors for plasma PAI-1 antigen, tPA antigen, fibrinogen, D -dimer, and vWF even after adjustment for age, sex, body mass index, triglyceride and cholesterol levels, and blood pressure. Our findings suggest that the ACE/DD genotype is associated with hemostasis balance disturbances reflecting hypercoagulability and endothelial damage in patients with untreated hypertension.

  2. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-01-01

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  3. Charged particle accelerator grating

    DOEpatents

    Palmer, R.B.

    1985-09-09

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams onto the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  4. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-09-02

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  5. HEAVY ION LINEAR ACCELERATOR

    DOEpatents

    Van Atta, C.M.; Beringer, R.; Smith, L.

    1959-01-01

    A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

  6. CLASHING BEAM PARTICLE ACCELERATOR

    DOEpatents

    Burleigh, R.J.

    1961-04-11

    A charged-particle accelerator of the proton synchrotron class having means for simultaneously accelerating two separate contra-rotating particle beams within a single annular magnet structure is reported. The magnet provides two concentric circular field regions of opposite magnetic polarity with one field region being of slightly less diameter than the other. The accelerator includes a deflector means straddling the two particle orbits and acting to collide the two particle beams after each has been accelerated to a desired energy. The deflector has the further property of returning particles which do not undergo collision to the regular orbits whereby the particles recirculate with the possibility of colliding upon subsequent passages through the deflector.

  7. Animal evolution during domestication: the domesticated fox as a model.

    PubMed

    Trut, Lyudmila; Oskina, Irina; Kharlamova, Anastasiya

    2009-03-01

    We review the evolution of domestic animals, emphasizing the effect of the earliest steps of domestication on its course. Using the first domesticated species, the dog (Canis familiaris), for illustration, we describe the evolutionary peculiarities during the historical domestication, such as the high level and wide range of diversity. We suggest that the process of earliest domestication via unconscious and later conscious selection of human-defined behavioral traits may accelerate phenotypic variations. The review is based on the results of a long-term experiment designed to reproduce early mammalian domestication in the silver fox (Vulpes vulpes) selected for tameability or amenability to domestication. We describe changes in behavior, morphology and physiology that appeared in the fox during its selection for tameability, which were similar to those observed in the domestic dog. Based on the data of the fox experiment and survey of relevant data, we discuss the developmental, genetic and possible molecular genetic mechanisms underlying these changes. We ascribe the causative role in evolutionary transformation of domestic animals to the selection for behavior and to the neurospecific regulatory genes it affects.

  8. Self-motion perception: assessment by real-time computer-generated animations

    NASA Technical Reports Server (NTRS)

    Parker, D. E.; Phillips, J. O.

    2001-01-01

    We report a new procedure for assessing complex self-motion perception. In three experiments, subjects manipulated a 6 degree-of-freedom magnetic-field tracker which controlled the motion of a virtual avatar so that its motion corresponded to the subjects' perceived self-motion. The real-time animation created by this procedure was stored using a virtual video recorder for subsequent analysis. Combined real and illusory self-motion and vestibulo-ocular reflex eye movements were evoked by cross-coupled angular accelerations produced by roll and pitch head movements during passive yaw rotation in a chair. Contrary to previous reports, illusory self-motion did not correspond to expectations based on semicircular canal stimulation. Illusory pitch head-motion directions were as predicted for only 37% of trials; whereas, slow-phase eye movements were in the predicted direction for 98% of the trials. The real-time computer-generated animations procedure permits use of naive, untrained subjects who lack a vocabulary for reporting motion perception and is applicable to basic self-motion perception studies, evaluation of motion simulators, assessment of balance disorders and so on.

  9. Animal evolution during domestication: the domesticated fox as a model

    PubMed Central

    Trut, Lyudmila; Oskina, Irina; Kharlamova, Anastasiya

    2009-01-01

    Summary We review the evolution of domestic animals, emphasizing the effect of the earliest steps of domestication on its course. Using the first domesticated species, the dog (Canis familiaris) as an illustration, we describe the evolutionary specificities of the historical domestication, such as the high level and wide range of diversity. We suggest that the process of earliest domestication via unconscious and later conscious selection of human-defined behavioral traits may accelerate phenotypic variations. The review is based on the results of the long-term experiment designed to reproduce early mammalian domestication in the silver fox (Vulpes vulpes) selected for tameability, or amenability to domestication. We describe changes in behavior, morphology and physiology that appeared in the fox during its selection for tameability and that were similar to those observed in the domestic dog. Based on the experimental fox data and survey of relevant data, we discuss the developmental, genetic and possible molecular-genetic mechanisms of these changes. We assign the causative role in evolutionary transformation of domestic animals to selection for behavior and to the neurospecific regulatory genes it affects. PMID:19260016

  10. Dusty-Plasma Particle Accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2005-01-01

    A dusty-plasma apparatus is being investigated as means of accelerating nanometer- and micrometer-sized particles. Applications for the dusty-plasma particle accelerators fall into two classes: Simulation of a variety of rapidly moving dust particles and micrometeoroids in outer-space environments that include micrometeoroid streams, comet tails, planetary rings, and nebulae and Deposition or implantation of nanoparticles on substrates for diverse industrial purposes that could include hardening, increasing thermal insulation, altering optical properties, and/or increasing permittivities of substrate materials. Relative to prior apparatuses used for similar applications, dusty-plasma particle accelerators offer such potential advantages as smaller size, lower cost, less complexity, and increased particle flux densities. A dusty-plasma particle accelerator exploits the fact that an isolated particle immersed in plasma acquires a net electric charge that depends on the relative mobilities of electrons and ions. Typically, a particle that is immersed in a low-temperature, partially ionized gas, wherein the average kinetic energy of electrons exceeds that of ions, causes the particle to become negatively charged. The particle can then be accelerated by applying an appropriate electric field. A dusty-plasma particle accelerator (see figure) includes a plasma source such as a radio-frequency induction discharge apparatus containing (1) a shallow cup with a biasable electrode to hold the particles to be accelerated and (2) a holder for the substrate on which the particles are to impinge. Depending on the specific design, a pair of electrostatic-acceleration grids between the substrate and discharge plasma can be used to both collimate and further accelerate particles exiting the particle holder. Once exposed to the discharge plasma, the particles in the cup quickly acquire a negative charge. Application of a negative voltage pulse to the biasable electrode results in the

  11. Animal welfare and use of silkworm as a model animal.

    PubMed

    Sekimizu, N; Paudel, A; Hamamoto, H

    2012-08-01

    Sacrificing model animals is required for developing effective drugs before being used in human beings. In Japan today, at least 4,210,000 mice and other mammals are sacrificed to a total of 6,140,000 per year for the purpose of medical studies. All the animals treated in Japan, including test animals, are managed under control of "Act on Welfare and Management of Animals". Under the principle of this Act, no person shall kill, injure, or inflict cruelty on animals without due cause. "Animal" addressed in the Act can be defined as a "vertebrate animal". If we can make use of invertebrate animals in testing instead of vertebrate ones, that would be a remarkable solution for the issue of animal welfare. Furthermore, there are numerous advantages of using invertebrate animal models: less space and small equipment are enough for taking care of a large number of animals and thus are cost-effective, they can be easily handled, and many biological processes and genes are conserved between mammals and invertebrates. Today, many invertebrates have been used as animal models, but silkworms have many beneficial traits compared to mammals as well as other insects. In a Genome Pharmaceutical Institute's study, we were able to achieve a lot making use of silkworms as model animals. We would like to suggest that pharmaceutical companies and institutes consider the use of the silkworm as a model animal which is efficacious both for financial value by cost cutting and ethical aspects in animals' welfare.

  12. The CUBLAS and CULA based GPU acceleration of adaptive finite element framework for bioluminescence tomography.

    PubMed

    Zhang, Bo; Yang, Xiang; Yang, Fei; Yang, Xin; Qin, Chenghu; Han, Dong; Ma, Xibo; Liu, Kai; Tian, Jie

    2010-09-13

    In molecular imaging (MI), especially the optical molecular imaging, bioluminescence tomography (BLT) emerges as an effective imaging modality for small animal imaging. The finite element methods (FEMs), especially the adaptive finite element (AFE) framework, play an important role in BLT. The processing speed of the FEMs and the AFE framework still needs to be improved, although the multi-thread CPU technology and the multi CPU technology have already been applied. In this paper, we for the first time introduce a new kind of acceleration technology to accelerate the AFE framework for BLT, using the graphics processing unit (GPU). Besides the processing speed, the GPU technology can get a balance between the cost and performance. The CUBLAS and CULA are two main important and powerful libraries for programming on NVIDIA GPUs. With the help of CUBLAS and CULA, it is easy to code on NVIDIA GPU and there is no need to worry about the details about the hardware environment of a specific GPU. The numerical experiments are designed to show the necessity, effect and application of the proposed CUBLAS and CULA based GPU acceleration. From the results of the experiments, we can reach the conclusion that the proposed CUBLAS and CULA based GPU acceleration method can improve the processing speed of the AFE framework very much while getting a balance between cost and performance.

  13. Current status of animal welfare and animal rights in China.

    PubMed

    Lu, Jiaqi; Bayne, Kathryn; Wang, Jianfei

    2013-11-01

    In the past few years, new social passions have sparked on the Chinese mainland. At the centre of these burgeoning passions is a focus on animal welfare, animal treatment, and even animal rights, by the public and academic sectors. With China's rapid economic changes and greater access to information from around the world, societal awareness of animal issues is rising very fast. Hastening this paradigm shift were several highly public incidents involving animal cruelty, including exposés on bear bile harvesting for traditional Chinese medicine, the thousands of dogs rescued from China's meat trade, and the call to boycott shark fin soup and bird nest soup. This article outlines the current status of campaigning by animal advocates in China (specifically the animal rights movement) from three interlinked perspectives: wildlife conservation, companion animal protection, and laboratory animal protection. By reviewing this campaigning, we attempt to present not only the political and social impact of the concept of animal rights, but also the perceptions of, and challenges to, animal rights activities in China. 2013 FRAME.

  14. Direct Laser Acceleration in Laser Wakefield Accelerators

    NASA Astrophysics Data System (ADS)

    Shaw, J. L.; Froula, D. H.; Marsh, K. A.; Joshi, C.; Lemos, N.

    2017-10-01

    The direct laser acceleration (DLA) of electrons in a laser wakefield accelerator (LWFA) has been investigated. We show that when there is a significant overlap between the drive laser and the trapped electrons in a LWFA cavity, the accelerating electrons can gain energy from the DLA mechanism in addition to LWFA. The properties of the electron beams produced in a LWFA, where the electrons are injected by ionization injection, have been investigated using particle-in-cell (PIC) code simulations. Particle tracking was used to demonstrate the presence of DLA in LWFA. Further PIC simulations comparing LWFA with and without DLA show that the presence of DLA can lead to electron beams that have maximum energies that exceed the estimates given by the theory for the ideal blowout regime. The magnitude of the contribution of DLA to the energy gained by the electron was found to be on the order of the LWFA contribution. The presence of DLA in a LWFA can also lead to enhanced betatron oscillation amplitudes and increased divergence in the direction of the laser polarization. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  15. The Los Alamos Laser Acceleration of Particles Workshop and beginning of the advanced accelerator concepts field

    NASA Astrophysics Data System (ADS)

    Joshi, C.

    2012-12-01

    The first Advanced Acceleration of Particles-AAC-Workshop (actually named Laser Acceleration of Particles Workshop) was held at Los Alamos in January 1982. The workshop lasted a week and divided all the acceleration techniques into four categories: near field, far field, media, and vacuum. Basic theorems of particle acceleration were postulated (later proven) and specific experiments based on the four categories were formulated. This landmark workshop led to the formation of the advanced accelerator R&D program in the HEP office of the DOE that supports advanced accelerator research to this day. Two major new user facilities at Argonne and Brookhaven and several more directed experimental efforts were built to explore the advanced particle acceleration schemes. It is not an exaggeration to say that the intellectual breadth and excitement provided by the many groups who entered this new field provided the needed vitality to then recently formed APS Division of Beams and the new online journal Physical Review Special Topics-Accelerators and Beams. On this 30th anniversary of the AAC Workshops, it is worthwhile to look back at the legacy of the first Workshop at Los Alamos and the fine groundwork it laid for the field of advanced accelerator concepts that continues to flourish to this day.

  16. Fostering Kinship with Animals: Animal Portraiture in Humane Education

    ERIC Educational Resources Information Center

    Kalof, Linda; Zammit-Lucia, Joe; Bell, Jessica; Granter, Gina

    2016-01-01

    Visual depictions of animals can alter human perceptions of, emotional responses to, and attitudes toward animals. Our study addressed the potential of a slideshow designed to activate emotional responses to animals to foster feelings of kinship with them. The personal meaning map measured changes in perceptions of animals. The participants were…

  17. Bio-Spectroscopic Imaging Provides Evidence of Hippocampal Zn Deficiency and Decreased Lipid Unsaturation in an Accelerated Ageing Mouse Model.

    PubMed

    Fimognari, Nicholas; Hollings, Ashley; Lam, Virginie; Tidy, Rebecca J; Kewish, Cameron M; Albrecht, Matthew A; Takechi, Ryu; Mamo, John C L; Hackett, Mark J

    2018-06-14

    Western society is facing a health epidemic due to the increasing incidence of dementia in ageing populations, and there are still few effective diagnostic methods, minimal treatment options, and no cure. Ageing is the greatest risk factor for memory loss that occurs during the natural ageing process, as well as being the greatest risk factor for neurodegenerative disease such as Alzheimer's disease. Therefore, greater understanding of the biochemical pathways that drive a healthy ageing brain towards dementia (pathological ageing or Alzheimer's disease), is required to accelerate the development of improved diagnostics and therapies. Unfortunately, many animal models of dementia model chronic amyloid precursor protein over-expression, which although highly relevant to mechanisms of amyloidosis and familial Alzheimer's disease, does not model well dementia during the natural ageing process. A promising animal model reported to model mechanisms of accelerated natural ageing and memory impairments, is the senescence accelerated murine prone strain 8 (SAMP8), which has been adopted by many research group to study the biochemical transitions that occur during brain ageing. A limitation to traditional methods of biochemical characterisation is that many important biochemical and elemental markers (lipid saturation, lactate, transition metals) cannot be imaged at meso- or micro-spatial resolution. Therefore, in this investigation we report the first multi-modal biospectroscopic characterisation of the SAMP8 model, and have identified important biochemical and elemental alterations, and co-localisations, between 4 month old SAMP8 mice and the relevant control (SAMR1) mice. Specifically, we demonstrate direct evidence of altered metabolism and disturbed lipid homeostasis within corpus callosum white matter, in addition to localised hippocampal metal deficiencies, in the accelerated ageing phenotype. Such findings have important implication for future research aimed at

  18. Intermittency of acceleration in isotropic turbulence.

    PubMed

    Lee, Sang; Lee, Changhoon

    2005-05-01

    The intermittency of acceleration is investigated for isotropic turbulence using direct numerical simulation. Intermittently found acceleration of large magnitude always points towards the rotational axis of a vortex filament, indicating that the intermittency of acceleration is associated with the rotational motion of the vortices that causes centripetal acceleration, which is consistent with the reported result for the near-wall turbulence. Furthermore, investigation on movements of such vortex filaments provides some insights into the dynamics of local dissipation, enstrophy and acceleration. Strong dissipation partially covering the edge of a vortex filament shows weak correlation with enstrophy, while it is strongly correlated with acceleration.

  19. Teleportation with Multiple Accelerated Partners

    NASA Astrophysics Data System (ADS)

    Sagheer, A.; Hamdoun, H.; Metwally, N.

    2015-09-01

    As the current revolution in communication is underway, quantum teleportation can increase the level of security in quantum communication applications. In this paper, we present a quantum teleportation procedure that capable to teleport either accelerated or non-accelerated information through different quantum channels. These quantum channels are based on accelerated multi-qubit states, where each qubit of each of these channels represents a partner. Namely, these states are the W state, Greenberger-Horne-Zeilinger (GHZ) state, and the GHZ-like state. Here, we show that the fidelity of teleporting accelerated information is higher than the fidelity of teleporting non-accelerated information, both through a quantum channel that is based on accelerated state. Also, the comparison among the performance of these three channels shows that the degree of fidelity depends on type of the used channel, type of the measurement, and value of the acceleration. The result of comparison concludes that teleporting information through channel that is based on the GHZ state is more robust than teleporting information through channels that are based on the other two states. For future work, the proposed procedure can be generalized later to achieve communication through a wider quantum network.

  20. An Adiabatic Phase-Matching Accelerator

    DOE PAGES

    Lemery, Francois; Floettmann, Klaus; Piot, Philippe; ...

    2018-05-25

    We present a general concept to accelerate non-relativistic charged particles. Our concept employs an adiabatically-tapered dielectric-lined waveguide which supports accelerating phase velocities for synchronous acceleration. We propose an ansatz for the transient field equations, show it satisfies Maxwell's equations under an adiabatic approximation and find excellent agreement with a finite-difference time-domain computer simulation. The fields were implemented into the particle-tracking program {\\sc astra} and we present beam dynamics results for an accelerating field with a 1-mm-wavelength and peak electric field of 100~MV/m. The numerical simulations indicate that amore » $$\\sim 200$$-keV electron beam can be accelerated to an energy of $$\\sim10$$~MeV over $$\\sim 10$$~cm. The novel scheme is also found to form electron beams with parameters of interest to a wide range of applications including, e.g., future advanced accelerators, and ultra-fast electron diffraction.« less

  1. An Adiabatic Phase-Matching Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lemery, Francois; Floettmann, Klaus; Piot, Philippe

    2017-12-22

    We present a general concept to accelerate non-relativistic charged particles. Our concept employs an adiabatically-tapered dielectric-lined waveguide which supports accelerating phase velocities for synchronous acceleration. We propose an ansatz for the transient field equations, show it satisfies Maxwell's equations under an adiabatic approximation and find excellent agreement with a finite-difference time-domain computer simulation. The fields were implemented into the particle-tracking program {\\sc astra} and we present beam dynamics results for an accelerating field with a 1-mm-wavelength and peak electric field of 100~MV/m. The numerical simulations indicate that amore » $$\\sim 200$$-keV electron beam can be accelerated to an energy of $$\\sim10$$~MeV over $$\\sim 10$$~cm. The novel scheme is also found to form electron beams with parameters of interest to a wide range of applications including, e.g., future advanced accelerators, and ultra-fast electron diffraction.« less

  2. Electrostatic Plasma Accelerator (EPA)

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Aston, Graeme

    1989-01-01

    The Electrostatic Plasma Accelerator (EPA) is a thruster concept which promises specific impulse levels between low power arcjets and those of the ion engine while retaining the relative simplicity of the arcjet. The EPA thruster produces thrust through the electrostatic acceleration of a moderately dense plasma. No accelerating electrodes are used and the specific impulse is a direct function of the applied discharge voltage and the propellant atomic mass. The goal of the present program is to demonstrate feasibility of the EPA thruster concept through experimental and theoretical investigations of the EPA acceleration mechanism and discharge chamber performance. Experimental investigations will include operating the test bed ion (TBI) engine as an EPA thruster and parametrically varying the thruster geometry and operating conditions to quantify the electrostatic plasma acceleration effect. The theoretical investigations will include the development of a discharge chamber model which describes the relationships between the engine size, plasma properties, and overall performance. For the EPA thruster to be a viable propulsion concept, overall thruster efficiencies approaching 30% with specific impulses approaching 1000 s must be achieved.

  3. Gaps in US Animal Welfare Law for Laboratory Animals: Perspectives From an Animal Law Attorney.

    PubMed

    Frasch, Pamela D

    2016-05-01

    The use of animals in biomedical, toxicological, and basic research has been common practice, and a tool for scientists and researchers, for many years. And yet, serious conflict continues to exist between those who believe that the use of animals in research will yield scientific results that benefit humans and those who believe such practices are unethical regardless of use or outcome. High-profile undercover cases have further raised public awareness and have put the entire industry under pressure to be transparent, accountable, and aggressive in its adoption of reduction, refinement, and replacement (3R) principles. Many animal law attorneys are deeply frustrated by what they see as weak US laws that are unevenly enforced, especially when compared with legal advances in other countries and regions. This article (1) explores those gaps in US animal welfare laws with an emphasis on the Animal Welfare Act, (2) argues in favor of stronger laws and rigorous enforcement, and (3) suggests steps to advance these goals. These steps include (1) expanding the definition of "animal" in the Animal Welfare Act (AWA), (2) improving and expanding minimum care requirements in USDA regulations, (3) instituting mandatory reporting requirements, improving Institutional Animal Care and Use Committees, and allowing easier accessibility to laboratory reports and plans, (4) adding a citizen suit provision to the AWA, and (5) continuing education about the emotional and social capacities of animals and a stronger commitment to 3R principles. © The Author 2017. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Perception of linear acceleration in weightlessness

    NASA Technical Reports Server (NTRS)

    Arrott, A. P.; Young, L. R.

    1987-01-01

    Eye movements and subjective detection of acceleration were measured on human experimental subjects during vestibular sled acceleration during the D1 Spacelab Mission. Methods and results are reported on the time to detection of small acceleration steps, the threshold for detection of linear acceleration, perceived motion path, and CLOAT. A consistently shorter time to detection of small acceleration steps is found. Subjective reports of perceived motion during sinusoidal oscillation in weightlessness were qualitatively similar to reports on earth.

  5. Accelerator based epithermal neutron source

    NASA Astrophysics Data System (ADS)

    Taskaev, S. Yu.

    2015-11-01

    We review the current status of the development of accelerator sources of epithermal neutrons for boron neutron capture therapy (BNCT), a promising method of malignant tumor treatment. Particular attention is given to the source of epithermal neutrons on the basis of a new type of charged particle accelerator: tandem accelerator with vacuum insulation and lithium neutron-producing target. It is also shown that the accelerator with specialized targets makes it possible to generate fast and monoenergetic neutrons, resonance and monoenergetic gamma-rays, alpha-particles, and positrons.

  6. Compact accelerator for medical therapy

    DOEpatents

    Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

    2010-05-04

    A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

  7. Safety evaluations under the proposed US Safe Cosmetics and Personal Care Products Act of 2013: animal use and cost estimates.

    PubMed

    Knight, Jean; Rovida, Costanca

    2014-01-01

    The proposed Safe Cosmetics and Personal Care Products Act of 2013 calls for a new evaluation program for cosmetic ingredients in the US, with the new assessments initially dependent on expanded animal testing. This paper considers possible testing scenarios under the proposed Act and estimates the number of test animals and cost under each scenario. It focuses on the impact for the first 10 years of testing, the period of greatest impact on animals and costs. The analysis suggests the first 10 years of testing under the Act could evaluate, at most, about 50% of ingredients used in cosmetics. Testing during this period would cost about $ 1.7-$ 9 billion and 1-11.5 million animals. By test year 10, alternative, high-throughput test methods under development are expected to be available, replacing animal testing and allowing rapid evaluation of all ingredients. Given the high cost in dollars and animal lives of the first 10 years for only about half of ingredients, a better choice may be to accelerate development of high-throughput methods. This would allow evaluation of 100% of cosmetic ingredients before year 10 at lower cost and without animal testing.

  8. Animals Alive! An Ecological Guide to Animal Activities.

    ERIC Educational Resources Information Center

    Holley, Dennis

    Animals Alive! is designed to help teachers develop an inquiry-oriented program for studying the animal kingdom in which, whenever possible, live animals are collected locally, studied, observed, and then released completely unharmed back into their natural habitats. By careful selection and modification of the chapter questions, activities, and…

  9. Gravitational adaptation of animals

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Burton, R. R.

    1982-01-01

    The effect of gravitational adaptation is studied in a group of five Leghorn cocks which had become physiologically adapted to 2 G after 162 days of centrifugation. After this period of adaptation, they are periodically exposed to a 2 G field, accompanied by five previously unexposed hatch-mates, and the degree of retained acceleration adaptation is estimated from the decrease in lymphocyte frequency after 24 hr at 2 G. Results show that the previously adapted birds exhibit an 84% greater lymphopenia than the unexposed birds, and that the lymphocyte frequency does not decrease to a level below that found at the end of 162 days at 2 G. In addition, the capacity for adaptation to chronic acceleration is found to be highly heritable. An acceleration tolerant strain of birds shows lesser mortality during chronic acceleration, particularly in intermediate fields, although the result of acceleration selection is largely quantitative (a greater number of survivors) rather than qualitative (behavioral or physiological changes).

  10. 38 CFR 9.14 - Accelerated Benefits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Accelerated Benefits. 9...' GROUP LIFE INSURANCE AND VETERANS' GROUP LIFE INSURANCE § 9.14 Accelerated Benefits. (a) What is an Accelerated Benefit? An Accelerated Benefit is a payment of a portion of your Servicemembers' Group Life...

  11. 38 CFR 9.14 - Accelerated Benefits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Accelerated Benefits. 9...' GROUP LIFE INSURANCE AND VETERANS' GROUP LIFE INSURANCE § 9.14 Accelerated Benefits. (a) What is an Accelerated Benefit? An Accelerated Benefit is a payment of a portion of your Servicemembers' Group Life...

  12. 38 CFR 9.14 - Accelerated Benefits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Accelerated Benefits. 9...' GROUP LIFE INSURANCE AND VETERANS' GROUP LIFE INSURANCE § 9.14 Accelerated Benefits. (a) What is an Accelerated Benefit? An Accelerated Benefit is a payment of a portion of your Servicemembers' Group Life...

  13. 38 CFR 9.14 - Accelerated Benefits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Accelerated Benefits. 9...' GROUP LIFE INSURANCE AND VETERANS' GROUP LIFE INSURANCE § 9.14 Accelerated Benefits. (a) What is an Accelerated Benefit? An Accelerated Benefit is a payment of a portion of your Servicemembers' Group Life...

  14. 38 CFR 9.14 - Accelerated Benefits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Accelerated Benefits. 9...' GROUP LIFE INSURANCE AND VETERANS' GROUP LIFE INSURANCE § 9.14 Accelerated Benefits. (a) What is an Accelerated Benefit? An Accelerated Benefit is a payment of a portion of your Servicemembers' Group Life...

  15. ELECTROSTATIC ACCELERATORS (in French)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gerbier, R.

    1962-04-01

    The various methods presently in use for producing the continuous high voltage necessary for the operation of electrostatic accelerators are reviewed. The methods considered are voltage multiplier units (Greinacher and Morganstern types) and electrostatic instruments (Van de Graaff and Trump machines and Felici rotnting cylinder instruments). The electrostatic accelerators used at Grenoble which give currents of several milliamperes at voltages up to 1.2 Mv are described. In this energy region electron accelerators and neutron generators offer very interesting possibilities. (auth)

  16. Optically pulsed electron accelerator

    DOEpatents

    Fraser, John S.; Sheffield, Richard L.

    1987-01-01

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  17. Optically pulsed electron accelerator

    DOEpatents

    Fraser, J.S.; Sheffield, R.L.

    1985-05-20

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  18. Concepts of animal welfare in relation to positions in animal ethics.

    PubMed

    Schmidt, Kirsten

    2011-06-01

    When animal ethicists deal with welfare they seem to face a dilemma: On the one hand, they recognize the necessity of welfare concepts for their ethical approaches. On the other hand, many animal ethicists do not want to be considered reformist welfarists. Moreover, animal welfare scientists may feel pressed by moral demands for a fundamental change in our attitude towards animals. The analysis of this conflict from the perspective of animal ethics shows that animal welfare science and animal ethics highly depend on each other. Welfare concepts are indispensable in the whole field of animal ethics. Evidence for this can be found by analyzing the structure of theories of animal ethics and the different ways in which these theories employ welfare concepts. Furthermore, the background of values underneath every welfare theory is essential to pursue animal welfare science. Animal ethics can make important contributions to the clarification of underlying normative assumptions with regard to the value of the animal, with regard to ideas about what is valuable for the animal, and with regard to the actions that should follow from the results of animal welfare science.

  19. Improvement of voltage holding and high current beam acceleration by MeV accelerator for ITER NB

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Taniguchi, M.; Kashiwagi, M.; Inoue, T.

    Voltage holding of -1 MV is an essential issue in development of a multi-aperture multi-grid (MAMuG) negative ion accelerator, of which target is to accelerate 200 A/m{sup 2} H{sup -} ion beam up to the energy of 1 MeV for several tens seconds. Review of voltage holding results ever obtained with various geometries of the accelerators showed that the voltage holding capability was about a half of designed value based on the experiment obtained from ideal small electrode. This is considered due to local electric field concentration in the accelerators, such as edge and steps between multi-aperture grids and itsmore » support structures. Based on the detailed investigation with electric field analysis, accelerator was modified to reduce the electric field concentration by reshaping the support structures and expanding the gap length between the grid supports. After the modifications, the accelerator succeeded in sustaining -1 MV for more than one hour in vacuum. Improvement of the voltage holding characteristics progressed the energy and current accelerated by the MeV accelerator. Up to 2010, beam parameters achieved by the MAMuG accelerator were increased to 879 keV, 0.36 A (157 A/m{sup 2}) at perveance matched condition and 937 keV, 0.33 A (144 A/m{sup 2}) slightly under perveance.« less

  20. [Alternatives to animal experimentation v.s. animal rights terrorism].

    PubMed

    Kurosawa, Tsutomu Miki

    2008-05-01

    Systematic modern animal experimentation was established by Bernard Claude who wrote "An Introduction to the Study of Experimental Medicine" in 1865. At this point, the public was already asking that the pain and distress of experimental animals be reduced. For this, scientists, William Russell and Rex Burch in 1959 proposed the principles of alternatives to animal experimentation, the "3Rs". Since that time, animal welfare advocates have promoted the 3Rs concept in biomedical research communities. However, cruel animal experiments have continued and there are reports of radical extremists showing their opposition by invasion, arson, theft and even bombing of institutions involved, resulting in killing of the animals. SHAC, one extremist group believed to be animal welfare activitists was recognized as a terrorist group after the 9.11 tragedy in USA and the government viewed their activities very seriously. In 2001, British animal extremists invaded Japanese universities and stole laboratory resources; one individual was arrested and sentenced to prison for three years; Japanese who assisted in the incident were arrested and one was sentenced for one year. In 2006, SHAC USA members were prosecuted and sentenced for up to 6 years for their terrorism activities including arson. We need to consider the background of these activities which are financially supported by animal welfare advocates. The way we, as scientists who conduct such experiments can respond is by promoting alternatives to this experimentation. In Japan, the animal welfare law was revised in 2005 stressing the importance of 3Rs in scientific activities with animals. The promotion of 3Rs should be strengthened in the pharmaceutical community.

  1. High-intensity-focused-ultrasound (HIFU) induced homeostasis and tissue ablation

    NASA Astrophysics Data System (ADS)

    Chauhan, Sunita; Michel, M. S.; Alken, Peter; Kohrmann, K. U.; Haecker, Axel

    2003-06-01

    At high intensity levels, ultrasound energy focused into remote tissue targets in human body has shown to produce thermal necrosis in circumscribed regions with sub-millimeter accuracy. The non-invasive modality known as HIFU has enormous potential for thermal ablation of cancers/tumors of the human body without any adverse effects in the surrounding normal tissue. In this paper, empirical results for parametric assessment and interdependence of several exposure variables are presented for producing thermal necrosis as well as hemostasis. Multiple HIFU transducers in selective spatial configuration have been deployed using a suitably designed experiemntal harness, with and without motorized jig scanning. The pre-planning and on-line procedure for treatment and specified instrumentation is described. Custom designed 25mm aperture HIFU probes resonating at 2 MHz focused at 64 and 80 mm are used. Results have been obtained in ex-vivo animal tissue and in vitro biological phantoms for hemostasis.

  2. Dynamics of animal movement in an ecological context: dragonfly wing damage reduces flight performance and predation success.

    PubMed

    Combes, S A; Crall, J D; Mukherjee, S

    2010-06-23

    Much of our understanding of the control and dynamics of animal movement derives from controlled laboratory experiments. While many aspects of animal movement can be probed only in these settings, a more complete understanding of animal locomotion may be gained by linking experiments on relatively simple motions in the laboratory to studies of more complex behaviours in natural settings. To demonstrate the utility of this approach, we examined the effects of wing damage on dragonfly flight performance in both a laboratory drop-escape response and the more natural context of aerial predation. The laboratory experiment shows that hindwing area loss reduces vertical acceleration and average flight velocity, and the predation experiment demonstrates that this type of wing damage results in a significant decline in capture success. Taken together, these results suggest that wing damage may take a serious toll on wild dragonflies, potentially reducing both reproductive success and survival.

  3. Dynamics of animal movement in an ecological context: dragonfly wing damage reduces flight performance and predation success

    PubMed Central

    Combes, S. A.; Crall, J. D.; Mukherjee, S.

    2010-01-01

    Much of our understanding of the control and dynamics of animal movement derives from controlled laboratory experiments. While many aspects of animal movement can be probed only in these settings, a more complete understanding of animal locomotion may be gained by linking experiments on relatively simple motions in the laboratory to studies of more complex behaviours in natural settings. To demonstrate the utility of this approach, we examined the effects of wing damage on dragonfly flight performance in both a laboratory drop–escape response and the more natural context of aerial predation. The laboratory experiment shows that hindwing area loss reduces vertical acceleration and average flight velocity, and the predation experiment demonstrates that this type of wing damage results in a significant decline in capture success. Taken together, these results suggest that wing damage may take a serious toll on wild dragonflies, potentially reducing both reproductive success and survival. PMID:20236968

  4. Accelerating Particles with Plasma

    ScienceCinema

    Litos, Michael; Hogan, Mark

    2018-05-18

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  5. Theory of unfolded cyclotron accelerator

    NASA Astrophysics Data System (ADS)

    Rax, J.-M.; Robiche, J.

    2010-10-01

    An acceleration process based on the interaction between an ion, a tapered periodic magnetic structure, and a circularly polarized oscillating electric field is identified and analyzed, and its potential is evaluated. A Hamiltonian analysis is developed in order to describe the interplay between the cyclotron motion, the electric acceleration, and the magnetic modulation. The parameters of this universal class of magnetic modulation leading to continuous acceleration without Larmor radius increase are expressed analytically. Thus, this study provides the basic scaling of what appears as a compact unfolded cyclotron accelerator.

  6. Particle acceleration on a chip: A laser-driven micro-accelerator for research and industry

    NASA Astrophysics Data System (ADS)

    Yoder, R. B.; Travish, G.

    2013-03-01

    Particle accelerators are conventionally built from radio-frequency metal cavities, but this technology limits the maximum energy available and prevents miniaturization. In the past decade, laser-powered acceleration has been intensively studied as an alternative technology promising much higher accelerating fields in a smaller footprint and taking advantage of recent advances in photonics. Among the more promising approaches are those based on dielectric field-shaping structures. These ``dielectric laser accelerators'' (DLAs) scale with the laser wavelength employed and can be many orders of magnitude smaller than conventional accelerators; DLAs may enable the production of high-intensity, ultra-short relativistic electron bunches in a chip-scale device. When combined with a high- Z target or an optical-period undulator, these systems could produce high-brilliance x-rays from a breadbox-sized device having multiple applications in imaging, medicine, and homeland security. In our research program we have developed one such DLA, the Micro-Accelerator Platform (MAP). We describe the fundamental physics, our fabrication and testing program, and experimental results to date, along with future prospects for MAP-based light-sources and some remaining challenges. Supported in part by the Defense Threat Reduction Agency and National Nuclear Security Administration.

  7. Correlations of metabolic rate and body acceleration in three species of coastal sharks under contrasting temperature regimes.

    PubMed

    Lear, Karissa O; Whitney, Nicholas M; Brewster, Lauran R; Morris, Jack J; Hueter, Robert E; Gleiss, Adrian C

    2017-02-01

    The ability to produce estimates of the metabolic rate of free-ranging animals is fundamental to the study of their ecology. However, measuring the energy expenditure of animals in the field has proved difficult, especially for aquatic taxa. Accelerometry presents a means of translating metabolic rates measured in the laboratory to individuals studied in the field, pending appropriate laboratory calibrations. Such calibrations have only been performed on a few fish species to date, and only one where the effects of temperature were accounted for. Here, we present calibrations between activity, measured as overall dynamic body acceleration (ODBA), and metabolic rate, measured through respirometry, for nurse sharks (Ginglymostoma cirratum), lemon sharks (Negaprion brevirostris) and blacktip sharks (Carcharhinus limbatus). Calibrations were made at a range of volitional swimming speeds and experimental temperatures. Linear mixed models were used to determine a predictive equation for metabolic rate based on measured ODBA values, with the optimal model using ODBA in combination with activity state and temperature to predict metabolic rate in lemon and nurse sharks, and ODBA and temperature to predict metabolic rate in blacktip sharks. This study lays the groundwork for calculating the metabolic rate of these species in the wild using acceleration data. © 2017. Published by The Company of Biologists Ltd.

  8. Accelerator Science: Circular vs. Linear

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lincoln, Don

    Particle accelerator are scientific instruments that allow scientists to collide particles together at incredible energies to study the secrets of the universe. However, there are many manners in which particle accelerators can be constructed. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of circular and linear accelerators.

  9. Nuclear lamina defects cause ATM-dependent NF-κB activation and link accelerated aging to a systemic inflammatory response.

    PubMed

    Osorio, Fernando G; Bárcena, Clea; Soria-Valles, Clara; Ramsay, Andrew J; de Carlos, Félix; Cobo, Juan; Fueyo, Antonio; Freije, José M P; López-Otín, Carlos

    2012-10-15

    Alterations in the architecture and dynamics of the nuclear lamina have a causal role in normal and accelerated aging through both cell-autonomous and systemic mechanisms. However, the precise nature of the molecular cues involved in this process remains incompletely defined. Here we report that the accumulation of prelamin A isoforms at the nuclear lamina triggers an ATM- and NEMO-dependent signaling pathway that leads to NF-κB activation and secretion of high levels of proinflammatory cytokines in two different mouse models of accelerated aging (Zmpste24(-/-) and Lmna(G609G/G609G) mice). Causal involvement of NF-κB in accelerated aging was demonstrated by the fact that both genetic and pharmacological inhibition of NF-κB signaling prevents age-associated features in these animal models, significantly extending their longevity. Our findings provide in vivo proof of principle for the feasibility of pharmacological modulation of the NF-κB pathway to slow down the progression of physiological and pathological aging.

  10. [Animal Health Law-- the National Animal Health Act and the European Animal Health Law].

    PubMed

    Bätza, Hans-Joachim; Mettenleiter, Thomas

    2013-01-01

    The Animal Health Act that replaces the Animal Disease Act, which is currently in force, creates a regulatory framework in order to not only, as has been the case so far, control animal diseases that had already broken out, but in order to already prevent in advance possible outbreaks of animal diseases by means of preventive measures. The instruments to this effect are described here. At European level, too, the idea of prevention is set to play a greater role in the future, with the draft EU legal instrument on animal health, that has to date only been discussed at Commission level, also contributing to a simplification and easier implementation by the persons subject to law by harmonising the currently fragmented Community law. It remains to be seen when the deliberations in the Council and European Parliament will begin.

  11. Possibility for ultra-bright electron beam acceleration in dielectric wakefield accelerators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Simakov, Evgenya I.; Carlsten, Bruce E.; Shchegolkov, Dmitry Yu.

    2012-12-21

    We describe a conceptual proposal to combine the Dielectric Wakefield Accelerator (DWA) with the Emittance Exchanger (EEX) to demonstrate a high-brightness DWA with a gradient of above 100 MV/m and less than 0.1% induced energy spread in the accelerated beam. We currently evaluate the DWA concept as a performance upgrade for the future LANL signature facility MaRIE with the goal of significantly reducing the electron beam energy spread. The preconceptual design for MaRIE is underway at LANL, with the design of the electron linear accelerator being one of the main research goals. Although generally the baseline design needs to bemore » conservative and rely on existing technology, any future upgrade would immediately call for looking into the advanced accelerator concepts capable of boosting the electron beam energy up by a few GeV in a very short distance without degrading the beam's quality. Scoping studies have identified large induced energy spreads as the major cause of beam quality degradation in high-gradient advanced accelerators for free-electron lasers. We describe simulations demonstrating that trapezoidal bunch shapes can be used in a DWA to greatly reduce the induced beam energy spread, and, in doing so, also preserve the beam brightness at levels never previously achieved. This concept has the potential to advance DWA technology to a level that would make it suitable for the upgrades of the proposed Los Alamos MaRIE signature facility.« less

  12. Adapting Animal-Assisted Therapy Trials to Prison-Based Animal Programs.

    PubMed

    Allison, Molly; Ramaswamy, Megha

    2016-09-01

    Prison-based animal programs have shown promise when it comes to increased sociability, responsibility, and levels of patience for inmates who participate in these programs. Yet there remains a dearth of scientific research that demonstrates the impact of prison-based animal programs on inmates' physical and mental health. Trials of animal-assisted therapy interventions, a form of human-animal interaction therapy most often used with populations affected by depression/anxiety, mental illness, and trauma, may provide models of how prison-based animal program research can have widespread implementation in jail and prison settings, whose populations have high rates of mental health problems. This paper reviews the components of prison-based animal programs most commonly practiced in prisons today, presents five animal-assisted therapy case studies, evaluates them based on their adaptability to prison-based animal programs, and discusses the institutional constraints that act as barriers for rigorous prison-based animal program research implementation. This paper can serve to inform the development of a research approach to animal-assisted therapy that nurses and other public health researchers can use in working with correctional populations. © 2016 Wiley Periodicals, Inc.

  13. Electron cyclotron harmonic wave acceleration

    NASA Technical Reports Server (NTRS)

    Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

  14. Efficient particle acceleration in shocks

    NASA Astrophysics Data System (ADS)

    Heavens, A. F.

    1984-10-01

    A self-consistent non-linear theory of acceleration of particles by shock waves is developed, using an extension of the two-fluid hydrodynamical model by Drury and Völk. The transport of the accelerated particles is governed by a diffusion coefficient which is initially assumed to be independent of particle momentum, to obtain exact solutions for the spectrum. It is found that steady-state shock structures with high acceleration efficiency are only possible for shocks with Mach numbers less than about 12. A more realistic diffusion coefficient is then considered, and this maximum Mach number is reduced to about 6. The efficiency of the acceleration process determines the relative importance of the non-relativistic and relativistic particles in the distribution of accelerated particles, and this determines the effective specific heat ratio.

  15. Future HEP Accelerators: The US Perspective

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bhat, Pushpalatha; Shiltsev, Vladimir

    2015-11-02

    Accelerator technology has advanced tremendously since the introduction of accelerators in the 1930s, and particle accelerators have become indispensable instruments in high energy physics (HEP) research to probe Nature at smaller and smaller distances. At present, accelerator facilities can be classified into Energy Frontier colliders that enable direct discoveries and studies of high mass scale particles and Intensity Frontier accelerators for exploration of extremely rare processes, usually at relatively low energies. The near term strategies of the global energy frontier particle physics community are centered on fully exploiting the physics potential of the Large Hadron Collider (LHC) at CERN throughmore » its high-luminosity upgrade (HL-LHC), while the intensity frontier HEP research is focused on studies of neutrinos at the MW-scale beam power accelerator facilities, such as Fermilab Main Injector with the planned PIP-II SRF linac project. A number of next generation accelerator facilities have been proposed and are currently under consideration for the medium- and long-term future programs of accelerator-based HEP research. In this paper, we briefly review the post-LHC energy frontier options, both for lepton and hadron colliders in various regions of the world, as well as possible future intensity frontier accelerator facilities.« less

  16. Accelerator Science: Circular vs. Linear

    ScienceCinema

    Lincoln, Don

    2018-06-12

    Particle accelerator are scientific instruments that allow scientists to collide particles together at incredible energies to study the secrets of the universe. However, there are many manners in which particle accelerators can be constructed. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of circular and linear accelerators.

  17. Three Dimensional Gait Analysis Using Wearable Acceleration and Gyro Sensors Based on Quaternion Calculations

    PubMed Central

    Tadano, Shigeru; Takeda, Ryo; Miyagawa, Hiroaki

    2013-01-01

    This paper proposes a method for three dimensional gait analysis using wearable sensors and quaternion calculations. Seven sensor units consisting of a tri-axial acceleration and gyro sensors, were fixed to the lower limbs. The acceleration and angular velocity data of each sensor unit were measured during level walking. The initial orientations of the sensor units were estimated using acceleration data during upright standing position and the angular displacements were estimated afterwards using angular velocity data during gait. Here, an algorithm based on quaternion calculation was implemented for orientation estimation of the sensor units. The orientations of the sensor units were converted to the orientations of the body segments by a rotation matrix obtained from a calibration trial. Body segment orientations were then used for constructing a three dimensional wire frame animation of the volunteers during the gait. Gait analysis was conducted on five volunteers, and results were compared with those from a camera-based motion analysis system. Comparisons were made for the joint trajectory in the horizontal and sagittal plane. The average RMSE and correlation coefficient (CC) were 10.14 deg and 0.98, 7.88 deg and 0.97, 9.75 deg and 0.78 for the hip, knee and ankle flexion angles, respectively. PMID:23877128

  18. Antimicrobial resistance in Escherichia coli isolates from food animals, animal food products and companion animals in China.

    PubMed

    Lei, Tao; Tian, Wei; He, Liu; Huang, Xian-Hui; Sun, Yong-Xue; Deng, Yu-Ting; Sun, Yan; Lv, Dian-Hong; Wu, Cong-Ming; Huang, Liang-Zong; Shen, Jian-Zhong; Liu, Jian-Hua

    2010-11-20

    One thousand and thirty Escherichia coli isolates from food animals, animals-derived foods, and companion animals between 2007 and 2008 in Southern China were used to investigate their antimicrobial susceptibility to 14 different antimicrobials by the standard agar dilution method. More than 70% of isolates showed resistance to tetracycline, trimethoprim-sulphamethoxazole, nalidixic acid, and ampicillin. In general, resistance was less frequent in companion animal isolates vs food animals isolates, but cephalosporin and amikacin resistance was more frequent in companion animal isolates, 42.6% to 56.2% vs 14.1% to 24.3%, and 28.5% vs 18.8%, respectively, which was most likely due to the common use of these antimicrobials as treatment in pet animals. Fluoroquinolones resistance was high in all animal isolates (>50%). Food products showed lowest resistance among isolates from these three resources. PFGE analysis indicated that a majority of multidrug-resistant E. coli isolates showed unique, unrelated PFGE profiles and were unlikely to be the spread of a specific clone. This study provides useful information about the prevalence of antimicrobial resistance in E. coli isolated from animals and food products in China and provided evidence of the linkage of the use of antimicrobials in animals and its selection of antimicrobial resistance in bacterial isolates. The data from this study further warns the prudent use of antimicrobials in food and pet animals to reduce the risks of transmission of antimicrobial resistance zoonotic pathogen to humans. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Burst muscle performance predicts the speed, acceleration, and turning performance of Anna’s hummingbirds

    PubMed Central

    Segre, Paolo S; Dakin, Roslyn; Zordan, Victor B; Dickinson, Michael H; Straw, Andrew D; Altshuler, Douglas L

    2015-01-01

    Despite recent advances in the study of animal flight, the biomechanical determinants of maneuverability are poorly understood. It is thought that maneuverability may be influenced by intrinsic body mass and wing morphology, and by physiological muscle capacity, but this hypothesis has not yet been evaluated because it requires tracking a large number of free flight maneuvers from known individuals. We used an automated tracking system to record flight sequences from 20 Anna's hummingbirds flying solo and in competition in a large chamber. We found that burst muscle capacity predicted most performance metrics. Hummingbirds with higher burst capacity flew with faster velocities, accelerations, and rotations, and they used more demanding complex turns. In contrast, body mass did not predict variation in maneuvering performance, and wing morphology predicted only the use of arcing turns and high centripetal accelerations. Collectively, our results indicate that burst muscle capacity is a key predictor of maneuverability. DOI: http://dx.doi.org/10.7554/eLife.11159.001 PMID:26583753

  20. Does the Animal Welfare Act apply to free-ranging animals?

    USGS Publications Warehouse

    Mulcahy, Daniel M.

    2003-01-01

    Despite the long-standing role that institutional animal care and use committees (IACUCs) have played in reviewing and approving studies at academic institutions, compliance with the Animal Welfare Act (AWA) is not always complete for government natural resource agencies that use free-ranging animals in research and management studies. Even at universities, IACUCs face uncertainties about what activities are covered and about how to judge proposed research on free-ranging animals. One reason for much of the confusion is the AWA vaguely worded exemption for "field studies." In particular, fish are problematic because of the AWA exclusion of poikilothermic animals. However, most university IACUCs review studies on all animals, and the Interagency Research Animal Committee (IRAC) has published the "IRAC Principles," which extend coverage to all vertebrates used by federal researchers. Despite this extended coverage, many scientists working on wild animals continue to view compliance with the AWA with little enthusiasm. IACUCs, IACUC veterinarians, wildlife veterinarians, and fish and wildlife biologists must learn to work together to comply with the law and to protect the privilege of using free-ranging animals in research.

  1. Accelerating axon growth to overcome limitations in functional recovery after peripheral nerve injury.

    PubMed

    Gordon, Tessa; Chan, K Ming; Sulaiman, Olawale A R; Udina, Esther; Amirjani, Nasim; Brushart, Thomas M

    2009-10-01

    Injured peripheral nerves regenerate at very slow rates. Therefore, proximal injury sites such as the brachial plexus still present major challenges, and the outcomes of conventional treatments remain poor. This is in part attributable to a progressive decline in the Schwann cells' ability to provide a supportive milieu for the growth cone to extend and to find the appropriate target. These challenges are compounded by the often considerable delay of regeneration across the site of nerve laceration. Recently, low-frequency electrical stimulation (as brief as an hour) has shown promise, as it significantly accelerated regeneration in animal models through speeding of axon growth across the injury site. To test whether this might be a useful clinical tool, we carried out a randomized controlled trial in patients who had experienced substantial axonal loss in the median nerve owing to severe compression in the carpal tunnel. To further elucidate the potential mechanisms, we applied rolipram, a cyclic adenosine monophosphate agonist, to rats after axotomy of the femoral nerve. We demonstrated that effects similar to those observed in animal studies could also be attained in humans. The mechanisms of action of electrical stimulation likely operate through up-regulation of neurotrophic factors and cyclic adenosine monophosphate. Indeed, the application of rolipram significantly accelerated nerve regeneration. With new mechanistic insights into the influencing factors of peripheral nerve regeneration, the novel treatments described above could form part of an armament of synergistic therapies that could make a meaningful difference to patients with peripheral nerve injuries.

  2. High field gradient particle accelerator

    DOEpatents

    Nation, J.A.; Greenwald, S.

    1989-05-30

    A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications is disclosed. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle. 10 figs.

  3. High field gradient particle accelerator

    DOEpatents

    Nation, John A.; Greenwald, Shlomo

    1989-01-01

    A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle.

  4. Companion Animal Death.

    PubMed

    Reisbig, Allison M J; Hafen, McArthur; Siqueira Drake, Adryanna A; Girard, Destiny; Breunig, Zachary B

    2017-06-01

    Human-animal relationships are increasingly incorporated into families as a normal part of family life. Despite this, relationships with animals are often viewed as inferior to human relationships. This becomes problematic during times of loss and grief when members of a grieving companion animal owner's support system do not understand the salience of the relationship with the animal. Veterinary and other helping professionals need basic information about the experience of companion animal loss in order to help support and normalize the experiences of grieving companion animal owners. The present study qualitatively describes human-animal relationships and the subsequent loss and coping experienced by owners of beloved companion animals. Comparison with human and other types of loss and factors unique to companion animal loss are discussed, and practical applications for veterinary and other helping professionals are provided.

  5. Competing explanations for cosmic acceleration or why is the expansion of the universe accelerating?

    NASA Astrophysics Data System (ADS)

    Ishak, Mustapha

    2012-06-01

    For more than a decade, a number of cosmological observations have been indicating that the expansion of the universe is accelerating. Cosmic acceleration and the questions associated with it have become one of the most challenging and puzzling problems in cosmology and physics. Cosmic acceleration can be caused by (i) a repulsive dark energy pervading the universe, (ii) an extension to General Relativity that takes effect at cosmological scales of distance, or (iii) the acceleration may be an apparent effect due to the fact that the expansion rate of space-time is uneven from one region to another in the universe. I will review the basics of these possibilities and provide some recent results including ours on these questions.

  6. Status of MAPA (Modular Accelerator Physics Analysis) and the Tech-X Object-Oriented Accelerator Library

    NASA Astrophysics Data System (ADS)

    Cary, J. R.; Shasharina, S.; Bruhwiler, D. L.

    1998-04-01

    The MAPA code is a fully interactive accelerator modeling and design tool consisting of a GUI and two object-oriented C++ libraries: a general library suitable for treatment of any dynamical system, and an accelerator library including many element types plus an accelerator class. The accelerator library inherits directly from the system library, which uses hash tables to store any relevant parameters or strings. The GUI can access these hash tables in a general way, allowing the user to invoke a window displaying all relevant parameters for a particular element type or for the accelerator class, with the option to change those parameters. The system library can advance an arbitrary number of dynamical variables through an arbitrary mapping. The accelerator class inherits this capability and overloads the relevant functions to advance the phase space variables of a charged particle through a string of elements. Among other things, the GUI makes phase space plots and finds fixed points of the map. We discuss the object hierarchy of the two libraries and use of the code.

  7. Artificial seismic acceleration

    USGS Publications Warehouse

    Felzer, Karen R.; Page, Morgan T.; Michael, Andrew J.

    2015-01-01

    In their 2013 paper, Bouchon, Durand, Marsan, Karabulut, 3 and Schmittbuhl (BDMKS) claim to see significant accelerating seismicity before M 6.5 interplate mainshocks, but not before intraplate mainshocks, reflecting a preparatory process before large events. We concur with the finding of BDMKS that their interplate dataset has significantly more fore- shocks than their intraplate dataset; however, we disagree that the foreshocks are predictive of large events in particular. Acceleration in stacked foreshock sequences has been seen before and has been explained by the cascade model, in which earthquakes occasionally trigger aftershocks larger than themselves4. In this model, the time lags between the smaller mainshocks and larger aftershocks follow the inverse power law common to all aftershock sequences, creating an apparent acceleration when stacked (see Supplementary Information).

  8. Critical Role for CD38-mediated Ca2+ Signaling in Thrombin-induced Procoagulant Activity of Mouse Platelets and Hemostasis*

    PubMed Central

    Mushtaq, Mazhar; Nam, Tae-Sik; Kim, Uh-Hyun

    2011-01-01

    CD38, a multifunctional enzyme that catalyzes the synthesis of intracellular Ca2+ messengers, cyclic ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP), is known to be expressed on platelets. However, the role of CD38 in platelets remains unclear. Our present results show that treatment of platelets with thrombin results in a rapid and sustained Ca2+ signal, resulting from a coordinated interplay of Ca2+-mobilizing messengers, inositol 1,4,5-trisphosphate, cADPR, and NAADP. By dissecting the signaling pathway using various agents, we delineated that cADPR and NAADP are sequentially produced through CD38 internalization by protein kinase C via myosin heavy chain IIA following phospholipase C activation in thrombin-induced platelets. An inositol 1,4,5-trisphosphate receptor antagonist blocked the thrombin-induced formation of cADPR and NAADP as well as Ca2+ signals. An indispensable response of platelets relying on cytosolic calcium is the surface exposure of phosphatidylserine (PS), which implicates platelet procoagulant activity. Scrutinizing this parameter reveals that CD38+/+ platelets fully express PS on the surface when stimulated with thrombin, whereas this response was decreased on CD38−/− platelets. Similarly, PS exposure and Ca2+ signals were attenuated when platelets were incubated with 8-bromo-cADPR, bafilomycin A1, and a PKC inhibitor. Furthermore, in vivo, CD38-deficient mice exhibited longer bleeding times and unstable formation of thrombus than wild type mice. These results demonstrate that CD38 plays an essential role in thrombin-induced procoagulant activity of platelets and hemostasis via Ca2+ signaling mediated by its products, cADPR and NAADP. PMID:21339289

  9. Modeling of Particle Acceleration at Multiple Shocks via Diffusive Shock Acceleration: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Parker, L. Neergaard; Zank, G. P.

    2013-01-01

    Successful forecasting of energetic particle events in space weather models require algorithms for correctly predicting the spectrum of ions accelerated from a background population of charged particles. We present preliminary results from a model that diffusively accelerates particles at multiple shocks. Our basic approach is related to box models in which a distribution of particles is diffusively accelerated inside the box while simultaneously experiencing decompression through adiabatic expansion and losses from the convection and diffusion of particles outside the box. We adiabatically decompress the accelerated particle distribution between each shock by either the method explored in Melrose and Pope (1993) and Pope and Melrose (1994) or by the approach set forth in Zank et al. (2000) where we solve the transport equation by a method analogous to operator splitting. The second method incorporates the additional loss terms of convection and diffusion and allows for the use of a variable time between shocks. We use a maximum injection energy (E(sub max)) appropriate for quasi-parallel and quasi-perpendicular shocks and provide a preliminary application of the diffusive acceleration of particles by multiple shocks with frequencies appropriate for solar maximum (i.e., a non-Markovian process).

  10. Investigations into dual-grating THz-driven accelerators

    NASA Astrophysics Data System (ADS)

    Wei, Y.; Ischebeck, R.; Dehler, M.; Ferrari, E.; Hiller, N.; Jamison, S.; Xia, G.; Hanahoe, K.; Li, Y.; Smith, J. D. A.; Welsch, C. P.

    2018-01-01

    Advanced acceleration technologies are receiving considerable interest in order to miniaturize future particle accelerators. One such technology is the dual-grating dielectric structures, which can support accelerating fields one to two orders of magnitude higher than the metal RF cavities in conventional accelerators. This opens up the possibility of enabling high accelerating gradients of up to several GV/m. This paper investigates numerically a quartz dual-grating structure which is driven by THz pulses to accelerate electrons. Geometry optimizations are carried out to achieve the trade-offs between accelerating gradient and vacuum channel gap. A realistic electron bunch available from the future Compact Linear Accelerator for Research and Applications (CLARA) is loaded into an optimized 100-period dual-grating structure for a detailed wakefield study. A THz pulse is then employed to interact with this CLARA bunch in the optimized structure. The computed beam quality is analyzed in terms of emittance, energy spread and loaded accelerating gradient. The simulations show that an accelerating gradient of 348 ± 12 MV/m with an emittance growth of 3.0% can be obtained.

  11. Pressure fluctuation caused by moderate acceleration

    NASA Astrophysics Data System (ADS)

    Tagawa, Yoshiyuki; Kurihara, Chihiro; Kiyama, Akihito

    2017-11-01

    Pressure fluctuation caused by acceleration of a liquid column is observed in various important technologies, e.g. water-hammer in a pipeline. The magnitude of fluctuation can be estimated by two different approaches: When the duration time of acceleration is much shorter than the propagation time for a pressure wave to travel the length of the liquid column, e.g. sudden valve closure for a long pipe, Joukowsky equation is applied. In contrast, if the acceleration duration is much longer, the liquid is modeled as a rigid column, ignoring compressibility of the fluid. However, many of practical cases exist between these two extremes. In this study we propose a model describing pressure fluctuation when the duration of acceleration is in the same order of the propagation time for a pressure wave, i.e. under moderate acceleration. The novel model considers both temporal and spatial evolutions of pressure propagation as well as gradual pressure rise during the acceleration. We conduct experiments in which we impose acceleration to a liquid with varying the length of the liquid column, acceleration duration, and properties of liquids. The ratio between the acceleration duration and the propagation time is in the range of 0.02 - 2. The model agrees well with measurement results. JSPS KAKENHI Grant Numbers 26709007 and 17H01246.

  12. Animal experimentation.

    PubMed

    Kolar, Roman

    2006-01-01

    Millions of animals are used every year in often times extremely painful and distressing scientific procedures. Legislation of animal experimentation in modern societies is based on the supposition that this is ethically acceptable when certain more or less defined formal (e.g. logistical, technical) demands and ethical principles are met. The main parameters in this context correspond to the "3Rs" concept as defined by Russel and Burch in 1959, i.e. that all efforts to replace, reduce and refine experiments must be undertaken. The licensing of animal experiments normally requires an ethical evaluation process, often times undertaken by ethics committees. The serious problems in putting this idea into practice include inter alia unclear conditions and standards for ethical decisions, insufficient management of experiments undertaken for specific (e.g. regulatory) purposes, and conflicts of interest of ethics committees' members. There is an ongoing societal debate about ethical issues of animal use in science. Existing EU legislation on animal experimentation for cosmetics testing is an example of both the public will for setting clear limits to animal experiments and the need to further critically examine other fields and aspects of animal experimentation.

  13. Angiotensin II–accelerated atherosclerosis and aneurysm formation is attenuated in osteopontin-deficient mice

    PubMed Central

    Bruemmer, Dennis; Collins, Alan R.; Noh, Grace; Wang, Wei; Territo, Mary; Arias-Magallona, Sarah; Fishbein, Michael C.; Blaschke, Florian; Kintscher, Ulrich; Graf, Kristof; Law, Ronald E.; Hsueh, Willa A.

    2003-01-01

    Osteopontin (OPN) is expressed in atherosclerotic lesions, particularly in diabetic patients. To determine the role of OPN in atherogenesis, ApoE–/–OPN+/+, ApoE–/–OPN+/–, and ApoE–/–OPN–/– mice were infused with Ang II, inducing vascular OPN expression and accelerating atherosclerosis. Compared with ApoE–/–OPN+/+ mice, ApoE–/–OPN+/– and ApoE–/–OPN–/– mice developed less Ang II–accelerated atherosclerosis. ApoE–/– mice transplanted with bone marrow derived from ApoE–/–OPN–/– mice had less Ang II–induced atherosclerosis compared with animals receiving ApoE–/–OPN+/+ cells. Aortae from Ang II–infused ApoE–/–OPN–/– mice expressed less CD68, C-C-chemokine receptor 2, and VCAM-1. In response to intraperitoneal thioglycollate, recruitment of leukocytes in OPN–/– mice was impaired, and OPN–/– leukocytes exhibited decreased basal and MCP-1–directed migration. Furthermore, macrophage viability in atherosclerotic lesions from Ang II–infused ApoE–/–OPN–/– mice was decreased. Finally, Ang II–induced abdominal aortic aneurysm formation in ApoE–/–OPN–/– mice was reduced and associated with decreased MMP-2 and MMP-9 activity. These data suggest an important role for leukocyte-derived OPN in mediating Ang II–accelerated atherosclerosis and aneurysm formation. PMID:14597759

  14. Accelerator Science: Proton vs. Electron

    ScienceCinema

    Lincoln, Don

    2018-06-12

    Particle accelerators are one of the most powerful ways to study the fundamental laws that govern the universe. However, there are many design considerations that go into selecting and building a particular accelerator. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of building an accelerator that collides pairs of protons to one that collides electrons.

  15. Accelerator Science: Proton vs. Electron

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lincoln, Don

    Particle accelerators are one of the most powerful ways to study the fundamental laws that govern the universe. However, there are many design considerations that go into selecting and building a particular accelerator. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of building an accelerator that collides pairs of protons to one that collides electrons.

  16. Radiotherapy using a laser proton accelerator

    NASA Astrophysics Data System (ADS)

    Murakami, Masao; Hishikawa, Yoshio; Miyajima, Satoshi; Okazaki, Yoshiko; Sutherland, Kenneth L.; Abe, Mitsuyuki; Bulanov, Sergei V.; Daido, Hiroyuki; Esirkepov, Timur Zh.; Koga, James; Yamagiwa, Mitsuru; Tajima, Toshiki

    2008-06-01

    Laser acceleration promises innovation in particle beam therapy of cancer where an ultra-compact accelerator system for cancer beam therapy can become affordable to a broad range of patients. This is not feasible without the introduction of a technology that is radically different from the conventional accelerator-based approach. Because of its compactness and other novel characteristics, the laser acceleration method provides many enhanced capabilities

  17. Accelerator Science: Why RF?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lincoln, Don

    Particle accelerators can fire beams of subatomic particles at near the speed of light. The accelerating force is generated using radio frequency technology and a whole lot of interesting features. In this video, Fermilab’s Dr. Don Lincoln explains how it all works.

  18. An integrated theoretical-experimental approach to accelerate translational tissue engineering.

    PubMed

    Coy, Rachel H; Evans, Owen R; Phillips, James B; Shipley, Rebecca J

    2018-01-01

    Implantable devices utilizing bioengineered tissue are increasingly showing promise as viable clinical solutions. The design of bioengineered constructs is currently directed according to the results of experiments that are used to test a wide range of different combinations and spatial arrangements of biomaterials, cells and chemical factors. There is an outstanding need to accelerate the design process and reduce financial costs, whilst minimizing the required number of animal-based experiments. These aims could be achieved through the incorporation of mathematical modelling as a preliminary design tool. Here we focus on tissue-engineered constructs for peripheral nerve repair, which are designed to aid nerve and blood vessel growth and repair after peripheral nerve injury. We offer insight into the role that mathematical modelling can play within tissue engineering, and motivate the use of modelling as a tool capable of improving and accelerating the design of nerve repair constructs in particular. Specific case studies are presented in order to illustrate the potential of mathematical modelling to direct construct design. Copyright © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd. Copyright © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.

  19. Keeper-Animal Interactions: Differences between the Behaviour of Zoo Animals Affect Stockmanship.

    PubMed

    Ward, Samantha J; Melfi, Vicky

    2015-01-01

    Stockmanship is a term used to describe the management of animals with a good stockperson someone who does this in a in a safe, effective, and low-stress manner for both the stock-keeper and animals involved. Although impacts of unfamiliar zoo visitors on animal behaviour have been extensively studied, the impact of stockmanship i.e familiar zoo keepers is a new area of research; which could reveal significant ramifications for zoo animal behaviour and welfare. It is likely that different relationships are formed dependant on the unique keeper-animal dyad (human-animal interaction, HAI). The aims of this study were to (1) investigate if unique keeper-animal dyads were formed in zoos, (2) determine whether keepers differed in their interactions towards animals regarding their attitude, animal knowledge and experience and (3) explore what factors affect keeper-animal dyads and ultimately influence animal behaviour and welfare. Eight black rhinoceros (Diceros bicornis), eleven Chapman's zebra (Equus burchellii), and twelve Sulawesi crested black macaques (Macaca nigra) were studied in 6 zoos across the UK and USA. Subtle cues and commands directed by keepers towards animals were identified. The animals latency to respond and the respective behavioural response (cue-response) was recorded per keeper-animal dyad (n = 93). A questionnaire was constructed following a five-point Likert Scale design to record keeper demographic information and assess the job satisfaction of keepers, their attitude towards the animals and their perceived relationship with them. There was a significant difference in the animals' latency to appropriately respond after cues and commands from different keepers, indicating unique keeper-animal dyads were formed. Stockmanship style was also different between keepers; two main components contributed equally towards this: "attitude towards the animals" and "knowledge and experience of the animals". In this novel study, data demonstrated unique dyads

  20. The Spallation Neutron Source accelerator system design

    NASA Astrophysics Data System (ADS)

    Henderson, S.; Abraham, W.; Aleksandrov, A.; Allen, C.; Alonso, J.; Anderson, D.; Arenius, D.; Arthur, T.; Assadi, S.; Ayers, J.; Bach, P.; Badea, V.; Battle, R.; Beebe-Wang, J.; Bergmann, B.; Bernardin, J.; Bhatia, T.; Billen, J.; Birke, T.; Bjorklund, E.; Blaskiewicz, M.; Blind, B.; Blokland, W.; Bookwalter, V.; Borovina, D.; Bowling, S.; Bradley, J.; Brantley, C.; Brennan, J.; Brodowski, J.; Brown, S.; Brown, R.; Bruce, D.; Bultman, N.; Cameron, P.; Campisi, I.; Casagrande, F.; Catalan-Lasheras, N.; Champion, M.; Champion, M.; Chen, Z.; Cheng, D.; Cho, Y.; Christensen, K.; Chu, C.; Cleaves, J.; Connolly, R.; Cote, T.; Cousineau, S.; Crandall, K.; Creel, J.; Crofford, M.; Cull, P.; Cutler, R.; Dabney, R.; Dalesio, L.; Daly, E.; Damm, R.; Danilov, V.; Davino, D.; Davis, K.; Dawson, C.; Day, L.; Deibele, C.; Delayen, J.; DeLong, J.; Demello, A.; DeVan, W.; Digennaro, R.; Dixon, K.; Dodson, G.; Doleans, M.; Doolittle, L.; Doss, J.; Drury, M.; Elliot, T.; Ellis, S.; Error, J.; Fazekas, J.; Fedotov, A.; Feng, P.; Fischer, J.; Fox, W.; Fuja, R.; Funk, W.; Galambos, J.; Ganni, V.; Garnett, R.; Geng, X.; Gentzlinger, R.; Giannella, M.; Gibson, P.; Gillis, R.; Gioia, J.; Gordon, J.; Gough, R.; Greer, J.; Gregory, W.; Gribble, R.; Grice, W.; Gurd, D.; Gurd, P.; Guthrie, A.; Hahn, H.; Hardek, T.; Hardekopf, R.; Harrison, J.; Hatfield, D.; He, P.; Hechler, M.; Heistermann, F.; Helus, S.; Hiatt, T.; Hicks, S.; Hill, J.; Hill, J.; Hoff, L.; Hoff, M.; Hogan, J.; Holding, M.; Holik, P.; Holmes, J.; Holtkamp, N.; Hovater, C.; Howell, M.; Hseuh, H.; Huhn, A.; Hunter, T.; Ilg, T.; Jackson, J.; Jain, A.; Jason, A.; Jeon, D.; Johnson, G.; Jones, A.; Joseph, S.; Justice, A.; Kang, Y.; Kasemir, K.; Keller, R.; Kersevan, R.; Kerstiens, D.; Kesselman, M.; Kim, S.; Kneisel, P.; Kravchuk, L.; Kuneli, T.; Kurennoy, S.; Kustom, R.; Kwon, S.; Ladd, P.; Lambiase, R.; Lee, Y. Y.; Leitner, M.; Leung, K.-N.; Lewis, S.; Liaw, C.; Lionberger, C.; Lo, C. C.; Long, C.; Ludewig, H.; Ludvig, J.; Luft, P.; Lynch, M.; Ma, H.; MacGill, R.; Macha, K.; Madre, B.; Mahler, G.; Mahoney, K.; Maines, J.; Mammosser, J.; Mann, T.; Marneris, I.; Marroquin, P.; Martineau, R.; Matsumoto, K.; McCarthy, M.; McChesney, C.; McGahern, W.; McGehee, P.; Meng, W.; Merz, B.; Meyer, R.; Meyer, R.; Miller, B.; Mitchell, R.; Mize, J.; Monroy, M.; Munro, J.; Murdoch, G.; Musson, J.; Nath, S.; Nelson, R.; Nelson, R.; O`Hara, J.; Olsen, D.; Oren, W.; Oshatz, D.; Owens, T.; Pai, C.; Papaphilippou, I.; Patterson, N.; Patterson, J.; Pearson, C.; Pelaia, T.; Pieck, M.; Piller, C.; Plawski, T.; Plum, M.; Pogge, J.; Power, J.; Powers, T.; Preble, J.; Prokop, M.; Pruyn, J.; Purcell, D.; Rank, J.; Raparia, D.; Ratti, A.; Reass, W.; Reece, K.; Rees, D.; Regan, A.; Regis, M.; Reijonen, J.; Rej, D.; Richards, D.; Richied, D.; Rode, C.; Rodriguez, W.; Rodriguez, M.; Rohlev, A.; Rose, C.; Roseberry, T.; Rowton, L.; Roybal, W.; Rust, K.; Salazer, G.; Sandberg, J.; Saunders, J.; Schenkel, T.; Schneider, W.; Schrage, D.; Schubert, J.; Severino, F.; Shafer, R.; Shea, T.; Shishlo, A.; Shoaee, H.; Sibley, C.; Sims, J.; Smee, S.; Smith, J.; Smith, K.; Spitz, R.; Staples, J.; Stein, P.; Stettler, M.; Stirbet, M.; Stockli, M.; Stone, W.; Stout, D.; Stovall, J.; Strelo, W.; Strong, H.; Sundelin, R.; Syversrud, D.; Szajbler, M.; Takeda, H.; Tallerico, P.; Tang, J.; Tanke, E.; Tepikian, S.; Thomae, R.; Thompson, D.; Thomson, D.; Thuot, M.; Treml, C.; Tsoupas, N.; Tuozzolo, J.; Tuzel, W.; Vassioutchenko, A.; Virostek, S.; Wallig, J.; Wanderer, P.; Wang, Y.; Wang, J. G.; Wangler, T.; Warren, D.; Wei, J.; Weiss, D.; Welton, R.; Weng, J.; Weng, W.-T.; Wezensky, M.; White, M.; Whitlatch, T.; Williams, D.; Williams, E.; Wilson, K.; Wiseman, M.; Wood, R.; Wright, P.; Wu, A.; Ybarrolaza, N.; Young, K.; Young, L.; Yourd, R.; Zachoszcz, A.; Zaltsman, A.; Zhang, S.; Zhang, W.; Zhang, Y.; Zhukov, A.

    2014-11-01

    The Spallation Neutron Source (SNS) was designed and constructed by a collaboration of six U.S. Department of Energy national laboratories. The SNS accelerator system consists of a 1 GeV linear accelerator and an accumulator ring providing 1.4 MW of proton beam power in microsecond-long beam pulses to a liquid mercury target for neutron production. The accelerator complex consists of a front-end negative hydrogen-ion injector system, an 87 MeV drift tube linear accelerator, a 186 MeV side-coupled linear accelerator, a 1 GeV superconducting linear accelerator, a 248-m circumference accumulator ring and associated beam transport lines. The accelerator complex is supported by ~100 high-power RF power systems, a 2 K cryogenic plant, ~400 DC and pulsed power supply systems, ~400 beam diagnostic devices and a distributed control system handling ~100,000 I/O signals. The beam dynamics design of the SNS accelerator is presented, as is the engineering design of the major accelerator subsystems.

  1. Hyperreactivity of junctional adhesion molecule A-deficient platelets accelerates atherosclerosis in hyperlipidemic mice.

    PubMed

    Karshovska, Ela; Zhao, Zhen; Blanchet, Xavier; Schmitt, Martin M N; Bidzhekov, Kiril; Soehnlein, Oliver; von Hundelshausen, Philipp; Mattheij, Nadine J; Cosemans, Judith M E M; Megens, Remco T A; Koeppel, Thomas A; Schober, Andreas; Hackeng, Tilman M; Weber, Christian; Koenen, Rory R

    2015-02-13

    Besides their essential role in hemostasis, platelets also have functions in inflammation. In platelets, junctional adhesion molecule (JAM)-A was previously identified as an inhibitor of integrin αIIbβ3-mediated outside-in signaling and its genetic knockdown resulted in hyperreactivity. This gain-of-function was specifically exploited to investigate the role of platelet hyperreactivity in plaque development. JAM-A-deficient platelets showed increased aggregation and cellular and sarcoma tyrosine-protein kinase activation. On αIIbβ3 ligation, JAM-A was shown to be dephosphorylated, which could be prevented by protein tyrosine phosphatase nonreceptor type 1 inhibition. Mice with or without platelet-specific (tr)JAM-A-deficiency in an apolipoprotein e (apoe(-/-)) background were fed a high-fat diet. After ≤12 weeks of diet, trJAM-A(-/-)apoe-/- mice showed increased aortic plaque formation when compared with trJAM-A(+/+) apoe(-/-) controls, and these differences were most evident at early time points. At 2 weeks, the plaques of the trJAM-A(-/-) apoe(-/-) animals revealed increased macrophage, T cell, and smooth muscle cell content. Interestingly, plasma levels of chemokines CC chemokine ligand 5 and CXC-chemokine ligand 4 were increased in the trJAM-A(-/-) apoe(-/-)mice, and JAM-A-deficient platelets showed increased binding to monocytes and neutrophils. Whole-blood perfusion experiments and intravital microscopy revealed increased recruitment of platelets and monocytes to the inflamed endothelium in blood of trJAM-A(-/-) apoe(-/-)mice. Notably, these proinflammatory effects of JAM-A-deficient platelets could be abolished by the inhibition of αIIbβ3 signaling in vitro. Deletion of JAM-A causes a gain-of-function in platelets, with lower activation thresholds and increased inflammatory activities. This leads to an increase of plaque formation, particularly in early stages of the disease. © 2014 American Heart Association, Inc.

  2. Biological basis of neuroprotection and neurotherapeutic effects of Whole Body Periodic Acceleration (pGz).

    PubMed

    Adams, Jose A; Uryash, Arkady; Bassuk, Jorge; Sackner, Marvin A; Kurlansky, Paul

    2014-06-01

    Exercise is a well known neuroprotective and neurotherapeutic strategy in animal models and humans with brain injury and cognitive dysfunction. In part, exercise induced beneficial effects relate to endothelial derived nitric oxide (eNO) production and induction of the neurotrophins; Brain Derived Neurotrophic Factor (BDNF) and Glial Derived Neurotrophic Factor (GDNF). Whole Body Periodic Acceleration (WBPA (pGz), is the motion of the supine body headward to footward in a sinusoidal fashion, at frequencies of 100-160 cycles/min, inducing pulsatile shear stress to the vascular endothelium. WBPA (pGz) increases eNO in the cardiovascular system in animal models and humans. We hypothesized that WBPA (pGz) has neuroprotective and neurotherapeutic effects due to enhancement of biological pathways that include eNOS, BDNF and GDNF. We discuss protein expression analysis of these in brain of rodents. Animal and observational human data affirm a neuroprotective and neurotherapeutic role for WBPA (pGz). These findings suggest that WBPA (pGz) in addition to its well known beneficial cardiovascular effects can be a simple non-invasive neuroprotective and neurotherapeutic strategy with far reaching health benefits. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Maximum Acceleration Recording Circuit

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  4. Solidarity with Animals: Assessing a Relevant Dimension of Social Identification with Animals.

    PubMed

    Amiot, Catherine E; Bastian, Brock

    2017-01-01

    Interactions with animals are pervasive in human life, a fact that is reflected in the burgeoning field of human-animal relations research. The goal of the current research was to examine the psychology of our social connection with other animals, by specifically developing a measure of solidarity with animals. In 8 studies using correlational, experimental, and longitudinal designs, solidarity with animals predicted more positive attitudes and behaviors toward animals, over and above existing scales of identification, and even when this implied a loss of resources and privileges for humans relative to animals. Solidarity with animals also displayed predicted relationships with relevant variables (anthropomorphism, empathy). Pet owners and vegetarians displayed higher levels of solidarity with animals. Correlational and experimental evidence confirmed that human-animal similarity heightens solidarity with animals. Our findings provide a useful measure that can facilitate important insights into the nature of our relationships with animals.

  5. Solidarity with Animals: Assessing a Relevant Dimension of Social Identification with Animals

    PubMed Central

    Amiot, Catherine E.; Bastian, Brock

    2017-01-01

    Interactions with animals are pervasive in human life, a fact that is reflected in the burgeoning field of human-animal relations research. The goal of the current research was to examine the psychology of our social connection with other animals, by specifically developing a measure of solidarity with animals. In 8 studies using correlational, experimental, and longitudinal designs, solidarity with animals predicted more positive attitudes and behaviors toward animals, over and above existing scales of identification, and even when this implied a loss of resources and privileges for humans relative to animals. Solidarity with animals also displayed predicted relationships with relevant variables (anthropomorphism, empathy). Pet owners and vegetarians displayed higher levels of solidarity with animals. Correlational and experimental evidence confirmed that human-animal similarity heightens solidarity with animals. Our findings provide a useful measure that can facilitate important insights into the nature of our relationships with animals. PMID:28045909

  6. Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator.

    PubMed

    Hiratsuka, Junichi; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Miyamoto, Kenji; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; Tobari, Hiroyuki

    2016-02-01

    To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ∼16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles.

  7. Allometry of animal-microbe interactions and global census of animal-associated microbes.

    PubMed

    Kieft, Thomas L; Simmons, Karen A

    2015-07-07

    Animals live in close association with microorganisms, mostly prokaryotes, living in or on them as commensals, mutualists or parasites, and profoundly affecting host fitness. Most animal-microbe studies focus on microbial community structure; for this project, allometry (scaling of animal attributes with animal size) was applied to animal-microbe relationships across a range of species spanning 12 orders of magnitude in animal mass, from nematodes to whales. Microbial abundances per individual animal were gleaned from published literature and also microscopically counted in three species. Abundance of prokaryotes/individual versus animal mass scales as a nearly linear power function (exponent = 1.07, R(2) = 0.94). Combining this power function with allometry of animal abundance indicates that macrofauna have an outsized share of animal-associated microorganisms. The total number of animal-associated prokaryotes in Earth's land animals was calculated to be 1.3-1.4 × 10(25) cells and the total of marine animal-associated microbes was calculated to be 8.6-9.0 × 10(24) cells. Animal-associated microbes thus total 2.1-2.3 × 10(25) of the approximately 10(30) prokaryotes on the Earth. Microbes associated with humans comprise 3.3-3.5% of Earth's animal-associated microbes, and domestic animals harbour 14-20% of all animal-associated microbes, adding a new dimension to the scale of human impact on the biosphere. This novel allometric power function may reflect underlying mechanisms involving the transfer of energy and materials between microorganisms and their animal hosts. Microbial diversity indices of animal gut communities and gut microbial species richness for 60 mammals did not indicate significant scaling relationships with animal body mass; however, further research in this area is warranted. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  8. Advanced Accelerator Development Strategy Report: DOE Advanced Accelerator Concepts Research Roadmap Workshop

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None, None

    Over a full two day period, February 2–3, 2016, the Office of High Energy Physics convened a workshop in Gaithersburg, MD to seek community input on development of an Advanced Accelerator Concepts (AAC) research roadmap. The workshop was in response to a recommendation by the HEPAP Accelerator R&D Subpanel [1] [2] to “convene the university and laboratory proponents of advanced acceleration concepts to develop R&D roadmaps with a series of milestones and common down selection criteria towards the goal for constructing a multi-TeV e+e– collider” (the charge to the workshop can be found in Appendix A). During the workshop, proponentsmore » of laser-driven plasma wakefield acceleration (LWFA), particle-beam-driven plasma wakefield acceleration (PWFA), and dielectric wakefield acceleration (DWFA), along with a limited number of invited university and laboratory experts, presented and critically discussed individual concept roadmaps. The roadmap workshop was preceded by several preparatory workshops. The first day of the workshop featured presentation of three initial individual roadmaps with ample time for discussion. The individual roadmaps covered a time period extending until roughly 2040, with the end date assumed to be roughly appropriate for initial operation of a multi-TeV e+e– collider. The second day of the workshop comprised talks on synergies between the roadmaps and with global efforts, potential early applications, diagnostics needs, simulation needs, and beam issues and challenges related to a collider. During the last half of the day the roadmaps were revisited but with emphasis on the next five to ten years (as specifically requested in the charge) and on common challenges. The workshop concluded with critical and unanimous endorsement of the individual roadmaps and an extended discussion on the characteristics of the common challenges. (For the agenda and list of participants see Appendix B.)« less

  9. [Animal ethics in the 19th century and Swiss animal protection law].

    PubMed

    Bloch, I

    2018-01-01

    The development of animal ethics and animal rights from the antiquity up to modern times is described. The relationship of humans to animals was primarily based on fear and animal cult, developed by the domestication to a partnership. The philosophers of the early modern age denied the animals the reason, what was disadvantageous to the position of the animals in the society and the behavior of humans to the animals. By the end of the 19th century the animal protection concept developed with numerous postulates for legal regulations. With the Swiss animal protection law, which came into force in 1981, most of the postulates could be realised. It is shown, how animal protection has developed since that time.

  10. Enhancing human-animal relationships through veterinary medical instruction in animal-assisted therapy and animal-assisted activities.

    PubMed

    Schaffer, Caroline Brunsman

    2008-01-01

    Instruction in animal-assisted therapy (AAT) and animal-assisted activities (AAAs) teaches veterinary medical students to confidently and assertively maximize the benefits and minimize the risks of this union of animals and people. Instruction in AAT/AAA also addresses requirements by the American Veterinary Medical Association Council on Education that accredited schools/colleges of veterinary medicine include in their standard curriculum the topics of the human-animal bond, behavior, and the contributions of the veterinarian to the overall public and professional health care teams. Entry-level veterinarians should be prepared to: (1) assure that animals who provide AAT/AAA are healthy enough to visit nursing homes, hospitals, or other institutions; (2) promote behavior testing that selects animals who will feel safe, comfortable, and connected; (3) advise facilities regarding infection control and ways to provide a safe environment where the animals, their handlers, and the people being visited will not be injured or become ill; and (4) advocate for their patients and show compassion for their clients when animals are determined to be inappropriate participants in AAT/AAA programs. This article presents AAT/AAA terminology, ways in which veterinarians can advocate for AAT/AAA, the advantages of being involved in AAT/AAA, a model AAT/AAA practicum from Tuskegee University's School of Veterinary Medicine (TUSVM), and examples of co-curricular activities in AAT/AAA by TUSVM's student volunteers.

  11. Combined use of two supervised learning algorithms to model sea turtle behaviours from tri-axial acceleration data.

    PubMed

    Jeantet, L; Dell'Amico, F; Forin-Wiart, M-A; Coutant, M; Bonola, M; Etienne, D; Gresser, J; Regis, S; Lecerf, N; Lefebvre, F; de Thoisy, B; Le Maho, Y; Brucker, M; Châtelain, N; Laesser, R; Crenner, F; Handrich, Y; Wilson, R; Chevallier, D

    2018-05-23

    Accelerometers are becoming ever more important sensors in animal-attached technology, providing data that allow determination of body posture and movement and thereby helping to elucidate behaviour in animals that are difficult to observe. We sought to validate the identification of sea turtle behaviours from accelerometer signals by deploying tags on the carapace of a juvenile loggerhead ( Caretta caretta ), an adult hawksbill ( Eretmochelys imbricata ) and an adult green turtle ( Chelonia mydas ) at Aquarium La Rochelle, France. We recorded tri-axial acceleration at 50 Hz for each species for a full day while two fixed cameras recorded their behaviours. We identified behaviours from the acceleration data using two different supervised learning algorithms, Random Forest and Classification And Regression Tree (CART), treating the data from the adult animals as separate from the juvenile data. We achieved a global accuracy of 81.30% for the adult hawksbill and green turtle CART model and 71.63% for the juvenile loggerhead, identifying 10 and 12 different behaviours, respectively. Equivalent figures were 86.96% for the adult hawksbill and green turtle Random Forest model and 79.49% for the juvenile loggerhead, for the same behaviours. The use of Random Forest combined with CART algorithms allowed us to understand the decision rules implicated in behaviour discrimination, and thus remove or group together some 'confused' or under--represented behaviours in order to get the most accurate models. This study is the first to validate accelerometer data to identify turtle behaviours and the approach can now be tested on other captive sea turtle species. © 2018. Published by The Company of Biologists Ltd.

  12. Acceleration sensitivity of micromachined pressure sensors

    NASA Astrophysics Data System (ADS)

    August, Richard; Maudie, Theresa; Miller, Todd F.; Thompson, Erik

    1999-08-01

    Pressure sensors serve a variety of automotive applications, some which may experience high levels of acceleration such as tire pressure monitoring. To design pressure sensors for high acceleration environments it is important to understand their sensitivity to acceleration especially if thick encapsulation layers are used to isolate the device from the hostile environment in which they reside. This paper describes a modeling approach to determine their sensitivity to acceleration that is very general and is applicable to different device designs and configurations. It also describes the results of device testing of a capacitive surface micromachined pressure sensor at constant acceleration levels from 500 to 2000 g's.

  13. Collective field accelerator

    DOEpatents

    Luce, John S.

    1978-01-01

    A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a .nu./.gamma. of .about. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam.

  14. Rolamite acceleration sensor

    DOEpatents

    Abbin, Joseph P.; Briner, Clifton F.; Martin, Samuel B.

    1993-01-01

    A rolamite acceleration sensor which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently.

  15. Can teaching veterinary and animal-science students about animal welfare affect their attitude toward animals and human-related empathy?

    PubMed

    Hazel, Susan J; Signal, Tania D; Taylor, Nicola

    2011-01-01

    Attitudes toward animals are important in influencing how animals are treated. Few studies have investigated attitudes toward animals in veterinary or animal-science students, and no studies have compared attitudes to animals before and after a course teaching animal welfare and ethics. In this study, students enrolled in veterinary (first-year) or animal-science (first- and third-year) programs completed a questionnaire on attitudes toward different categories of animals before and after the course. Higher attitude scores suggest a person more concerned about how an animal is treated. Normally distributed data were compared using parametric statistics, and non-normally distributed data were compared using non-parametric tests, with significance p < .05. Attitudes toward pets (45.5-47.6) were higher than those toward pests (34.2-38.4) or profit animals (30.3-32.1). Attitude scores increased from before to after the course in the veterinary cohort on the Pest (36.9 vs. 38.4, respectively, n = 27, p < .05) and Profit (30.3 vs. 32.1, respectively, n = 28, p < .05) subscales, but not in the animal-science cohorts. Attitude scores in all categories were higher for women than for men. Currently having an animal was associated with higher pet scores (46.8 vs. 43.8, ns = 120 and 13, respectively, p < .05), and having an animal as a child was associated with higher profit scores (31.0 vs. 26.6, ns = 129 and 8, respectively, p < .05). Students electing to work with livestock had lower scores on the Pest and Profit subscales, and students wanting to work with wildlife had significantly higher scores on the Pest and Profit subscales. This study demonstrates attitudinal changes after an animal-welfare course, with significant increases in veterinary but not animal-science students.

  16. Petawatt pulsed-power accelerator

    DOEpatents

    Stygar, William A.; Cuneo, Michael E.; Headley, Daniel I.; Ives, Harry C.; Ives, legal representative; Berry Cottrell; Leeper, Ramon J.; Mazarakis, Michael G.; Olson, Craig L.; Porter, John L.; Wagoner; Tim C.

    2010-03-16

    A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

  17. Principles of Induction Accelerators

    NASA Astrophysics Data System (ADS)

    Briggs*, Richard J.

    The basic concepts involved in induction accelerators are introduced in this chapter. The objective is to provide a foundation for the more detailed coverage of key technology elements and specific applications in the following chapters. A wide variety of induction accelerators are discussed in the following chapters, from the high current linear electron accelerator configurations that have been the main focus of the original developments, to circular configurations like the ion synchrotrons that are the subject of more recent research. The main focus in the present chapter is on the induction module containing the magnetic core that plays the role of a transformer in coupling the pulsed power from the modulator to the charged particle beam. This is the essential common element in all these induction accelerators, and an understanding of the basic processes involved in its operation is the main objective of this chapter. (See [1] for a useful and complementary presentation of the basic principles in induction linacs.)

  18. Overview of Accelerator Applications in Energy

    NASA Astrophysics Data System (ADS)

    Garnett, Robert W.; Sheffield, Richard L.

    An overview of the application of accelerators and accelerator technology in energy is presented. Applications span a broad range of cost, size, and complexity and include large-scale systems requiring high-power or high-energy accelerators to drive subcritical reactors for energy production or waste transmutation, as well as small-scale industrial systems used to improve oil and gas exploration and production. The enabling accelerator technologies will also be reviewed and future directions discussed.

  19. Accelerated and Airy-Bloch oscillations

    NASA Astrophysics Data System (ADS)

    Longhi, Stefano

    2016-09-01

    A quantum particle subjected to a constant force undergoes an accelerated motion following a parabolic path, which differs from the classical motion just because of wave packet spreading (quantum diffusion). However, when a periodic potential is added (such as in a crystal) the particle undergoes Bragg scattering and an oscillatory (rather than accelerated) motion is found, corresponding to the famous Bloch oscillations (BOs). Here, we introduce an exactly-solvable quantum Hamiltonian model, corresponding to a generalized Wannier-Stark Hamiltonian Ĥ, in which a quantum particle shows an intermediate dynamical behavior, namely an oscillatory motion superimposed to an accelerated one. Such a novel dynamical behavior is referred to as accelerated BOs. Analytical expressions of the spectrum, improper eigenfunctions and propagator of the generalized Wannier-Stark Hamiltonian Ĥ are derived. Finally, it is shown that acceleration and quantum diffusion in the generalized Wannier-Stark Hamiltonian are prevented for Airy wave packets, which undergo a periodic breathing dynamics that can be referred to as Airy-Bloch oscillations.

  20. SHEAR ACCELERATION IN EXPANDING FLOWS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rieger, F. M.; Duffy, P., E-mail: frank.rieger@mpi-hd.mpg.de, E-mail: peter.duffy@ucd.ie

    Shear flows are naturally expected to occur in astrophysical environments and potential sites of continuous non-thermal Fermi-type particle acceleration. Here we investigate the efficiency of expanding relativistic outflows to facilitate the acceleration of energetic charged particles to higher energies. To this end, the gradual shear acceleration coefficient is derived based on an analytical treatment. The results are applied to the context of the relativistic jets from active galactic nuclei. The inferred acceleration timescale is investigated for a variety of conical flow profiles (i.e., power law, Gaussian, Fermi–Dirac) and compared to the relevant radiative and non-radiative loss timescales. The results exemplifymore » that relativistic shear flows are capable of boosting cosmic-rays to extreme energies. Efficient electron acceleration, on the other hand, requires weak magnetic fields and may thus be accompanied by a delayed onset of particle energization and affect the overall jet appearance (e.g., core, ridge line, and limb-brightening).« less