WorldWideScience

Sample records for bench-to-bedside review mechanisms

  1. Bench-to-bedside review

    DEFF Research Database (Denmark)

    Janum, Susanne; Zingg, Walter; Classen, Volker

    2013-01-01

    Central venous catheters (CVCs) are indispensable in modern pediatric medicine. CVCs provide secure vascular access, but are associated with a risk of severe complications, in particular bloodstream infection. We provide a review of the recent literature about the diagnostic and therapeutic...... challenges of catheter-related bloodstream infection (CRBSI) in children and its prevention. Variations in blood sampling and limitations in blood culturing interfere with accurate and timely diagnosis of CRBSI. Although novel molecular testing methods appear promising in overcoming some of the present...... diagnostic limitations of conventional blood sampling in children, they still need to solidly prove their accuracy and reliability in clinical practice. Standardized practices of catheter insertion and care remain the cornerstone of CRBSI prevention although their implementation in daily practice may...

  2. Mechanisms of Inflammation in Proliferative Vitreoretinopathy: From Bench to Bedside

    Directory of Open Access Journals (Sweden)

    Stavros N. Moysidis

    2012-01-01

    Full Text Available Proliferative vitreoretinopathy (PVR is a vision-threatening disease and a common complication of surgery to correct rhegmatogenous retinal detachment (RRD. Several models of the pathogenesis of this disease have been described with some of these models focusing on the role of inflammatory cells and other models focusing on the role of growth factors and cytokines in the vitreous which come into contact with intraretinal and retinal pigment epithelial cells. New experiments have shed light on the pathogenesis of PVR and offer promising avenues for clinical intervention before PVR develops. One such target is the indirect pathway of activation of platelet-derived growth factor receptor alpha (PDGRα, which plays an important role in PVR. Clinical trials assessing the efficacy of 5-fluorouracil (5-FU and low-molecular-weight heparin (LMWH, daunorubicin, and 13-cis-retinoic acid, among other therapies, have yielded mixed results. Here we review inflammatory and other mechanisms involved in the pathogenesis of PVR, we highlight important clinical trials, and we discuss how findings at the bench have the potential to be translated to the bedside.

  3. Advances in cardiovascular fluid mechanics: bench to bedside.

    Science.gov (United States)

    Dasi, Lakshmi P; Sucosky, Philippe; de Zelicourt, Diane; Sundareswaran, Kartik; Jimenez, Jorge; Yoganathan, Ajit P

    2009-04-01

    This paper presents recent advances in cardiovascular fluid mechanics that define the current state of the art. These studies include complex multimodal investigations with advanced measurement and simulation techniques. We first discuss the complex flows within the total cavopulmonary connection in Fontan patients. We emphasize the quantification of energy losses by studying the importance of caval offsets as well as the differences among various Fontan surgical protocols. In our studies of the fluid mechanics of prosthetic heart valves, we reveal for the first time the full three-dimensional complexity of flow fields in the vicinity of bileaflet and trileaflet valves and the microscopic hinge flow dynamics. We also present results of these valves functioning in a patient-specific native aorta geometry. Our in vitro mitral valve studies show the complex mechanism of the native mitral valve apparatus. We demonstrate that the different components of the mitral valve have independent and synergistically complex functions that allow the valve to operate efficiently. We also show how valve mechanics change under pathological and repair conditions associated with enlarged ventricles. Finally, our ex vivo studies on the interactions between the aortic valve and its surrounding hemodynamic environment are aimed at providing insights into normal valve function and valve pathology. We describe the development of organ- and tissue-culture systems and the biological response of the tissue subjected to their respective simulated mechanical environment. The studies noted above have enhanced our understanding of the complex fluid mechanics associated with the cardiovascular system and have led to new translational technologies.

  4. Bench-to-bedside review: Human subjects research – are more standards needed?

    Science.gov (United States)

    Huang, David T; Hadian, Mehrnaz

    2006-01-01

    There are many controversial issues surrounding ethics in study design and conduct of human subjects research. In this review we briefly touch on the origin of ethics in clinical research and how the current regulations and standards came into practice. We then discuss current controversies regarding informed consent, conflicts of interest, institutional review boards, and other relevant issues such as innovative procedures and quality improvement projects. The question of whether we need more standards is a very important yet challenging one to which there is no simple answer. We address this question by reviewing and commenting on relevant literature. We conclude that what is needed are not more standards per se, but rather refinement and uniformity of current standards, and their interpretation and application both to protect human subjects and to advance medicine. PMID:17184560

  5. Bench-to-bedside review: human subjects research--are more standards needed?

    Science.gov (United States)

    Huang, David T; Hadian, Mehrnaz

    2006-01-01

    There are many controversial issues surrounding ethics in study design and conduct of human subjects research. In this review we briefly touch on the origin of ethics in clinical research and how the current regulations and standards came into practice. We then discuss current controversies regarding informed consent, conflicts of interest, institutional review boards, and other relevant issues such as innovative procedures and quality improvement projects. The question of whether we need more standards is a very important yet challenging one to which there is no simple answer. We address this question by reviewing and commenting on relevant literature. We conclude that what is needed are not more standards per se, but rather refinement and uniformity of current standards, and their interpretation and application both to protect human subjects and to advance medicine.

  6. Bench-to-bedside review: Treating acid–base abnormalities in the intensive care unit – the role of buffers

    Science.gov (United States)

    Gehlbach, Brian K; Schmidt, Gregory A

    2004-01-01

    The recognition and management of acid–base disorders is a commonplace activity for intensivists. Despite the frequency with which non-bicarbonate-losing forms of metabolic acidosis such as lactic acidosis occurs in critically ill patients, treatment is controversial. This article describes the properties of several buffering agents and reviews the evidence for their clinical efficacy. The evidence supporting and refuting attempts to correct arterial pH through the administration of currently available buffers is presented. PMID:15312208

  7. Bench-to-bedside review: treating acid-base abnormalities in the intensive care unit - the role of buffers.

    Science.gov (United States)

    Gehlbach, Brian K; Schmidt, Gregory A

    2004-08-01

    The recognition and management of acid-base disorders is a commonplace activity for intensivists. Despite the frequency with which non-bicarbonate-losing forms of metabolic acidosis such as lactic acidosis occurs in critically ill patients, treatment is controversial. This article describes the properties of several buffering agents and reviews the evidence for their clinical efficacy. The evidence supporting and refuting attempts to correct arterial pH through the administration of currently available buffers is presented.

  8. Bench-to-bedside review

    DEFF Research Database (Denmark)

    Afshari, Arash; Schrenzel, Jacques; Ieven, Margareta

    2012-01-01

    ABSTRACT: Among critically ill patients, the diagnosis of bloodstream infection poses a major challenge. Current standard bacterial identification based on blood culture platforms is intrinsically time-consuming and slow. The continuous evolvement of molecular techniques has the potential of prov...

  9. Stem Cell Transplantation from Bench to Bedside

    Indian Academy of Sciences (India)

    Table of contents. Stem Cell Transplantation from Bench to Bedside · Slide 2 · Slide 3 · Slide 4 · Principles of an allogeneic stem cell transplant · Principle of an allogeneic stem cell transplant · Principle of an autologous Stem Cell Transplant · Slide 8 · Conditioning · Slide 10 · Slide 11 · Stem Cell Transplantation · Slide 13.

  10. Sepsis: from bench to bedside

    Directory of Open Access Journals (Sweden)

    Eliézer Silva

    2008-01-01

    Full Text Available Sepsis is a syndrome related to severe infections. It is defined as the systemic host response to microorganisms in previously sterile tissues and is characterized by end-organ dysfunction away from the primary site of infection. The normal host response to infection is complex and aims to identify and control pathogen invasion, as well as to start immediate tissue repair. Both the cellular and humoral immune systems are activated, giving rise to both anti-inflammatory and proinflammatory responses. The chain of events that leads to sepsis is derived from the exacerbation of these mechanisms, promoting massive liberation of mediators and the progression of multiple organ dysfunction. Despite increasing knowledge about the pathophysiological pathways and processes involved in sepsis, morbidity and mortality remain unacceptably high. A large number of immunomodulatory agents have been studied in experimental and clinical settings in an attempt to find an efficacious anti-inflammatory drug that reduces mortality. Even though preclinical results had been promising, the vast majority of these trials actually showed little success in reducing the overwhelmingly high mortality rate of septic shock patients as compared with that of other critically ill intensive care unit patients. Clinical management usually begins with prompt recognition, determination of the probable infection site, early administration of antibiotics, and resuscitation protocols based on "early-goal" directed therapy. In this review, we address the research efforts that have been targeting risk factor identification, including genetics, pathophysiological mechanisms and strategies to recognize and treat these patients as early as possible.

  11. Diabetic Cardiomyopathy: Bench to Bedside

    Science.gov (United States)

    Schilling, Joel D.; Mann, Douglas L.

    2012-01-01

    The study of diabetic cardiomyopathy (diabetic CM) is an area of significant interest given the strong association between diabetes and the risk of heart failure. Many unanswered questions remain regarding the clinical definition and pathogenesis of this metabolic cardiomyopathy. This article reviews the current understanding of diabetic CM with a particular emphasis on the unresolved issues that have limited translation of scientific discovery to patient bedside. PMID:22999244

  12. Cellular and Molecular Anesthesia: from Bench to Bedside

    Directory of Open Access Journals (Sweden)

    Ali Dabbagh

    2015-12-01

    Full Text Available Cellular and Molecular Anesthesia: from Bench to BedsideIn the current practice of anesthesia, each day, anesthesiologists deal with a great work: they use the cellular mechanisms of drug molecules to induce their desired effects for induction and maintenance of anesthesia to achieve appropriate tolerance of surgery and its pain, modulation of stress response, sedation needed for performing a variety of procedures, emergency anesthesia care, acute and chronic pain management or other everyday jobs of anesthesiologists during perioperative period.As a matter of fact, molecular anesthesia has been cited for more than 6 decades though in avery limited scale. In 1956, the molecular mechanisms of morphine and pethidine are described (1. Pauling in 1961 published an article in Science describing a molecular theorey for general anesthesia (2.In its report “the World in 2025”, Thomson Reuters has predicted clinical medicine would be the most active research front; while molecular biology has the 9th rank (3. But are we still practicing in clinic the same as today?In fact, the future trend of anesthesia is highly dependent on finding the novel cellular and molecular mechanisms and the possible interactions of the newly discovered molecules and inreraction mechanisms with organ systems. Today, we emphasize on the role of pharmacologists, physiologists, immunologists, anatomists, embryologists, geneticians, cellular medicine specialists, physicists and other basic science specialists; some very interesting examples are published in this volume of the Journal (4-7.However, changes that have well started now would “revolutionize” our daily practice during the next decade in such a way that it will change the basis of medicine: presumably we will have a new model medicine known as “personalized medicine” or “precision medicine”. In this approach, the content of each patient’s genes accompanied with his/her cellular and molecular analysis is

  13. Nutrition in cachexia: from bench to bedside.

    OpenAIRE

    Konishi, Masaaki; Ishida, Junichi; von Haehling, Stephan; Anker, Stefan D.; Springer, Jochen

    2016-01-01

    As malnutrition is often present in cachexia, nutritional intervention has been one of the widely accepted strategies. A literature review of cachexia models with dietary interventions in the present issue of this journal pointed out that the majority of nutrient intervention studies were of n-3 fatty acid, mainly eicosapentaenoic acid and docosahexaenoic acid. Effect on protein catabolism and anti-inflammation are most pronounced benefits of n-3 fatty acid. The effectiveness of n-3 fatty aci...

  14. Nutrition in cachexia: from bench to bedside.

    Science.gov (United States)

    Konishi, Masaaki; Ishida, Junichi; von Haehling, Stephan; Anker, Stefan D; Springer, Jochen

    2016-05-01

    As malnutrition is often present in cachexia, nutritional intervention has been one of the widely accepted strategies. A literature review of cachexia models with dietary interventions in the present issue of this journal pointed out that the majority of nutrient intervention studies were of n-3 fatty acid, mainly eicosapentaenoic acid and docosahexaenoic acid. Effect on protein catabolism and anti-inflammation are most pronounced benefits of n-3 fatty acid. The effectiveness of n-3 fatty acid may depend on control diet or even be attributed to the polyunsaturated fatty acid deficiency inadvertently produced in control group. However, there is not enough clinical evidence to support a benefit of n-3 fatty acid substitution in patients with cachexia. The second important result from this review is that the majority of studies did not provide information about dietary design or did not standardize design, content, source, and overall composition. To guide dietary design for researchers in preclinical studies, a model has been proposed in this review, which may be useful to predict the efficacy of new dietary intervention in cachexia science. From a clinical point of view, the limited effectiveness of nutritional support in cachexia may partly be explained by the multifactorial nature of this condition. Cachexia differs from malnutrition inasmuch as malnutrition can be reversed by adequate nutrition and/or by overcoming problems of absorption or utilization of nutrients, but cachexia cannot be successfully treated by nutrition alone. Multidisciplinary approach including the assessment and intervention in feeding, appetite, swallowing, exercise, psychosocial, and psychological issue may be needed to improve nutrition in patients with cachexia.

  15. Stem cell therapy: From bench to bedside

    International Nuclear Information System (INIS)

    Tamarat, R.; Lataillade, J. J.; Bey, E.; Gourmelon, P.; Benderitter, M.

    2012-01-01

    Several countries have increased efforts to develop medical countermeasures to protect against radiation toxicity due to acts of bio-terrorism as well as cancer treatment. Both acute radiation injuries and delayed effects such as cutaneous effects and impaired wound repair depend, to some extent, on angiogenesis deficiency. Vascular damage influences levels of nutrients, oxygen available to skin tissue and epithelial cell viability. Consequently, the evolution of radiation lesions often becomes uncontrolled and surgery is the final option-amputation leading to a disability. Therefore, the development of strategies designed to promote healing of radiation injuries is a major therapeutic challenge. Adult mesenchymal stem cell therapy has been combined with surgery in some cases and not in others and successfully applied in patients with accidental radiation injuries. Although research in the field of radiation skin injury management has made substantial progress in the past 10 y, several strategies are still needed in order to enhance the beneficial effect of stem cell therapy and to counteract the deleterious effect of an irradiated tissue environment. This review summarises the current and evolving advances concerning basic and translational research based on stem cell therapy for the management of radiological burns. (authors)

  16. Eating disorders: from bench to bedside and back.

    Science.gov (United States)

    Gaetani, Silvana; Romano, Adele; Provensi, Gustavo; Ricca, Valdo; Lutz, Thomas; Passani, Maria Beatrice

    2016-12-01

    The central nervous system and viscera constitute a functional ensemble, the gut-brain axis, that allows bidirectional information flow that contributes to the control of feeding behavior based not only on the homeostatic, but also on the hedonic aspects of food intake. The prevalence of eating disorders, such as anorexia nervosa, binge eating and obesity, poses an enormous clinical burden, and involves an ever-growing percentage of the population worldwide. Clinical and preclinical research is constantly adding new information to the field and orienting further studies with the aim of providing a foundation for developing more specific and effective treatment approaches to pathological conditions. A recent symposium at the XVI Congress of the Societá Italiana di Neuroscienze (SINS, 2015) 'Eating disorders: from bench to bedside and back' brought together basic scientists and clinicians with the objective of presenting novel perspectives in the neurobiology of eating disorders. Clinical studies presented by V. Ricca illustrated some genetic aspects of the psychopathology of anorexia nervosa. Preclinical studies addressed different issues ranging from the description of animal models that mimic human pathologies such as anorexia nervosa, diet-induced obesity, and binge eating disorders (T. Lutz), to novel interactions between peripheral signals and central circuits that govern food intake, mood and stress (A. Romano and G. Provensi). The gut-brain axis has received increasing attention in the recent years as preclinical studies are demonstrating that the brain and visceral organs such as the liver and guts, but also the microbiota are constantly engaged in processes of reciprocal communication, with unexpected physiological and pathological implications. Eating is controlled by a plethora of factors; genetic predisposition, early life adverse conditions, peripheral gastrointestinal hormones that act directly or indirectly on the central nervous system, all are

  17. From bench to bedside: use of human adipose-derived stem cells

    Directory of Open Access Journals (Sweden)

    Feisst V

    2015-11-01

    Full Text Available Vaughan Feisst,1 Sarah Meidinger,1 Michelle B Locke2 1Dunbar Laboratory, School of Biological Sciences, 2Department of Surgery, Faculty of Medicine and Health Sciences, The University of Auckland, Auckland, New Zealand Abstract: Since the discovery of adipose-derived stem cells (ASC in human adipose tissue nearly 15 years ago, significant advances have been made in progressing this promising cell therapy tool from the laboratory bench to bedside usage. Standardization of nomenclature around the different cell types used is finally being adopted, which facilitates comparison of results between research groups. In vitro studies have assessed the ability of ASC to undergo mesenchymal differentiation as well as differentiation along alternate lineages (transdifferentiation. Recently, focus has shifted to the immune modulatory and paracrine effects of transplanted ASC, with growing interest in the ASC secretome as a source of clinical effect. Bedside use of ASC is advancing alongside basic research. An increasing number of safety-focused Phase I and Phase IIb trials have been published without identifying any significant risks or adverse events in the short term. Phase III trials to assess efficacy are currently underway. In many countries, regulatory frameworks are being developed to monitor their use and assure their safety. As many trials rely on ASC injected at a distant site from the area of clinical need, strategies to improve the homing and efficacy of transplanted cells are also being explored. This review highlights each of these aspects of the bench-to-bedside use of ASC and summarizes their clinical utility across a variety of medical specialties. Keywords: standardization, bystander effect, stromal cells, mesenchymal stem cells, stromal vascular fraction

  18. Missing Links Between Genetically Inherited Molecules in Split Cord Malformation and Other Anomaly: A Bench to Bedside Approach.

    Science.gov (United States)

    Barik, Mayadhar; Mishra, Pravash R; Mohapatra, Ashok Kumar

    2018-01-01

    Split cord malformation (SCM) is associated with extensive vertebral fusions (Klippel-Feil anomaly). In light of previous embryological theories and recent research findings, we attempt to document the origin of split cord, and vertebral fusions involvement of spectrum of genes is necessary to know better the etiopathogenesis of SCM and its associated diseases. We used the various databases such as PubMed/MEDLINE, Cochrane Review, Hinari, and Google Scholar for the recently published medical literature. The women had been living and still born infants had SCM. The relative risk (RR) and possible molecular mechanism are described details of major genes and its variants in details. Although molecular genetics involvement including with recent advances of study add an evidence of both Mendelian and Non-Mendelian fashion is discussed with all genetic components. We mentioned our earlier experience and responsibility of SCM and its associated diseases. Although different mechanisms are suggested for the development of SCM observed in our experience, there is a midline lesion bisecting the neuroepithelium and the notochordal plate, which is responsible for complete splitting of the cervical cord with anterior bony defect. The localized disturbance of cervical neural tube closure accounts for SCM with partial dorsal splitting of the cord with posterior vertebral defect and associated diseases. According to the best of our knowledge, this report is the first one to be documented by wider spectrum of variants from (experimental studies to human subject). This add a complex interaction of mutant variants drive toward an additional second-hit alterations for the SCM. The up-to-date information, documented in proper order, derived the bench-to-bedside approach to overcome this burden of SCM, which is globally noticed with other additional diseases.

  19. From bench to bedside: editorial | Pettengell | South African ...

    African Journals Online (AJOL)

    South African Gastroenterology Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 2, No 1 (2004) >. Log in or Register to get access to full text downloads.

  20. Cranberry for Urinary Tract Infection: From Bench to Bedside.

    Science.gov (United States)

    Nabavi, Seyed Fazel; Sureda, Antoni; Daglia, Maria; Izadi, Morteza; Nabavi, Seyed Mohammad

    2017-01-01

    Urinary tract infections are common infectious diseases which can occur in any part of the urinary tract such as bladder, kidney, ureters, and urethra. They are commonly caused by bacteria that enter through the urethra. Urinary tract infections commonly develop in the bladder and spread to renal tissues. Up to now, there are different antimicrobial agents which have beneficial role on urinary tract infections. However, most of them cause different adverse effects and therefore, much attention has been paid to the search for effective therapeutic agents with negligible adverse effects. Cranberry is known as one of the most important edible plants, which possesses potent antimicrobial effects against the bacteria responsible for urinary tract infections. Growing evidence has shown that cranberry suppresses urinary tract infections and eradicates the bacteria. Therefore, the aim of this study is to critically review the available literature regarding the antimicrobial activities of cranberry against urinary tract infection microorganisms. In addition, we discuss etiology, epidemiology, risk factors, and current drugs of urinary tract infections to provide a more complete picture of this disease.

  1. Pathophysiology of septic shock: From bench to bedside.

    Science.gov (United States)

    McConnell, Kevin W; Coopersmith, Craig M

    2016-04-01

    Our understanding of sepsis and its resultant outcomes remains a paradox. On the one hand, we know more about the pathophysiology of sepsis than ever before. However, this knowledge has not been successfully translated to the bedside, as the vast majority of clinical trials for sepsis have been negative. Yet even in the general absence of positive clinical trials, mortality from sepsis has fallen to its lowest point in history, in large part due to educational campaigns that stress timely antibiotics and hemodynamic support. While additional improvements in outcome will assuredly result from further compliance with evidence based practices, a deeper understanding of the science that underlies the host response in sepsis is critical to the development of novel therapeutics. In this review, we outline immunopathologic abnormalities in sepsis, and then look at potential approaches to therapeutically modulate them. Ultimately, an understanding of the science underlying sepsis should allow the critical care community to utilize precision medicine to combat this devastating disease on an individual basis leading to improved outcomes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. Antimicrobial resistance in Acinetobacter baumannii: From bench to bedside

    Science.gov (United States)

    Lin, Ming-Feng; Lan, Chung-Yu

    2014-01-01

    Acinetobacter baumannii (A. baumannii) is undoubtedly one of the most successful pathogens in the modern healthcare system. With invasive procedures, antibiotic use and immunocompromised hosts increasing in recent years, A. baumannii has become endemic in hospitals due to its versatile genetic machinery, which allows it to quickly evolve resistance factors, and to its remarkable ability to tolerate harsh environments. Infections and outbreaks caused by multidrug-resistant A. baumannii (MDRAB) are prevalent and have been reported worldwide over the past twenty or more years. To address this problem effectively, knowledge of species identification, typing methods, clinical manifestations, risk factors, and virulence factors is essential. The global epidemiology of MDRAB is monitored by persistent surveillance programs. Because few effective antibiotics are available, clinicians often face serious challenges when treating patients with MDRAB. Therefore, a deep understanding of the resistance mechanisms used by MDRAB can shed light on two possible strategies to combat the dissemination of antimicrobial resistance: stringent infection control and antibiotic treatments, of which colistin-based combination therapy is the mainstream strategy. However, due to the current unsatisfying therapeutic outcomes, there is a great need to develop and evaluate the efficacy of new antibiotics and to understand the role of other potential alternatives, such as antimicrobial peptides, in the treatment of MDRAB infections. PMID:25516853

  3. Clinical utility of asthma biomarkers: from bench to bedside

    Directory of Open Access Journals (Sweden)

    Vijverberg SJH

    2013-08-01

    Full Text Available Susanne JH Vijverberg,1,2,* Bart Hilvering,2,* Jan AM Raaijmakers,1 Jan-Willem J Lammers,2 Anke-Hilse Maitland-van der Zee,1,* Leo Koenderman2,* 1Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands; 2Department of Respiratory Medicine, University Medical Centre Utrecht, Utrecht, The Netherlands *These authors contributed equally to this work Abstract: Asthma is a chronic disease characterized by airway inflammation, bronchial hyperresponsiveness, and recurrent episodes of reversible airway obstruction. The disease is very heterogeneous in onset, course, and response to treatment, and seems to encompass a broad collection of heterogeneous disease subtypes with different underlying pathophysiological mechanisms. There is a strong need for easily interpreted clinical biomarkers to assess the nature and severity of the disease. Currently available biomarkers for clinical practice – for example markers in bronchial lavage, bronchial biopsies, sputum, or fraction of exhaled nitric oxide (FeNO – are limited due to invasiveness or lack of specificity. The assessment of markers in peripheral blood might be a good alternative to study airway inflammation more specifically, compared to FeNO, and in a less invasive manner, compared to bronchoalveolar lavage, biopsies, or sputum induction. In addition, promising novel biomarkers are discovered in the field of breath metabolomics (eg, volatile organic compounds and (pharmacogenomics. Biomarker research in asthma is increasingly shifting from the assessment of the value of single biomarkers to multidimensional approaches in which the clinical value of a combination of various markers is studied. This could eventually lead to the development of a clinically applicable algorithm composed of various markers and clinical features to phenotype asthma and improve diagnosis and asthma management

  4. Mesenchymal stromal cell therapy in COPD: from bench to bedside

    Directory of Open Access Journals (Sweden)

    Antunes MA

    2017-10-01

    markers of inflammation. The present review summarizes and describes the more recent preclinical studies that have been published about MSC therapy for COPD/emphysema and discusses what has already been applied about MSCs treatment in COPD patients in the clinical setting. Keywords: emphysema, mesenchymal stromal cells, inflammation, remodeling, repair

  5. From bench to bedside: successful translational nanomedicine: highlights of the Third Annual Meeting of the American Academy of Nanomedicine.

    Science.gov (United States)

    Wei, Chiming; Liu, Nanhai; Xu, Pingyi; Heller, Mike; Tomalia, Donald A; Haynie, Donald T; Chang, Esther H; Wang, Kuan; Lee, Yoon-Sik; Lyubchenko, Yuri L; Bawa, Raj; Tian, Ryan; Hanes, Justin; Pun, Suzie; Meiners, Jens-Christian; Guo, Peixuan

    2007-12-01

    The Third Annual Meeting of the American Academy of Nanomedicine (AANM) was held at the University of California San Diego, in San Diego, California during September 7-8, 2007. The meeting was focused on successful translational nanomedicine: from bench to bedside. There were four keynote lectures and eight scientific symposiums in this meeting. The researchers and investigators reported the results and process of current nanomedicine research and approaches to clinical applications. The meeting provided exciting information for nanomedicine clinical-related researches and strategy for further development of nanomedicine research which will be benefits to clinical practice.

  6. Bench-to-bedside review: Rhabdomyolysis – an overview for clinicians

    Science.gov (United States)

    Huerta-Alardín, Ana L; Varon, Joseph; Marik, Paul E

    2005-01-01

    Rhabdomyolysis ranges from an asymptomatic illness with elevation in the creatine kinase level to a life-threatening condition associated with extreme elevations in creatine kinase, electrolyte imbalances, acute renal failure and disseminated intravascular coagulation. Muscular trauma is the most common cause of rhabdomyolysis. Less common causes include muscle enzyme deficiencies, electrolyte abnormalities, infectious causes, drugs, toxins and endocrinopathies. Weakness, myalgia and tea-colored urine are the main clinical manifestations. The most sensitive laboratory finding of muscle injury is an elevated plasma creatine kinase level. The management of patients with rhabdomyolysis includes early vigorous hydration. PMID:15774072

  7. Bench-to-bedside review: Dealing with increased intensive care unit staff turnover: a leadership challenge

    Science.gov (United States)

    Laporta, Denny P; Burns, Judy; Doig, Chip J

    2005-01-01

    Critical care leaders frequently must face challenging situations requiring specific leadership and management skills for which they are, not uncommonly, poorly prepared. Such a fictitious scenario was discussed at a Canadian interdisciplinary critical care leadership meeting, whereby increasing intensive care unit (ICU) staff turnover had led to problems with staff recruitment. Participants discussed and proposed solutions to the scenario in a structured format. The results of the discussion are presented. In situations such as this, the ICU leader should first define the core problem, its complexity, its duration and its potential for reversibility. These factors often reside within workload and staff support issues. Some examples of core problems discussed that are frequently associated with poor retention and recruitment are a lack of a positive team culture, a lack of a favorable ICU image, a lack of good working relationships between staff and disciplines, and a lack of specific supportive resources. Several tools or individuals (typically outside the ICU environment) are available to help determine the core problem. Once the core problem is identified, specific solutions can be developed. Such solutions often require originality and flexibility, and must be planned, with specific short-term, medium-term and long-term goals. The ICU leader will need to develop an implementation strategy for these solutions, in which partners who can assist are identified from within the ICU and from outside the ICU. It is important that the leader communicates to all stakeholders frequently as the process moves forward. PMID:16277732

  8. Bench-to-bedside review: leadership and conflict management in the intensive care unit.

    Science.gov (United States)

    Strack van Schijndel, Rob J M; Burchardi, Hilmar

    2007-01-01

    In the management of critical care units, leadership and conflict management are vital areas for the successful performance of the unit. In this article a practical approach to define competencies for leadership and principles and practices of conflict management are offered. This article is, by lack of relevant intensive care unit (ICU) literature, not evidence based, but it is the result of personal experience and a study of literature on leadership as well on conflicts and negotiations in non-medical areas. From this, information was selected that was recognisable to the authors and, thus, also seems to be useful knowledge for medical doctors in the ICU environment.

  9. Microvesicles in Atherosclerosis and Angiogenesis: From Bench to Bedside and Reverse

    Directory of Open Access Journals (Sweden)

    Lina Badimon

    2017-12-01

    Full Text Available Atherosclerosis (AT is a progressive chronic disease involving lipid accumulation, fibrosis, and inflammation in medium and large-sized arteries, and it is the main cause of cardiovascular disease (CVD. AT is caused by dyslipidemia and mediated by both innate and adaptive immune responses. Despite lipid-lowering drugs have shown to decrease the risk of cardiovascular events (CVEs, there is a significant burden of AT-related morbidity and mortality. Identification of subjects at increased risk for CVE as well as discovery of novel therapeutic targets for improved treatment strategies are still unmet clinical needs in CVD. Microvesicles (MVs, small extracellular plasma membrane particles shed by activated and apoptotic cells have been widely linked to the development of CVD. MVs from vascular and resident cells by facilitating exchange of biological information between neighboring cells serve as cellular effectors in the bloodstream and play a key role in all stages of disease progression. This article reviews the current knowledge on the role of MVs in AT and CVD. Attention is focused on novel aspects of MV-mediated regulatory mechanisms from endothelial dysfunction, vascular wall inflammation, oxidative stress, and apoptosis to coagulation and thrombosis in the progression and development of atherothrombosis. MV contribution to vascular remodeling is also discussed, with a particular emphasis on the effect of MVs on the crosstalk between endothelial cells and smooth muscle cells, and their role regulating the active process of AT-driven angiogenesis and neovascularization. This review also highlights the latest findings and main challenges on the potential prognostic, diagnostic, and therapeutic value of cell-derived MVs in CVD. In summary, MVs have emerged as new regulators of biological functions in atherothrombosis and might be instrumental in cardiovascular precision medicine; however, significant efforts are still needed to translate into

  10. Clearing up the hazy road from bench to bedside: A framework for integrating the fourth hurdle into translational medicine

    Directory of Open Access Journals (Sweden)

    John Jürgen H

    2008-09-01

    Full Text Available Abstract Background New products evolving from research and development can only be translated to medical practice on a large scale if they are reimbursed by third-party payers. Yet the decision processes regarding reimbursement are highly complex and internationally heterogeneous. This study develops a process-oriented framework for monitoring these so-called fourth hurdle procedures in the context of product development from bench to bedside. The framework is suitable both for new drugs and other medical technologies. Methods The study is based on expert interviews and literature searches, as well as an analysis of 47 websites of coverage decision-makers in England, Germany and the USA. Results Eight key steps for monitoring fourth hurdle procedures from a company perspective were determined: entering the scope of a healthcare payer; trigger of decision process; assessment; appraisal; setting level of reimbursement; establishing rules for service provision; formal and informal participation; and publication of the decision and supplementary information. Details are given for the English National Institute for Health and Clinical Excellence, the German Federal Joint Committee, Medicare's National and Local Coverage Determinations, and for Blue Cross Blue Shield companies. Conclusion Coverage determination decisions for new procedures tend to be less formalized than for novel drugs. The analysis of coverage procedures and requirements shows that the proof of patient benefit is essential. Cost-effectiveness is likely to gain importance in future.

  11. The rotator cuff: from bench to bedside. Developments in tissue engineering, surgical techniques and pathogenetic factors

    NARCIS (Netherlands)

    Longo, U.G.

    2012-01-01

    This thesis originates from the difficulties in the management of patients with rotator cuff tears. Since tendon healing rate is relatively slow compared with other connective tissues, we reviewed the available literature on tissue engineered biological augmentation for tendon healing, including

  12. Emerging hematological targets and therapy for cardiovascular disease: From bench to bedside

    Directory of Open Access Journals (Sweden)

    Ana Villegas

    2008-09-01

    Full Text Available Ana Villegas, Fernando A Gonzalez, Leopoldo Llorente, Santiago RedondoService of Hematology and Hemotherapy, Hospital Clinico Universitario San Carlos, Madrid, SpainAbstract: Atherosclerotic cardiovascular disease is the leading cause of death and a major part of its pathophysiology remains obscure. Some hematological targets have been related to the development and clinical outcome of this disease, especially soluble cytokines, leukocytes, red blood cells, hemostatic factors and platelets, and bone-marrow vascular progenitors. These emerging factors may be modulated by current antiatherosclerotic pharmacotherapy, target-designed novel drugs or progenitor cell therapy. The aim of current review article is to comprehensively review the role of these antiatherosclerotic targets and therapy.Keywords: atherosclerosis, blood, progenitor cells, cytokines, therapy

  13. Promising role for Gc-MAF in cancer immunotherapy: from bench to bedside

    OpenAIRE

    Saburi, Ehsan; Saburi, Amin; Ghanei, Mostafa

    2017-01-01

    Immunotherapy has been used for years in many types of cancer therapy. Recently, cancer immunotherapy has focused on mechanisms which can enhance the development of cell-mediated immunity. Anticancer medications are administered to inhibit immunosuppressive factors such as nagalase enzyme, which is produced by neoplastic cells and destroys macrophage activating factor (Gc-MAF). Anti-neoplastics medications can also enhance immune-cell activity against tumors. Such medications show great poten...

  14. New strategies to improve the efficacy of colorectal cancer vaccines: from bench to bedside.

    Science.gov (United States)

    Mocellin, Simone

    2006-12-01

    By exploiting a naturally occurring defense system, anticancer vaccination embodies an ideal non-toxic treatment capable of evoking tumor-specific immune responses that can ultimately recognize and kill colorectal cancer (CRC) cells. Despite the enormous theoretical potential of active specific immunotherapy, no vaccination regimen has achieved sufficient therapeutic efficacy necessary for clinical implementation. Nevertheless, several immunological advances have opened new avenues of research to decipher the biological code governing tumor immune responsiveness, and this is leading to the design of potentially more effective immunotherapeutic protocols. This review briefly summarizes the principles behind anti-CRC vaccination and describes the most promising immunological strategies that have been developed, which are expected to renew interest in this molecularly targeted anticancer approach.

  15. Bench-to-bedside translation of dendrimers: Reality or utopia? A concise analysis.

    Science.gov (United States)

    Mignani, Serge; Rodrigues, João; Tomas, Helena; Roy, René; Shi, Xiangyang; Majoral, Jean-Pierre

    2017-11-16

    Nanomedicine, which is an application of nanotechnologies in healthcare is developed to improve the treatments and lives of patients suffering from a range of disorders and to increase the successes of drug candidates. Within the nanotechnology universe, the remarkable unique and tunable properties of dendrimers have made them promising tools for diverse biomedical applications such as drug delivery, gene therapy and diagnostic. Up-to-date, very few dendrimers has yet gained regulatory approval for systemic administration, why? In this critical review, we briefly focus on the list of desired basic dendrimer requirements for decision-making purpose by the scientists (go/no-go decision), in early development stages, to become clinical candidates, and to move towards Investigational New Drugs (IND) application submission. In addition, the successful translation between research and clinic should be performed by the implementation of a simple roadmap to jump the 'valley of death' successfully. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Contrast agents and cardiac MR imaging of myocardial ischemia: from bench to bedside

    International Nuclear Information System (INIS)

    Croisille, Pierre; Revel, Didier; Saeed, Maythem

    2006-01-01

    This review paper presents, in the first part, the different classes of contrast media that are already used or are in development for cardiac magnetic resonance imaging. A classification of the different types of contrast media is proposed based on the distribution of the compounds in the body, their type of relaxivity and their potential affinity to particular molecules. In the second part, the different uses of the extracellular type of T1-enhancing contrast agent for myocardial imaging is covered from the detection of stable coronary artery disease to the detection and characterization of chronic infarction. A particular emphasis is placed on the clinical use of gadolinium-chelates, which are the universally used type of MRI contrast agent in the clinical routine. Both approaches, first-pass magnetic resonance imaging (FP-MRI) as well as delayed-enhanced magnetic resonance imaging (DE-MRI), are covered in the different situations of acute and chronic myocardial infarction. (orig.)

  17. Bioprosthetic Valve Fracture During Valve-in-valve TAVR: Bench to Bedside.

    Science.gov (United States)

    Saxon, John T; Allen, Keith B; Cohen, David J; Chhatriwalla, Adnan K

    2018-01-01

    Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) has been established as a safe and effective means of treating failed surgical bioprosthetic valves (BPVs) in patients at high risk for complications related to reoperation. Patients who undergo VIV TAVR are at risk of patient-prosthesis mismatch, as the transcatheter heart valve (THV) is implanted within the ring of the existing BPV, limiting full expansion and reducing the maximum achievable effective orifice area of the THV. Importantly, patient-prosthesis mismatch and high residual transvalvular gradients are associated with reduced survival following VIV TAVR. Bioprosthetic valve fracture (BVF) is as a novel technique to address this problem. During BPV, a non-compliant valvuloplasty balloon is positioned within the BPV frame, and a highpressure balloon inflation is performed to fracture the surgical sewing ring of the BPV. This allows for further expansion of the BPV as well as the implanted THV, thus increasing the maximum effective orifice area that can be achieved after VIV TAVR. This review focuses on the current evidence base for BVF to facilitate VIV TAVR, including initial bench testing, procedural technique, clinical experience and future directions.

  18. SPME as a promising tool in translational medicine and drug discovery: From bench to bedside.

    Science.gov (United States)

    Goryński, Krzysztof; Goryńska, Paulina; Górska, Agnieszka; Harężlak, Tomasz; Jaroch, Alina; Jaroch, Karol; Lendor, Sofia; Skobowiat, Cezary; Bojko, Barbara

    2016-10-25

    Solid phase microextraction (SPME) is a technology where a small amount of an extracting phase dispersed on a solid support is exposed to the sample for a well-defined period of time. The open-bed geometry and biocompatibility of the materials used for manufacturing of the devices makes it very convenient tool for direct extraction from complex biological matrices. The flexibility of the formats permits tailoring the method according the needs of the particular application. Number of studies concerning monitoring of drugs and their metabolites, analysis of metabolome of volatile as well as non-volatile compounds, determination of ligand-protein binding, permeability and compound toxicity was already reported. All these applications were performed in different matrices including biological fluids and tissues, cell cultures, and in living animals. The low invasiveness of in vivo SPME, ability of using very small sample volumes and analysis of cell cultures permits to address the rule of 3R, which is currently acknowledged ethical standard in R&D labs. In the current review systematic evaluation of the applicability of SPME to studies required to be conduct at different stages of drug discovery and development and translational medicine is presented. The advantages and challenges are discussed based on the examples directly showing given experimental design or on the studies, which could be translated to the models routinely used in drug development process. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Cytokines and Biologics in non-infectious autoimmune uveitis: Bench to Bedside

    Directory of Open Access Journals (Sweden)

    Rupesh Agrawal

    2014-01-01

    Full Text Available Intraocular inflammatory eye disease is one of the important causes of ocular morbidity. Even though the prevalence of uveitis is less common in relation to diabetic retinopathy, glaucoma or age related macular degeneration, the complexity and heterogeneity of the disease makes it more unique. Putative uveitogenic retinal antigens incite innate immunity by the process of antigen mimicry and have been shown to be associated in patients with intraocular inflammatory disease by numerous experimental studies. Laboratory diagnostic tools to aid the etiologic association in intraocular inflammatory disease have evolved over the last two decades and we are entering into an era of molecular diagnostic tests. Sophisticated novel technologies such as multiplex bead assays to assess biological signatures have revolutionized the management of complex refractory uveitis. Nevertheless, there is still a long way to go to establish the causal relationship between these biomarkers and specific uveitic entities. Experimental studies have shown the supreme role of infliximab in the management of Behcet′s disease. Despite significant experimental and case control studies, the deficiency of randomized clinical trials using these biologic agents has handicapped us in exploring them as a front line therapy in severe refractory uveitis. Studies still need to answer the safety of these potentially life threatening drugs in a selected group of patients and determine when to commence and for how long the treatment has to be given. This review article covers some basic concepts of cytokines in uveitis and their potential application for therapy in refractory uveitis.

  20. CAR-T cell therapy in gastrointestinal tumors and hepatic carcinoma: From bench to bedside.

    Science.gov (United States)

    Zhang, Qi; Zhang, Zimu; Peng, Meiyu; Fu, Shuyu; Xue, Zhenyi; Zhang, Rongxin

    2016-01-01

    The chimeric antigen receptor (CAR) is a genetically engineered receptor that combines a scFv domain, which specifically recognizes the tumor-specific antigen, with T cell activation domains. CAR-T cell therapies have demonstrated tremendous efficacy against hematologic malignancies in many clinical trials. Recent studies have extended these efforts to the treatment of solid tumors. However, the outcomes of CAR-T cell therapy for solid tumors are not as remarkable as the outcomes have been for hematologic malignancies. A series of hurdles has arisen with respect to CAR-T cell-based immunotherapy, which needs to be overcome to target solid tumors. The major challenge for CAR-T cell therapy in solid tumors is the selection of the appropriate specific antigen to demarcate the tumor from normal tissue. In this review, we discuss the application of CAR-T cells to gastrointestinal and hepatic carcinomas in preclinical and clinical research. Furthermore, we analyze the usefulness of several specific markers in the study of gastrointestinal tumors and hepatic carcinoma.

  1. Translating induced pluripotent stem cells from bench to bedside: application to retinal diseases.

    Science.gov (United States)

    Cramer, Alona O; MacLaren, Robert E

    2013-04-01

    Induced pluripotent stem cells (iPSc) are a scientific and medical frontier. Application of reprogrammed somatic cells for clinical trials is in its dawn period; advances in research with animal and human iPSc are paving the way for retinal therapies with the ongoing development of safe animal cell transplantation studies and characterization of patient- specific and disease-specific human iPSc. The retina is an optimal model for investigation of neural regeneration; amongst other advantageous attributes, it is the most accessible part of the CNS for surgery and outcome monitoring. A recent clinical trial showing a degree of visual restoration via a subretinal electronic prosthesis implies that even a severely degenerate retina may have the capacity for repair after cell replacement through potential plasticity of the visual system. Successful differentiation of neural retina from iPSc and the recent generation of an optic cup from human ESc invitro increase the feasibility of generating an expandable and clinically suitable source of cells for human clinical trials. In this review we shall present recent studies that have propelled the field forward and discuss challenges in utilizing iPS cell derived retinal cells as reliable models for clinical therapies and as a source for clinical cell transplantation treatment for patients suffering from genetic retinal disease.

  2. Traditional Chinese medicine for prevention and treatment of hepatocarcinoma: From bench to bedside

    Science.gov (United States)

    Hu, Bing; Wang, Shuang-Shuang; Du, Qin

    2015-01-01

    Traditional Chinese medicine (TCM) has played a positive role in the management of hepatocarcinoma. Hepatocarcinoma patients may present Qi-stagnation, damp-heat, blood stasis, Qi-deficiency, Yin-deficiency and other TCM syndromes (Zheng). Modern treatments such as surgery, transarterial chemoembolization (TACE) and high intensity focus ultrasound treatment would influence the manifestation of TCM syndromes. Herbs with traditional efficacy of tonifying Qi, blood and Yin, soothing liver-Qi stagnation, clearing heat and detoxifying and dissolving stasis, have been demonstrated to be potent to prevent hepatocarcinogenesis. TCM has been widely used in all aspects of integrative therapy in hepatocarcinoma, including surgical resection, liver transplantation, TACE, local ablative therapies and even as monotherapy for middle-advanced stage hepatocarcinoma. Clinical practices have confirmed that TCM is effective to alleviate clinical symptoms, improve quality of life and immune function, prevent recurrence and metastasis, delay tumor progression, and prolong survival time in hepatocarcinoma patients. The effective mechanism of TCM against hepatocarcinoma is related to inducing apoptosis, autophagy, anoikis and cell senescence, arresting cell cycle, regulating immune function, inhibiting metastasis and angiogenesis, reversing drug resistance and enhancing effects of chemotherapy. Along with the progress of research in this field, TCM will contribute more to the prevention and treatment of hepatocarcinoma. PMID:26019736

  3. Bench to bedside molecular functional imaging in translational cancer medicine: to image or to imagine?

    International Nuclear Information System (INIS)

    Mahajan, A.; Goh, V.; Basu, S.; Vaish, R.; Weeks, A.J.; Thakur, M.H.; Cook, G.J.

    2015-01-01

    Ongoing research on malignant and normal cell biology has substantially enhanced the understanding of the biology of cancer and carcinogenesis. This has led to the development of methods to image the evolution of cancer, target specific biological molecules, and study the anti-tumour effects of novel therapeutic agents. At the same time, there has been a paradigm shift in the field of oncological imaging from purely structural or functional imaging to combined multimodal structure–function approaches that enable the assessment of malignancy from all aspects (including molecular and functional level) in a single examination. The evolving molecular functional imaging using specific molecular targets (especially with combined positron-emission tomography [PET] computed tomography [CT] using 2- [ 18 F]-fluoro-2-deoxy-D-glucose [FDG] and other novel PET tracers) has great potential in translational research, giving specific quantitative information with regard to tumour activity, and has been of pivotal importance in diagnoses and therapy tailoring. Furthermore, molecular functional imaging has taken a key place in the present era of translational cancer research, producing an important tool to study and evolve newer receptor-targeted therapies, gene therapies, and in cancer stem cell research, which could form the basis to translate these agents into clinical practice, popularly termed “theranostics”. Targeted molecular imaging needs to be developed in close association with biotechnology, information technology, and basic translational scientists for its best utility. This article reviews the current role of molecular functional imaging as one of the main pillars of translational research. -- Highlights: •Molecular functional imaging (MFI) gives insight into the tumor biology and intratumoral heterogeneity. •It has potential role in identifying radiomic signatures associated with underlying gene-expression. •Radiomics can be used to create a road map

  4. Bone Marrow Aspirate Concentrate for Cartilage Defects of the Knee: From Bench to Bedside Evidence.

    Science.gov (United States)

    Cotter, Eric J; Wang, Kevin C; Yanke, Adam B; Chubinskaya, Susan

    2018-04-01

    Objective To critically evaluate the current basic science, translational, and clinical data regarding bone marrow aspirate concentrate (BMAC) in the setting of focal cartilage defects of the knee and describe clinical indications and future research questions surrounding the clinical utility of BMAC for treatment of these lesions. Design A literature search was performed using the PubMed and Ovid MEDLINE databases for studies in English (1980-2017) using keywords, including ["bone marrow aspirate" and "cartilage"], ["mesenchymal stem cells" and "cartilage"], and ["bone marrow aspirate" and "mesenchymal stem cells" and "orthopedics"]. A total of 1832 articles were reviewed by 2 independent authors and additional literature found through scanning references of cited articles. Results BMAC has demonstrated promising results in the clinical application for repair of chondral defects as an adjuvant procedure or as an independent management technique. A subcomponent of BMAC, bone marrow derived-mesenchymal stem cells (MSCs) possess the ability to differentiate into cells important for osteogenesis and chondrogenesis. Modulation of paracrine signaling is perhaps the most important function of BM-MSCs in this setting. In an effort to increase the cellular yield, authors have shown the ability to expand BM-MSCs in culture while maintaining phenotype. Conclusions Translational studies have demonstrated good clinical efficacy of BMAC both concomitant with cartilage restoration procedures, at defined time points after surgery, and as isolated injections. Early clinical data suggests BMAC may help stimulate a more robust hyaline cartilage repair tissue response. Numerous questions remain regarding BMAC usage, including cell source, cell expansion, optimal pathology, and injection timing and quantity.

  5. Tea phytochemicals for breast cancer prevention and intervention: From bench to bedside and beyond.

    Science.gov (United States)

    Sinha, Dona; Biswas, Jaydip; Nabavi, Seyed Mohammad; Bishayee, Anupam

    2017-10-01

    The National Cancer Institute of the United States had projected breast cancer as one of the topmost prevalent malignancies of 2016. It was estimated that in 2016, 246,660 new cases of invasive breast cancer were expected to be diagnosed in women in the US, along with 61,000 new cases of non-invasive (in situ) breast cancer. The heterogeneity of breast cancer accounts for its differential molecular subtyping. Recent incorporation of high throughput approaches helps early prognosis of breast cancer, but recurrence of the disease stands to be one of the most daunting fact behind non-availability of third line treatment. At this point of crisis, application of chemopreventive measures could possibly resolve the enigma of breast cancer. The world class beverage tea has proven its efficacy in ameliorating various genetic and epigenetic anomalies in breast cancer. Tea phytoconstituents are known to modulate myriad molecular events which include prominent regulators of intracellular signaling, such as phosphatidylinositide 3-kinase/protein kinase B/nuclear factor-κB, epidermal growth factor receptor, vascular endothelial growth factor, B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X protein in the development and progression of breast carcinoma. This review aims to encompass the detailed modulatory roles of tea phytochemicals, their analogs and nanoformulations against mammary carcinoma and the probability of using tea in therapeutic management of breast cancer. Finally, current limitations, challenges and future directions of tea and breast cancer research are also critically discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Synopsis on Managment Strategies for Neurodegenerative Disorders: Challenges from Bench to Bedside in Successful Drug Discovery and Development.

    Science.gov (United States)

    Bhat, Sheraz Ahmad; Kamal, Mohammad Amjad; Yarla, Nagendra Sastry; Ashraf, Ghulam Md

    2017-01-01

    The maintenance of health requires successful cell functioning, which in turn depends upon the proper and active conformation of proteins besides other biomolecules. However, occasionally these proteins may misfold and lead to the appearance and progression of protein conformational diseases. These diseases apart from others include several neurodegenerative disorders (NDDs) such as Alzheimer's disease, Parkinson disease, Huntington's disease, multiple sclerosis, amyotrophic lateral sclerosis, and other lesser known diseases. Although much knowledge has been gained, these NDDs still warrant advance research in the elucidation of their mechanisms as well as effective therapeutic interventions and proper management. There is an ever-growing and urgent need to improve the diagnosis and management of NDDs due to their devastating nature, serious social impact and neuropsychiatric symptoms. It is also envisioned that we may be able to encourage, develop, and strengthen the cell defenses against amyloid toxicity and prevent neuronal destruction and consequently neurodegeneration. In this review, the implications of protein misfolding and aggregation in NDDs are discussed along with some of the most recent findings on the curative and beneficial effects of natural molecules such as polyphenols. This paper also reviews the anti-aggregation and protective effects of some organic and peptidic compounds duly supported experimentally, as prospective future therapeutics for NDDs. The synopses presented in this review shall prove helpful in further understanding of the causes, cures and management of lethal NDDs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Current knowledge on alleviating Helicobacter pylori infections through the use of some commonly known natural products: bench to bedside

    Directory of Open Access Journals (Sweden)

    Malliga Raman Murali

    2014-09-01

    Full Text Available Helicobacter pylori, a spiral-shaped Gram-negative bacterium, has been classified as a class I carcinogen by the World Health Organization and recognized as the causative agent for peptic ulcers, duodenal ulcer, gastritis, mucosa-associated lymphoid tissue lymphomas, and gastric cancer. Owing to their alarming rate of drug resistance, eradication of H. pylori remains a global challenge. Triple therapy consisting of a proton pump inhibitor, clarithromycin, and either amoxicillin or metronidazole, is generally the recommended standard for the treatment of H. pylori infection. Complementary and alternative medicines have a long history in the treatment of gastrointestinal ailments and various compounds has been tested for anti-H. pylori activity both in vitro and in vivo; however, their successful use in human clinical trials is sporadic. Hence, the aim of this review is to analyze the role of some well-known natural products that have been tested in clinical trials in preventing, altering, or treating H. pylori infections. Whereas some in vitro and in vivo studies in the literature have demonstrated the successful use of a few potential natural products for the treatment of H. pylori-related infections, others indicate a need to consider natural products, with or without triple therapy, as a useful alternative in treating H. pylori-related infections. Thus, the reported mechanisms include killing of H. pylori urease inhibition, induction of bacterial cell damage, and immunomodulatory effect on the host immune system. Furthermore, both in vitro and in vivo studies have demonstrated the successful use of some potential natural products for the treatment of H. pylori-related infections. Nevertheless, the routine prescription of potential complementary and alternative medicines continues to be restrained, and evidence on the safety and efficacy of the active compounds remains a subject of ongoing debate.

  8. From Bench to Bedside: Understanding Stress-Obesity Research Within the Context of Translation to Improve Pediatric Behavioral Weight Management.

    Science.gov (United States)

    Sato, Amy F; Fahrenkamp, Amy J

    2016-06-01

    A growing body of literature suggests that stress, including chronic stress and acute physiologic stress reactivity, is one contributor to the development and maintenance of obesity in youth. Little has been done to apply the literature on stress and obesity risk to inform the development of pediatric behavioral weight control (BWC) interventions. The aims of this review are to (1) discuss research linking stress and pediatric obesity, (2) provide examples of the implications of the stress-obesity research for pediatric BWC development, and (3) propose that a mindfulness-based approach may be useful in targeting stress reduction within pediatric BWC. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Consequences of the 118A>G polymorphism in the OPRM1 gene: translation from bench to bedside?

    Directory of Open Access Journals (Sweden)

    Mura E

    2013-05-01

    Full Text Available Elisa Mura,1 Stefano Govoni,1 Marco Racchi,1 Valeria Carossa,1 Guglielmina Nadia Ranzani,2 Massimo Allegri,3,4 Ron HN van Schaik5 1Department of Drug Sciences, Centre of Excellence in Applied Biology, University of Pavia, Pavia, Italy; 2Department of Biology and Biotechnology, University of Pavia, Pavia, Italy; 3Pain Therapy Service, Foundation IRCCS San Matteo Hospital, Pavia, Italy; 4Department of Clinical, Surgical Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy; 5Department of Clinical Chemistry, Erasmus University Medical Center, Rotterdam, The Netherlands Abstract: The 118A>G single nucleotide polymorphism (SNP in the µ-opioid receptor (OPRM1 gene has been the most described variant in pharmacogenetic studies regarding opioid drugs. Despite evidence for an altered biological function encoded by this variant, this knowledge is not yet utilized clinically. The aim of the present review was to collect and discuss the available information on the 118A>G SNP in the OPRM1 gene, at the molecular level and in its clinical manifestations. In vitro biochemical and molecular assays have shown that the variant receptor has higher binding affinity for ß-endorphins, that it has altered signal transduction cascade, and that it has a lower expression compared with wild-type OPRM1. Studies using animal models for 118A>G have revealed a double effect of the variant receptor, with an apparent gain of function with respect to the response to endogenous opioids but a loss of function with exogenous administered opioid drugs. Although patients with this variant have shown a lower pain threshold and a higher drug consumption in order to achieve the analgesic effect, clinical experiences have demonstrated that patients carrying the variant allele are not affected by the increased opioid consumption in terms of side effects. Keywords: µ-opioid receptor, opioids, pharmacogenetics, pain, analgesia

  10. Distinct immune response in two MERS-CoV-infected patients: can we go from bench to bedside?

    Directory of Open Access Journals (Sweden)

    Emmanuel Faure

    Full Text Available One year after the occurrence of the first case of infection by the Middle East Respiratory Syndrome coronavirus (MERS-CoV there is no clear consensus on the best treatment to propose. The World Health Organization, as well as several other national agencies, are still working on different clinical approaches to implement the most relevant treatment in MERS-CoV infection. We compared innate and adaptive immune responses of two patients infected with MERS-CoV to understand the underlying mechanisms involved in the response and propose potential therapeutic approaches. Broncho-alveolar lavage (BAL of the first week and sera of the first month from the two patients were used in this study. Quantitative polymerase chain reaction (qRTPCR was performed after extraction of RNA from BAL cells of MERS-CoV infected patients and control patients. BAL supernatants and sera were used to assess cytokines and chemokines secretion by enzyme-linked immunosorbent assay. The first patient died rapidly after 3 weeks in the intensive care unit, the second patient still recovers from infection. The patient with a poor outcome (patient 1, compared to patient 2, did not promote type-1 Interferon (IFN, and particularly IFNα, in response to double stranded RNA (dsRNA from MERS-CoV. The absence of IFNα, known to promote antigen presentation in response to viruses, impairs the development of a robust antiviral adaptive Th-1 immune response. This response is mediated by IL-12 and IFNγ that decreases viral clearance; levels of both of these mediators were decreased in patient 1. Finally, we confirm previous in vitro findings that MERS-CoV can drive IL-17 production in humans. Host recognition of viral dsRNA determines outcome in the early stage of MERS-CoV infection. We highlight the critical role of IFNα in this initial stage to orchestrate a robust immune response and bring substantial arguments for the indication of early IFNα treatment during MERS-CoV infection.

  11. Pneumococcusuria: From bench to bedside.

    Science.gov (United States)

    Krishna, S; Sanjeevan, K V; Sudheer, A; Dinesh, K R; Kumar, A; Karim, S

    2012-01-01

    The present study highlights six cases of pneumococcusuria during the time period of May 2008 to May 2010. All the patients had a co-existing predisposing factor with the isolation of Streptococcus pneumoniae in urine. Five of the six patients having signs and symptoms of urinary tract infections (UTI) were treated and cured of the same. It becomes essential to consider pneumococcal UTI in the presence of clinical signs and symptoms associated with urinary tract abnormalities like hydronephrosis and renal stones. S. pneumoniae may be regarded as an emerging pathogen in UTI. Precise microbiological diagnosis must correlate with the clinical signs and symptoms for the administration of appropriate antibiotic therapy.

  12. Bench-to-bedside review: Treating acid–base abnormalities in the intensive care unit – the role of renal replacement therapy

    OpenAIRE

    Naka, Toshio; Bellomo, Rinaldo

    2004-01-01

    Acid–base disorders are common in critically ill patients. Metabolic acid–base disorders are particularly common in patients who require acute renal replacement therapy. In these patients, metabolic acidosis is common and multifactorial in origin. Analysis of acid–base status using the Stewart–Figge methodology shows that these patients have greater acidemia despite the presence of hypoalbuminemic alkalosis. This acidemia is mostly secondary to hyperphosphatemia, hyperlactatemia, and the accu...

  13. Bcl-2 family of proteins as drug targets for cancer chemotherapy: the long way of BH3 mimetics from bench to bedside.

    Science.gov (United States)

    Vela, Laura; Marzo, Isabel

    2015-08-01

    Bcl-2 proteins are key determinants in the life-death balance. In recent years, proteins in this family have been identified as drug targets in the design of new anti-tumor therapies. Advances in the knowledge of the mechanism of action of anti-apoptotic and pro-apoptotic members of the Bcl-2 family have enabled the development of the so-called 'BH3 mimetics'. These compounds act by inhibiting anti-apoptotic proteins of the family, imitating the function of the BH3-only subset of pro-apoptotic members. Combinations of BH3-mimetics with anti-tumor drugs are being evaluated in both preclinical models and clinical trials. Recent advances in these approaches will be reviewed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Present and future breast cancer management--bench to bedside and back: a positioning paper of academia, regulatory authorities and pharmaceutical industry.

    Science.gov (United States)

    Bartsch, R; Frings, S; Marty, M; Awada, A; Berghoff, A S; Conte, P; Dickin, S; Enzmann, H; Gnant, M; Hasmann, M; Hendriks, H R; Llombart, A; Massacesi, C; von Minckwitz, G; Penault-Llorca, F; Scaltriti, M; Yarden, Y; Zwierzina, H; Zielinski, C C

    2014-04-01

    Insights into tumour biology of breast cancer have led the path towards the introduction of targeted treatment approaches; still, breast cancer-related mortality remains relatively high. Efforts in the field of basic research revealed new druggable targets which now await validation within the context of clinical trials. Therefore, questions concerning the optimal design of future studies are becoming even more pertinent. Aspects such as the ideal end point, availability of predictive markers to identify the optimal cohort for drug testing, or potential mechanisms of resistance need to be resolved. An expert panel representing the academic community, the pharmaceutical industry, as well as European Regulatory Authorities met in Vienna, Austria, in November 2012, in order to discuss breast cancer biology, identification of novel biological targets and optimal drug development with the aim of treatment individualization. This article summarizes statements and perspectives provided by the meeting participants.

  15. From bench to bedside: What do we know about hormone receptor-positive and human epidermal growth factor receptor 2-positive breast cancer?

    Science.gov (United States)

    Wu, Victoria Shang; Kanaya, Noriko; Lo, Chiao; Mortimer, Joanne; Chen, Shiuan

    2015-09-01

    Breast cancer is a heterogeneous disease. Thanks to extensive efforts from research scientists and clinicians, treatment for breast cancer has advanced into the era of targeted medicine. With the use of several well-established biomarkers, such as hormone receptors (HRs) (i.e., estrogen receptor [ER] and progesterone receptor [PgR]) and human epidermal growth factor receptor-2 (HER2), breast cancer patients can be categorized into multiple subgroups with specific targeted treatment strategies. Although therapeutic strategies for HR-positive (HR+) HER2-negative (HER2-) breast cancer and HR-negative (HR-) HER2-positive (HER2+) breast cancer are well-defined, HR+ HER2+ breast cancer is still an overlooked subgroup without tailored therapeutic options. In this review, we have summarized the molecular characteristics, etiology, preclinical tools and therapeutic options for HR+ HER2+ breast cancer. We hope to raise the attention of both the research and the medical community on HR+ HER2+ breast cancer, and to advance patient care for this subtype of disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Evolution of regorafenib from bench to bedside in colorectal cancer: Is it an attractive option or merely a “me too” drug?

    Directory of Open Access Journals (Sweden)

    Goel G

    2018-03-01

    Full Text Available Gaurav Goel Division of Hematology-Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA Abstract: Colorectal cancer (CRC is a major public health problem in the United States with an estimated 50,260 deaths in 2017. Over the past two decades, several agents have been approved by the US Food and Drug Administration (FDA for the treatment of patients with metastatic CRC (mCRC. Regorafenib (BAY 73-4506 is a small-molecule multikinase inhibitor that was approved for the treatment of mCRC in 2012. This agent is a novel oral diphenylurea-based multikinase inhibitor that is active against several angiogenic receptor tyrosine kinases (RTKs; VEGFR-1, VEGFR-2, VEGFR-3, TIE-2, oncogenic RTKs (c-KIT, RET, stromal RTKs (PDGFR-B, FGFR-1, and intracellular signaling kinases (c-RAF/RAF-1, BRAF, BRAFV600E. Preclinical studies have documented its broad-spectrum activity against different solid tumor types including CRC. Phase I studies showed that it had an acceptable safety profile in advanced refractory mCRC. A subsequent Phase III trial (CORRECT demonstrated significant clinical efficacy of regorafenib in patients with refractory or advanced mCRC, which eventually led to its FDA approval for the treatment of mCRC in September 2012. However, the drug was associated with significant toxicity in clinical practice when administered at the approved doses, which necessitated a thorough reassessment of its dosing schedule and toxicity profile. This review summarizes the development of regorafenib from the initial preclinical studies to the Phase III trials and critically examines the current clinical space occupied by regorafenib in the treatment of mCRC, at 5 years after its initial FDA approval. Keywords: regorafenib, multikinase inhibitor, angiogenesis, colorectal cancer, colon cancer, stivarga, BAY 73-4506

  17. Neuroimaging in psychiatry: from bench to bedside

    Directory of Open Access Journals (Sweden)

    David E Linden

    2009-12-01

    Full Text Available This perspective considers the present and the future role of different neuroimaging techniques in the field of psychiatry. After identifying shortcomings of the mainly symptom-focussed diagnostic processes and treatment decisions in modern psychiatry, we suggest topics where neuroimaging methods have the potential to help. These include better understanding of the pathophysiology, improved diagnoses, assistance in therapeutic decisions and the supervision of treatment success by direct assessment of improvement in disease-related brain functions. These different questions are illustrated by examples from neuroimaging studies, with a focus on severe mental and neuropsychiatric illnesses such as schizophrenia, depression and dementia. Despite all reservations addressed in the article, we are optimistic, that neuroimaging has a huge potential with regard to the above-mentioned questions. We expect that neuroimaging will play an increasing role in the future refinement of the diagnostic process and aid in the development of new therapies in the field of psychiatry.

  18. Technological innovations: from bench to bedside.

    Science.gov (United States)

    Robert, Glenn

    2009-09-01

    The NHS is perceived to be slower than other healthcare systems in adopting innovative technologies that can deliver patient benefits. This article summarises what is known about the role of nurses in assimilating such innovations into clinical care, and outlines the challenges facing nurse leaders.

  19. STEM CELL IMAGING: FROM BENCH TO BEDSIDE

    Science.gov (United States)

    Nguyen, Patricia K.; Riegler, Johannes; Wu, Joseph C.

    2014-01-01

    Although cellular therapies hold great promise for the treatment of human disease, results from several initial clinical trials have not shown a level of efficacy required for their use as a first line therapy. Here we discuss how in vivo molecular imaging has helped identify barriers to clinical translation and potential strategies that may contribute to successful transplantation and improved outcomes, with a focus on cardiovascular and neurological diseases. We conclude with a perspective on the future role of molecular imaging in defining safety and efficacy for stem cell clinical implementation. PMID:24702995

  20. Helicobacter pylori: From Bench to Bedside

    Directory of Open Access Journals (Sweden)

    N Chiba

    1997-01-01

    Full Text Available With the exponential increase in research in the field of Helicobacter pylori a paradigm shift has occurred. It is now recognized that H pylori is a chronic infection of the stomach causing inflammation. Some patients remain asymptomatic, while others may develop dyspepsia, duodenal or gastric ulcer, gastric cancer or a mucosa-associated lymphoid tissue lymphoma. However, the role of H pylori in contributing to nonulcer dyspepsia or nonsteroidal anti-inflammatory drug gastropathy remains controversial. An effective vaccine against H pylori is years away. Major interest has focused on the questions "who should be investigated and therefore treated" and "what is the latest gold standard for eradication of H pylori"? In Europe, guidelines have been developed to help the practitioner answer these important questions. Canadian guidelines will soon be available. For persons with known peptic ulcer disease there should be unequivocal acceptance that the good clinical practice of eradicating H pylori will result in substantial savings in health care expenses. The original 'classical triple therapy' (bismuth, metronidazole and tetracycline [BMT] has now been surpassed by the combination of a proton pump inhibitor (PPI plus two antibiotics (metronidazole plus clarithromycin; amoxicillin plus clarithromycin; or amoxicillin plus metronidazole, each given twice a day for one week. In Canada, the regimen of omeprazole plus one antibiotic (amoxicillin or clarithromycin was approved recently but gives an eradication rate that is lower than the current target of 90%. According to the European (Mäastricht recommendations, if a single treatment attempt with PPI plus two antibiotics fails, PPI plus BMT is recommended.

  1. Beyond the VAD: Human Factors Engineering for Mechanically Assisted Circulation in the 21st Century.

    Science.gov (United States)

    Throckmorton, Amy L; Patel-Raman, Sonna M; Fox, Carson S; Bass, Ellen J

    2016-06-01

    Thousands of ventricular assist devices (VADs) currently provide circulatory support to patients worldwide, and dozens of heart pump designs for adults and pediatric patients are under various stages of development in preparation for translation to clinical use. The successful bench-to-bedside development of a VAD involves a structured evaluation of possible system states, including human interaction with the device and auxiliary component usage in the hospital or home environment. In this study, we review the literature and present the current landscape of preclinical design and assessment, decision support tools and procedures, and patient-centered therapy. Gaps of knowledge are identified. The study findings support the need for more attention to user-centered design approaches for medical devices, such as mechanical circulatory assist systems, that specifically involve detailed qualitative and quantitative assessments of human-device interaction to mitigate risk and failure. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  2. Dashboard systems: implementing pharmacometrics from bench to bedside.

    Science.gov (United States)

    Mould, Diane R; Upton, Richard N; Wojciechowski, Jessica

    2014-09-01

    In recent years, there has been increasing interest in the development of medical decision-support tools, including dashboard systems. Dashboard systems are software packages that integrate information and calculations about therapeutics from multiple components into a single interface for use in the clinical environment. Given the high cost of medical care, and the increasing need to demonstrate positive clinical outcomes for reimbursement, dashboard systems may become an important tool for improving patient outcome, improving clinical efficiency and containing healthcare costs. Similarly the costs associated with drug development are also rising. The use of model-based drug development (MBDD) has been proposed as a tool to streamline this process, facilitating the selection of appropriate doses and making informed go/no-go decisions. However, complete implementation of MBDD has not always been successful owing to a variety of factors, including the resources required to provide timely modeling and simulation updates. The application of dashboard systems in drug development reduces the resource requirement and may expedite updating models as new data are collected, allowing modeling results to be available in a timely fashion. In this paper, we present some background information on dashboard systems and propose the use of these systems both in the clinic and during drug development.

  3. The Virtual Liver Network: systems understanding from bench to bedside.

    Science.gov (United States)

    Henney, Adriano; Coaker, Hannah

    2014-01-01

    Adriano Henney speaks to Hannah Coaker, Commissioning Editor. After achieving a PhD in medicine and spending many years in academic research in the field of cardiovascular disease, Adriano Henney was recruited by Zeneca Pharmaceuticals from a British Heart Foundation Senior Fellowship, where he led the exploration of new therapeutic approaches in atherosclerosis, specifically focusing on his research interests in vascular biology. Following the merger with Astra to form AstraZeneca, Henney became responsible for exploring strategic improvements to the company's approaches to pharmaceutical target identification and the reduction of attrition in early development, directing projects across research sites and across functional project teams in the USA, Sweden and the UK. This resulted in the creation of a new multidisciplinary department that focused on pathway mapping, modeling and simulation and supporting projects across research and development, which evolved into the establishment of the practice of systems biology within the company. Here, projects prototyped the application of mechanistic disease-modeling approaches in order to support the discovery of innovative new medicines, such as Iressa®. Since leaving AstraZeneca, Henney has continued his interest in systems biology, synthetic biology and systems medicine through his company, Obsidian Biomedical Consulting Ltd. He now directs a major €50 million German national flagship program – the Virtual Liver Network – which is currently the largest systems biology program in Europe.

  4. Emerging therapies for Parkinson's disease: from bench to bedside.

    Science.gov (United States)

    Tarazi, F I; Sahli, Z T; Wolny, M; Mousa, S A

    2014-11-01

    The prevalence of Parkinson's disease (PD) increases with age and is projected to increase in parallel to the rising average age of the population. The disease can have significant health-related, social, and financial implications not only for the patient and the caregiver, but for the health care system as well. While the neuropathology of this neurodegenerative disorder is fairly well understood, its etiology remains a mystery, making it difficult to target therapy. The currently available drugs for treatment provide only symptomatic relief and do not control or prevent disease progression, and as a result patient compliance and satisfaction are low. Several emerging pharmacotherapies for PD are in different stages of clinical development. These therapies include adenosine A2A receptor antagonists, glutamate receptor antagonists, monoamine oxidase inhibitors, anti-apoptotic agents, and antioxidants such as coenzyme Q10, N-acetyl cysteine, and edaravone. Other emerging non-pharmacotherapies include viral vector gene therapy, microRNAs, transglutaminases, RTP801, stem cells and glial derived neurotrophic factor (GDNF). In addition, surgical procedures including deep brain stimulation, pallidotomy, thalamotomy and gamma knife surgery have emerged as alternative interventions for advanced PD patients who have completely utilized standard treatments and still suffer from persistent motor fluctuations. While several of these therapies hold much promise in delaying the onset of the disease and slowing its progression, more pharmacotherapies and surgical interventions need to be investigated in different stages of PD. It is hoped that these emerging therapies and surgical procedures will strengthen our clinical armamentarium for improved treatment of PD. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. [Alpha-melanocyte-stimulating hormone. From bench to bedside].

    Science.gov (United States)

    Böhm, M; Luger, T A

    2010-06-01

    Alpha-melanocyte-stimulating hormone (alpha-MSH) is a tridecapeptide that is produced by the skin itself from the precursor proopiomelanocortin. It crucially mediates ultraviolet light-induced tanning after binding to melanocortin-1 receptors (MC-1R) expressed on the surface of epidermal melanocytes. The potent pigment-inducing and also cytoprotective actions of alpha-MSH are the rationale for the performance of first phase II clinical trials with Nle4-D-Phe7-alpha-MSH (NDP-alpha-MSH), a subcutaneously administered synthetic and superpotent alpha-MSH analogue, in patients with photodermatoses such as erythropoietic protoporphyria. Since alpha-MSH has shown promising anti-inflammatory and antifibrotic properties in numerous preclinical studies, it will be most interesting to evaluate these effects in further clinical pilot studies with NDP-alpha-MSH. In addition to alpha-MSH analogues, truncated tripeptides such as KDPT which do not bind to MC-1R but have sustained anti-inflammatory properties are currently emerging as another novel therapeutic strategy in dermatology.

  6. Tubulins as therapeutic targets in cancer: from bench to bedside

    Czech Academy of Sciences Publication Activity Database

    Katsetos, C.D.; Dráber, Pavel

    2012-01-01

    Roč. 18, č. 19 (2012), s. 2778-2792 ISSN 1381-6128 R&D Projects: GA ČR GA204/09/1777; GA AV ČR KAN200520701; GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : microtubules * tubulin * cancer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.311, year: 2012

  7. From Bench to Bedside: Translating the Prolactin/Vasoinhibin Axis

    Directory of Open Access Journals (Sweden)

    Jakob Triebel

    2017-12-01

    Full Text Available The prolactin/vasoinhibin axis defines an endocrine system, in which prolactin (PRL and vasoinhibins regulate blood vessel growth and function, the secretion of other hormones, inflammatory and immune processes, coagulation, and behavior. The core element of the PRL/vasoinhibin axis is the generation of vasoinhibins, which consists in the proteolytic cleavage of their precursor molecule PRL. Vasoinhibins can interact with multiple different partners to mediate their effects in various tissues and anatomical compartments, indicating their pleiotropic nature. Based on accumulating knowledge about the PRL/vasoinhibin axis, two clinical trials were initiated, in which vasoinhibin levels are the target of therapeutic interventions. One trial investigates the effect of levosulpiride, a selective dopamine D2-receptor antagonist, on retinal alterations in patients with diabetic macular edema and retinopathy. The rationale of this trial is that the levosulpiride-induced hyperprolactinemia resulting in increased retinal vasoinhibins could lead to beneficiary outcomes in terms of a vasoinhibin-mediated antagonization of diabetes-induced retinal alterations. Another trial investigated the effect of bromocriptine, a dopamine D2-receptor agonist, for the treatment of peripartum cardiomyopathy. The rationale of treatment with bromocriptine is the inhibition of vasoinhibin generation by substrate depletion to prevent detrimental effects on the myocardial microvascularization. The trial demonstrated that bromocriptine treatment was associated with a high rate of left ventricular recovery and low morbidity and mortality. Therapeutic interventions into the PRL/vasoinhibin axis bear the risk of side effects in the areas of blood coagulation, blood pressure, and alterations of the mental state.

  8. Evaluating genomic tests from bench to bedside: a practical framework

    Directory of Open Access Journals (Sweden)

    Lin Jennifer S

    2012-10-01

    Full Text Available Abstract The development of genomic tests is one of the most significant technological advances in medical testing in recent decades. As these tests become increasingly available, so does the need for a pragmatic framework to evaluate the evidence base and evidence gaps in order to facilitate informed decision-making. In this article we describe such a framework that can provide a common language and benchmarks for different stakeholders of genomic testing. Each stakeholder can use this framework to specify their respective thresholds for decision-making, depending on their perspective and particular needs. This framework is applicable across a broad range of test applications and can be helpful in the application and communication of a regulatory science for genomic testing. Our framework builds upon existing work and incorporates principles familiar to researchers involved in medical testing (both diagnostic and prognostic generally, as well as those involved in genomic testing. This framework is organized around six phases in the development of genomic tests beginning with marker identification and ending with population impact, and highlights the important knowledge gaps that need to be filled in establishing the clinical relevance of a test. Our framework focuses on the clinical appropriateness of the four main dimensions of test research questions (population/setting, intervention/index test, comparators/reference test, and outcomes rather than prescribing a hierarchy of study designs that should be used to address each phase.

  9. Targeted alpha therapy for melanoma : from bench to bedside

    International Nuclear Information System (INIS)

    Allen, B.J.; Rizvi, S.M.A.; Li, Y.; Tsui, W.; Douglas, S.; Raja, C.; Graham, P.; Smart, R.; Butler, P.; Kearsley, J.; Thompson, J.

    2001-01-01

    Full text: The control of metastatic melanoma remains an elusive objective. Targeted alpha therapy (TAT) offers a new approach to the control of micrometastases and regression of tumours. The alpha emitting immunoconjugate (AIC) against malignant melanoma has been prepared by chelating Bi-213 to the anti-melanoma antibody 9.2.27, and injected locally at 2 d post-inoculation of 1.5 million melanoma cells, or intralesionally into skin tumours. Human subjects receive 50μCi intralesional dose, escalating to 1 mCi. The clearances from the tumour, kidneys and bladder are monitored by a NaI detector that detects the 440 keV gamma ray. Blood samples and tumour photographs are taken at O. 2 and 4 weeks; tumours are excised at 4 weeks. Isolated cancer cells and preangiogenic cell clusters in mice can be eliminated with 25 μCi local AIC injection, and intra-lesional injections of 100 μCi are sufficient to completely regress melanomas with volumes up to 300 mm 3 without side-effects. Systemic TAT with a single administration is less effective with 100% growth delay of tumours observed, and ∼20% complete inhibition. The clinical TAT trial for recurrent subcutaneous melanoma has been approved by the NSW Radiation Advisory Committee and the SES Human Ethics Committee. In a world first phase 1 study, the first 5 subjects have been treated by intralesional injection, 3 at 50 μCi, and 2 at 150 μCi. All subjects having unchanged blood profiles at 2 and 4 weeks post-therapy. Tumour volumes appear little changed. However, histology of a 3 cm melanoma shows that almost complete cell kill occurred at 150 μCi, with only a few small cell clusters surviving. Local TAT inhibits tumourogenesis and intralesional TAT completely regresses melanoma in mice. Intralesional TAT for melanoma in human subjects is non-toxic so far and appears to be a promising modality. The ultimate objective is to apply systemic TAT for the control of melanoma micrometastases. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  10. Food addiction and obesity: evidence from bench to bedside.

    Science.gov (United States)

    Liu, Yijun; von Deneen, Karen M; Kobeissy, Firas H; Gold, Mark S

    2010-06-01

    Obesity has become a major health problem and epidemic. However, much of the current debate has been fractious and etiologies of obesity have been attributed to eating behavior or fast food, personality issues, depression, addiction, or genetics. One of the interesting new hypotheses for epidemic obesity is food addiction, which is associated with both substance-related disorder and eating disorder. Accumulating evidences have shown that there are many shared neural and hormonal pathways as well as distinct differences that may help researchers find why certain individuals overeat and become obese. Functional neuroimaging studies have further revealed that good or great smelling, looking, tasting, and reinforcing food has characteristics similar to that of drugs of abuse. Many of the brain changes reported for hedonic eating and obesity are also seen in various forms of addictions. Most importantly, overeating and obesity may have an acquired drive like drug addiction with respect to motivation and incentive; craving, wanting, and liking occur after early and repeated exposures to stimuli. The acquired drive for great food and relative weakness of the satiety signal would cause an imbalance between the drive and hunger/reward centers in the brain and their regulation.

  11. From bench to bedside: the social orientation of research leaders

    NARCIS (Netherlands)

    van der Weijden, I.C.M.; Verbree, M.; van den Besselaar, P.A.A.

    2012-01-01

    This paper answers five questions about the societal impact of research. Firstly, we examine the opinions of research group leaders about the increased emphasis on societal impact, i.e. does it influence their research agenda, communication with stakeholders, and knowledge dissemination to

  12. Intensive Sleep Re-Training: From Bench to Bedside

    Directory of Open Access Journals (Sweden)

    Leon Lack

    2017-03-01

    Full Text Available Intensive sleep re-training is a promising new therapy for chronic insomnia. Therapy is completed over a 24-h period during a state of sleep deprivation. Improvements of sleep and daytime impairments are comparable to the use of stimulus control therapy but with the advantage of a rapid reversal of the insomnia. The initial studies have been laboratory based and not readily accessible to the patient population. However, new smart phone technology, using a behavioral response to external stimuli as a measure of sleep/wake state instead of EEG determination of sleep, has made this new therapy readily available. Technological improvements are still being made allowing the therapy to provide further improvements in the effectiveness of Intensive Sleep Re-training.

  13. Experimental models of brain ischemia: a review of techniques, magnetic resonance imaging and investigational cell-based therapies

    Directory of Open Access Journals (Sweden)

    Alessandra eCanazza

    2014-02-01

    Full Text Available Stroke continues to be a significant cause of death and disability worldwide. Although major advances have been made in the past decades in prevention, treatment and rehabilitation, enormous challenges remain in the way of translating new therapeutic approaches from bench to bedside. Thrombolysis, while routinely used for ischemic stroke, is only a viable option within a narrow time window. Recently, progress in stem cell biology has opened up avenues to therapeutic strategies aimed at supporting and replacing neural cells in infarcted areas. Realistic experimental animal models are crucial to understand the mechanisms of neuronal survival following ischemic brain injury and to develop therapeutic interventions. Current studies on experimental stroke therapies evaluate the efficiency of neuroprotective agents and cell-based approaches using primarily rodent models of permanent or transient focal cerebral ischemia. In parallel, advancements in imaging techniques permit better mapping of the spatial-temporal evolution of the lesioned cortex and its functional responses. This review provides a condensed conceptual review of the state of the art of this field, from models and magnetic resonance imaging techniques through to stem cell therapies.

  14. Bench to Bedside: Understanding Symptom Response to Acupuncture Treatment and Designing a Successful Acupuncture Treatment Program

    Science.gov (United States)

    2016-10-01

    non -periodical, one-time publications. Nothing to Report Other publications, conference papers, and presentations. An overview of our Army work...alcoholic beverages/day and were less likely to be current smokers 1. In 2013, our study team competed the Army funded project “The Effectiveness of... never ) to 7 (always). The WAI has strong published support for reliability and validity. The WAI was administered to both subjects and clinicians

  15. Emerging therapies for the management of decompensated heart failure: from bench to bedside.

    Science.gov (United States)

    deGoma, Emil M; Vagelos, Randall H; Fowler, Michael B; Ashley, Euan A

    2006-12-19

    While pharmaceutical innovation has been highly successful in reducing mortality in chronic heart failure, this has not been matched by similar success in decompensated heart failure syndromes. Despite outstanding issues over definitions and end points, we argue in this paper that an unprecedented wealth of pharmacologic innovation may soon transform the management of these challenging patients. Agents that target contractility, such as cardiac myosin activators and novel adenosine triphosphate-dependent transmembrane sodium-potassium pump inhibitors, provide inotropic support without arrhythmogenic increases in cytosolic calcium or side effects of more traditional agents. Adenosine receptor blockade may improve glomerular filtration and diuresis by exerting a direct beneficial effect on glomerular blood flow while vasopressin antagonists promote free water excretion without compromising renal function and may simultaneously inhibit myocardial remodeling. Urodilatin, the renally synthesized isoform of atrial natriuretic peptide, may improve pulmonary congestion via vasodilation and enhanced diuresis. Finally, metabolic modulators such as perhexiline may optimize myocardial energy utilization by shifting adenosine triphosphate production from free fatty acids to glucose, a unique and conceptually appealing approach to the management of heart failure. These advances allow optimism not only for the advancement of our understanding and management of decompensated heart failure syndromes but for the translational research effort in heart failure biology in general.

  16. Nanotechnology and nanomedicine for healthcare: challenges in translating innovations from bench to bedside.

    Science.gov (United States)

    Bellare, Jayesh R

    2011-02-01

    Nanobioengineering has led to development of human health care products of diagnostic as well as therapeutic nature. Safety and regulatory issues require extensive in vitro and in vivo trials for human applications in near future.

  17. Bench to Bedside: Understanding Symptom Response to Acupuncture Treatment and Designing a Successful Acupuncture Treatment Program

    Science.gov (United States)

    2017-09-01

    P). Characteristic Age-year +/- SD Female sex -N(%) Self reported Race-N(% of total) White Black or African-American Asian American Indian...completing scale construction for remaining psychosocial and clinical measures, and_ determining the relationships between dose of acupuncture and effect...recommended for funding: Aim 2: Complete scale construction for remaining psychosocial and clinical measures, Aim 3: Determine the relationships between dose

  18. Surgery course evaluation. Expectations of medical students in surgery rotation? From bench to bedside.

    Science.gov (United States)

    Sniadecki, Marcin; Kiszkielis, Marta; Wydra, Dariusz

    2011-10-01

    The curriculum of the Medical Faculty is a result of a compromise between the need to upgrade and extend the material and the immutability of study duration. In result of reduction of time for acquisition of basic practical skills. THE AIM OF THE STUDY was to evaluate the current curriculum by students and answer the question: What are the students' expectations of teaching surgery? and to compare the opinion in two academic centers in Poland. The survey embraced 85 students of the Medical Faculty of IV (25.9%), V (22.35%) and VI (51.75%) year of the Medical University of Gdańsk and VI year students of the Pomeranian University of Szczecin (PUM--34%). Students completed a 19-item questionnaire, send by e-mail. Questions were closed (yes / no or grades 1-5) with the option of opinion adding to each item. The Statistica (version 9) package for calculations was used. Differences with ppay attention to the lack of affordable learning materials. Students expect a full "non-corridor" utilization of classes, learn and practice the basic and most frequent activities at the patient. They are dissatisfied with the current training methods, and would be taught in a diverse and active way.

  19. Peptide receptor chemoradionuclide therapy in small cell carcinoma: from bench to bedside

    International Nuclear Information System (INIS)

    Lewin, Jeremy; Rao, Aparna; Mileshkin, Linda; Cullinane, Carleen; Akhurst, Tim; Eu, Peter; Waldeck, Kelly; Watkins, D.N.; Hicks, Rodney J.

    2015-01-01

    Small cell cancers (SmCC), whether pulmonary (SCLC) or extrapulmonary, have a poor prognosis unless localised at diagnosis. Given a proportion of these cancers express somatostatin receptor subtype 2 (SSTR2), we aimed to investigate the efficacy of targeted peptide receptor chemoradionuclide therapy (PRCRT). In this preclinical study, we used a SCLC xenograft mouse model with high expression of SSTR2 to investigate the effect of peptide receptor radionuclide therapy (PRRT) with chemotherapy compared to either alone. We subsequently explored the clinical utility in a patient with SmCC with high SSTR expression treated with PRCRT. Robust expression of SSTR2 in NCI-H69 SCLC xenografts was documented by 68 Ga-DOTA-octreotate (GaTate) (tumour to background uptake ratio = 35). The combination of PRRT using 177 Lu-DOTA-octreotate (LuTate) with carboplatin/etoposide (C/E) chemotherapy was more effective than either LuTate or C/E alone for regression of the NCI-H69 model (p value < 0.05). PRCRT was associated with significantly prolonged survival versus PRRT (p value = 0.0001) or chemotherapy alone (p value = 0.0058). In the subsequent case study, a patient with relapsed SmCC with high SSTR2 expression on GaTate PET underwent PRCRT with radiosensitising etoposide with evidence of a complete metabolic response for 4 months. Given the limited treatment options in this setting, PRCRT is a promising therapeutic option for SSTR2-expressing SmCC. (orig.)

  20. Mammalian target of rapamycin inhibition in polycystic kidney disease: From bench to bedside

    Directory of Open Access Journals (Sweden)

    Hyun-Jung Kim

    2012-09-01

    Full Text Available Autosomal dominant polycystic kidney disease (ADPKD is the most common life-threatening hereditary disease in the USA resulting in chronic kidney disease and the need for dialysis and transplantation. Approximately 85% of cases of ADPKD are caused by a mutation in the Pkd1 gene that encodes polycystin-1, a large membrane receptor. The Pkd1 gene mutation results in abnormal proliferation in tubular epithelial cells, which plays a crucial role in cyst development and/or growth in PKD. Activation of the proliferative mammalian target of rapamycin (mTOR signaling pathway has been demonstrated in polycystic kidneys from rodents and humans. mTOR inhibition with sirolimus or everolimus decreases cysts in most animal models of PKD including Pkd1 and Pkd2 gene deficient orthologous models of human disease. On the basis of animal studies, human studies were undertaken. Two large randomized clinical trials published in the New England Journal of Medicine of everolimus or sirolimus in ADPKD patients were very unimpressive and associated with a high side-effect profile. Possible reasons for the unimpressive nature of the human studies include their short duration, the high drop-out rate, suboptimal dosing, lack of randomization of “fast” and “slow progressors” and the lack of correlation between kidney size and kidney function in ADPKD. The future of mTOR inhibition in ADPKD is discussed.

  1. Tethered capsule OCT endomicroscopy: from bench to bedside at the primary care office (Conference Presentation)

    Science.gov (United States)

    Gora, Michalina J.; Simmons, Leigh H.; Tiernan, Aubrey R.; Grant, Catriona N.; Soomro, Amna R.; Walker Corkery, Elizabeth S.; Rosenberg, Mireille; Metlay, Joshua P.; Tearney, Guillermo J.

    2016-03-01

    We have developed a swallowable tethered capsule OCT endomicroscopy (TCE) device that acquires microscopic images of the entire esophagus in unsedated subjects in a quick and comfortable procedure. To test its capabilities of TCE to become a population-based screening device, we conducted a clinical feasibility study in the primary care office. The swept-source OCT imaging system (1310nm central wavelength, 40kHz A-line rate, 10um axial resolution) together with the tethered capsule catheter (11x25mm capsule attached to a flexible tether) were transferred to the PCP office where unsedated patients scheduled for non-urgent PCP visits swallowed the capsule and microscopic OCT images of the entire esophagus were collected. After the whole length of the esophagus was imaged, the catheter was disinfected for reuse. Twenty subjects were enrolled in the study, including nine female and eleven male. All TCE procedures were performed by a nurse and lasted in average 5:42 ± 1:54 min. High-resolution images of the esophagus were obtained in all seventeen subjects that swallowed the capsule. Our clinical experience in this cohort, subject feedback, image quality, and technological adaptations for efficient utilization in this setting will be presented. The ease and simplicity of the procedure combined with high quality of the images demonstrate the potential for this technology to become a population-based screening device. Technology limitations and future development guided by findings from this initial experience will be discussed with the goal of effectively translating TCE to the outpatient primary care setting.

  2. Bench to Bedside: Future Therapies For Treatment Of Anemia In Patients With Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    KM Murali

    2017-10-01

    Full Text Available The link between chronic kidney disease (CKD and anemia has been known for over 180 years ever since it was highlighted by the legendary Richard Bright. The key etiological factors responsible for anemia due to renal disease were identified in the 1950s as relative deficiency of erythropoietin and reduced red cell survival as well as abnormalities in iron metabolism. This knowledge was not translated to therapeutics for the next three decades and red cell transfusions were the main-stay of treatment of renal anemia till recombinant human erythropoietin (rHuEPO was introduced in the 1980s. Recurrent transfusions, in addition to causing HLA sensitization, frequently resulted in iron overload with subsequent parenchymal iron deposition and organ dysfunction - a well-known scenario in the pre-erythropoetin era and use of iron chelation therapy was a feasible therapeutic option in long-term dialysis patients. This situation changed dramatically with the widespread clinical use of erythropoiesis stimulating agents (ESA, and polar opposite to the iron overload problems, most patient on erythropoietin therapy required oral or parenteral iron supplements to replenish iron stores for optimal erythropoiesis. Over the last three decades developments in molecular engineering lead to the modification of the original rHuEPO to longer acting analogues such as darbepoetin (Aranesp ® and methoxy polyethylene glycol-epoetin beta (Mircera ® and a raft of EPO biosimilars. In India, where the cost of medications constrains the universal access to ESA therapy, biosimilar erythropoetins offer a relative advantage in that they cost less than half the price of the premium brands. Nevertheless, the progress in clinically prescribed ESA therapy since the discovery of rHuEPO has resulted from modest modification of existing knowledge rather than a revolutionary break from convention. Over the last few years newer molecules capable of revolutionizing the therapy of renal anemia have been or are being developed and tested in clinical trials. Some of these have the potential to become realistic treatment options in the near future.

  3. Bench to Bedside: From the Science to the Practice of Addiction Medicine.

    Science.gov (United States)

    Levounis, Petros

    2016-03-01

    The current understanding of addiction is based on a biopsychosocial model of illness. From a neurobiological perspective, addiction can be seen as the hijacking of the pleasure-reward pathways of the brain with a concomitant weakening of its executive function. The fundamental model has been expanded to include newer concepts such as multiple levels of severity of illness, motivational circuitry, and anti-reward pathways. These neurobiological concepts can explain some of the successes and failures of addiction treatment in the second half of the 20th century and the beginning of the 21st century. Psychosocial interventions (primarily cognitive behavior therapy, mutual help groups, and motivational interviewing) and pharmacological treatments (such as agonists, antagonists, and partial agonists) form the basis of addiction treatment today.

  4. From bench to bedside and to health policies (and back: ethics in translational research

    Directory of Open Access Journals (Sweden)

    Carlo Petrini

    2014-03-01

    Full Text Available INTRODUCTION: The medical aim of translational research is to smooth the transition of discoveries made through basic research from the laboratory bench to their diagnostic or therapeutic applications for patients. These applications may be extended to current clinical practice and to health policies. AIM: The converse is also important: health policies should provide a point of departure when identifying research priorities. Translational research poses the same ethical problems as trials with human subjects - albeit in different ways. One of the more significant problems is the risk for participants in trials: it is thus necessary to ensure that the risks to which these subjects are exposed are not out of proportion to the expected benefits. DISCUSSION: Translational research does not require new ethical principles, but existing biomedical principles need to be adjusted to the specific context. The well-being of participants should always be the primary objective; these persons should never be considered as means for the advancement of knowledge or for the improvement of applications.

  5. Great expectations – Epigenetics and the meandering path from bench to bedside

    Directory of Open Access Journals (Sweden)

    Sophia J. Häfner

    2016-06-01

    Full Text Available Making quick promises of major biomedical breakthroughs based on exciting discoveries at the bench is tempting. But the meandering path from fundamental science to life-saving clinical applications can be fraught with many hurdles. Epigenetics, the study of potentially heritable changes of gene function without modification of the underlying DNA sequence, has dominated the biological research field during the last decade and encountered a large public success. Driven by the unfolding of molecular biology and recent technological progress, the term has evolved significantly and shifted from a conceptual framework to a mechanistic understanding. This shift was accompanied by much hype and raised high hopes that epigenetics might hold both the key to deciphering the molecular underpinning of complex, non-Mendelian diseases and offer novel therapeutic approaches for a large panel of pathologies. However, while exciting reports of biological phenomena involving DNA methylation and histone modifications fill up the scientific literature, the realistic clinical applications of epigenetic medicines remain somewhat blurry. Here, we discuss the state of the art and speculate how epigenetics might contribute to prognostic and therapy approaches in the future.

  6. Great expectations - Epigenetics and the meandering path from bench to bedside

    DEFF Research Database (Denmark)

    Häfner, Sophia J; Lund, Anders H

    2016-01-01

    Making quick promises of major biomedical breakthroughs based on exciting discoveries at the bench is tempting. But the meandering path from fundamental science to life-saving clinical applications can be fraught with many hurdles. Epigenetics, the study of potentially heritable changes of gene...... function without modification of the underlying DNA sequence, has dominated the biological research field during the last decade and encountered a large public success. Driven by the unfolding of molecular biology and recent technological progress, the term has evolved significantly and shifted from....... However, while exciting reports of biological phenomena involving DNA methylation and histone modifications fill up the scientific literature, the realistic clinical applications of epigenetic medicines remain somewhat blurry. Here, we discuss the state of the art and speculate how epigenetics might...

  7. Stromal-Epithelial Interactions and Tamoxifen-Sensitivity: A Bench-to-Bedside Model of Chemoprevention

    National Research Council Canada - National Science Library

    Rowell, Craig

    2008-01-01

    .... Understanding of changes to the genetic as well as broader biochemical constituents of individual cells or cell types may have greater influence in our ability to detect and or track cancer development...

  8. Regulatory challenges for autologous tissue engineered products on their way from bench to bedside in Europe.

    Science.gov (United States)

    Ram-Liebig, Gouya; Bednarz, Juergen; Stuerzebecher, Burkard; Fahlenkamp, Dirk; Barbagli, Guido; Romano, Giuseppe; Balsmeyer, Ulf; Spiegeler, Maria-Elsa; Liebig, Soeren; Knispel, Helmut

    2015-03-01

    Since the late eighties of last century the high potential of tissue engineered products (TEP)s has been shown for the treatment of various diseases and many scientific publications appeared in this field. However, only few products reached the market since. Development of TEPs is a promising but owing to its novelty a very challenging task that requires experts in this still developing field as well as ample financial resources. This paper summarises relevant regulatory challenges during quality, preclinical and clinical development of autologous TEPs in Europe. Selected strategies on how to manage major issues are presented, together with some examples from the development of an autologous TEP for urethroplasty. Considering these aspects may help other investigators with potential strategies during the development of novel TEPs. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Induced Pluripotent Stem Cell-Derived Red Blood Cells and Platelet Concentrates: From Bench to Bedside.

    Science.gov (United States)

    Focosi, Daniele; Amabile, Giovanni

    2017-12-27

    Red blood cells and platelets are anucleate blood components indispensable for oxygen delivery and hemostasis, respectively. Derivation of these blood elements from induced pluripotent stem (iPS) cells has the potential to develop blood donor-independent and genetic manipulation-prone products to complement or replace current transfusion banking, also minimizing the risk of alloimmunization. While the production of erythrocytes from iPS cells has challenges to overcome, such as differentiation into adult-type phenotype that functions properly after transfusion, platelet products are qualitatively and quantitatively approaching a clinically-applicable level owing to advances in expandable megakaryocyte (MK) lines, platelet-producing bioreactors, and novel reagents. Guidelines that assure the quality of iPS cells-derived blood products for clinical application represent a novel challenge for regulatory agencies. Considering the minimal risk of tumorigenicity and the expected significant demand of such products, ex vivo production of iPS-derived blood components can pave the way for iPS translation into the clinic.

  10. (188)Re-SSS/Lipiodol: Development of a Potential Treatment for HCC from Bench to Bedside.

    Science.gov (United States)

    Lepareur, Nicolas; Ardisson, Valérie; Noiret, Nicolas; Garin, Etienne

    2012-01-01

    Hepatocellular carcinoma (HCC) is the 5th most common tumour worldwide and has a dark prognosis. For nonoperable cases, metabolic radiotherapy with Lipiodol labelled with β-emitters is a promising therapeutic option. The Comprehensive Cancer Centre Eugène Marquis and the National Graduate School of Chemistry of Rennes (ENSCR) have jointly developed a stable and efficient labelling of Lipiodol with rhenium-188 (E(βmax) = 2.1 MeV) for the treatment of HCC. The major "milestones" of this development, from the first syntheses to the recent first injection in man, are described.

  11. Peptide receptor chemoradionuclide therapy in small cell carcinoma: from bench to bedside

    Energy Technology Data Exchange (ETDEWEB)

    Lewin, Jeremy; Rao, Aparna; Mileshkin, Linda [Division of Hematology and Medical Oncology, East Melbourne, VIC (Australia); Cullinane, Carleen [Division of Cancer Research, East Melbourne, VIC (Australia); The University of Melbourne, Sir Peter MacCallum Department of Oncology, Melbourne, VIC (Australia); Akhurst, Tim; Eu, Peter [Centre for Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Waldeck, Kelly [Division of Cancer Research, East Melbourne, VIC (Australia); Watkins, D.N. [Monash University, Monash Institute of Medical Research, Clayton, VIC (Australia); Hicks, Rodney J. [Centre for Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); The University of Melbourne, Sir Peter MacCallum Department of Oncology, Melbourne, VIC (Australia)

    2015-01-15

    Small cell cancers (SmCC), whether pulmonary (SCLC) or extrapulmonary, have a poor prognosis unless localised at diagnosis. Given a proportion of these cancers express somatostatin receptor subtype 2 (SSTR2), we aimed to investigate the efficacy of targeted peptide receptor chemoradionuclide therapy (PRCRT). In this preclinical study, we used a SCLC xenograft mouse model with high expression of SSTR2 to investigate the effect of peptide receptor radionuclide therapy (PRRT) with chemotherapy compared to either alone. We subsequently explored the clinical utility in a patient with SmCC with high SSTR expression treated with PRCRT. Robust expression of SSTR2 in NCI-H69 SCLC xenografts was documented by {sup 68}Ga-DOTA-octreotate (GaTate) (tumour to background uptake ratio = 35). The combination of PRRT using {sup 177}Lu-DOTA-octreotate (LuTate) with carboplatin/etoposide (C/E) chemotherapy was more effective than either LuTate or C/E alone for regression of the NCI-H69 model (p value < 0.05). PRCRT was associated with significantly prolonged survival versus PRRT (p value = 0.0001) or chemotherapy alone (p value = 0.0058). In the subsequent case study, a patient with relapsed SmCC with high SSTR2 expression on GaTate PET underwent PRCRT with radiosensitising etoposide with evidence of a complete metabolic response for 4 months. Given the limited treatment options in this setting, PRCRT is a promising therapeutic option for SSTR2-expressing SmCC. (orig.)

  12. Mitochondrial function and tissue vitality: bench-to-bedside real-time optical monitoring system

    Science.gov (United States)

    Mayevsky, Avraham; Walden, Raphael; Pewzner, Eliyahu; Deutsch, Assaf; Heldenberg, Eitan; Lavee, Jacob; Tager, Salis; Kachel, Erez; Raanani, Ehud; Preisman, Sergey; Glauber, Violete; Segal, Eran

    2011-06-01

    Background: The involvement of mitochondria in pathological states, such as neurodegenerative diseases, sepsis, stroke, and cancer, are well documented. Monitoring of nicotinamide adenine dinucleotide (NADH) fluorescence in vivo as an intracellular oxygen indicator was established in 1950 to 1970 by Britton Chance and collaborators. We use a multiparametric monitoring system enabling assessment of tissue vitality. In order to use this technology in clinical practice, the commercial developed device, the CritiView (CRV), is tested in animal models as well as in patients. Methods and Results: The new CRV enables the optical monitoring of four different parameters, representing the energy balance of various tissues in vivo. Mitochondrial NADH is measured by surface fluorometry/reflectometry. In addition, tissue microcirculatory blood flow, tissue reflectance and oxygenation are measured as well. The device is tested both in vitro and in vivo in a small animal model and in preliminary clinical trials in patients undergoing vascular or open heart surgery. In patients, the monitoring is started immediately after the insertion of a three-way Foley catheter (urine collection) to the patient and is stopped when the patient is discharged from the operating room. The results show that monitoring the urethral wall vitality provides information in correlation to the surgical procedure performed.

  13. The 18-kDa mitochondrial translocator protein in gliomas: from the bench to bedside.

    OpenAIRE

    Janczar, Karolina; Su, Zhangjie; Raccagni, Isabella; Anfosso, Andrea; Kelly, Charlotte; Durrenberger, Pascal F; Gerhard, Alexander; Roncaroli, Federic

    2015-01-01

    The 18-kDa mitochondrial translocator protein (TSPO) is known to be highly expressed in several types of cancer, including gliomas, whereas expression in normal brain is low. TSPO functions in glioma are still incompletely understood. The TSPO can be quantified pre-operatively with molecular imaging making it an ideal candidate for personalized treatment of patient with glioma. Studies have proposed to exploit the TSPO as a transporter of chemotherapics to selectively target tumour cells in t...

  14. Cell therapy from bench to bedside: Hepatocytes from fibroblasts - the truth and myth of transdifferentiation.

    Science.gov (United States)

    Sanal, Madhusudana Girija

    2015-06-07

    Hepatocyte transplantation is an alternative to liver transplantation in certain disorders such as inherited liver diseases and liver failure. It is a relatively less complicated surgical procedure, and has the advantage that it can be repeated several times if unsuccessful. Another advantage is that hepatocytes can be isolated from partly damaged livers which are not suitable for liver transplantation. Despite these advantages hepatocyte transplantation is less popular. Important issues are poor engraftment of the transplanted cells and the scarcity of donor hepatocytes. Generation of "hepatocyte like cells"/iHeps from embryonic stem cells (ES) and induced pluripotent stem cells (iPSCs) by directed differentiation is an emerging solution to the latter issue. Direct conversation or trans-differentiation of fibroblasts to "hepatocyte like cells" is another way which is, being explored. However this method has several inherent and technical disadvantages compared to the directed differentiation from ES or iPSC. There are several methods claiming to be "highly efficient" for generating "highly functional" "hepatocyte like cells". Currently different groups are working independently and coming up with differentiation protocols and each group claiming an advantage for their protocol. Directed differentiation protocols need to be designed, compared, analyzed and tweaked systematically and logically than empirically. There is a need for a well-coordinated global initiative comparable to the Human Genome Project to achieve this goal in the near future.

  15. Physical mechanism and modeling of heat generation and transfer in magnetic fluid hyperthermia through Néelian and Brownian relaxation: a review.

    Science.gov (United States)

    Suriyanto; Ng, E Y K; Kumar, S D

    2017-03-23

    Current clinically accepted technologies for cancer treatment still have limitations which lead to the exploration of new therapeutic methods. Since the past few decades, the hyperthermia treatment has attracted the attention of investigators owing to its strong biological rationales in applying hyperthermia as a cancer treatment modality. Advancement of nanotechnology offers a potential new heating method for hyperthermia by using nanoparticles which is termed as magnetic fluid hyperthermia (MFH). In MFH, superparamagnetic nanoparticles dissipate heat through Néelian and Brownian relaxation in the presence of an alternating magnetic field. The heating power of these particles is dependent on particle properties and treatment settings. A number of pre-clinical and clinical trials were performed to test the feasibility of this novel treatment modality. There are still issues yet to be solved for the successful transition of this technology from bench to bedside. These issues include the planning, execution, monitoring and optimization of treatment. The modeling and simulation play crucial roles in solving some of these issues. Thus, this review paper provides a basic understanding of the fundamental and rationales of hyperthermia and recent development in the modeling and simulation applied to depict the heat generation and transfer phenomena in the MFH.

  16. Molecular biology from bench-to-bedside - which colorectal cancer patients should be referred for genetic counselling and risk assessment

    DEFF Research Database (Denmark)

    Jensen, Lars Henrik; Dysager, Lars; Lindebjerg, Jan

    2010-01-01

    Lynch syndrome is associated with deficiency of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2. However, most MLH1 deficient tumours are sporadic in origin, and they can be identified if harbouring a BRAF V600E mutation or hypermethylation of the MLH1 gene promoter. The aim of this study...... (PMS2 were negative in 29 cases (10%). DNA quality allowed BRAF analysis in 27 of these with 14 mutations and 13 wild-type. DNA quality allowed methylation analysis in 11 of the 13 BRAF wild-type, and all but one were methylated. Subsequently, Lynch syndrome could...... was to validate our previously suggested clinically applicable strategy based on molecular characteristics for identifying which patients to refer for genetic counselling. The strategy was validated in an unselected cohort of 287 colorectal cancer patients. All tumours were tested for MLH1, PMS2, MSH2 and MSH6...

  17. From Bench to Bedside: Researchers of NIH’s Clinical Center | NIH MedlinePlus the Magazine

    Science.gov (United States)

    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [1.5 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  18. From Bench to Bedside: Attempt to Evaluate Repositioning of Drugs in the Treatment of Metastatic Small Cell Lung Cancer (SCLC)

    Science.gov (United States)

    Lohinai, Zoltan; Dome, Peter; Szilagyi, Zsuzsa; Ostoros, Gyula; Moldvay, Judit; Hegedus, Balazs

    2016-01-01

    Backgrounds Based on in vitro data and results of a recent drug repositioning study, some medications approved by the FDA for the treatment of various non-malignant disorders were demonstrated to have anti-SCLC activity in preclinical models. The aim of our study is to confirm whether use of these medications is associated with survival benefit. Methods Consecutive patients with pathologically confirmed, stage 4 SCLC were analyzed in this retrospective study. Patients that were prescribed statins, aspirin, clomipramine (tricyclic antidepressant; TCA), selective serotonin reuptake inhibitors (SSRIs), doxazosin or prazosin (α1-adrenergic receptor antagonists; ADRA1) were identified. Results There were a total of 876 patients. Aspirin, statins, SSRIs, ADRA1, and TCA were administered in 138, 72, 20, 28, and 5 cases, respectively. A statistically significant increase in median OS was observed only in statin-treated patients when compared to those not receiving any of the aforementioned medications (OS, 8.4 vs. 6.1 months, respectively; p = 0.002). The administration of SSRIs, aspirin, and ADRA1 did not result in a statistically significant OS benefit (median OS, 8.5, 6.8, and 6.0 months, respectively). The multivariate Cox model showed that, besides age and ECOG PS, radiotherapy was an independent survival predictor (Hazard Ratio, 2.151; 95% confidence interval, 1.828–2.525; p <0.001). Conclusions Results of drug repositioning studies using only preclinical data or small numbers of patients should be treated with caution before application in the clinic. Our data demonstrated that radiotherapy appears to be an independent survival predictor in stage 4 SCLC, therefore confirming the results of other prospective and retrospective studies. PMID:26735301

  19. From Bench to Bedside: Attempt to Evaluate Repositioning of Drugs in the Treatment of Metastatic Small Cell Lung Cancer (SCLC.

    Directory of Open Access Journals (Sweden)

    Zoltan Lohinai

    Full Text Available Based on in vitro data and results of a recent drug repositioning study, some medications approved by the FDA for the treatment of various non-malignant disorders were demonstrated to have anti-SCLC activity in preclinical models. The aim of our study is to confirm whether use of these medications is associated with survival benefit.Consecutive patients with pathologically confirmed, stage 4 SCLC were analyzed in this retrospective study. Patients that were prescribed statins, aspirin, clomipramine (tricyclic antidepressant; TCA, selective serotonin reuptake inhibitors (SSRIs, doxazosin or prazosin (α1-adrenergic receptor antagonists; ADRA1 were identified.There were a total of 876 patients. Aspirin, statins, SSRIs, ADRA1, and TCA were administered in 138, 72, 20, 28, and 5 cases, respectively. A statistically significant increase in median OS was observed only in statin-treated patients when compared to those not receiving any of the aforementioned medications (OS, 8.4 vs. 6.1 months, respectively; p = 0.002. The administration of SSRIs, aspirin, and ADRA1 did not result in a statistically significant OS benefit (median OS, 8.5, 6.8, and 6.0 months, respectively. The multivariate Cox model showed that, besides age and ECOG PS, radiotherapy was an independent survival predictor (Hazard Ratio, 2.151; 95% confidence interval, 1.828-2.525; p <0.001.Results of drug repositioning studies using only preclinical data or small numbers of patients should be treated with caution before application in the clinic. Our data demonstrated that radiotherapy appears to be an independent survival predictor in stage 4 SCLC, therefore confirming the results of other prospective and retrospective studies.

  20. The Genetic Intersection of Neurodevelopmental Disorders and Shared Medical Comorbidities – Relations that Translate from Bench to Bedside

    Directory of Open Access Journals (Sweden)

    Jamsine Plummer

    2016-08-01

    Full Text Available Most psychiatric disorders are considered neurodevelopmental, and the associated genes often are expressed in tissues outside of the brain. This suggests a biological relatedness with medical co-occurrences that could have broad clinical implications for diagnosis and patient management over a lifetime. A qualitative integration of public data from genetic consortia of psychiatric disorders and medical comorbidities explores the question of whether genetically associated psychiatric illnesses present with co-occurring disturbances can be used to define specific mental-physical health relations. Novel patterns of gene-disorder relations appear with approximately one-third of conservatively defined, consortia-generated candidate risk genes with multiple psychiatric diagnoses. Moreover, nearly as many genes overlap with non-psychiatric phenotypes, including cardiovascular, renal, respiratory and metabolic disturbances. While the landscape of genetic risk will change as study populations are expanded and biological confirmations accrue, the current relationships suggest that a mostly siloed perspective of gene relatedness to one categorical psychiatric diagnosis is not clinically useful. The future holds the promise that once candidates are fully validated, genome screening and mutation identification will bring more precision for predicting the risk for complex health conditions. Our view is that as genetic data is refined, continuing to decipher a shared pattern of genetic risk for brain and peripheral organ pathophysiology is not simply an academic exercise. Rather, determining relatedness will impact predictions of multifaceted health risks, patient treatment and management.

  1. Mechanical engineering department technical review

    International Nuclear Information System (INIS)

    Carr, R.B.; Denney, R.M.

    1981-01-01

    The Mechanical Engineering Department Technical Review is published to: (1) inform the readers of various technical activities within the department, (2) promote exchange of ideas, and (3) give credit to the personnel who are achieving the results. The report is formatted into two parts: technical acievements and publication abstracts. The first is divided into eight sections, one for each division in the department providing the reader with the names of the personnel and the division accomplishing the work

  2. Mechanical Engineering Department. Technical review

    Energy Technology Data Exchange (ETDEWEB)

    Simecka, W.B.; Condouris, R.A.; Talaber, C. (eds.)

    1980-01-01

    The Mechanical Engineering Department Technical Review is published to (1) inform the readers of various technical activities within the Department, (2) promote exchange of ideas, and (3) give credit to the personnel who are achieving the results. The report is formatted into two parts: technical achievements and publication abstracts. The first is divided into eight sections, one for each Division in the Department providing the reader with the names of the personnel and the Division accomplishing the work.

  3. Mechanical Engineering Department Technical Review

    International Nuclear Information System (INIS)

    Carr, R.B.; Denney, R.M.

    1981-01-01

    The Mechanical Engineering Department Technical Review is published to inform readers of various technical activities within the Department, promote exchange of ideas, and give credit to personnel who are achieving the results. The report is presented in two parts: technical achievements and publication abstracts. The first is divided into seven sections, each of which reports on an engineering division and its specific activities related to nuclear tests, nuclear explosives, weapons, energy systems, engineering sciences, magnetic fusion, and materials fabrication

  4. Mechanical Engineering Department. Technical review

    International Nuclear Information System (INIS)

    Simecka, W.B.; Condouris, R.A.; Talaber, C.

    1980-01-01

    The Mechanical Engineering Department Technical Review is published to (1) inform the readers of various technical activities within the Department, (2) promote exchange of ideas, and (3) give credit to the personnel who are achieving the results. The report is formatted into two parts: technical achievements and publication abstracts. The first is divided into eight sections, one for each Division in the Department providing the reader with the names of the personnel and the Division accomplishing the work

  5. BOOK REVIEWS: Quantum Mechanics: Fundamentals

    Science.gov (United States)

    Whitaker, A.

    2004-02-01

    This review is of three books, all published by Springer, all on quantum theory at a level above introductory, but very different in content, style and intended audience. That of Gottfried and Yan is of exceptional interest, historical and otherwise. It is a second edition of Gottfried’s well-known book published by Benjamin in 1966. This was written as a text for a graduate quantum mechanics course, and has become one of the most used and respected accounts of quantum theory, at a level mathematically respectable but not rigorous. Quantum mechanics was already solidly established by 1966, but this second edition gives an indication of progress made and changes in perspective over the last thirty-five years, and also recognises the very substantial increase in knowledge of quantum theory obtained at the undergraduate level. Topics absent from the first edition but included in the second include the Feynman path integral, seen in 1966 as an imaginative but not very useful formulation of quantum theory. Feynman methods were given only a cursory mention by Gottfried. Their practical importance has now been fully recognised, and a substantial account of them is provided in the new book. Other new topics include semiclassical quantum mechanics, motion in a magnetic field, the S matrix and inelastic collisions, radiation and scattering of light, identical particle systems and the Dirac equation. A topic that was all but totally neglected in 1966, but which has flourished increasingly since, is that of the foundations of quantum theory. John Bell’s work of the mid-1960s has led to genuine theoretical and experimental achievement, which has facilitated the development of quantum optics and quantum information theory. Gottfried’s 1966 book played a modest part in this development. When Bell became increasingly irritated with the standard theoretical approach to quantum measurement, Viki Weisskopf repeatedly directed him to Gottfried’s book. Gottfried had devoted a

  6. Mechanical Engineering Department technical review

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R.B.; Abrahamson, L.; Denney, R.M.; Dubois, B.E (eds.)

    1982-01-01

    Technical achievements and publication abstracts related to research in the following Divisions of Lawrence Livermore Laboratory are reported in this biannual review: Nuclear Fuel Engineering; Nuclear Explosives Engineering; Weapons Engineering; Energy Systems Engineering; Engineering Sciences; Magnetic Fusion Engineering; and Material Fabrication. (LCL)

  7. Skin mechanical properties and modeling: A review.

    Science.gov (United States)

    Joodaki, Hamed; Panzer, Matthew B

    2018-04-01

    The mechanical properties of the skin are important for various applications. Numerous tests have been conducted to characterize the mechanical behavior of this tissue, and this article presents a review on different experimental methods used. A discussion on the general mechanical behavior of the skin, including nonlinearity, viscoelasticity, anisotropy, loading history dependency, failure properties, and aging effects, is presented. Finally, commonly used constitutive models for simulating the mechanical response of skin are discussed in the context of representing the empirically observed behavior.

  8. Mechanisms of radioprotection - a review

    International Nuclear Information System (INIS)

    Copeland, E.S.

    1978-01-01

    Theories of radiation protection can be considered at both the molecular and biochemical-physiological levels. Four molecular level protection hypotheses, radical scavenging, hydrogen transfer reactions, the mixed disulfide hypothesis and the endogenous non-protein sulfhydryl hypothesis, probably describe different aspects of the actual protection mechanism, although each has inconsistencies. At the biochemical-physiological level, hypothermia induction and biochemical shock may be involved in protection of the organism against radiation induced damage and death. It is most likely that no single mechanism can account for the protection offered by a radioprotective drug. Certain compounds may operate primarily by means of physiological effects resulting in hypoxia or hypothermia in critical tissues. Others may operate primarily by influencing the intrinsic radiosensitivity of target molecules by causing localized radical scavenging or by donating a hydrogen atom. Metabolic effects such as biochemical shock, release of endogenous non-protein sulfhydryls, induction of structural changes in target molecules or delay in DNA synthesis and cell division are also possible mechanisms for radioprotection. (author)

  9. Review of heavy ion reaction mechanisms

    International Nuclear Information System (INIS)

    Ngo, C.

    1986-04-01

    We review some of the many aspects of heavy-ion reaction mechanisms observed at bombarding energies smaller than approximately 50 MeV/u that is to say in what is called the low bombarding energy domain and the intermediate bombarding energy domain. We emphasize the results concerning the use of very heavy projectiles which has led to the observation of new mechanisms

  10. Shooting mechanisms in Nature : A systematic review

    NARCIS (Netherlands)

    Sakes, A.; van der Wiel, M.; Henselmans, P.W.J.; van Leeuwen, J.L.; Dodou, D.; Breedveld, P.

    2016-01-01

    Background
    In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these

  11. ERG review of waste package corrosion mechanisms

    International Nuclear Information System (INIS)

    Geisert, R.E.

    1988-01-01

    The Engineering Review Group (ERG) was established by the Office of Nuclear Waste Isolation (ONWI) to help evaluate engineering-related issues in the US Department of Energy's nuclear waste repository program. The ERG reviewed the waste package corrosion mechanisms. This report documents the ERG's comments and recommendations on these subjects and the ONWI response to the specific points raised by the ERG. 1 ref

  12. Mechanisms of beryl flotation: a literature review

    International Nuclear Information System (INIS)

    Torem, M.L.

    1988-01-01

    This paper shows a review about the investigations that have been done on the mechanisms of flotation of beryl and its dependence in relation to the presence of fluoride species. It is also analised the anionic flotation of the mineral and the effect of cations in the pulp of flotation. (author) [pt

  13. Osteoarthritis year in review 2015: mechanics.

    Science.gov (United States)

    Varady, N H; Grodzinsky, A J

    2016-01-01

    Motivated by the conceptual framework of multi-scale biomechanics, this narrative review highlights recent major advances with a focus on gait and joint kinematics, then tissue-level mechanics, cell mechanics and mechanotransduction, matrix mechanics, and finally the nanoscale mechanics of matrix macromolecules. A literature review was conducted from January 2014 to April 2015 using PubMed to identify major developments in mechanics related to osteoarthritis (OA). Studies of knee adduction, flexion, rotation, and contact mechanics have extended our understanding of medial compartment loading. In turn, advances in measurement methodologies have shown how injuries to both the meniscus and ligaments, together, can alter joint kinematics. At the tissue scale, novel findings have emerged regarding the mechanics of the meniscus as well as cartilage superficial zone. Moving to the cell level, poroelastic and poro-viscoelastic mechanisms underlying chondrocyte deformation have been reported, along with the response to osmotic stress. Further developments have emerged on the role of calcium signaling in chondrocyte mechanobiology, including exciting findings on the function of mechanically activated cation channels newly found to be expressed in chondrocytes. Finally, AFM-based nano-rheology systems have enabled studies of thin murine tissues and brush layers of matrix molecules over a wide range of loading rates including high rates corresponding to impact injury. With OA acknowledged to be a disease of the joint as an organ, understanding mechanical behavior at each length scale helps to elucidate the connections between cell biology, matrix biochemistry and tissue structure/function that may play a role in the pathomechanics of OA. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  14. Osteoarthritis Year in Review 2015: Mechanics

    Science.gov (United States)

    Varady, Nathan H.; Grodzinsky, Alan J.

    2015-01-01

    Motivated by the conceptual framework of multi-scale biomechanics, this narrative review highlights recent major advances with a focus on gait and joint kinematics, then tissue-level mechanics, cell mechanics and mechanotransduction, matrix mechanics, and finally the nanoscale mechanics of matrix macromolecules. A literature review was conducted from January 2014 to April 2015 using PubMed to identify major developments in mechanics related to osteoarthritis (OA). Studies of knee adduction, flexion, rotation, and contact mechanics have extended our understanding of medial compartment loading. In turn, advances in measurement methodologies have shown how injuries to both the meniscus and ligaments, together, can alter joint kinematics. At the tissue scale, novel findings have emerged regarding the mechanics of the meniscus as well as cartilage superficial zone. Moving to the cell level, poroelastic and poroviscoelastic mechanisms underlying chondrocyte deformation have been reported, along with the response to osmotic stress. Further developments have emerged on the role of calcium signaling in chondrocyte mechanobiology, including exciting findings on the function of mechanically activated cation channels newly found to be expressed in chondrocytes. Finally, AFM-based nano-rheology systems have enabled studies of thin murine tissues and brush layers of matrix molecules over a wide range of loading rates including high rates corresponding to impact injury. With OA acknowledged to be a disease of the joint as an organ, understanding mechanical behavior at each length scale helps to elucidate the connections between cell biology, matrix biochemistry and tissue structure/function that may play a role in the pathomechanics of OA. PMID:26707990

  15. The use of GRADE approach in systematic reviews of animal studies.

    Science.gov (United States)

    Wei, Dang; Tang, Kun; Wang, Qi; Estill, Janne; Yao, Liang; Wang, Xiaoqin; Chen, Yaolong; Yang, Kehu

    2016-03-15

    The application of GRADE (Grading of Recommendations Assessment, Development and Evaluation) in SR of animal studies can promote the translation from bench to bedside. We aim to explore the use of GRADE in systematic reviews of animal studies. We used a theoretical analysis method to explore the use of GRADE in SR of animal studies and applied in a SR of animal studies. Meanwhile, we presented and discussed our results in two international conferences. Five downgrade factors were considered as follows in systematic reviews of animal studies: 1) Risk of bias: the SYRCLE tool can be used for assessing the risk of bias of animal studies. 2) Indirectness: we can assess indirectness in systematic reviews of animal studies from the PICO. 3) Inconsistency: similarity of point estimates, extent of overlap of confidence intervals and statistical heterogeneity are also suitable to evaluate inconsistency of evidence from animal studies. 4) Imprecision: optimal information size (OIS) and 95% confidence intervals (CIs) are also suitable for systematic reviews of animal studies, like those of clinical trials. 5) Publication bias: we need to consider publication bias comprehensively through the qualitative and quantitative methods. The methods about the use of GRADE in systematic review of animal studies are explicit. However, the principle about GRADE in developing the policy based on the evidence from animal studies when there is an emergency of public health. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Respiratory mechanics in brain injury: A review.

    Science.gov (United States)

    Koutsoukou, Antonia; Katsiari, Maria; Orfanos, Stylianos E; Kotanidou, Anastasia; Daganou, Maria; Kyriakopoulou, Magdalini; Koulouris, Nikolaos G; Rovina, Nikoletta

    2016-02-04

    Several clinical and experimental studies have shown that lung injury occurs shortly after brain damage. The responsible mechanisms involve neurogenic pulmonary edema, inflammation, the harmful action of neurotransmitters, or autonomic system dysfunction. Mechanical ventilation, an essential component of life support in brain-damaged patients (BD), may be an additional traumatic factor to the already injured or susceptible to injury lungs of these patients thus worsening lung injury, in case that non lung protective ventilator settings are applied. Measurement of respiratory mechanics in BD patients, as well as assessment of their evolution during mechanical ventilation, may lead to preclinical lung injury detection early enough, allowing thus the selection of the appropriate ventilator settings to avoid ventilator-induced lung injury. The aim of this review is to explore the mechanical properties of the respiratory system in BD patients along with the underlying mechanisms, and to translate the evidence of animal and clinical studies into therapeutic implications regarding the mechanical ventilation of these critically ill patients.

  17. Incorporation of autopsy case-based learning into PhD graduate education: a novel approach to bridging the "bench-to-bedside" gap.

    Science.gov (United States)

    Brooks, Erin G; Thornton, Joanne M; Ranheim, Erik A; Fabry, Zsuzsanna

    2017-10-01

    Given the current rapid expansion of biological knowledge and the challenges of translating that knowledge into clinical practice, finding effective methods of teaching graduate students clinical medicine concepts has become even more critical. The utility of autopsy in medical student and resident education has been well established. Multiple studies have reported it to be a helpful means of teaching anatomy, pathophysiology, clinical problem-solving skills, and medical diagnostic techniques. Although various models of training PhD candidates in clinical medicine have been reported, an autopsy-based curriculum has not been previously described. For over 4 years, our pathology department has offered a novel semester-long autopsy-based course to educate future Cellular and Molecular Pathology scientists about clinical medicine. Our results indicate that this "hands-on" approach is a popular as well as effective means of teaching the pathogenesis of disease at the level of the cell, organ, and patient. The course reputation has recently led to requests to open registration to graduate students from other university programs as well as undergraduate students. Additionally, it has played an important role in our Cellular and Molecular Pathology program's recent receipt of a 5-year renewal National Institutes of Health-funded T32 award. Overall, this course model has been successful at our own institution and could provide a useful template for other institutions seeking to provide graduate investigators with in-depth exposure to clinical medicine. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Addressing challenges of training a new generation of clinician-innovators through an interdisciplinary medical technology design program: Bench-to-Bedside.

    Science.gov (United States)

    Loftus, Patrick D; Elder, Craig T; D'Ambrosio, Troy; Langell, John T

    2015-01-01

    Graduate medical education has traditionally focused on training future physicians to be outstanding clinicians with basic and clinical science research skills. This focus has resulted in substantial knowledge gains, but a modest return on investment based on direct improvements in clinical care. In today's shifting healthcare landscape, a number of important challenges must be overcome to not only improve the delivery of healthcare, but to prepare future physicians to think outside the box, focus on and create healthcare innovations, and navigate the complex legal, business and regulatory hurdles of bringing innovation to the bedside. We created an interdisciplinary and experiential medical technology design competition to address these challenges and train medical students interested in moving new and innovative clinical solutions to the forefront of medicine. Medical students were partnered with business, law, design and engineering students to form interdisciplinary teams focused on developing solutions to unmet clinical needs. Over the course of six months teams were provided access to clinical and industry mentors, $500 prototyping funds, development facilities, and non-mandatory didactic lectures in ideation, design, intellectual property, FDA regulatory requirements, prototyping, market analysis, business plan development and capital acquisition. After four years of implementation, the program has supported 396 participants, seen the development of 91 novel medical devices, and launched the formation of 24 new companies. From our perspective, medical education programs that develop innovation training programs and shift incentives from purely traditional basic and clinical science research to also include high-risk innovation will see increased student engagement in improving healthcare delivery and an increase in the quality and quantity of innovative solutions to medical problems being brought to market.

  19. Translating cognitive behavioral interventions from bench to bedside: The feasibility and acceptability of cognitive remediation in research as compared to clinical settings.

    Science.gov (United States)

    Medalia, Alice; Erlich, Matthew D; Soumet-Leman, Charlotte; Saperstein, Alice M

    2017-07-30

    Cognitive remediation (CR) research typically addresses internal validity, and few studies consider CR in a real-world context. This study evaluated the fit between the program conditions and treatment model in research and clinical settings, with the goal of informing future research on the contextual challenges associated with the implementation of CR. Data was drawn from an initiative by New York State's Office of Mental Health (OMH), to implement CR programs for adults with Serious Mental Illness (SMI) in 16 state operated outpatient clinics. One of these clinics first became a research site for a CR randomized clinical trial, which allowed for a comparison of the feasibility and acceptability of CR in a research as compared to a clinical setting. The research site averaged almost triple the number of referrals as the clinical sites. Over nine months 46.51% of clinic referrals were enrolled in the CR program whereas 64.29% of research referrals were enrolled. Clinical site utilization averaged 70.53% while research site utilization averaged 90.47%. At the clinical sites, 97% of respondents reported CR was an excellent or good experience. There was high treatment fidelity for program structure and content across sites. This comparison of CR in clinical and research sites highlights the decrease in referrals, enrollment and utilization that occurs when a program moves from a highly controlled setting to the real world. Still, the acceptability, fill rates and utilization indicated that CR can be successfully implemented in large scale, geographically diverse, publically funded clinic settings. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. From Bench to Bedside to Bug: An Update of Clinically Relevant Advances in the Care of Persons with Helicobacter pylori Associated Diseases

    Directory of Open Access Journals (Sweden)

    N Chiba

    2000-01-01

    Full Text Available In-depth meetings of the XIth International Workshop on Gastroduodenal Pathology and Helicobacter pylori led to the presentation and discussion of extensive new data on H pylori and its diseases. The mode of transmission of H pylori remains unclear, and it remains unknown why only a small proportion of infected individuals develop duodenal or gastric ulcer disease and even fewer develop gastric cancer. The role of H pylori eradication in persons with uninvestigated dyspepsia remains controversial. New clinical trials of H pylori treatment show symptom relief and improvement in the quality of life of persons with functional dyspepsia, especially in those with ulcer-like or reflux-like dyspepsia. Clearly the move is toward symptom-based management of persons with dyspepsia, with fewer endoscopies being needed in the otherwise healthy young dyspeptic patients. It remains controversial whether eradicating H pylori in duodenal ulcer or functional dyspepsia increases the risk of subsequent development of gastroesophageal reflux disease. The one-week proton pump inhibitor-based triple regimens remain the gold standard of H pylori therapy, but some of the ranitidine bismuth citrate plus two antibiotic regimens also achieve an 80% H pylori eradication rate on an intention-to-treat basis. While the urea breath test remains the noninvasive test of choice, interesting new data are available on the use of stool antigen testing to diagnose H pylori infection. The number of H pylori-associated gastroduodenal diseases grows to include possible liver, vascular, immune and skin conditions.

  1. Topical review: spins and mechanics in diamond

    Science.gov (United States)

    Lee, Donghun; Lee, Kenneth W.; Cady, Jeffrey V.; Ovartchaiyapong, Preeti; Bleszynski Jayich, Ania C.

    2017-03-01

    There has been rapidly growing interest in hybrid quantum devices involving a solid-state spin and a macroscopic mechanical oscillator. Such hybrid devices create exciting opportunities to mediate interactions between disparate quantum bits (qubits) and to explore the quantum regime of macroscopic mechanical objects. In particular, a system consisting of the nitrogen-vacancy defect center (NV center) in diamond coupled to a high-quality-factor mechanical oscillator is an appealing candidate for such a hybrid quantum device, as it utilizes the highly coherent and versatile spin properties of the defect center. In this paper, we will review recent experimental progress on diamond-based hybrid quantum devices in which the spin and orbital dynamics of single defects are driven by the motion of a mechanical oscillator. In addition, we discuss prospective applications for this device, including long-range, phonon-mediated spin-spin interactions, and phonon cooling in the quantum regime. We conclude the review by evaluating the experimental limitations of current devices and identifying alternative device architectures that may reach the strong coupling regime.

  2. Flow measurement in mechanical ventilation: a review.

    Science.gov (United States)

    Schena, Emiliano; Massaroni, Carlo; Saccomandi, Paola; Cecchini, Stefano

    2015-03-01

    Accurate monitoring of flow rate and volume exchanges is essential to minimize ventilator-induced lung injury. Mechanical ventilators employ flowmeters to estimate the amount of gases delivered to patients and use the flow signal as a feedback to adjust the desired amount of gas to be delivered. Since flowmeters play a crucial role in this field, they are required to fulfill strict criteria in terms of dynamic and static characteristics. Therefore, mechanical ventilators are equipped with only the following kinds of flowmeters: linear pneumotachographs, fixed and variable orifice meters, hot wire anemometers, and ultrasonic flowmeters. This paper provides an overview of these sensors. Their working principles are described together with their relevant advantages and disadvantages. Furthermore, the most promising emerging approaches for flowmeters design (i.e., fiber optic technology and three dimensional micro-fabrication) are briefly reviewed showing their potential for this application. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  3. Annual review of fluid mechanics. Volume 23

    International Nuclear Information System (INIS)

    Lumley, J.L.; Van Dyke, M.; Reed, H.L.

    1991-01-01

    Recent advances in theoretical, experimental, and computational fluid mechanics are discussed in a collection of annual review essays. Topics addressed include Lagrangian ocean studies, drag reduction in nature, the hydraulics of rotating strait and sill flow, analytical methods for the development of Reynolds-stress closures in turbulence, and exact solutions of the Navier-Stokes equations. Consideration is given to the theory of hurricanes, flow phenomena in CVD of thin films, particle-imaging techniques for experimental fluid mechanics, symmetry and symmetry-breaking bifurcations in fluid dynamics, turbulent mixing in stratified fluids, numerical simulation of transition in wall-bounded shear flows, fractals and multifractals in fluid turbulence, and coherent motions in the turbulent boundary layer

  4. Shooting Mechanisms in Nature: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Aimée Sakes

    Full Text Available In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these mechanisms fulfill.We systematically searched the literature using Scopus and Web of Knowledge to retrieve articles about solid projectiles that either are produced in the body of the organism or belong to the body and undergo a ballistic phase. The shooting mechanisms were categorized based on the energy management prior to and during shooting.Shooting mechanisms were identified with projectile masses ranging from 1·10-9 mg in spores of the fungal phyla Ascomycota and Zygomycota to approximately 10,300 mg for the ballistic tongue of the toad Bufo alvarius. The energy for shooting is generated through osmosis in fungi, plants, and animals or muscle contraction in animals. Osmosis can be induced by water condensation on the system (in fungi, or water absorption in the system (reaching critical pressures up to 15.4 atmospheres; observed in fungi, plants, and animals, or water evaporation from the system (reaching up to -197 atmospheres; observed in plants and fungi. The generated energy is stored as elastic (potential energy in cell walls in fungi and plants and in elastic structures in animals, with two exceptions: (1 in the momentum catapult of Basidiomycota the energy is stored in a stalk (hilum by compression of the spore and droplets and (2 in Sphagnum energy is mainly stored in compressed air. Finally, the stored energy is transformed into kinetic energy of the projectile using a catapult mechanism delivering up to 4,137 J/kg in the osmotic shooting mechanism in cnidarians and 1,269 J/kg in the muscle-powered appendage strike of the mantis shrimp Odontodactylus scyllarus. The launch accelerations range from 6.6g in the frog Rana pipiens to 5,413,000g in

  5. Understanding Key Mechanisms of Exercise-Induced Cardiac Protection to Mitigate Disease: Current Knowledge and Emerging Concepts.

    Science.gov (United States)

    Bernardo, Bianca C; Ooi, Jenny Y Y; Weeks, Kate L; Patterson, Natalie L; McMullen, Julie R

    2018-01-01

    The benefits of exercise on the heart are well recognized, and clinical studies have demonstrated that exercise is an intervention that can improve cardiac function in heart failure patients. This has led to significant research into understanding the key mechanisms responsible for exercise-induced cardiac protection. Here, we summarize molecular mechanisms that regulate exercise-induced cardiac myocyte growth and proliferation. We discuss in detail the effects of exercise on other cardiac cells, organelles, and systems that have received less or little attention and require further investigation. This includes cardiac excitation and contraction, mitochondrial adaptations, cellular stress responses to promote survival (heat shock response, ubiquitin-proteasome system, autophagy-lysosomal system, endoplasmic reticulum unfolded protein response, DNA damage response), extracellular matrix, inflammatory response, and organ-to-organ crosstalk. We summarize therapeutic strategies targeting known regulators of exercise-induced protection and the challenges translating findings from bench to bedside. We conclude that technological advancements that allow for in-depth profiling of the genome, transcriptome, proteome and metabolome, combined with animal and human studies, provide new opportunities for comprehensively defining the signaling and regulatory aspects of cell/organelle functions that underpin the protective properties of exercise. This is likely to lead to the identification of novel biomarkers and therapeutic targets for heart disease.

  6. CEMENT BONDED COMPOSITES – A MECHANICAL REVIEW

    Directory of Open Access Journals (Sweden)

    Stephan Frybort

    2008-05-01

    Full Text Available Over the last years promising cement bonded wood composites for structural purposes have evolved. Durability, toughness, high dimen-sional stability, resistance against environmental influences such as biodegradation or weathering but also availability of the raw material as well as economic factors are features which can make cement-bonded composites superior to conventionally bonded composites. This paper reviews the relationship of diverse parameters, including density and particle size on mechanical and physical properties of cement bonded composites, based on published sources from the last 60 years. For general and recent information about bonding mechanisms, compatibility and setting problems, determination and improvement of compatibility, the used raw materials as well as accelerators are discussed. The main part deals with failure mechanisms in connection with several production parameters. Furthermore, the influence of particle size and geometry, orientation of the particles, cement-wood ratio and the effect of accelerators and treatment of the particles on modulus of elasticity, modulus of rupture as well as thickness swelling are discussed.

  7. Annual review of fluid mechanics. Volume 15

    International Nuclear Information System (INIS)

    Van Dyke, M.; Wehausen, J.V.; Lumley, J.L.

    1983-01-01

    A survey of experimental results and analytical techniques for modelling various flows and the behavior of flows around flown-driven machinery is presented. Attention is given to analytical models for wind flows and power extraction by horizontal axis wind turbines. The phenomena occurring in the impact of compressible fluids with a solid body are described, as are the instabilities, pattern formation, and turbulence in flames. Homogeneous turbulence is explored, theories for autorotation by falling bodies are discussed, and attention is devoted to theoretical models for magneto-atmospheric waves and their presence in solar activity. The design characteristics of low Reynolds number airfoils are explored, and numerical and fluid mechanics formulations for integrable, chaotic, and turbulent vortex motion in two-dimensional flows are reviewed. Finally, measurements and models of turbulent wall jets for engineering purposes are examined

  8. The review conference mechanism in nuclear law: issues and opportunities

    International Nuclear Information System (INIS)

    Stoiber, C.

    2009-01-01

    This paper seeks to assess the major issues arising from reliance on the review conference mechanism as a measure for enhancing the effectiveness of multilateral legal instruments, particularly those in the nuclear field. In view of the perceived failure of the 2005 review conference of the Parties to the Treaty on the non-proliferation of nuclear weapons and the need to avoid a similar result at the upcoming 2010 review conference, it is hoped that this analysis will provide a timely review of the review conference mechanism. (N.C.)

  9. Respiratory mechanics in brain injury: A review

    OpenAIRE

    Koutsoukou, Antonia; Katsiari, Maria; Orfanos, Stylianos E; Kotanidou, Anastasia; Daganou, Maria; Kyriakopoulou, Magdalini; Koulouris, Nikolaos G; Rovina, Nikoletta

    2016-01-01

    Several clinical and experimental studies have shown that lung injury occurs shortly after brain damage. The responsible mechanisms involve neurogenic pulmonary edema, inflammation, the harmful action of neurotransmitters, or autonomic system dysfunction. Mechanical ventilation, an essential component of life support in brain-damaged patients (BD), may be an additional traumatic factor to the already injured or susceptible to injury lungs of these patients thus worsening lung injury, in case ...

  10. Review: The fundamental mechanism of aqueous contaminant ...

    African Journals Online (AJOL)

    Contaminant co-precipitation with continuously generated and transformed iron corrosion products has received relatively little attention in comparison to other possible removal mechanisms (adsorption, oxidation, precipitation) in Fe0/H2O systems at near neutral pH values. A primary reason for this is that the use of ...

  11. Design review of the INTOR mechanical configuration

    International Nuclear Information System (INIS)

    Brown, T.G.

    1981-01-01

    The INTOR conceptual design has been carried out by design teams working in the home countries with periodic workshop sessions in Vienna to review the ongoing work and to make decisions on the evolving design. The decisions taken at each workshop session were then incorporated into each national design activity, so that the four national design contributions would progressively converge toward a single design with increasingly greater detail. This paper defines the final INTOR configuration that has evolved during the conceptual design phase, defining the major system design alternatives that were considered and the rationale for selecting the final system configuration

  12. Annual review of fluid mechanics. Volume 22

    International Nuclear Information System (INIS)

    Lumley, J.L.; Van Dyke, M.; Reed, H.L.

    1990-01-01

    Topics presented include rapid granular flows, issues in viscoelastic fluid mechanics, wave loads on offshore structures, boundary layers in the general ocean circulation, parametrically forced surface waves, wave-mean flow interactions in the equatorial ocean, and local and global instabilities in spatially developing flows. Also presented are aerodynamics of human-powered flight, aerothermodynamics and transition in high-speed wind tunnels at NASA-Langley, wakes behind blunt bodies, and mixing, chaotic advection, and turbulence. Also addressed are the history of the Reynolds number, panel methods in computational fluid dynamics, numerical multipole and boundary integral equation techniques in Stokes flow, plasma turbulence, optical rheometry, and viscous-flow paradoxes

  13. Mechanical properties on geopolymer brick: A review

    Science.gov (United States)

    Deraman, L. M.; Abdullah, M. M. A.; Ming, L. Y.; Ibrahim, W. M. W.; Tahir, M. F. M.

    2017-09-01

    Bricks has stand for many years as durable construction substantial, especially in the area of civil engineering to construct buildings. Brick commonly used in the structure of buildings as a construction wall, cladding, facing perimeter, paving, garden wall and flooring. The contribution of ordinary Portland cement (OPC) in cement bricks production worldwide to greenhouse gas emissions. Due to this issue, some researchers have done their study with other materials to produce bricks, especially as a by-product material. Researchers take effort in this regard to synthesizing from by-product materials such as fly ash, bottom ash and kaolin that are rich in silicon and aluminium in the development of inorganic alumina-silicate polymer, called geopolymer Geopolymer is a polymerization reaction between various aluminosilicate oxides with silicates solution or alkali hydroxide solution forming polymerized Si-O-Al-O bonds. This paper summarized some research finding of mechanical properties of geopolymer brick using by-product materials.

  14. Mechanisms of action of lumbar supports : a systematic review

    NARCIS (Netherlands)

    van Poppel, M N; de Looze, M P; Koes, B W; Smid, T; Bouter, L M

    2000-01-01

    STUDY DESIGN: A systematic review and meta-analysis of studies on the putative mechanisms of action of lumbar supports in lifting activities. OBJECTIVE: To summarize the evidence bearing on the putative mechanisms of action of lumbar supports. SUMMARY OF BACKGROUND DATA: A restriction of trunk

  15. Mechanisms of action of lumbar supports: a sytematic review

    NARCIS (Netherlands)

    van Poppel-Bruinvels, M.N.M.; de Looze, M.P.; Koes, B.W.; Smid, T.; Bouter, L.M.

    2000-01-01

    Study Design. A systematic review and meta-analysis of studies on the putative mechanisms of action of lumbar supports in lifting activities. Objective. To summarize the evidence bearing on the putative mechanisms of action of lumbar supports. Summary of Background Data. A restriction of trunk

  16. Review of Mechanisms and Theories of Aging

    Directory of Open Access Journals (Sweden)

    Gholam Reza Azari

    2006-10-01

    Full Text Available Several factors have incentive role for study of aging which includes increasing of the average and maximum of human life span, the increase in percentage of elderly in the societies and proportion of the national expenditure utilized by them. The Recent views of aging indicating that aging is extremely a complex multifactorial process despite of earlier views about definite cause aging like gene or decline of a key factor(1. This brief review tries to inspect aging at the molecular, cellular, and systemic levels; and consider interaction between genetic and environmental factors. Evolutionary theories argue that aging results from a decline in the force of natural selection. On the other hand, molecular theories emphasis on the genetically regulation of aging and argue that aging results from changing in genes. There are cellular theories that telomere theory is most famous. Stress induced aging is in this group too. free radical theory is next known way for cellular damages. Finally, we see systemic theories that contain two main groups, neuroendocrine and immunologic theories.

  17. Reaction mechanisms in cellulose pyrolysis: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Molton, P.M.; Demmitt, T.F.

    1977-08-01

    A bibliographic review of 195 references is presented outlining the history of the research into the mechanisms of cellulose pyrolysis. Topics discussed are: initial product identification, mechanism of initial formation of levoglucosan, from cellulose and from related compounds, decomposition of cellulose to other compounds, formation of aromatics, pyrolysis of levoglucosan, crosslinking of cellulose, pyrolytic reactions of cellulose derivatives, and the effects of inorganic salts on the pyrolysis mechanism. (JSR)

  18. Mechanical Restraint - Which Interventions Prevent Episodes of Mechanical Restraint? - A Systematic Review

    DEFF Research Database (Denmark)

    Bak, Jesper; Brandt-Christensen, Anne Mette; Sestoft, Dorte Maria

    2012-01-01

    PURPOSE:  To identify interventions preventing mechanical restraints. DESIGN AND METHODS:  Systematic review of international research papers dealing with mechanical restraint. The review combines qualitative and quantitative research in a new way, describing the quality of evidence and the effect...... of intervention. FINDINGS:  Implementation of cognitive milieu therapy, combined interventions, and patient-centered care were the three interventions most likely to reduce the number of mechanical restraints. PRACTICE IMPLICATIONS:  There is a lack of high-quality and effective intervention studies. This leaves...... patients and metal health professionals with uncertainty when choosing interventions in an attempt to prevent mechanical restraints....

  19. Mechanical profiles of murder and murderers: An extensive review.

    Science.gov (United States)

    Kamaluddin, M R; Md Shariff, N S; Mat Saat, G A

    2018-04-01

    Murder is an extreme form of violent crime which occurs across all social, cultural, and ethnic spheres. It is therefore, crucial to understand the nature and the extent of mechanical profiles of murder and murderers. The purpose of this article is to review such critical aspects of murder in a nutshell. An archival research methodology was employed in this study where relevant search for literatures on these mechanical aspects related to murder was made across search engines such as Google Scholar and Elsevier with relevant articles selected for this review. This review discusses in an in-depth manner, pivotal mechanical profiles which include motives, methods of killing, choice of weapon, settings, targeted body parts, and murder victim concealment. In-depth understanding of each mechanical aspect offers an opportunity to the public at large to expand their knowledge on murder prevention manners which is vital for crime prevention efforts in the future.

  20. BOOK REVIEW: Statistical Mechanics of Turbulent Flows

    Science.gov (United States)

    Cambon, C.

    2004-10-01

    This is a handbook for a computational approach to reacting flows, including background material on statistical mechanics. In this sense, the title is somewhat misleading with respect to other books dedicated to the statistical theory of turbulence (e.g. Monin and Yaglom). In the present book, emphasis is placed on modelling (engineering closures) for computational fluid dynamics. The probabilistic (pdf) approach is applied to the local scalar field, motivated first by the nonlinearity of chemical source terms which appear in the transport equations of reacting species. The probabilistic and stochastic approaches are also used for the velocity field and particle position; nevertheless they are essentially limited to Lagrangian models for a local vector, with only single-point statistics, as for the scalar. Accordingly, conventional techniques, such as single-point closures for RANS (Reynolds-averaged Navier-Stokes) and subgrid-scale models for LES (large-eddy simulations), are described and in some cases reformulated using underlying Langevin models and filtered pdfs. Even if the theoretical approach to turbulence is not discussed in general, the essentials of probabilistic and stochastic-processes methods are described, with a useful reminder concerning statistics at the molecular level. The book comprises 7 chapters. Chapter 1 briefly states the goals and contents, with a very clear synoptic scheme on page 2. Chapter 2 presents definitions and examples of pdfs and related statistical moments. Chapter 3 deals with stochastic processes, pdf transport equations, from Kramer-Moyal to Fokker-Planck (for Markov processes), and moments equations. Stochastic differential equations are introduced and their relationship to pdfs described. This chapter ends with a discussion of stochastic modelling. The equations of fluid mechanics and thermodynamics are addressed in chapter 4. Classical conservation equations (mass, velocity, internal energy) are derived from their

  1. A Critical Review of Landslide Failure Mechanisms

    Science.gov (United States)

    Stead, D.; Wolter, A.; Clague, J. J.

    2011-12-01

    During the last ten years several comprehensive geotechnical studies have been completed on major historic landslides including Randa in Switzerland, Frank in Canada, Aknes in Norway, La Clapiere in France and Vaiont in Italy. In addition, numerous researchers have documented deep-seated gravitational deformations and a wide variety of large prehistoric rock slope failures. The information provided by these studies is evidence of the significant advances made in our ability to map, monitor and model landslides. Over the same period, the mining industry has developed large open pits with slope heights exceeding 1000 m that provide important analogues to high mountain slopes. In this paper we analyse data from the literature to illustrate the importance of brittle fracture, 3D controls, anisotropy, overburden stress, geomorphic processes, groundwater and temperature in major landslides and provide some indicators as to the research required to further understand the complexity of rock slope failure mechanisms. The nature of the landslide failure surface has received inadequate attention in the past, with failure surfaces typically considered in 2D and simulated as discrete, smooth and often planar features. Current work shows that failure surfaces are inherently three-dimensional and have much structural variability across the area of the landslide scarp, reflecting complex structural histories. Such anisotropy and variations may result in multiple events or distinct blocks that move at different rates. Just as most failure surfaces vary spatially, they may also change with depth and thus should more realistically be considered failure zones rather than discrete surfaces. The increasing recognition of the importance of step-path failures, internal dilation and brittle fracture are indicative of the complexity in slope failure surfaces. Related to the variation in failure surface characteristics is the importance of 3D rotational displacements and both the

  2. Imaging of placental transport mechanisms: a review.

    Science.gov (United States)

    Sölder, Elisabeth; Rohr, Irena; Kremser, Christian; Hutzler, Peter; Debbage, Paul L

    2009-05-01

    Functional analysis of material transfers requires precise statement of residence times in each tissue compartment. For the placenta, neither extractive biochemistry, isotope partitioning, nor mass-based quantitative assays provide adequate spatial resolution to allow the necessary precision. Dual-perfusion assays of material transfer in isolated placental cotyledons provide time-series data for two compartments, the maternal and fetal blood, but fail to distinguish the two cellular compartments (syncytiotrophoblast, fetal endothelium) which actively regulate rates of transfer in each direction for essentially every important molecule type. At present, no definitive technology exists for functional analysis of placental transfer functions. The challenge in developing such a technology lies in the exquisitely small and delicate structures involved, which are scaled at cellular and subcellular sizes (between 50 nm and 50 microm). The only available technologies attaining this high spatial resolution are imaging technologies, primarily light and electron microscopy. To achieve the high-quality images necessary, confocal laser scanning microscopy (CLSM) is required, to provide a uniform optical sectioning plane. In turn, this requires relatively high fluorescence intensities. Design of an adequate technology therefore bases on CLSM imaging fluorochrome-tagged tracers. The temporal resolution necessary to analyse placental material transfers is expected to be of the order of a few seconds, so that conventional wet-fixation protocols are too slow. For adequately rapid fixation, snap-freezing is required. As part of this review we report results obtained from an appropriately designed experimental protocol, analysed by CLSM and transmission electron microscopy (TEM). The images acquired were tested for uniformity of illumination and fluorescence emission strength. Relevant data was encoded in the green channel of the trichrome images obtained, and this was thresholded by

  3. Biofilms and mechanics: a review of experimental techniques and findings

    International Nuclear Information System (INIS)

    Gordon, Vernita D; Davis-Fields, Megan; Kovach, Kristin; Rodesney, Christopher A

    2017-01-01

    Biofilms are developmentally-dynamic communities of sessile microbes that adhere to each other and, often, to other structures in their environment. The cohesive mechanical forces binding microbes to each other confer mechanical and structural stability on the biofilm and give rise to biofilm viscoelasticity. The adhesive mechanical forces binding microbes to other structures in their environment can promote biofilm initiation and mechanosensing that leads to changes in biological activity. Thus, physical mechanics is intrinsic to characteristics that distinguish biofilms from free-swimming or free-floating microbes in liquid culture. However, very little is known about the specifics of what mechanical traits characterize different types of biofilms at different stages of development. Even less is known about how mechanical inputs impact microbial biology and how microbes can adjust their mechanical coupling to, and interaction with, their environment. These knowledge gaps arise, in part, from the challenges associated with experimental measurements of microbial and biofilm biomechanics. Here, we review extant experimental techniques and their most-salient findings to date. At the end of this review we indicate areas where significant advances in the state-of-the art are heading. (topical review)

  4. Finite element modelling of cornea mechanics: a review

    Directory of Open Access Journals (Sweden)

    Talisa Mohammad Nejad

    2014-01-01

    Full Text Available The cornea is a transparent tissue in front of the eye that refracts light and facilitates vision. A slight change in the geometry of the cornea remarkably affects the optical power. Because of this sensitivity, biomechanical study of the cornea can reveal much about its performance and function. In vivo and in vitro studies have been conducted to investigate the mechanics of the cornea and determine its characteristics. Numerical techniques such as the finite element method (FEM have been extensively implemented as effective and noninvasive methods for analyzing corneal mechanics and possible disorders. This article reviews the use of FEM for assessing the mechanical behavior of the cornea. Different applications of FEM in corneal disease studies, surgical predictions, impact simulations, and clinical applications have been reviewed. Some suggestions for the future of this type of modeling in the area of corneal mechanics are also discussed.

  5. The African Peer Review Mechanism: The South African Experience ...

    African Journals Online (AJOL)

    This article compares the results of the African Peer Review Mechanism (APRM) report on South Africa with the evaluation done on the same issues by three academics from different health professions. Four areas which closely affect health and health care (democracy and good political governance; economic governance ...

  6. A review of mechanisms underlying anticarcinogenicity by brassica vegetables

    NARCIS (Netherlands)

    Verhoeven, D.T.H.; Verhagen, H.; Goldbohm, R.A.; Brandt, P.A. van den; Poppel, G. van

    1997-01-01

    The mechanisms by which brassica vegetables might decrease the risk of cancer are reviewed in this paper. Brassicas, including all types of cabbages, broccoli, cauliflower and Brussels sprouts, may be protective against cancer due to their relatively high glucosinolate content. Glucosinolates are

  7. Biofilms and mechanics: a review of experimental techniques and findings

    Science.gov (United States)

    Gordon, Vernita D.; Davis-Fields, Megan; Kovach, Kristin; Rodesney, Christopher A.

    2017-06-01

    Biofilms are developmentally-dynamic communities of sessile microbes that adhere to each other and, often, to other structures in their environment. The cohesive mechanical forces binding microbes to each other confer mechanical and structural stability on the biofilm and give rise to biofilm viscoelasticity. The adhesive mechanical forces binding microbes to other structures in their environment can promote biofilm initiation and mechanosensing that leads to changes in biological activity. Thus, physical mechanics is intrinsic to characteristics that distinguish biofilms from free-swimming or free-floating microbes in liquid culture. However, very little is known about the specifics of what mechanical traits characterize different types of biofilms at different stages of development. Even less is known about how mechanical inputs impact microbial biology and how microbes can adjust their mechanical coupling to, and interaction with, their environment. These knowledge gaps arise, in part, from the challenges associated with experimental measurements of microbial and biofilm biomechanics. Here, we review extant experimental techniques and their most-salient findings to date. At the end of this review we indicate areas where significant advances in the state-of-the art are heading.

  8. Social Information Processing Mechanisms and Victimization: A Literature Review.

    Science.gov (United States)

    van Reemst, Lisa; Fischer, Tamar F C; Zwirs, Barbara W C

    2016-01-01

    The aim of the current literature review, which is based on 64 empirical studies, was to assess to what extent mechanisms of the Social Information Processing (SIP) model of Crick and Dodge (1994) are related to victimization. The reviewed studies have provided support for the relation between victimization and several social information processing mechanisms, especially the interpretation of cues and self-efficacy (as part of the response decision). The relationship between victimization and other mechanisms, such as the response generation, was only studied in a few articles. Until now research has often focused on just one step of the model, instead of attempting to measure the associations between multiple mechanisms and victimization in multivariate analyses. Such analyses would be interesting to gain more insight into the SIP model and its relationship with victimization. The few available longitudinal studies show that mechanisms both predict victimization (internal locus of control, negative self-evaluations and less assertive response selection) and are predicted by victimization (hostile attribution of intent and negative evaluations of others). Associations between victimization and SIP mechanisms vary across different types and severity of victimization (stronger in personal and severe victimization), and different populations (stronger among young victims). Practice could focus on these stronger associations and the interpretation of cues. More research is needed however, to investigate whether intervention programs that address SIP mechanisms are suitable for victimization and all relevant populations. © The Author(s) 2014.

  9. Review of Mechanics and Applications of Auxetic Structures

    Directory of Open Access Journals (Sweden)

    Mariam Mir

    2014-01-01

    Full Text Available One of the important mechanical properties of materials is Poisson’s ratio, which is positive for most of the materials. However, certain materials exhibit “auxetic” properties; that is, they have a negative Poisson’s ratio. Thus auxetic and non-auxetic materials exhibit different deformation mechanisms. A specific microscopic structure in the auxetic materials is important for maintaining a negative Poisson’s ratio. Based on their distinct nature auxetic materials execute certain unique properties in contrast to other materials, which are reviewed in this paper. Thus auxetic materials have important applications in the biomedical field which are also a part of this review article. Many auxetic materials have been discovered, fabricated, and synthesized which differ on the basis of structure, scale and deformation mechanism. The different types of auxetic materials such as auxetic cellular solids, microscopic auxetic polymers, molecular auxetic materials, and auxetic composites have been reviewed comprehensively in this paper. Modeling of auxetic structures is of considerable importance and needs appropriate stress strain configurations; thus different aspects of auxetic modeling have also been reviewed. Packing parameters and relative densities are of prime importance in this regard. This review would thus help the researchers in determining and deciding the various aspects of auxetic nature for their products.

  10. Changing the Translational Research Landscape: A Review of the Impacts of Biomedical Research Units in England.

    Science.gov (United States)

    Marjanovic, Sonja; Soper, Bryony; Ismail, Sharif; Reding, Anais; Ling, Tom

    2012-01-01

    This article describes a review of the Biomedical Research Units (BRU) scheme, undertaken for the Department of Health. This review was a perceptions audit of senior executives involved in the scheme, and explored what impact they felt the scheme is having on the translational research landscape. More specifically, we investigated whether and how institutional relationships between NHS and academic partners, industry and other health research system players are changing because of the scheme; how the scheme is helping build critical mass in specific priority disease areas; and the effects of any changes on efforts to deliver the broader goals set out in Best Research for Best Health. The views presented are those of study informants only. The information obtained through our interviews suggests that the BRU scheme is significantly helping shape the health research system to pursue translational research and innovation, with the clear goal of realising patient benefit. The BRUs are already contributing to observable changes in institutional relationships between the NHS and academic partners: trusts and medical schools are collaborating more closely than in the past, have signed up to the same vision of translational research from bench to bedside, and are managing and governing targeted research resources more professionally and transparently than in the past. There is also a stronger emphasis on engaging industry and more strategic thinking about strengthening regional and national collaboration with other hospital trusts, PCTs, research organisations, networks and development agencies. The scheme is also transforming capacity building in the health research system. This includes (i) developing and modernising facilities and equipment for translation; (ii) building a critical mass of human resources through recruitment and training, as well as improving retention of existing expertise; and (iii) helping ensure a steady flow of funds needed to sustain research

  11. Toughening Mechanisms in Nanolayered MAX Phase Ceramics—A Review

    Directory of Open Access Journals (Sweden)

    Xinhua Chen

    2017-03-01

    Full Text Available Advanced engineering and functional ceramics are sensitive to damage cracks, which delay the wide applications of these materials in various fields. Ceramic composites with enhanced fracture toughness may trigger a paradigm for design and application of the brittle components. This paper reviews the toughening mechanisms for the nanolayered MAX phase ceramics. The main toughening mechanisms for these ternary compounds were controlled by particle toughening, phase-transformation toughening and fiber-reinforced toughening, as well as texture toughening. Based on the various toughening mechanisms in MAX phase, models of SiC particles and fibers toughening Ti3SiC2 are established to predict and explain the toughening mechanisms. The modeling work provides insights and guidance to fabricate MAX phase-related composites with optimized microstructures in order to achieve the desired mechanical properties required for harsh application environments.

  12. Resilience in LGB Youths: A Systematic Review of Protection Mechanisms

    Directory of Open Access Journals (Sweden)

    Daniela Fonseca Freitas

    Full Text Available Abstract: Given the mental health disparities among LGB and heterosexual youth, literature has increasingly emphasized the need to identify the mechanisms that promote resilience among sexual minorities. This systematic review sought to answer the question: what are the protection mechanisms against homophobia among LGB youth? Of the 147 references located in the search, 13 studies were analyzed. The identified protection mechanisms were organized by two criteria: specific to sexual orientation or general, and considered to be at the personal, relational and contextual level. Most of the mechanisms revealed to solely promote the positive adjustment in the presence of risk. General protective mechanisms frequently revealed to be more compensatory of the risks than those specific to sexual orientation.

  13. Detoxification Mechanisms of Mercury Toxicity in Plants: A Review

    Directory of Open Access Journals (Sweden)

    Shilpa Shrivastava

    2015-12-01

    Full Text Available Mercury is one of the most toxic heavy metals present in the earth’s crust. It has been considered as environmental pollutant because of its potent toxicity to plants and humans. In this review, we discuss mercury toxicity responses on plant metabolism and its detoxification mechanism by phytochelatins and antioxidant enzymes. Some light is also shed on selenium antagonistic study with mercury. Due to its potential toxicity, it has attracted attention in fields of soil science and plant nutrition. Mercury has harmful toxic effects on the molecular and physiobiochemical behavior of plants. Mostly research work has been done on seed germination, and shoot, root, and leaf morphology. Enzyme responses with respect to mercury as a result Hg accumulated in food chain is also reviewed here. Hence, this review may provide a compiled data for other researches in this direction, to provide a better mechanism or details about mercury’s noxious effect in the ecosystem.

  14. The mechanisms underpinning peer support: a literature review.

    Science.gov (United States)

    Watson, Emma

    2017-12-20

    The employment of Peer Support Workers, who themselves have experience of significant emotional distress, can promote recovery at an individual and organisational level. While research examining the benefits of peer support within mental health services continues to grow, an understanding of how, and through what processes, these benefits are reached remains under-developed. To review the published research literature relating to the process of peer support and its underpinning mechanisms to better understand how and why it works. A scoping review of published literature identified studies relating to peer support mechanisms, processes and relationships. Studies were summarised and findings analysed. Five mechanisms were found to underpin peer support relationships (lived experience, love labour, the liminal position of the peer worker, strengths-focussed social and practical support, and the helper role). The identified mechanisms can underpin both the success and difficulties associated with peer support relationships. Further research should review a broader range of literature and clarify how these mechanisms contribute to peer support in different contexts.

  15. Biomechanics and mechanical signaling in the ovary: a systematic review.

    Science.gov (United States)

    Shah, Jaimin S; Sabouni, Reem; Cayton Vaught, Kamaria C; Owen, Carter M; Albertini, David F; Segars, James H

    2018-04-24

    Mammalian oogenesis and folliculogenesis share a dynamic connection that is critical for gamete development. For maintenance of quiescence or follicular activation, follicles must respond to soluble signals (growth factors and hormones) and physical stresses, including mechanical forces and osmotic shifts. Likewise, mechanical processes are involved in cortical tension and cell polarity in oocytes. Our objective was to examine the contribution and influence of biomechanical signaling in female mammalian gametogenesis. We performed a systematic review to assess and summarize the effects of mechanical signaling and mechanotransduction in oocyte maturation and folliculogenesis and to explore possible clinical applications. The review identified 2568 publications of which 122 met the inclusion criteria. The integration of mechanical and cell signaling pathways in gametogenesis is complex. Follicular activation or quiescence are influenced by mechanical signaling through the Hippo and Akt pathways involving the yes-associated protein (YAP), transcriptional coactivator with PDZ-binding motif (TAZ), phosphatase and tensin homolog deleted from chromosome 10 (PTEN) gene, the mammalian target of rapamycin (mTOR), and forkhead box O3 (FOXO3) gene. There is overwhelming evidence that mechanical signaling plays a crucial role in development of the ovary, follicle, and oocyte throughout gametogenesis. Emerging data suggest the complexities of mechanotransduction and the biomechanics of oocytes and follicles are integral to understanding of primary ovarian insufficiency, ovarian aging, polycystic ovary syndrome, and applications of fertility preservation.

  16. Portraying mechanics of plant growth promoting rhizobacteria (PGPR: A review

    Directory of Open Access Journals (Sweden)

    Dweipayan Goswami

    2016-12-01

    Full Text Available Population growth and increase in food requirement is the global problem. It is inevitable to introduce new practices that help to increase agricultural productivity. Use of plant growth promoting rhizobacteria (PGPR has shown potentials to be a promising technique in the practice of sustainable agriculture. A group of natural soil microbial flora acquire dwelling in the rhizosphere and on the surface of the plant roots which impose beneficial effect on the overall well-being of the plant are categorized as PGPR. Researchers are actively involved in understanding plant growth promoting mechanics employed by PGPR. Broadly, these are divided into direct and indirect mechanics. Any mechanism that directly enhances plant growth either by providing nutrients or by producing growth regulators are portrayed as direct mechanics. Whereas, any mechanisms that protects plant from acquiring infections (biotic stress or helps plant to grow healthily under environmental stresses (abiotic stress are considered indirect mechanics. This review is focused to describe cogent mechanics employed by PGPR that assists plant to sustain healthy growth. Also, we emphasized on the PGPR-based products which have been commercially developed exploiting these mechanics of PGPR.

  17. Review of student difficulties in upper-level quantum mechanics

    Directory of Open Access Journals (Sweden)

    Chandralekha Singh

    2015-09-01

    Full Text Available [This paper is part of the Focused Collection on Upper Division Physics Courses.] Learning advanced physics, in general, is challenging not only due to the increased mathematical sophistication but also because one must continue to build on all of the prior knowledge acquired at the introductory and intermediate levels. In addition, learning quantum mechanics can be especially challenging because the paradigms of classical mechanics and quantum mechanics are very different. Here, we review research on student reasoning difficulties in learning upper-level quantum mechanics and research on students’ problem-solving and metacognitive skills in these courses. Some of these studies were multiuniversity investigations. The investigations suggest that there is large diversity in student performance in upper-level quantum mechanics regardless of the university, textbook, or instructor, and many students in these courses have not acquired a functional understanding of the fundamental concepts. The nature of reasoning difficulties in learning quantum mechanics is analogous to reasoning difficulties found via research in introductory physics courses. The reasoning difficulties were often due to overgeneralizations of concepts learned in one context to another context where they are not directly applicable. Reasoning difficulties in distinguishing between closely related concepts and in making sense of the formalism of quantum mechanics were common. We conclude with a brief summary of the research-based approaches that take advantage of research on student difficulties in order to improve teaching and learning of quantum mechanics.

  18. Myositis non-inflammatory mechanisms: An up-dated review.

    Science.gov (United States)

    Manole, Emilia; Bastian, Alexandra E; Butoianu, Niculina; Goebel, Hans H

    2017-01-01

    Idiopathic inflammatory myopathies (IIM) represent a heterogeneous group of rare muscular diseases, with no clearly known causes. IIM frequently have an incomplete response to treatment due to the difficulty in distinguishing between IIM forms, and due to neglect their non-inflammatory causes. Important data concerning non-immune mechanisms in IIM pathology have been recently accumulated. There is a correlation between inflammatory and non-inflammatory mechanisms, but their involvement in IIM pathogenesis is still unknown. Here we review some of the most important data regarding the non-immune IIM pathology, highlighting possible future therapeutic targets: endoplasmic reticulum stress, ATP metabolism, ROS generation, autophagy, and microRNAs disturbances.

  19. Mental Models for Mechanical Comprehension. A Review of Literature.

    Science.gov (United States)

    1986-06-01

    models, constructionism , infinirm t - ,’a f.mrfn.~ gl 19 ABSTRACT (Continue on reverse if necessary and identify by block number) 4 This literature...review describes the recent research on mental models of mechanical comprehension. Three methodological approaches ( constructionism , information...things for a teacher to do to aid students’ attempts at understanding the forces involved: 1. Prepare an engaging social context. 2. Juxtapose several

  20. Underlying mechanisms of transient luminous events: a review

    OpenAIRE

    V. V. Surkov; M. Hayakawa

    2012-01-01

    Transient luminous events (TLEs) occasionally observed above a strong thunderstorm system have been the subject of a great deal of research during recent years. The main goal of this review is to introduce readers to recent theories of electrodynamics processes associated with TLEs. We examine the simplest versions of these theories in order to make their physics as transparent as possible. The study is begun with the conventional mechanism for air breakdown at stratospheric...

  1. Metal Additive Manufacturing: A Review of Mechanical Properties

    Science.gov (United States)

    Lewandowski, John J.; Seifi, Mohsen

    2016-07-01

    This article reviews published data on the mechanical properties of additively manufactured metallic materials. The additive manufacturing techniques utilized to generate samples covered in this review include powder bed fusion (e.g., EBM, SLM, DMLS) and directed energy deposition (e.g., LENS, EBF3). Although only a limited number of metallic alloy systems are currently available for additive manufacturing (e.g., Ti-6Al-4V, TiAl, stainless steel, Inconel 625/718, and Al-Si-10Mg), the bulk of the published mechanical properties information has been generated on Ti-6Al-4V. However, summary tables for published mechanical properties and/or key figures are included for each of the alloys listed above, grouped by the additive technique used to generate the data. Published values for mechanical properties obtained from hardness, tension/compression, fracture toughness, fatigue crack growth, and high cycle fatigue are included for as-built, heat-treated, and/or HIP conditions, when available. The effects of test orientation/build direction on properties, when available, are also provided, along with discussion of the potential source(s) (e.g., texture, microstructure changes, defects) of anisotropy in properties. Recommendations for additional work are also provided.

  2. Exercise-induced rhabdomyolysis mechanisms and prevention: A literature review

    Directory of Open Access Journals (Sweden)

    Jooyoung Kim

    2016-09-01

    Full Text Available Exercise-induced rhabdomyolysis (exRML, a pathophysiological condition of skeletal muscle cell damage that may cause acute renal failure and in some cases death. Increased Ca2+ level in cells along with functional degradation of cell signaling system and cell matrix have been suggested as the major pathological mechanisms associated with exRML. The onset of exRML may be exhibited in athletes as well as in general population. Previous studies have reported that possible causes of exRML were associated with excessive eccentric contractions in high temperature, abnormal electrolytes balance, and nutritional deficiencies possible genetic defects. However, the underlying mechanisms of exRML have not been clearly established among health professionals or sports medicine personnel. Therefore, we reviewed the possible mechanisms and correlated prevention of exRML, while providing useful and practical information for the athlete and general exercising population.

  3. Neural mechanisms underlying morphine withdrawal in addicted patients: a review

    Directory of Open Access Journals (Sweden)

    Nima Babhadiashar

    2015-06-01

    Full Text Available Morphine is one of the most potent alkaloid in opium, which has substantial medical uses and needs and it is the first active principle purified from herbal source. Morphine has commonly been used for relief of moderate to severe pain as it acts directly on the central nervous system; nonetheless, its chronic abuse increases tolerance and physical dependence, which is commonly known as opiate addiction. Morphine withdrawal syndrome is physiological and behavioral symptoms that stem from prolonged exposure to morphine. A majority of brain regions are hypofunctional over prolonged abstinence and acute morphine withdrawal. Furthermore, several neural mechanisms are likely to contribute to morphine withdrawal. The present review summarizes the literature pertaining to neural mechanisms underlying morphine withdrawal. Despite the fact that morphine withdrawal is a complex process, it is suggested that neural mechanisms play key roles in morphine withdrawal.

  4. Bioinspired Bouligand cellulose nanocrystal composites: a review of mechanical properties

    Science.gov (United States)

    Natarajan, Bharath; Gilman, Jeffrey W.

    2017-12-01

    The twisted plywood, or Bouligand, structure is the most commonly observed microstructural motif in natural materials that possess high mechanical strength and toughness, such as that found in bone and the mantis shrimp dactyl club. These materials are isotropically toughened by a low volume fraction of soft, energy-dissipating polymer and by the Bouligand structure itself, through shear wave filtering and crack twisting, deflection and arrest. Cellulose nanocrystals (CNCs) are excellent candidates for the bottom-up fabrication of these structures, as they naturally self-assemble into `chiral nematic' films when cast from solutions and possess outstanding mechanical properties. In this article, we present a review of the fabrication techniques and the corresponding mechanical properties of Bouligand biomimetic CNC nanocomposites, while drawing comparison to the performance standards set by tough natural composite materials. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

  5. Bio-mimetic mechanisms of natural hierarchical materials: a review.

    Science.gov (United States)

    Chen, Qiang; Pugno, Nicola M

    2013-03-01

    Natural selection and evolution develop a huge amount of biological materials in different environments (e.g. lotus in water and opuntia in desert). These biological materials possess many inspiring properties, which hint scientists and engineers to find some useful clues to create new materials or update the existing ones. In this review, we highlight some well-studied (e.g. nacre shell) and newly-studied (e.g. turtle shell) natural materials, and summarize their hierarchical structures and mechanisms behind their mechanical properties, from animals to plants. These fascinating mechanisms suggest to researchers to investigate natural materials deeply and broadly, and to design or fabricate new bio-inspired materials to serve our life. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Summary review of rock mechanics workshop on radioactive waste disposal

    International Nuclear Information System (INIS)

    Carter, N.L.; Goodman, R.E.; Merrill, R.H.

    1977-01-01

    Presentations, critiques and recommendations for the disposal of commercial radioactive waste based upon an analysis of the information presented at the Rock Mechanics Review/Workshop, Denver, Colorado, December 16-17, 1976 are summarized. The workshop, comprised of both formal and informal sessions, with about 50 participants, was hosted by RE/SPEC Inc. and Dr. Paul F. Gnirk, President and was sponsored by the Office of Waste Isolation (OWI), led by Dr. William C. McClain. The panel of reviewers, responsible for this report, consisted of Neville L. Carter, Richard E. Goodman, and Robert H. Merrill. These panel members were selected not only on the basis of their experience in various aspects of Rock Mechanics and Mining Engineering but also because they have had no previous active participation in problems concerning disposal of radioactive waste. By way of a general comment, the review panel was very favorably impressed with the Rock Mechanics research efforts, supported by OWI, on this problem and with the level of technical competence of those carrying out the research. Despite the rather preliminary nature of the results presented and the youth of the program itself, it is clear that the essential ingredients for a successful program are at hand, especially as regards disposal in natural salt formations. These include laboratory studies of appropriate rock deformation, numerical analyses of thermal and mechanical stresses around openings, and in situ field tests. We shall comment on each of these three major areas in turn. We shall then offer recommendations for their improvement, and, finally, we shall make more general recommendations for future considerations of the OWI radioactive waste disposal program

  7. Yogurt and Cardiometabolic Diseases: A Critical Review of Potential Mechanisms.

    Science.gov (United States)

    Fernandez, Melissa Anne; Panahi, Shirin; Daniel, Noémie; Tremblay, Angelo; Marette, André

    2017-11-01

    Associations between yogurt intake and risk of diet-related cardiometabolic diseases (CMDs) have been the subject of recent research in epidemiologic nutrition. A healthy dietary pattern has been identified as a pillar for the prevention of weight gain and CMDs. Epidemiologic studies suggest that yogurt consumption is linked to healthy dietary patterns, lifestyles, and reduced risk of CMDs, particularly type 2 diabetes. However, to our knowledge, few to no randomized controlled trials have investigated yogurt intake in relation to cardiometabolic clinical outcomes. Furthermore, there has been little attempt to clarify the mechanisms that underlie the potential beneficial effects of yogurt consumption on CMDs. Yogurt is a nutrient-dense dairy food and has been suggested to reduce weight gain and prevent CMDs by contributing to intakes of protein, calcium, bioactive lipids, and several other micronutrients. In addition, fermentation with bacterial strains generates bioactive peptides, resulting in a potentially greater beneficial effect of yogurt on metabolic health than nonfermented dairy products such as milk. To date, there is little concrete evidence that the mechanisms proposed in observational studies to explain positive results of yogurt on CMDs or parameters are valid. Many proposed mechanisms are based on assumptions that commercial yogurts contain strain-specific probiotics, that viable yogurt cultures are present in adequate quantities, and that yogurt provides a minimum threshold dose of nutrients or bioactive components capable of exerting a physiologic effect. Therefore, the primary objective of this review is to investigate the plausibility of potential mechanisms commonly cited in the literature in order to shed light on the inverse associations reported between yogurt intake and various cardiometabolic health parameters that are related to its nutrient profile, bacterial constituents, and food matrix. This article reviews current gaps and challenges

  8. Underlying mechanisms of transient luminous events: a review

    Directory of Open Access Journals (Sweden)

    V. V. Surkov

    2012-08-01

    Full Text Available Transient luminous events (TLEs occasionally observed above a strong thunderstorm system have been the subject of a great deal of research during recent years. The main goal of this review is to introduce readers to recent theories of electrodynamics processes associated with TLEs. We examine the simplest versions of these theories in order to make their physics as transparent as possible. The study is begun with the conventional mechanism for air breakdown at stratospheric and mesospheric altitudes. An electron impact ionization and dissociative attachment to neutrals are discussed. A streamer size and mobility of electrons as a function of altitude in the atmosphere are estimated on the basis of similarity law. An alternative mechanism of air breakdown, runaway electron mechanism, is discussed. In this section we focus on a runaway breakdown field, characteristic length to increase avalanche of runaway electrons and on the role played by fast seed electrons in generation of the runaway breakdown. An effect of thunderclouds charge distribution on initiation of blue jets and gigantic jets is examined. A model in which the blue jet is treated as upward-propagating positive leader with a streamer zone/corona on the top is discussed. Sprite models based on streamer-like mechanism of air breakdown in the presence of atmospheric conductivity are reviewed. To analyze conditions for sprite generation, thunderstorm electric field arising just after positive cloud-to-ground stroke is compared with the thresholds for propagation of positively/negatively charged streamers and with runway breakdown. Our own estimate of tendril's length at the bottom of sprite is obtained to demonstrate that the runaway breakdown can trigger the streamer formation. In conclusion we discuss physical mechanisms of VLF (very low frequency and ELF (extremely low frequency phenomena associated with sprites.

  9. Mini-review: Molecular mechanisms of antifouling compounds

    KAUST Repository

    Qian, Pei-Yuan

    2013-04-01

    Various antifouling (AF) coatings have been developed to protect submerged surfaces by deterring the settlement of the colonizing stages of fouling organisms. A review of the literature shows that effective AF compounds with specific targets are ones often considered non-toxic. Such compounds act variously on ion channels, quorum sensing systems, neurotransmitters, production/release of adhesive, and specific enzymes that regulate energy production or primary metabolism. In contrast, AF compounds with general targets may or may not act through toxic mechanisms. These compounds affect a variety of biological activities including algal photosynthesis, energy production, stress responses, genotoxic damage, immunosuppressed protein expression, oxidation, neurotransmission, surface chemistry, the formation of biofilms, and adhesive production/release. Among all the targets, adhesive production/release is the most common, possibly due to a more extensive research effort in this area. Overall, the specific molecular targets and the molecular mechanisms of most AF compounds have not been identified. Thus, the information available is insufficient to draw firm conclusions about the types of molecular targets to be used as sensitive biomarkers for future design and screening of compounds with AF potential. In this review, the relevant advantages and disadvantages of the molecular tools available for studying the molecular targets of AF compounds are highlighted briefly and the molecular mechanisms of the AF compounds, which are largely a source of speculation in the literature, are discussed. © 2013 Copyright Taylor and Francis Group, LLC.

  10. Mechanical characterization of composite materials by optical techniques: A review

    Science.gov (United States)

    Bruno, Luigi

    2018-05-01

    The present review provides an overview of work published in recent years dealing with the mechanical characterization of composite materials performed by optical techniques. The paper emphasizes the strengths derived from the employment of full-field methods when the strain field of an anisotropic material must be evaluated. This is framed in contrast to the use of conventional measurement techniques, which provide single values of the measured quantities unable to offer thorough descriptions of deformation distribution. The review outlines the intensity and articulation of work in this research field to date and its ongoing importance not only in the academy, but also in industrial sectors where composite materials represent a strategic resource for development.

  11. Review of coaxial flow gas core nuclear rocket fluid mechanics

    International Nuclear Information System (INIS)

    Weinstein, H.

    1976-01-01

    In a prematurely aborted attempt to demonstrate the feasibility of using a gas core nuclear reactor as a rocket engine, NASA initiated a number of studies on the relevant fluid mechanics problems. These studies were carried out at NASA laboratories, universities and industrial research laboratories. Because of the relatively sudden termination of most of this work, a unified overview was never presented which demonstrated the accomplishments of the program and pointed out the areas where additional work was required for a full understanding of the cavity flow. This review attempts to fulfill a part of this need in two important areas

  12. [Review: plant polyphenols modulate lipid metabolism and related molecular mechanism].

    Science.gov (United States)

    Dai, Yan-li; Zou, Yu-xiao; Liu, Fan; Li, Hong-zhi

    2015-11-01

    Lipid metabolism disorder is an important risk factor to obesity, hyperlipidemia and type 2 diabetes as well as other chronic metabolic disease. It is also a key target in preventing metabolic syndrome, chronic disease prevention. Plant polyphenol plays an important role in maintaining or improving lipid profile in a variety of ways. including regulating cholesterol absorption, inhibiting synthesis and secretion of triglyceride, and lowering plasma low density lipoprotein oxidation, etc. The purpose of this article is to review the lipid regulation effects of plant polyphenols and its related mechanisms.

  13. A Review of Disintegration Mechanisms and Measurement Techniques.

    Science.gov (United States)

    Markl, Daniel; Zeitler, J Axel

    2017-05-01

    Pharmaceutical solid dosage forms (tablets or capsules) are the predominant form to administer active pharmaceutical ingredients (APIs) to the patient. Tablets are typically powder compacts consisting of several different excipients in addition to the API. Excipients are added to a formulation in order to achieve the desired fill weight of a dosage form, to improve the processability or to affect the drug release behaviour in the body. These complex porous systems undergo different mechanisms when they come in contact with physiological fluids. The performance of a drug is primarily influenced by the disintegration and dissolution behaviour of the powder compact. The disintegration process is specifically critical for immediate-release dosage forms. Its mechanisms and the factors impacting disintegration are discussed and methods used to study the disintegration in-situ are presented. This review further summarises mathematical models used to simulate disintegration phenomena and to predict drug release kinetics.

  14. A review of acrylamide toxicity and its mechanism

    Directory of Open Access Journals (Sweden)

    Ehsan Zamani

    2017-05-01

    Full Text Available Acrylamide (AA is an important industrial chemical agent that is mainly used in the production of polymers and copolymers. Recently it has been attention because of its production in the diet at high-temperature (>120 ºC processes such as cooking, frying, toasting, roasting or baking of high carbohydrate foods. According to high exposure to acrylamide, recognition of its toxic effect is necessary. Neurotoxicity, reproductive toxicity and immunotoxicity of AA were observed in several studies. There isn’t a clear mechanism that justifies this toxicity. In this study we reviewed the mechanisms of AA toxicity especially oxidative stress and apoptosis. AA can cause neurotoxicity, reproductive toxicity and genotoxicity on animal models. It showed neurotoxicity in human. We suggested the oxidative stress is the main factor for inducing of acrylamide toxicities. We advised that modifying of food processing methods can be as a good way for decreasing of AA production in foods.

  15. Mechanical behavior and stress effects in hard superconductors: a review

    International Nuclear Information System (INIS)

    Koch, C.C.; Easton, D.S.

    1977-11-01

    The mechanical properties of type II superconducting materials are reviewed as well as the effect of stress on the superconducting properties of these materials. The bcc alloys niobium-titanium and niobium-zirconium exhibit good strength and extensive ductility at room temperature. Mechanical tests on these alloys at 4.2 0 K revealed serrated stress-strain curves, nonlinear elastic effects and reduced ductility. The nonlinear behavior is probably due to twinning and detwinning or a reversible stress-induced martensitic transformation. The brittle A-15 compound superconductors, such as Nb 3 Sn and V 3 Ga, exhibit unusual elastic properties and structural instabilities at cryogenic temperatures. Multifilamentary composites consisting of superconducting filaments in a normal metal matrix are generally used for superconducting devices. The mechanical properties of alloy and compound composites, tapes, as well as composites of niobium carbonitride chemically vapor deposited on high strength carbon fibers are presented. Hysteretic stress-strain behavior in the metal matrix composites produces significant heat generation, an effect which may lead to degradation in the performance of high field magnets. Measurements of the critical current density, J/sub c/, under stress in a magnetic field are reported. Modest stress-reversible degradation in J/sub c/ was observed in niobium-titanium composites, while more serious degradation was found in Nb 3 Sn samples. The importance of mechanical behavior to device performance is discussed

  16. Humidity Sensors Principle, Mechanism, and Fabrication Technologies: A Comprehensive Review

    Science.gov (United States)

    Farahani, Hamid; Wagiran, Rahman; Hamidon, Mohd Nizar

    2014-01-01

    Humidity measurement is one of the most significant issues in various areas of applications such as instrumentation, automated systems, agriculture, climatology and GIS. Numerous sorts of humidity sensors fabricated and developed for industrial and laboratory applications are reviewed and presented in this article. The survey frequently concentrates on the RH sensors based upon their organic and inorganic functional materials, e.g., porous ceramics (semiconductors), polymers, ceramic/polymer and electrolytes, as well as conduction mechanism and fabrication technologies. A significant aim of this review is to provide a distinct categorization pursuant to state of the art humidity sensor types, principles of work, sensing substances, transduction mechanisms, and production technologies. Furthermore, performance characteristics of the different humidity sensors such as electrical and statistical data will be detailed and gives an added value to the report. By comparison of overall prospects of the sensors it was revealed that there are still drawbacks as to efficiency of sensing elements and conduction values. The flexibility offered by thick film and thin film processes either in the preparation of materials or in the choice of shape and size of the sensor structure provides advantages over other technologies. These ceramic sensors show faster response than other types. PMID:24784036

  17. Humidity Sensors Principle, Mechanism, and Fabrication Technologies: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Hamid Farahani

    2014-04-01

    Full Text Available Humidity measurement is one of the most significant issues in various areas of applications such as instrumentation, automated systems, agriculture, climatology and GIS. Numerous sorts of humidity sensors fabricated and developed for industrial and laboratory applications are reviewed and presented in this article. The survey frequently concentrates on the RH sensors based upon their organic and inorganic functional materials, e.g., porous ceramics (semiconductors, polymers, ceramic/polymer and electrolytes, as well as conduction mechanism and fabrication technologies. A significant aim of this review is to provide a distinct categorization pursuant to state of the art humidity sensor types, principles of work, sensing substances, transduction mechanisms, and production technologies. Furthermore, performance characteristics of the different humidity sensors such as electrical and statistical data will be detailed and gives an added value to the report. By comparison of overall prospects of the sensors it was revealed that there are still drawbacks as to efficiency of sensing elements and conduction values. The flexibility offered by thick film and thin film processes either in the preparation of materials or in the choice of shape and size of the sensor structure provides advantages over other technologies. These ceramic sensors show faster response than other types.

  18. Mechanisms Involved in Exercise-Induced Cardioprotection: A Systematic Review

    Science.gov (United States)

    Borges, Juliana Pereira; Lessa, Marcos Adriano

    2015-01-01

    Background Acute myocardial infarction is the leading cause of morbidity and mortality worldwide. Furthermore, research has shown that exercise, in addition to reducing cardiovascular risk factors, can also protect the heart against injury due to ischemia and reperfusion through a direct effect on the myocardium. However, the specific mechanism involved in exerciseinduced cardiac preconditioning is still under debate. Objective To perform a systematic review of the studies that have addressed the mechanisms by which aerobic exercise promotes direct cardioprotection against ischemia and reperfusion injury. Methods A search was conducted using MEDLINE, Literatura Latino-Americana e do Caribe de Informação em Ciências da Saúde, and Scientific Electronic Library Online databases. Data were extracted in a standardized manner by two independent researchers, who were responsible for assessing the methodological quality of the studies. Results The search retrieved 78 studies; after evaluating the abstracts, 30 studies were excluded. The manuscripts of the remaining 48 studies were completely read and, of these, 20 were excluded. Finally, 28 studies were included in this systematic review. Conclusion On the basis of the selected studies, the following are potentially involved in the cardioprotective response to exercise: increased heat shock protein production, nitric oxide pathway involvement, increased cardiac antioxidant capacity, improvement in ATP-dependent potassium channel function, and opioid system activation. Despite all the previous investigations, further research is still necessary to obtain more consistent conclusions. PMID:25830711

  19. Fracture Mechanics Analyses for Interface Crack Problems - A Review

    Science.gov (United States)

    Krueger, Ronald; Shivakumar, Kunigal; Raju, Ivatury S.

    2013-01-01

    Recent developments in fracture mechanics analyses of the interfacial crack problem are reviewed. The intent of the review is to renew the awareness of the oscillatory singularity at the crack tip of a bimaterial interface and the problems that occur when calculating mode mixity using numerical methods such as the finite element method in conjunction with the virtual crack closure technique. Established approaches to overcome the nonconvergence issue of the individual mode strain energy release rates are reviewed. In the recent literature many attempts to overcome the nonconvergence issue have been developed. Among the many approaches found only a few methods hold the promise of providing practical solutions. These are the resin interlayer method, the method that chooses the crack tip element size greater than the oscillation zone, the crack tip element method that is based on plate theory and the crack surface displacement extrapolation method. Each of the methods is validated on a very limited set of simple interface crack problems. However, their utility for a wide range of interfacial crack problems is yet to be established.

  20. Mechanical valve obstruction: Review of diagnostic and treatment strategies

    Science.gov (United States)

    Salamon, Jason; Munoz-Mendoza, Jerson; Liebelt, Jared J; Taub, Cynthia C

    2015-01-01

    Prosthetic valve obstruction (PVO) is a rare but feared complication of mechanical valve replacement. Diagnostic evaluation should focus on differentiating prosthetic valve thrombosis (PVT) from pannus formation, as their treatment options differ. History of sub-optimal anti-coagulation and post-op time course to development of PVO are useful clinical characteristics in differentiating thrombus from pannus formation. Treatment of PVT is influenced by the patient’s symptoms, valve location, degree of obstruction and thrombus size and may include thrombolysis or surgical intervention. Alternatively, pannus formation requires surgical intervention. The purpose of this article is to review the pathophysiology, epidemiology, diagnostic approach and treatment options for aortic and mitral valve PVO. PMID:26730292

  1. Epoxy Resin Based Composites, Mechanical and Tribological Properties: A Review

    Directory of Open Access Journals (Sweden)

    S.A. Bello

    2015-12-01

    Full Text Available High fuel consumption by automobile and aerospace vehicles built from legacy alloys has been a great challenge to global design and material engineers. This has called for researches into material development for the production of lighter materials of the same or even superior mechanical properties to the existing materials in this area of applications. This forms a part of efforts to achieve the global vision 2025 i.e to reduce the fuel consumption by automobile and aerospace vehicles by at least 75 %. Many researchers have identified advanced composites as suitable materials in this regard. Among the common matrices used for the development of advanced composites, epoxy resin has attained a dominance among its counterparts because of its excellent properties including chemical, thermal and electrical resistance properties, mechanical properties and dimensional stability. This review is a reflection of the extensive study on the currently ongoing research aimed at development of epoxy resin hybrid nanocomposites for engineering applications. In this paper, brief explanation has been given to different terms related to the research work and also, some previous works (in accordance with materials within authors’ reach in the area of the ongoing research have been reported.

  2. A review of NOx formation mechanisms in recovery furnaces

    International Nuclear Information System (INIS)

    Nichols, K.M.; Thompson, L.M.; Empie, H.J.

    1993-01-01

    Review of NOx formation studies shows that NO forms in recovery furnaces primarily by two independent mechanisms, thermal and fuel. Thermal NO formation is extremely temperature-sensitive. However, theoretical predictions indicate that recovery furnace temperatures are not high enough to form significant thermal NO. Fuel NO formation is less temperature-sensitive, and is related to fuel nitrogen content. Black liquors are shown to contain 0.05 to 0.24 weight percent fuel nitrogen. Conversion of just 20% of this would yield approximately 25-120 ppm NOx (at 8% 0 2 ) in the flue gas, enough to represent the majority of the total NOx. Data from operating recovery furnaces show NOx emissions ranging from near zero to over 100 ppm at 8% 0 2 . An apparent increase in recovery furnace NOx emissions was observed with increasing solids. This increase is much less than predicted by thermal NO formation theory, indicating that other NO formation/destruction mechanisms, such as fuel NO formation, are important. No data are available to show the relative importance of thermal and fuel NO to total NOx during black liquor combustion

  3. Review: Bioenergetic Fields and Their Biologic Effects Mechanism

    Directory of Open Access Journals (Sweden)

    Zahra Movaffaghi

    2007-04-01

    Full Text Available As interests in complementary and alternative medicine grows, the scientists are looking forward in researches which determine the mechanisms in which they exert their effectiveness. Some of these modalities like Yoga, Acupuncture, and especially other bio-field therapies such as none contact therapeutic touch, affects the bio-field which spreads throughout the body and into the space around it. According to physic’s law, when electricity flows throw the living tissues, like what happens in our heart and brain, biomagnetic fields are being induced in the surrounding space. Beside that moving charges like ions and free radicals which finally produce electromagnetic fields. Using very sensitive magnetometers, biomagnetic fields have been detected and get amplified up to 1000 times by meditation. This phenomenon could be the basis for most of most complementaty therapeutic approaches like therapeutic touch. On the other hand the electrical, magnetic and bio-magnetic fields have a well known application in conventional medicine. Modern research about bio-magnetism and magneto-biology suggests that in term of both aspects, the effects and the mechanisms for all the different looking modalities used in conventional medicine and complementary medicine which have commons in their fundamentals. This article reviews some of the recent works on biological effects of natural or artificial electromagnetic fields.

  4. Underlying Mechanisms of Tinnitus: Review and Clinical Implications

    Science.gov (United States)

    Henry, James A.; Roberts, Larry E.; Caspary, Donald M.; Theodoroff, Sarah M.; Salvi, Richard J.

    2016-01-01

    Background The study of tinnitus mechanisms has increased tenfold in the last decade. The common denominator for all of these studies is the goal of elucidating the underlying neural mechanisms of tinnitus with the ultimate purpose of finding a cure. While these basic science findings may not be immediately applicable to the clinician who works directly with patients to assist them in managing their reactions to tinnitus, a clear understanding of these findings is needed to develop the most effective procedures for alleviating tinnitus. Purpose The goal of this review is to provide audiologists and other health-care professionals with a basic understanding of the neurophysiological changes in the auditory system likely to be responsible for tinnitus. Results It is increasingly clear that tinnitus is a pathology involving neuroplastic changes in central auditory structures that take place when the brain is deprived of its normal input by pathology in the cochlea. Cochlear pathology is not always expressed in the audiogram but may be detected by more sensitive measures. Neural changes can occur at the level of synapses between inner hair cells and the auditory nerve and within multiple levels of the central auditory pathway. Long-term maintenance of tinnitus is likely a function of a complex network of structures involving central auditory and nonauditory systems. Conclusions Patients often have expectations that a treatment exists to cure their tinnitus. They should be made aware that research is increasing to discover such a cure and that their reactions to tinnitus can be mitigated through the use of evidence-based behavioral interventions. PMID:24622858

  5. Plant effects on soil denitrification - a review of potential mechanisms

    Science.gov (United States)

    Malique, Francois; Butterbach-Bahl, Klaus; Dannenmann, Michael

    2017-04-01

    Denitrification is a microbial process occurring in soils, both producing and consuming the potent greenhouse gas nitrous oxide (NO), competing for nitrate with plants and hydrological leaching pathways, removing nutrients and reactive nitrogen from the biosphere, and closing the global nitrogen cycle. Despite its obvious importance, denitrification remained among the least well quantified biogeochemical processes in soils. This is due to enormous methodological difficulties involved in the direct quantification of soil microbial denitrification rates (mainly with regard to the terminal product N2) and the denitrification nitrogen gas product ratios (NO:N2O:N2), Plants may affect denitrification through a myriad of mechanisms such as e.g., competition for nitrate and water, through oxygen consumption, by regulating litter quality and changing soil pH, and via the exudation of labile carbon or secondary plant compounds involved in shaping the rhizospheric microbial community. However, plant effects on denitrification so far hardly were quantified so that the actual extent of plant control on denitrification is largely unknown. Here, we summarize the current knowledge on mechanisms how plants can affect denitrification rates and N gas product ratios in soils at temporal scales from hours to days and years. We review earlier research to quantify plant effects on denitrification as well as critically discuss the limited methods currently available to quantify plant-soil-denitrifier interactions. Finally, we provide pointers to use plants as tools to manage denitrification, e.g. to improve N use efficiency in agricultural ecosystems and to minimize soil nitrous oxide emissions.

  6. Mechanics of aerosols in nuclear reactor safety: a review

    International Nuclear Information System (INIS)

    Loyalka, S.K.

    1983-01-01

    Although the estimated public risks from nuclear reactors are not high, a significant fraction of these arises from the accident sequences that lead to severe core damage. Calculation of release fractions of the core radioactive inventories for such accidents requires an understanding of the evolution of aerosols in primary coolant systems and reactor containment. The state-of-the-art in the mechanics of a single aerosol particle is reviewed and available work on coagulation of two aerosol particles is discussed. Progress in kinetic theory descriptions and experimental works is described and directions of future work are noted. The General Dynamic Equation for the aerosol distribution is considered, and several forms of this for conditions of interest are noted. Methods of solution that are discussed include analytical techniques, similarity transforms, moments methods and numerical techniques. Computer programs that have been developed in the past few years are also discussed, and their capabilities and limitations are noted. Finally, the comparison of computed results with the available experimental data is discussed, and needs for future research are emphasized. (author)

  7. Innovation and problem solving: a review of common mechanisms.

    Science.gov (United States)

    Griffin, Andrea S; Guez, David

    2014-11-01

    Behavioural innovations have become central to our thinking about how animals adjust to changing environments. It is now well established that animals vary in their ability to innovate, but understanding why remains a challenge. This is because innovations are rare, so studying innovation requires alternative experimental assays that create opportunities for animals to express their ability to invent new behaviours, or use pre-existing ones in new contexts. Problem solving of extractive foraging tasks has been put forward as a suitable experimental assay. We review the rapidly expanding literature on problem solving of extractive foraging tasks in order to better understand to what extent the processes underpinning problem solving, and the factors influencing problem solving, are in line with those predicted, and found, to underpin and influence innovation in the wild. Our aim is to determine whether problem solving can be used as an experimental proxy of innovation. We find that in most respects, problem solving is determined by the same underpinning mechanisms, and is influenced by the same factors, as those predicted to underpin, and to influence, innovation. We conclude that problem solving is a valid experimental assay for studying innovation, propose a conceptual model of problem solving in which motor diversity plays a more central role than has been considered to date, and provide recommendations for future research using problem solving to investigate innovation. This article is part of a Special Issue entitled: Cognition in the wild. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. An Updated Review of the Molecular Mechanisms in Drug Hypersensitivity

    Directory of Open Access Journals (Sweden)

    Chun-Bing Chen

    2018-01-01

    Full Text Available Drug hypersensitivity may manifest ranging from milder skin reactions (e.g., maculopapular exanthema and urticaria to severe systemic reactions, such as anaphylaxis, drug reactions with eosinophilia and systemic symptoms (DRESS/drug-induced hypersensitivity syndrome (DIHS, or Stevens–Johnson syndrome (SJS/toxic epidermal necrolysis (TEN. Current pharmacogenomic studies have made important strides in the prevention of some drug hypersensitivity through the identification of relevant genetic variants, particularly for genes encoding drug-metabolizing enzymes and human leukocyte antigens (HLAs. The associations identified by these studies are usually drug, phenotype, and ethnic specific. The drug presentation models that explain how small drug antigens might interact with HLA and T cell receptor (TCR molecules in drug hypersensitivity include the hapten theory, the p-i concept, the altered peptide repertoire model, and the altered TCR repertoire model. The broad spectrum of clinical manifestations of drug hypersensitivity involving different drugs, as well as the various pathomechanisms involved, makes the diagnosis and management of it more challenging. This review highlights recent advances in our understanding of the predisposing factors, immune mechanisms, pathogenesis, diagnostic tools, and therapeutic approaches for drug hypersensitivity.

  9. Anthocyanin Biosynthesis and Degradation Mechanisms in Solanaceous Vegetables: A Review

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2018-03-01

    Full Text Available Anthocyanins are a group of polyphenolic pigments that are ubiquitously found in the plant kingdom. In plants, anthocyanins play a role not only in reproduction, by attracting pollinators and seed dispersers, but also in protection against various abiotic and biotic stresses. There is accumulating evidence that anthocyanins have health-promoting properties, which makes anthocyanin metabolism an interesting target for breeders and researchers. In this review, the state of the art knowledge concerning anthocyanins in the Solanaceous vegetables, i.e., pepper, tomato, eggplant, and potato, is discussed, including biochemistry and biological function of anthocyanins, as well as their genetic and environmental regulation. Anthocyanin accumulation is determined by the balance between biosynthesis and degradation. Although the anthocyanin biosynthetic pathway has been well-studied in Solanaceous vegetables, more research is needed on the inhibition of biosynthesis and, in particular, the anthocyanin degradation mechanisms if we want to control anthocyanin content of Solanaceous vegetables. In addition, anthocyanin metabolism is distinctly affected by environmental conditions, but the molecular regulation of these effects is poorly understood. Existing knowledge is summarized and current gaps in our understanding are highlighted and discussed, to create opportunities for the development of anthocyanin-rich crops through breeding and environmental management.

  10. Nonextensive statistical mechanics: a brief review of its present status

    Directory of Open Access Journals (Sweden)

    CONSTANTINO TSALLIS

    2002-09-01

    Full Text Available We briefly review the present status of nonextensive statistical mechanics. We focus on (i the central equations of the formalism, (ii the most recent applications in physics and other sciences, (iii the a priori determination (from microscopic dynamics of the entropic index q for two important classes of physical systems, namely low-dimensional maps (both dissipative and conservative and long-range interacting many-body hamiltonian classical systems.Revisamos sumariamente o estado presente da mecânica estatística não-extensiva. Focalizamos em (i as equacões centrais do formalismo; (ii as aplicações mais recentes na física e em outras ciências, (iii a determinação a priori (da dinâmica microscópica do índice entrópico q para duas classes importantes de sistemas físicos, a saber, mapas de baixa dimensão (tanto dissipativos quanto conservativos e sistemas clássicos hamiltonianos de muitos corpos com interações de longo alcance.

  11. An Updated Review of the Molecular Mechanisms in Drug Hypersensitivity

    Science.gov (United States)

    Abe, Riichiro; Pan, Ren-You; Wang, Chuang-Wei

    2018-01-01

    Drug hypersensitivity may manifest ranging from milder skin reactions (e.g., maculopapular exanthema and urticaria) to severe systemic reactions, such as anaphylaxis, drug reactions with eosinophilia and systemic symptoms (DRESS)/drug-induced hypersensitivity syndrome (DIHS), or Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). Current pharmacogenomic studies have made important strides in the prevention of some drug hypersensitivity through the identification of relevant genetic variants, particularly for genes encoding drug-metabolizing enzymes and human leukocyte antigens (HLAs). The associations identified by these studies are usually drug, phenotype, and ethnic specific. The drug presentation models that explain how small drug antigens might interact with HLA and T cell receptor (TCR) molecules in drug hypersensitivity include the hapten theory, the p-i concept, the altered peptide repertoire model, and the altered TCR repertoire model. The broad spectrum of clinical manifestations of drug hypersensitivity involving different drugs, as well as the various pathomechanisms involved, makes the diagnosis and management of it more challenging. This review highlights recent advances in our understanding of the predisposing factors, immune mechanisms, pathogenesis, diagnostic tools, and therapeutic approaches for drug hypersensitivity. PMID:29651444

  12. Anthocyanin biosynthesis and degradation mechanisms in Solanaceous vegetables: a review

    Science.gov (United States)

    Liu, Ying; Tikunov, Yury; Schouten, Rob E.; Marcelis, Leo F. M.; Visser, Richard G. F.; Bovy, Arnaud

    2018-03-01

    Anthocyanins are a group of polyphenolic pigments that are ubiquitously found in the plant kingdom. In plants, anthocyanins play a role not only in reproduction, by attracting pollinators and seed dispersers, but also in protection against various abiotic and biotic stresses. There is accumulating evidence that anthocyanins have health-promoting properties, which makes anthocyanin metabolism an interesting target for breeders and researchers. In this review, the state of the art knowledge concerning anthocyanins in the Solanaceous vegetables, i.e. pepper, tomato, eggplant and potato, is discussed, including biochemistry and biological function of anthocyanins, as well as their genetic and environmental regulation. Anthocyanin accumulation is determined by the balance between biosynthesis and degradation. Although the anthocyanin biosynthetic pathway has been well studied in Solanaceous vegetables, more research is needed on the inhibition of biosynthesis and, in particular, the anthocyanin degradation mechanisms if we want to control anthocyanin content of Solanaceous vegetables. In addition, anthocyanin metabolism is distinctly affected by environmental conditions, but the molecular regulation of these effects is poorly understood. Existing knowledge is summarized and current gaps in our understanding are highlighted and discussed, to create opportunities for the development of anthocyanin-rich crops through breeding and environmental management.

  13. A review on mechanical properties of magnesium based nano composites

    Science.gov (United States)

    Tarafder, Nilanjan; Prasad, M. Lakshmi Vara

    2018-04-01

    A review was done on Magnesium (Mg) based composite materials reinforced with different nano particles such as TiO2, Cu, Y2O3, SiC, ZrO2 and Al2O3. TiO2 and Al2O3 nanoparticles were synthesised by melt deposition process. Cu, Y2O3, SiC and ZrO2 nanoparticles were synthesised by powder metallurgy process. Composite microstructural characteristics shows that the nano-size reinforcements are uniformly distributed in the composite matrix and also minimum porosity with solid interfacial integrity. The mechanical properties showed yield strength improvement by 0.2 percentage and Ultimate tensile strength (UTS) was also improved for all the nano-particles. But UTS was adversely affected with TiO2 reinforcement while ductility was increased. With Cu reinforcement elastic modulus, hardness and fracture resistance increased and improved the co-efficient of thermal expansion (CTE) of Mg based matrix. By Y2O3 reinforcement hardness, fracture resistance was improved and ductility reached maximum by 0.22 volume percentage of Y2O3 and decreased with succeeding increase in Y2O3 reinforcement. The readings exposed that mechanical properties were gathered from the composite comprising 2.0 weight percentage of Y2O3. Ductility and fracture resistance increased with ZrO2 reinforcement in Mg matrix. Using Al2O3 as reinforcement in Mg composite matrix hardness, elastic modulus and ductility was increased but porosity reduced with well interfacial integrity. Dissipation of energy in the form of damping capacity was resolved by classical vibration theory. The result showed that an increasing up to 0.4 volume percentage alumina content increases the damping capacity up to 34 percent. In another sample, addition of 2 weight percentage nano-Al2O3 particles showed big possibility in reducing CTE from 27.9-25.9×10-6 K-1 in Magnesium, tensile and yield strength amplified by 40MPa. In another test, Mg/1.1Al2O3 nanocomposite was manufactured by solidification process followed by hot extrusion

  14. Plastic deformation mechanisms of the uranium-alpha. Review

    International Nuclear Information System (INIS)

    Loureiro, A.P.

    1975-01-01

    A survey of the bibliography on the behaviour of the alpha-Uranium during its plastic deformation is made, with the aim of knowing the mechanisms which control that deformation. An analysis is made of some of the mechanisms suggested in the literature as controlling, with particular emphasis on the Peierls-Nabarro mechanism

  15. Obesity and Pulmonary Hypertension: A Review of Pathophysiologic Mechanisms

    Directory of Open Access Journals (Sweden)

    Scott E. Friedman

    2012-01-01

    Full Text Available Pulmonary hypertension (PH is a potentially life-threatening condition arising from a wide variety of pathophysiologic mechanisms. Effective treatment requires a systematic diagnostic approach to identify all reversible mechanisms. Many of these mechanisms are relevant to those afflicted with obesity. The unique mechanisms of PH in the obese include obstructive sleep apnea, obesity hypoventilation syndrome, anorexigen use, cardiomyopathy of obesity, and pulmonary thromboembolic disease. Novel mechanisms of PH in the obese include endothelial dysfunction and hyperuricemia. A wide range of effective therapies exist to mitigate the disability of PH in the obese.

  16. Genetic and epigenetic mechanisms of epilepsy: a review

    Directory of Open Access Journals (Sweden)

    Chen T

    2017-07-01

    Full Text Available Tian Chen,1,* Mohan Giri,2,* Zhenyi Xia,3 Yadu Nanda Subedi,2 Yan Li1 1Department of Health Management Center, Chongqing Three Gorges Central Hospital, Chongqing, People’s Republic of China; 2National Center for Rheumatic Diseases, Ratopul, Gaushala, Kathmandu, Nepal; 3Department of Thoracic Surgery, Chongqing Three Gorges Central Hospital, Chongqing, People’s Republic of China *These authors contributed equally to this work Abstract: Epilepsy is a common episodic neurological disorder or condition characterized by recurrent epileptic seizures, and genetics seems to play a key role in its etiology. Early linkage studies have localized multiple loci that may harbor susceptibility genes to epilepsy, and mutational analyses have detected a number of mutations involved in both ion channel and nonion channel genes in patients with idiopathic epilepsy. Genome-wide studies of epilepsy have found copy number variants at 2q24.2-q24.3, 7q11.22, 15q11.2-q13.3, and 16p13.11-p13.2, some of which disrupt multiple genes, such as NRXN1, AUTS2, NLGN1, CNTNAP2, GRIN2A, PRRT2, NIPA2, and BMP5, implicated for neurodevelopmental disorders, including intellectual disability and autism. Unfortunately, only a few common genetic variants have been associated with epilepsy. Recent exome-sequencing studies have found some genetic mutations, most of which are located in nonion channel genes such as the LGI1, PRRT2, EFHC1, PRICKLE, RBFOX1, and DEPDC5 and in probands with rare forms of familial epilepsy, and some of these genes are involved with the neurodevelopment. Since epigenetics plays a role in neuronal function from embryogenesis and early brain development to tissue-specific gene expression, epigenetic regulation may contribute to the genetic mechanism of neurodevelopment through which a gene and the environment interacting with each other affect the development of epilepsy. This review focused on the analytic tools used to identify epilepsy and then provided a

  17. Nacre biomineralisation: A review on the mechanisms of crystal nucleation.

    Science.gov (United States)

    Nudelman, Fabio

    2015-10-01

    The wide diversity of biogenic minerals that is found in nature, each with its own morphology, mechanical properties and composition, is remarkable. In order to produce minerals that are optimally adapted for their function, biomineralisation usually occurs under strict cellular control. This control is exerted by specialised proteins and polysaccharides that assemble into a 3-dimensional organic matrix framework, forming a microenvironment where mineral deposition takes place. Molluscs are unique in that they use a striking variety of structural motifs to build their shells, each made of crystals with different morphologies and different calcium carbonate polymorphs. Much of want is known about mollusc shell formation comes from studies on the nacreous layer, or mother-of-pearl. In this review, we discuss two existing models on the nucleation of aragonite crystals during nacre formation: heteroepitaxial nucleation and mineral bridges. The heteroepitaxial nucleation model is based on the identification of chemical functional groups and aragonite-nucleating proteins at the centre of crystal imprints. It proposes that during nacre formation, each aragonite tablet nucleates independently on a nucleation site that is formed by acidic proteins and/or glycoproteins adsorbed on the chitin scaffold. The mineral bridges model is based on the identification of physical connections between the crystals in a stack, which results in a large number of crystals across several layers sharing the same crystallographic orientation. These observations suggest that there is one nucleation event per stack of tablets. Once the first crystal nucleates and reaches the top interlamellar matrix, it continues growing through pores, giving rise to the next layer of nacre, subsequently propagating into a stack. We compare both models and propose that they work in concert to control crystal nucleation in nacre. De novo crystal nucleation has to occur at least once per stack of aligned crystals

  18. Woody biomass comminution and sorting - a review of mechanical methods

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Gunnar [Swedish Univ. of Agricultural Sciences, Dept. of Forest Resource Management, Umeaa (Sweden)], e-mail: gunnar.eriksson@slu.se

    2012-11-01

    The increased demand for woody biomass for heat and electricity and biorefineries means that each bio component must be used efficiently. Any increase in raw material supply in the short term is likely to require the use of trees from early thinnings, logging residues and stumps, assortments of low value compared to stemwood. However, sorting of the novel materials into bio components may increase their value considerably. The challenge is to 1) maximise the overall values of the different raw material fractions for different users, 2) minimise costs for raw material extraction, processing, storage and transportation. Comminution of the raw material (e.g. to chips, chunks, flakes and powder) and sorting the bio components (e.g. separating bark from pulp chips and separating alkali-rich needles and shots for combustion and gasification applications) are crucial processes in this optimisation. The purpose of this study has been to make a literature review of principles for comminution and sorting, with an emphasis on mechanical methods suitable outside industries. More efficient comminution methods can be developed when the wood is to a larger extent cut along the fibre direction, and closer to the surface (with less pressure to the sides of the knife). By using coarse comminution (chunking) rather than fine comminution (chipping), productivity at landings can be increased and energy saved, the resulting product will have better storage and drying properties. At terminals, any further comminution (if necessary) could use larger-scale equipment of higher efficiency. Rolls and flails can be used to an increasing extent for removing foliage and twigs, possibly in the terrain (for instance fitted on grapples). Physical parameters used for sorting of the main components of trees include particle size, density and shape (aerodynamic drag and lift), optical and IR properties and X-ray fluorescence. Although methods developed for pulp chip production from whole trees may not

  19. A Review of Sex Determining Mechanisms in Geckos (Gekkota: Squamata)

    OpenAIRE

    Gamble, T.

    2010-01-01

    Geckos are a species-rich clade of reptiles possessing diverse sex determining mechanisms. Some species possess genetic sex determination, with both male and female heterogamety, while other species have temperature-dependent sex determination. I compiled information from the literature on the taxonomic distribution of these sex determining mechanisms in geckos. Using phylogenetic data from the literature, I reconstructed the minimum number of transitions among these sex determining mechanism...

  20. 78 FR 36190 - Agency Information Collection Activities; Submission for OMB Review; IT Dashboard Feedback Mechanism

    Science.gov (United States)

    2013-06-17

    ... Information Collection Activities; Submission for OMB Review; IT Dashboard Feedback Mechanism AGENCY: Office... to review and approve a previously approved information collection requirement regarding IT Dashboard... identified by Information Collection 3090- 0285, IT Dashboard Feedback Mechanism, by any of the following...

  1. Sufficient Flexibility and Capacity in Electricity Markets with Renewables: A Review of Innovative Market Mechanisms

    DEFF Research Database (Denmark)

    Sekamane, Jonas Khubute; Katz, Jonas; Skytte, Klaus

    2017-01-01

    This review of the literature collects innovative market mechanisms that tend to get overlooked in the discussion of whether unassisted energy-only markets can ensure sufficient capacity or if capacity remuneration mechanisms are required. The paper complements existing literature reviews...... and pinpoints advantageous research areas relating to the market design of electricity systems with high shares of variable renewable energy...

  2. Proceedings of the Annual Mechanics of Composites Review (6th),

    Science.gov (United States)

    1981-02-01

    LONG RANGE ARTILLERY PROJECTILES: E. Lenoe, D. Oplinger, K. Ghandi , Army Materials & Mechanics Research Center 129 PRELIMINARY DESIGN ASSESSMENT OF...RANGE ARTILLERY PROJECTILES E. Lenoe, D. Oplinger, K. Ghandi Army Materials & Mechanics Research Center/DRXMR-TM Watertown, MA 02172 Material not

  3. Mini-review: Molecular mechanisms of antifouling compounds

    KAUST Repository

    Qian, Pei-Yuan; Chen, Lianguo; Xu, Ying

    2013-01-01

    Various antifouling (AF) coatings have been developed to protect submerged surfaces by deterring the settlement of the colonizing stages of fouling organisms. A review of the literature shows that effective AF compounds with specific targets

  4. Policy-Relevant Systematic Reviews to Strengthen Health Systems: Models and Mechanisms to Support Their Production

    Science.gov (United States)

    Oliver, Sandra; Dickson, Kelly

    2016-01-01

    Support for producing systematic reviews about health systems is less well developed than for those about clinical practice. From interviewing policy makers and systematic reviewers we identified institutional mechanisms which bring systematic reviews and policy priorities closer by harnessing organisational and individual motivations, emphasising…

  5. Potential mechanisms linking probiotics to diabetes: a narrative review of the literature

    OpenAIRE

    Miraghajani, Maryam; Dehsoukhteh, Somayeh Shahraki; Rafie, Nahid; Hamedani, Sahar Golpour; Sabihi, Sima; Ghiasvand, Reza

    2017-01-01

    ABSTRACT CONTEXT AND OBJECTIVE: Some studies have suggested a wide range of possible mechanisms through which probiotics may play a role in diabetes prevention and treatment. However, the underlying mechanisms are not fully understood. We conducted this study to review the potential mechanisms suggested for the effect of probiotics in diabetes. DESIGN AND SETTING: Narrative review conducted at the Food Security Research Center of Isfahan. METHODS: A search in the electronic databases ME...

  6. Conservative management of mechanical neck disorders: a systematic review

    NARCIS (Netherlands)

    Gross, Anita R.; Goldsmith, Charlie; Hoving, Jan L.; Haines, Ted; Peloso, Paul; Aker, Peter; Santaguida, Pasqualina; Myers, Cynthia

    2007-01-01

    OBJECTIVE: To determine if conservative treatments (manual therapies, physical medicine methods, medication, and patient education) relieved pain or improved function/disability, patient satisfaction, and global perceived effect in adults with acute, subacute, and chronic mechanical neck disorders

  7. A Review of Sex Determining Mechanisms in Geckos (Gekkota: Squamata)

    Science.gov (United States)

    Gamble, T.

    2010-01-01

    Geckos are a species-rich clade of reptiles possessing diverse sex determining mechanisms. Some species possess genetic sex determination, with both male and female heterogamety, while other species have temperature-dependent sex determination. I compiled information from the literature on the taxonomic distribution of these sex determining mechanisms in geckos. Using phylogenetic data from the literature, I reconstructed the minimum number of transitions among these sex determining mechanisms with parsimony-based ancestral state reconstruction. While only a small number of gecko species have been characterized, numerous changes among sex determining mechanisms were inferred. This diversity, coupled with the high frequency of transitions, makes geckos excellent candidates as a model clade for the study of vertebrate sex determination and evolution. PMID:20234154

  8. Methods, Mechanism, and Applications of Photodeposition in Photocatalysis: A Review

    NARCIS (Netherlands)

    Wenderich, Kasper; Mul, Guido

    2016-01-01

    In this review, for a variety of metals and semiconductors, an attempt is made to generalize observations in the literature on the effect of process conditions applied during photodeposition on (i) particle size distributions, (ii) oxidation states of the metals obtained, and (iii) consequences for

  9. Pain and disability in osteoarthritis : a review of biobehavioral mechanisms

    NARCIS (Netherlands)

    Dekker, J; Boot, B; van der Woude, L H; Bijlsma, J W

    Pain and disability are cardinal symptoms in osteoarthritis. The literature is reviewed in order to identify causes of these symptoms at the articular, kinesiological, and psychological level. It is concluded that pain and disability are associated with degeneration of cartilage and bone (articular

  10. A review on the molecular mechanism of plants rooting modulated ...

    African Journals Online (AJOL)

    Phytohormones, especially auxin, played an essential role in regulating roots developments. This review focused on recent advances in the research of plants rooting genomics and proteomics, including auxin biosynthesis, metabolism, transport, and signaling pathway which are involved in modulating plants rooting and ...

  11. Book review: Partial Differential Equations and Fluid Mechanics

    NARCIS (Netherlands)

    Muntean, A.

    2011-01-01

    The baak is the result of the workshop Partial Differential Equations and Fluid Dynamics that look place at the Mathematics Institute of the University of Warwick. May 21st - 23rd, 2007. It contains ten review and research papers which provide an accessible summary of a wide range of active research

  12. Review of Student Difficulties in Upper-Level Quantum Mechanics

    Science.gov (United States)

    Singh, Chandralekha; Marshman, Emily

    2015-01-01

    Learning advanced physics, in general, is challenging not only due to the increased mathematical sophistication but also because one must continue to build on all of the prior knowledge acquired at the introductory and intermediate levels. In addition, learning quantum mechanics can be especially challenging because the paradigms of classical…

  13. Tumor necrosis factor antagonist mechanisms of action: a comprehensive review

    NARCIS (Netherlands)

    Tracey, Daniel; Klareskog, Lars; Sasso, Eric H.; Salfeld, Jochen G.; Tak, Paul P.

    2008-01-01

    During the past 30 years, elucidation of the pathogenesis of rheumatoid arthritis, Crohn's disease, psoriasis, psoriatic arthritis and ankylosing spondylitis at the cellular and molecular levels has revealed that these diseases share common mechanisms and are more closely related than was previously

  14. Suicide Clusters: A Review of Risk Factors and Mechanisms

    Science.gov (United States)

    Haw, Camilla; Hawton, Keith; Niedzwiedz, Claire; Platt, Steve

    2013-01-01

    Suicide clusters, although uncommon, cause great concern in the communities in which they occur. We searched the world literature on suicide clusters and describe the risk factors and proposed psychological mechanisms underlying the spatio-temporal clustering of suicides (point clusters). Potential risk factors include male gender, being an…

  15. Current Status of Mechanical Circulatory Support: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Kyriakos Spiliopoulos

    2012-01-01

    Full Text Available Heart failure is a major public health problem and its management requires a significant amount of health care resources. Even with administration of the best available medical treatment, the mortality associated with the disease remains high. As therapeutical strategies for heart failure have been refined, the number of patients suffering from the disease has expanded dramatically. Although heart transplantation still represents the gold standard therapeutical approach, the implantation of mechanical circulatory support devices (MCSDs evolved to a well-established management for this disease. The limited applicability of heart transplantation caused by a shortage of donor organs and the concurrent expand of the patient population with end-stage heart failure led to a considerable utilization of MCSDs. This paper outlines the current status of mechanical circulatory support.

  16. A Review of the Mechanical Properties of Concrete Containing Biofillers

    Science.gov (United States)

    Ezdiani Mohamad, Mazizah; Mahmood, Ali A.; Min, Alicia Yik Yee; Khalid, Nur Hafizah A.

    2016-11-01

    Sustainable construction is a rapidly increasing research area. Investigators of all backgrounds are using industrial and agro wastes to replace Portland cement in concrete to reduce greenhouse emissions and the corresponding decline in general health. Many types of wastes have been used as cement replacements in concrete including: fly ash, slag and rice husk ash in addition to others. This study investigates the possibility of producing a sustainable approach to construction through the partial replacement of concrete using biofillers. This will be achieved by studying the physical and mechanical properties of two widely available biological wastes in Malaysia; eggshell and palm oil fuel ash (POFA). The mechanical properties tests that were studied and compared are the compression, tensile and flexural tests.

  17. Review of research on the mechanical properties of the human tooth

    Science.gov (United States)

    Zhang, Ya-Rong; Du, Wen; Zhou, Xue-Dong; Yu, Hai-Yang

    2014-01-01

    ‘Bronze teeth' reflect the mechanical properties of natural teeth to a certain extent. Their mechanical properties resemble those of a tough metal, and the gradient of these properties lies in the direction from outside to inside. These attributes confer human teeth with effective mastication ability. Understanding the various mechanical properties of human teeth and dental materials is the basis for the development of restorative materials. In this study, the elastic properties, dynamic mechanical properties (visco-elasticity) and fracture mechanical properties of enamel and dentin were reviewed to provide a more thorough understanding of the mechanical properties of human teeth. PMID:24743065

  18. A Review of Neuropathic Pain: From Diagnostic Tests to Mechanisms

    OpenAIRE

    Truini, Andrea

    2017-01-01

    Neuropathic pain develops when the somatosensory nervous system is affected by a lesion or disease. Diagnostic tests aimed at assessing somatosensory afferent pathway damage are therefore useful for diagnosing neuropathic pain. Neuropathic pain manifests with a range of different symptoms such as ongoing burning pain, squeezing or pressure pain, paroxysmal electric shock-like sensations, stabbing pain, or mechanical dynamic allodynia. The various types of neuropathic pain are associated with ...

  19. Chest physiotherapy in mechanically ventilated children: a review.

    Science.gov (United States)

    Krause, M F; Hoehn, T

    2000-05-01

    Many physicians, nurses, and respiratory care practitioners consider chest physiotherapy (CP) a standard therapy in mechanically ventilated children beyond the newborn period. CP includes percussion, vibration, postural drainage, assisted coughing, and suctioning via the endotracheal tube. We searched the medical literature by using the key words "chest physiotherapy" and "chest physical therapy" (among others) by means of the MEDLINE and Current Contents databases. Because of the paucity of objective data, we examined all reports dealing with this topic, including studies on adult patients. For data extraction, not enough material existed to perform a meta-analysis. Despite its widespread use, almost no literature dealing with this treatment modality in pediatric patients exists. Studies with mechanically ventilated pediatric and adult patients have shown that CP is the most irritating routine intensive care procedure to patients. An increase in oxygen consumption often occurs when a patient receives CP accompanied by an elevation in heart rate, blood pressure, and intracranial pressure. CP leads to short-term decreases in oxygen, partial pressure in the blood, and major fluctuations in cardiac output. Changes in these vital signs and other variables may be even more pronounced in pediatric patients because the lung of a child is characterized by a higher closing capacity and the chest walls are characterized by a much higher compliance, thus predisposing the child to the development of atelectasis secondary to percussion and vibration. CP in mechanically ventilated children may not be considered a standard therapy. Controlled studies examining the impact of CP on the duration of mechanical ventilatory support, critical illness, and hospital stay are needed.

  20. Mechanisms of the anorexia of aging-a review.

    Science.gov (United States)

    Wysokiński, Adam; Sobów, Tomasz; Kłoszewska, Iwona; Kostka, Tomasz

    2015-08-01

    Many, even healthy, older people fail to adequately regulate food intake and experience loss of weight. Aging-associated changes in the regulation of appetite and the lack of hunger have been termed as the anorexia of aging. The etiology of the anorexia of aging is multi-factorial and includes a combination of physiological changes associated with aging (decline in smell and taste, reduced central and peripheral drive to eat, delayed gastric emptying), pathological conditions (depression, dementia, somatic diseases, medications and iatrogenic interventions, oral-health status), and social factors (poverty, loneliness). However, exact mechanisms of the anorexia of aging remain to be elucidated. Many neurobiological mechanisms may be secondary to age-related changes in body composition and not associated with anorexia per se. Therefore, further studies on pathophysiological mechanisms of the anorexia of aging should employ accurate measurement of body fat and lean mass. The anorexia of aging is associated with protein-energy malnutrition, sarcopenia, frailty, functional deterioration, morbidity, and mortality. Since this symptom can lead to dramatic consequences, early identification and effective interventions are needed. One of the most important goals in the geriatric care is to optimize nutritional status of the elderly.

  1. Multi-axial mechanical stimulation of tissue engineered cartilage: Review

    Directory of Open Access Journals (Sweden)

    S D Waldman

    2007-04-01

    Full Text Available The development of tissue engineered cartilage is a promising new approach for the repair of damaged or diseased tissue. Since it has proven difficult to generate cartilaginous tissue with properties similar to that of native articular cartilage, several studies have used mechanical stimuli as a means to improve the quantity and quality of the developed tissue. In this study, we have investigated the effect of multi-axial loading applied during in vitro tissue formation to better reflect the physiological forces that chondrocytes are subjected to in vivo. Dynamic combined compression-shear stimulation (5% compression and 5% shear strain amplitudes increased both collagen and proteoglycan synthesis (76 ± 8% and 73 ± 5%, respectively over the static (unstimulated controls. When this multi-axial loading condition was applied to the chondrocyte cultures over a four week period, there were significant improvements in both extracellular matrix (ECM accumulation and the mechanical properties of the in vitro-formed tissue (3-fold increase in compressive modulus and 1.75-fold increase in shear modulus. Stimulated tissues were also significantly thinner than the static controls (19% reduction suggesting that there was a degree of ECM consolidation as a result of long-term multi-axial loading. This study demonstrated that stimulation by multi-axial forces can improve the quality of the in vitro-formed tissue, but additional studies are required to further optimize the conditions to favour improved biochemical and mechanical properties of the developed tissue.

  2. BOOK REVIEW: Mind, Matter and Quantum Mechanics (2nd edition)

    Science.gov (United States)

    Mahler, G.

    2004-07-01

    Quantum mechanics is usually defined in terms of some loosely connected axioms and rules. Such a foundation is far from the beauty of, e.g., the `principles' underlying classical mechanics. Motivated, in addition, by notorious interpretation problems, there have been numerous attempts to modify or `complete' quantum mechanics. A first attempt was based on so-called hidden variables; its proponents essentially tried to expel the non-classical nature of quantum mechanics. More recent proposals intend to complete quantum mechanics not within mechanics proper but on a `higher (synthetic) level'; by means of a combination with gravitation theory (R Penrose), with quantum information theory (C M Caves, C A Fuchs) or with psychology and brain science (H P Stapp). I think it is fair to say that in each case the combination is with a subject that, per se, suffers from a very limited understanding that is even more severe than that of quantum mechanics. This was acceptable, though, if it could convincingly be argued that scientific progress desperately needs to join forces. Quantum mechanics of a closed system was a beautiful and well understood theory with its respective state being presented as a point on a deterministic trajectory in Liouville space---not unlike the motion of a classical N-particle system in its 6N-dimensional phase-space. Unfortunately, we need an inside and an outside view, we need an external reference frame, we need an observer. This unavoidable partition is the origin of most of the troubles we have with quantum mechanics. A pragmatic solution is introduced in the form of so-called measurement postulates: one of the various incompatible properties of the system under consideration is supposed to be realized (i.e. to become a fact, to be defined without fundamental dispersion) based on `instantaneous' projections within some externally selected measurement basis. As a result, the theory becomes essentially statistical rather than deterministic

  3. Metal Additive Manufacturing: A Review of Mechanical Properties (Postprint)

    Science.gov (United States)

    2016-04-21

    treated 1,257 1,436 Laser IN718 As built NA NA 590 845 11 NA 188 Heat treated 1,133 1,240 9 EBF3 IN718 As built XY 159 580 910 22 NA 189 EBF3 IN718 As... Raman S, Christensen A. 2010. Mechanical evaluation of porous titanium (Ti6Al4V) structures with electron beam melting (EBM). J. Mech. Behav. Biomed...335 Raman Studies of Carbon Nanostructures Ado Jorio and Antonio G. Souza Filho

  4. A literature review of empirical studies of philanthropy : eight mechanisms that drive charitable giving.

    NARCIS (Netherlands)

    Bekkers, René; Wiepking, Pamala

    2010-01-01

    The authors present an overview of the academic literature on charitable giving based on a literature review of more than 500 articles. They structure their review around the central question of why people donate money to charitable organizations. We identify eight mechanisms as the most important

  5. Insights into teaching quantum mechanics in secondary and lower undergraduate education: A literature review

    NARCIS (Netherlands)

    Krijtenburg-Lewerissa, Kim; Pol, Henk; Brinkman, Alexander; van Joolingen, Wouter|info:eu-repo/dai/nl/073458872

    2017-01-01

    This study presents a review of the current state of research on teaching quantum mechanics in secondary and lower undergraduate education. A conceptual approach to quantum mechanics is being implemented in more and more introductory physics courses around the world. Because of the differences

  6. Methods for Force Analysis of Overconstrained Parallel Mechanisms: A Review

    Science.gov (United States)

    Liu, Wen-Lan; Xu, Yun-Dou; Yao, Jian-Tao; Zhao, Yong-Sheng

    2017-11-01

    The force analysis of overconstrained PMs is relatively complex and difficult, for which the methods have always been a research hotspot. However, few literatures analyze the characteristics and application scopes of the various methods, which is not convenient for researchers and engineers to master and adopt them properly. A review of the methods for force analysis of both passive and active overconstrained PMs is presented. The existing force analysis methods for these two kinds of overconstrained PMs are classified according to their main ideas. Each category is briefly demonstrated and evaluated from such aspects as the calculation amount, the comprehensiveness of considering limbs' deformation, and the existence of explicit expressions of the solutions, which provides an important reference for researchers and engineers to quickly find a suitable method. The similarities and differences between the statically indeterminate problem of passive overconstrained PMs and that of active overconstrained PMs are discussed, and a universal method for these two kinds of overconstrained PMs is pointed out. The existing deficiencies and development directions of the force analysis methods for overconstrained systems are indicated based on the overview.

  7. Raynaud's Phenomenon: a Brief Review of the Underlying Mechanisms

    Directory of Open Access Journals (Sweden)

    Manal Fardoun

    2016-11-01

    Full Text Available Raynaud's phenomenon (RP is characterized by exaggerated cold-induced vasoconstriction. This augmented vasoconstriction occurs by virtue of a reflex response to cooling via the sympathetic nervous system as well as by local activation of α2C adrenoceptors (α2C-AR. In a cold-initiated, mitochondrion-mediated mechanism involving reactive oxygen species and the Rho/ROCK pathway, cytoskeletal rearrangement in vascular smooth muscle cells (VSMCs orchestrates the translocation of α2C-AR to the cell membrane, where this receptor readily interacts with its ligand. Different parameters are involved in this spatial and functional rescue of α2C-AR. Of notable relevance is the female hormone, 17β-estradiol, or estrogen. This is consistent with the high prevalence of RP in pre-menopausal women compared to age-matched males. In addition to dissecting the role of these various players, the contribution of pollution as well as genetic background to the onset and prevalence of RP are also discussed. Different therapeutic approaches employed as treatment modalities for this disease are also highlighted and analyzed. The lack of an appropriate animal model for RP mandates that more efforts be undertaken in order to better understand and eventually treat this disease. Although several lines of treatment are utilized, it is important to note that precaution is often effective in reducing severity or frequency of RP attacks.

  8. Review: Wind impacts on plant growth, mechanics and damage.

    Science.gov (United States)

    Gardiner, Barry; Berry, Peter; Moulia, Bruno

    2016-04-01

    Land plants have adapted to survive under a range of wind climates and this involve changes in chemical composition, physical structure and morphology at all scales from the cell to the whole plant. Under strong winds plants can re-orientate themselves, reconfigure their canopies, or shed needles, leaves and branches in order to reduce the drag. If the wind is too strong the plants oscillate until the roots or stem fail. The mechanisms of root and stem failure are very similar in different plants although the exact details of the failure may be different. Cereals and other herbaceous crops can often recover after wind damage and even woody plants can partially recovery if there is sufficient access to water and nutrients. Wind damage can have major economic impacts on crops, forests and urban trees. This can be reduced by management that is sensitive to the local site and climatic conditions and accounts for the ability of plants to acclimate to their local wind climate. Wind is also a major disturbance in many plant ecosystems and can play a crucial role in plant regeneration and the change of successional stage. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Psychological and neural mechanisms of experimental extinction: a selective review.

    Science.gov (United States)

    Delamater, Andrew R; Westbrook, R Frederick

    2014-02-01

    The present review examines key psychological concepts in the study of experimental extinction and implications these have for an understanding of the underlying neurobiology of extinction learning. We suggest that many of the signature characteristics of extinction learning (spontaneous recovery, renewal, reinstatement, rapid reacquisition) can be accommodated by the standard associative learning theory assumption that extinction results in partial erasure of the original learning together with new inhibitory learning. Moreover, we consider recent behavioral and neural evidence that supports the partial erasure view of extinction, but also note shortcomings in our understanding of extinction circuits as these relate to the negative prediction error concept. Recent work suggests that common prediction error and stimulus-specific prediction error terms both may be required to explain neural plasticity both in acquisition and extinction learning. In addition, we suggest that many issues in the content of extinction learning have not been fully addressed in current research, but that neurobiological approaches should be especially helpful in addressing such issues. These include questions about the nature of extinction learning (excitatory CS-No US, inhibitory CS-US learning, occasion setting processes), especially as this relates to studies of the micro-circuitry of extinction, as well as its representational content (sensory, motivational, response). An additional understudied problem in extinction research is the role played by attention processes and their underlying neural networks, although some research and theory converge on the idea that extinction is accompanied by attention decrements (i.e., habituation-like processes). Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Parameters affecting mechanical and thermal responses in bone drilling: A review.

    Science.gov (United States)

    Lee, JuEun; Chavez, Craig L; Park, Joorok

    2018-04-11

    Surgical bone drilling is performed variously to correct bone fractures, install prosthetics, or for therapeutic treatment. The primary concern in bone drilling is to extract donor bone sections and create receiving holes without damaging the bone tissue either mechanically or thermally. We review current results from experimental and theoretical studies to investigate the parameters related to such effects. This leads to a comprehensive understanding of the mechanical and thermal aspects of bone drilling to reduce their unwanted complications. This review examines the important bone-drilling parameters of bone structure, drill-bit geometry, operating conditions, and material evacuation, and considers the current techniques used in bone drilling. We then analyze the associated mechanical and thermal effects and their contributions to bone-drilling performance. In this review, we identify a favorable range for each parameter to reduce unwanted complications due to mechanical or thermal effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Review of International Experience with Renewable Energy Obligation Support Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Wiser, R.

    2005-06-01

    The main policy instruments currently used in the EU Member States to achieve the targets set for electricity produced from renewable energy sources are: (1) the quota obligation system; (2) the feed-in tariff system; and (3) the tendering system. The current study aims to review the experience gained with the quota obligation system. The report provides an overview of the regions where obligation systems have been implemented and contains a detailed evaluation of the performance of the obligation systems in the USA, the UK and in Sweden. The obligation systems in these countries have been evaluated based on the following criteria: Effectiveness; Market efficiency; Certainty for the renewable energy industry; Cost effectiveness; Stakeholder support for the obligation system; and Equity. The evaluation of international experiences with the obligation system gives rise to a mixed picture. Although an obligation in theory is effective and cost effective, it seems too early to conclude that the system delivers these promises in practice. On the one hand this is due to the limited period of implementation that makes it hard to distinguish between the direct effect of the system and some teething problems that will be solved in due time. On the other hand, the conclusion can be drawn that the obligation is a complex system, which will only function well if designed carefully. It does seem worthwhile, however, to continue monitoring the experiences with the obligation system abroad, because this will further reveal whether the system is indeed effective and cost effective in practice. In the longer term, e.g. beyond 2010, the introduction of an obligation system in the Netherlands could be considered. Finally, as the design of support schemes is being improved, it appears that the basic concepts of both the obligation system and the feed in system have been refined in such a way that the two systems are gradually converging. An important difference between the two systems

  12. Review on structural fatigue of NiTi shape memory alloys: Pure mechanical and thermo-mechanical ones

    Directory of Open Access Journals (Sweden)

    Guozheng Kang

    2015-11-01

    Full Text Available Structural fatigue of NiTi shape memory alloys is a key issue that should be solved in order to promote their engineering applications and utilize their unique shape memory effect and super-elasticity more sufficiently. In this paper, the latest progresses made in experimental and theoretical analyses for the structural fatigue features of NiTi shape memory alloys are reviewed. First, macroscopic experimental observations to the pure mechanical and thermo-mechanical fatigue features of the alloys are summarized; then the state-of-arts in the mechanism analysis of fatigue rupture are addressed; further, advances in the construction of fatigue failure models are provided; finally, summary and future topics are outlined.

  13. Technical note. A review of the mechanical integrity of the canister

    International Nuclear Information System (INIS)

    Segle, Peter

    2012-01-01

    Background: The Swedish Radiation Safety Authority (SSM) reviews the Swedish Nuclear Fuel Company's (SKB) applications under the Act on Nuclear Activities (SFS 1984:3) for the construction and operation of a repository for spent nuclear fuel and for an encapsulation facility. As part of the review, SSM commissions consultants to carry out work in order to obtain information on specific issues. The results from the consultants' tasks are reported in SSM's Technical Note series. Objectives of the project: This project is part of SSM:s review of SKB:s license application for final disposal of spent nuclear fuel. The assignment concerns a review of the mechanical integrity of the canister. Summary by the author: An introductory review of SR-Site has been conducted with respect to the mechanical integrity of the canister. The review is focused on the copper canister and the nodular cast iron insert. Review results show that a number of loads and loading scenarios for the copper canister has not been analysed by SKB. The importance of sufficient creep ductility of the copper material and sufficient ductility and fracture toughness of the nodular cast iron material is pointed out in the review. A sensitivity study is suggested where the impact of these properties on the mechanical integrity of the canister is investigated. It is also suggested that potential damage mechanisms influencing these properties are further investigated. SKB's modelling of creep elongation at rupture under repository conditions is questioned. Needs for complementary information from SKB for the main review of SR-Site is listed. A list of review topics for SSM is also suggested

  14. Endocrine-disrupting Chemicals: Review of Toxicological Mechanisms Using Molecular Pathway Analysis

    Science.gov (United States)

    Yang, Oneyeol; Kim, Hye Lim; Weon, Jong-Il; Seo, Young Rok

    2015-01-01

    Endocrine disruptors are known to cause harmful effects to human through various exposure routes. These chemicals mainly appear to interfere with the endocrine or hormone systems. As importantly, numerous studies have demonstrated that the accumulation of endocrine disruptors can induce fatal disorders including obesity and cancer. Using diverse biological tools, the potential molecular mechanisms related with these diseases by exposure of endocrine disruptors. Recently, pathway analysis, a bioinformatics tool, is being widely used to predict the potential mechanism or biological network of certain chemicals. In this review, we initially summarize the major molecular mechanisms involved in the induction of the above mentioned diseases by endocrine disruptors. Additionally, we provide the potential markers and signaling mechanisms discovered via pathway analysis under exposure to representative endocrine disruptors, bisphenol, diethylhexylphthalate, and nonylphenol. The review emphasizes the importance of pathway analysis using bioinformatics to finding the specific mechanisms of toxic chemicals, including endocrine disruptors. PMID:25853100

  15. The meridian system and mechanism of acupuncture: a comparative review. Part 3: Mechanisms of acupuncture therapies.

    Science.gov (United States)

    Chang, Shyang

    2013-06-01

    The human body is a hierarchical organism containing many levels of mutually interacting oscillatory systems. From the viewpoint of traditional Chinese medicine, health is a state of harmony emergent from the interactions of these systems and disease is a state of discord. Hence, human diseases are considered as disturbed functions rather than changed structures. Indeed, the change from normal to abnormal structure may be beneficent rather than maleficent. For example, when one kidney becomes twice the normal size following the destruction of the other kidney, it is good and not bad for us because we might be dead otherwise. Therefore, in Part 3 of this three-part series, emphasis is mainly laid on the acupuncture mechanisms of treating disturbed physiological functions rather than disordered structures. At first, the basic tenets of conventional neuroscience and cardiology are reevaluated so that clear understanding of how nervous and cardiovascular systems work together can be obtained. Then, the general principles of diagnosis and treatment in traditional Chinese medicine from the integrative perspective of complex dynamic systems are proposed. Finally, mechanisms of acupuncture therapies for treating 14 different categories of disorders will be elucidated via the magneto-electric inductive effects of the meridian system. Copyright © 2013. Published by Elsevier B.V.

  16. A review of protective factors and causal mechanisms that enhance the mental health of Indigenous Circumpolar youth

    OpenAIRE

    Petrasek MacDonald, Joanna; Ford, James D.; Cunsolo Willox, Ashlee; Ross, Nancy A.

    2013-01-01

    Objectives To review the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. Study design A systematic literature review of peer-reviewed English-language research was conducted to systematically examine the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. Methods This review followed the Preferred Reporting Items for Systematic Reviews and Meta-An...

  17. Standard Review Plan for the review of financial assurance mechanisms for decommissioning under 10 CFR Parts 30, 40, 70, and 72

    International Nuclear Information System (INIS)

    1989-08-01

    Standard Review Plan (SRP) for the Review of Financial Assurance Mechanisms for Decommissioning under 10 CFR Parts 30, 40, 70 and 72, is prepared for the guidance of Nuclear Regulatory Commission staff reviewers in performing reviews of applications from material licensees affected by the decommissioning regulations established June 27, 1988 (53FR24018). The principal purpose of the SRP is to assure the quality and uniformity of staff reviews and to present a base from which to evaluate the financial assurance aspects of the applications. The SRP identifies who performs the review, the matters that are reviewed, the basis for the review, how the review is performed, and the conclusions that are sought

  18. APPLIED MECHANICS REVIEWS, WADEX WORD AND AUTHOR INDEX, VOLUME XVI, 1963,

    Science.gov (United States)

    Author inDEX ) an IBM 1401 prepared mechanical index, extension of KWIC. WADEX usable for browsing and searching. This second WADEX is based on 8,000 titles of APPLIED MECHANICS REVIEWS (AMR), Vol. 16, 1963, an international critical review magazine. In WADEX, titles printed fully with author names, and as many lines used as necessary (60 characters per line). WADEX entry: word in title (except forbidden word) or author’s name. Alphabetically sequenced entries printed out of context. Words are single words or hypenated word pairs or ’Tagged Words’ (TW).

  19. The meridian system and mechanism of acupuncture—A comparative review. Part 1: The meridian system

    Directory of Open Access Journals (Sweden)

    Shyang Chang

    2012-12-01

    Full Text Available In traditional Chinese medicine (TCM, acupuncture has been used to heal various diseases and physiologic malfunctions in clinical practice for more than 2500 years. Due to its efficacy, acupuncture has been recommended by the World Health Organization in 1980 as an effective alternative therapy for 43 different disorders. Over the past few decades, various theories of the meridian system and mechanisms have been proposed to explain how acupuncture might work. Most of these mechanisms, however, cannot yet explain conclusively why acupuncture is efficacious in treating so many different diseases. A plausible mechanism has been unavailable until recently. This is the first of a three-part series that aims to provide a comparative review of the aforementioned topics. Part 1 reviews the current indications for acupuncture, basic concepts of TCM, and the essence of the meridian system. To establish a mathematically rigorous framework of TCM, the chaotic wave theory of fractal continuum is proposed. This theory is then applied to characterize the essence of the meridian system. Parts 2 and 3 will review the possible mechanisms of acupuncture analgesia and acupuncture therapies, respectively, based on biochemical, bioelectromagnetic, chaotic wave, and neurophysiologic approaches. It is sincerely hoped that this series of review articles can promote an understanding of the meridian system and acupuncture mechanisms to help patients in a logical and passionate way.

  20. The Role of Malware in Reported Cyber Espionage: A Review of the Impact and Mechanism

    OpenAIRE

    Gaute Wangen

    2015-01-01

    This is the journal's PDF originally published in Information, http://dx.doi.org/10.3390/info6020183 The recent emergence of the targeted use of malware in cyber espionage versus industry requires a systematic review for better understanding of its impact and mechanism. This paper proposes a basic taxonomy to document major cyber espionage incidents, describing and comparing their impacts (geographic or political targets, origins and motivations) and their mechanisms (dropper, propagation,...

  1. Concise review: Bone marrow for the treatment of spinal cord injury: mechanisms and clinical applications.

    OpenAIRE

    Wright, KT; El Masri, W; Osman, A; Chowdhury, J; Johnson, WEB

    2011-01-01

    Transplantation of bone marrow stem cells into spinal cord lesions enhances axonal regeneration and promotes functional recovery in animal studies. There are two types of adult bone marrow stem cell; hematopoietic stem cells (HSCs), and mesenchymal stem cells (MSCs). The mechanisms by which HSCs and MSCs might promote spinal cord repair following transplantation have been extensively investigated. The objective of this review is to discuss these mechanisms; we briefly consider the controversi...

  2. Resonance-Based Sparse Signal Decomposition and its Application in Mechanical Fault Diagnosis: A Review.

    Science.gov (United States)

    Huang, Wentao; Sun, Hongjian; Wang, Weijie

    2017-06-03

    Mechanical equipment is the heart of industry. For this reason, mechanical fault diagnosis has drawn considerable attention. In terms of the rich information hidden in fault vibration signals, the processing and analysis techniques of vibration signals have become a crucial research issue in the field of mechanical fault diagnosis. Based on the theory of sparse decomposition, Selesnick proposed a novel nonlinear signal processing method: resonance-based sparse signal decomposition (RSSD). Since being put forward, RSSD has become widely recognized, and many RSSD-based methods have been developed to guide mechanical fault diagnosis. This paper attempts to summarize and review the theoretical developments and application advances of RSSD in mechanical fault diagnosis, and to provide a more comprehensive reference for those interested in RSSD and mechanical fault diagnosis. Followed by a brief introduction of RSSD's theoretical foundation, based on different optimization directions, applications of RSSD in mechanical fault diagnosis are categorized into five aspects: original RSSD, parameter optimized RSSD, subband optimized RSSD, integrated optimized RSSD, and RSSD combined with other methods. On this basis, outstanding issues in current RSSD study are also pointed out, as well as corresponding instructional solutions. We hope this review will provide an insightful reference for researchers and readers who are interested in RSSD and mechanical fault diagnosis.

  3. Review of collapse triggering mechanism of collapsible soils due to wetting

    Directory of Open Access Journals (Sweden)

    Ping Li

    2016-04-01

    Full Text Available Loess soil deposits are widely distributed in arid and semi-arid regions and constitute about 10% of land area of the world. These soils typically have a loose honeycomb-type meta-stable structure that is susceptible to a large reduction in total volume or collapse upon wetting. Collapse characteristics contribute to various problems to infrastructures that are constructed on loess soils. For this reason, collapse triggering mechanism for loess soils has been of significant interest for researchers and practitioners all over the world. This paper aims at providing a state-of-the-art review on collapse mechanism with special reference to loess soil deposits. The collapse mechanism studies are summarized under three different categories, i.e. traditional approaches, microstructure approach, and soil mechanics-based approaches. The traditional and microstructure approaches for interpreting the collapse behavior are comprehensively summarized and critically reviewed based on the experimental results from the literature. The soil mechanics-based approaches proposed based on the experimental results of both compacted soils and natural loess soils are reviewed highlighting their strengths and limitations for estimating the collapse behavior. Simpler soil mechanics-based approaches with less parameters or parameters that are easy-to-determine from conventional tests are suggested for future research to better understand the collapse behavior of natural loess soils. Such studies would be more valuable for use in conventional geotechnical engineering practice applications.

  4. BOOK REVIEW: Advanced Mechanics and General Relativity Advanced Mechanics and General Relativity

    Science.gov (United States)

    Louko, Jorma

    2011-04-01

    Joel Franklin's textbook `Advanced Mechanics and General Relativity' comprises two partially overlapping, partially complementary introductory paths into general relativity at advanced undergraduate level. Path I starts with the Lagrangian and Hamiltonian formulations of Newtonian point particle motion, emphasising the action principle and the connection between symmetries and conservation laws. The concepts are then adapted to point particle motion in Minkowski space, introducing Lorentz transformations as symmetries of the action. There follows a focused development of tensor calculus, parallel transport and curvature, using examples from Newtonian mechanics and special relativity, culminating in the field equations of general relativity. The Schwarzschild solution is analysed, including a detailed discussion of the tidal forces on a radially infalling observer. Basics of gravitational radiation are examined, highlighting the similarities to and differences from electromagnetic radiation. The final topics in Path I are equatorial geodesics in Kerr and the motion of a relativistic string in Minkowski space. Path II starts by introducing scalar field theory on Minkowski space as a limit of point masses connected by springs, emphasising the action principle, conservation laws and the energy-momentum tensor. The action principle for electromagnetism is introduced, and the coupling of electromagnetism to a complex scalar field is developed in a detailed and pedagogical fashion. A free symmetric second-rank tensor field on Minkowski space is introduced, and the action principle of general relativity is recovered from coupling the second-rank tensor to its own energy-momentum tensor. Path II then merges with Path I and, supplanted with judicious early selections from Path I, can proceed to the Schwarzschild solution. The choice of material in each path is logical and focused. A notable example in Path I is that Lorentz transformations in Minkowki space are introduced

  5. Atomic Force Microscopy in Characterizing Cell Mechanics for Biomedical Applications: A Review.

    Science.gov (United States)

    Li, Mi; Dang, Dan; Liu, Lianqing; Xi, Ning; Wang, Yuechao

    2017-09-01

    Cell mechanics is a novel label-free biomarker for indicating cell states and pathological changes. The advent of atomic force microscopy (AFM) provides a powerful tool for quantifying the mechanical properties of single living cells in aqueous conditions. The wide use of AFM in characterizing cell mechanics in the past two decades has yielded remarkable novel insights in understanding the development and progression of certain diseases, such as cancer, showing the huge potential of cell mechanics for practical applications in the field of biomedicine. In this paper, we reviewed the utilization of AFM to characterize cell mechanics. First, the principle and method of AFM single-cell mechanical analysis was presented, along with the mechanical responses of cells to representative external stimuli measured by AFM. Next, the unique changes of cell mechanics in two types of physiological processes (stem cell differentiation, cancer metastasis) revealed by AFM were summarized. After that, the molecular mechanisms guiding cell mechanics were analyzed. Finally the challenges and future directions were discussed.

  6. Schizophrenia and depression: A systematic review of the effectiveness and the working mechanisms behind acupuncture

    NARCIS (Netherlands)

    Bosch, M.P.C.; Noort, M.W.M.L. van den; Staudte, H.; Lim, S.

    2015-01-01

    OBJECTIVE: This systematic review assessed clinical evidence for the use of acupuncture as an add-on treatment in patients with depression and schizophrenia and for its underlying working mechanisms. DATA SOURCES: Four databases (Medline, Scopus, ERIC, and the Cochrane Library) were searched with a

  7. Respiratory Care year in review 2013: airway management, noninvasive monitoring, and invasive mechanical ventilation.

    Science.gov (United States)

    Durbin, Charles G; Blanch, Lluís; Fan, Eddy; Hess, Dean R

    2014-04-01

    Fundamental to respiratory care practice are airway management, noninvasive monitoring, and invasive mechanical ventilation. The purpose of this paper is to review the recent literature related to these topics in a manner that is most likely to have interest to the readers of Respiratory Care.

  8. Tutorial review of spent-fuel degradation mechanisms under dry-storage conditions

    International Nuclear Information System (INIS)

    Einziger, R.E.

    1983-02-01

    This tutorial reviews our present understanding of fuel-rod degradation over a range of possible dry-storage environments. Three areas are covered: (1) why study fuel-rod degradation; (2) cladding-degradation mechanisms; and (3) the status of fuel-oxidation studies

  9. Chronic post-thoracotomy pain: a critical review of pathogenic mechanisms and strategies for prevention

    DEFF Research Database (Denmark)

    Wildgaard, Kim; Ravn, Jesper; Kehlet, Henrik

    2009-01-01

    Chronic pain complaints after thoracic surgery represent a significant clinical problem in 25-60% of patients. Results from thoracic and other surgical procedures suggest multiple pathogenic mechanisms that include pre-, intra-, and postoperative factors. This review attempts to analyse the metho...

  10. Order information coding in working memory: Review of behavioural studies and cognitive mechanisms

    Directory of Open Access Journals (Sweden)

    Barbara Dolenc

    2014-06-01

    Full Text Available Executive processes, such as coding for sequential order, are of extreme importance for higher-order cognitive tasks. One of the significant questions is, how order information is coded in working memory and what cognitive mechanisms and processes mediate it. The aim of this review paper is to summarize results of studies that explore whether order and item memory are two separable processes. Furthermore, we reviewed evidence for each of the proposed cognitive mechanism that might mediate order processing. Previous behavioural and neuroimaging data suggest different representation and processing of item and order information in working memory. Both information are maintained and recalled separately and this separation seems to hold for recognition as well as for recall. To explain the result of studies of order coding, numerous cognitive mechanisms were proposed. We focused on four different mechanisms by which order information might be coded and retrieved, namely inter-item associations, direct coding, hierarchical coding and magnitude coding. Each of the mechanisms can explain some of the aspect of order information coding, however none of them is able to explain all of the empirical findings. Due to its complex nature it is not surprising that a single mechanism has difficulties accounting for all the behavioral data and order memory may be more accurately characterized as the result of a set of mechanisms rather than a single one. Moreover, the findings beget a question of whether different types of memory for order information might exist.

  11. Modified Continuum Mechanics Modeling on Size-Dependent Properties of Piezoelectric Nanomaterials: A Review

    Directory of Open Access Journals (Sweden)

    Zhi Yan

    2017-01-01

    Full Text Available Piezoelectric nanomaterials (PNs are attractive for applications including sensing, actuating, energy harvesting, among others in nano-electro-mechanical-systems (NEMS because of their excellent electromechanical coupling, mechanical and physical properties. However, the properties of PNs do not coincide with their bulk counterparts and depend on the particular size. A large amount of efforts have been devoted to studying the size-dependent properties of PNs by using experimental characterization, atomistic simulation and continuum mechanics modeling with the consideration of the scale features of the nanomaterials. This paper reviews the recent progresses and achievements in the research on the continuum mechanics modeling of the size-dependent mechanical and physical properties of PNs. We start from the fundamentals of the modified continuum mechanics models for PNs, including the theories of surface piezoelectricity, flexoelectricity and non-local piezoelectricity, with the introduction of the modified piezoelectric beam and plate models particularly for nanostructured piezoelectric materials with certain configurations. Then, we give a review on the investigation of the size-dependent properties of PNs by using the modified continuum mechanics models, such as the electromechanical coupling, bending, vibration, buckling, wave propagation and dynamic characteristics. Finally, analytical modeling and analysis of nanoscale actuators and energy harvesters based on piezoelectric nanostructures are presented.

  12. Modified Continuum Mechanics Modeling on Size-Dependent Properties of Piezoelectric Nanomaterials: A Review.

    Science.gov (United States)

    Yan, Zhi; Jiang, Liying

    2017-01-26

    Piezoelectric nanomaterials (PNs) are attractive for applications including sensing, actuating, energy harvesting, among others in nano-electro-mechanical-systems (NEMS) because of their excellent electromechanical coupling, mechanical and physical properties. However, the properties of PNs do not coincide with their bulk counterparts and depend on the particular size. A large amount of efforts have been devoted to studying the size-dependent properties of PNs by using experimental characterization, atomistic simulation and continuum mechanics modeling with the consideration of the scale features of the nanomaterials. This paper reviews the recent progresses and achievements in the research on the continuum mechanics modeling of the size-dependent mechanical and physical properties of PNs. We start from the fundamentals of the modified continuum mechanics models for PNs, including the theories of surface piezoelectricity, flexoelectricity and non-local piezoelectricity, with the introduction of the modified piezoelectric beam and plate models particularly for nanostructured piezoelectric materials with certain configurations. Then, we give a review on the investigation of the size-dependent properties of PNs by using the modified continuum mechanics models, such as the electromechanical coupling, bending, vibration, buckling, wave propagation and dynamic characteristics. Finally, analytical modeling and analysis of nanoscale actuators and energy harvesters based on piezoelectric nanostructures are presented.

  13. Interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials: A review.

    Science.gov (United States)

    He, Jie; Yang, Xiaofang; Men, Bin; Wang, Dongsheng

    2016-01-01

    The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals (OH) from reactions between recyclable solid catalysts and H2O2 at acidic or even circumneutral pH. Hence, it can effectively oxidize refractory organics in water or soils and has become a promising environmentally friendly treatment technology. Due to the complex reaction system, the mechanism behind heterogeneous Fenton reactions remains unresolved but fascinating, and is crucial for understanding Fenton chemistry and the development and application of efficient heterogeneous Fenton technologies. Iron-based materials usually possess high catalytic activity, low cost, negligible toxicity and easy recovery, and are a superior type of heterogeneous Fenton catalysts. Therefore, this article reviews the fundamental but important interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials. OH, hydroperoxyl radicals/superoxide anions (HO2/O2(-)) and high-valent iron are the three main types of reactive oxygen species (ROS), with different oxidation reactivity and selectivity. Based on the mechanisms of ROS generation, the interfacial mechanisms of heterogeneous Fenton systems can be classified as the homogeneous Fenton mechanism induced by surface-leached iron, the heterogeneous catalysis mechanism, and the heterogeneous reaction-induced homogeneous mechanism. Different heterogeneous Fenton systems catalyzed by characteristic iron-based materials are comprehensively reviewed. Finally, related future research directions are also suggested. Copyright © 2015. Published by Elsevier B.V.

  14. Potential mechanisms linking probiotics to diabetes: a narrative review of the literature

    Directory of Open Access Journals (Sweden)

    Maryam Miraghajani

    Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Some studies have suggested a wide range of possible mechanisms through which probiotics may play a role in diabetes prevention and treatment. However, the underlying mechanisms are not fully understood. We conducted this study to review the potential mechanisms suggested for the effect of probiotics in diabetes. DESIGN AND SETTING: Narrative review conducted at the Food Security Research Center of Isfahan. METHODS: A search in the electronic databases MEDLINE (PubMed, Cochrane Library, Web of Science and Google scholar was performed up to October 2016. RESULTS: The initial search yielded 1214 reports. After removing duplicates, 704 titles and abstracts were screened. Finally, out of 83 full-text articles that were reviewed for eligibility, 30 articles were included in the final analysis. The anti-diabetic mechanisms for probiotics reported encompass intraluminal and direct effects on the intestinal mucosa and microbiota (n = 13, anti-inflammatory and immunomodulatory effects (n = 10, antioxidative effects (n = 5, effects on endoplasmic reticulum (ER stress and expression of genes involved in glucose homeostasis and insulin resistance (n = 6, with some studies pointing to more than one mechanism. CONCLUSION: The results may throw some light on the capacity of probiotics as a novel approach towards controlling diabetes. However, further human studies are warranted to elucidate and confirm the potential role of probiotics in diabetes prevention and treatment. Also, it needs to be ascertained whether the effectiveness of probiotics in diabetes prevention and treatment is dependent on the strain of the microorganisms.

  15. Mechanism change in a simulation of peer review: from junk support to elitism.

    Science.gov (United States)

    Paolucci, Mario; Grimaldo, Francisco

    2014-01-01

    Peer review works as the hinge of the scientific process, mediating between research and the awareness/acceptance of its results. While it might seem obvious that science would regulate itself scientifically, the consensus on peer review is eroding; a deeper understanding of its workings and potential alternatives is sorely needed. Employing a theoretical approach supported by agent-based simulation, we examined computational models of peer review, performing what we propose to call redesign , that is, the replication of simulations using different mechanisms . Here, we show that we are able to obtain the high sensitivity to rational cheating that is present in literature. In addition, we also show how this result appears to be fragile against small variations in mechanisms. Therefore, we argue that exploration of the parameter space is not enough if we want to support theoretical statements with simulation, and that exploration at the level of mechanisms is needed. These findings also support prudence in the application of simulation results based on single mechanisms, and endorse the use of complex agent platforms that encourage experimentation of diverse mechanisms.

  16. Review of thermodinamic and mechanical properties of hydrogen-transition metal systems

    International Nuclear Information System (INIS)

    Mathias, H.; Katz, Y.

    1978-04-01

    A large body of fundamental and empirical knowledge has been acquired during many years of research concerning the interactions between hydrogen and metals, the location of hydrogen in metal structures, its mobility in metals and its influence on mechanical properties of metals. Much progress has been made in the understanding of related phenomena, and various theories have been proposed, but considerable disagreement still exist about basic mechanisms involved. The growing interest in these subjects and their important role in science and technology are well documented by many reviews and symposia. A general survey of these topics with reference to experimental results and theories related to thermodynamic and mechanical properties of hydrogen-transition metal systems, such as H-Pd, H-Ti, H-Fe etc. is given in the present review. Special emphasis is given to hydrogen embrittlement of metals

  17. Regulatory mechanisms for absenteeism in the health sector: a systematic review of strategies and their implementation.

    Science.gov (United States)

    Kisakye, Angela N; Tweheyo, Raymond; Ssengooba, Freddie; Pariyo, George W; Rutebemberwa, Elizeus; Kiwanuka, Suzanne N

    2016-01-01

    A systematic review was undertaken to identify regulatory mechanisms aimed at mitigating health care worker absenteeism, to describe where and how they have been implemented as well as their possible effects. The goal was to propose potential policy options for managing the problem of absenteeism among human resources for health in low- and middle-income countries. Mechanisms described in this review are at the local workplace and broader national policy level. A comprehensive online search was conducted on EMBASE, CINAHL, PubMed, Google Scholar, Google, and Social Science Citation Index using MEDLINE search terms. Retrieved studies were uploaded onto reference manager and screened by two independent reviewers. Only publications in English were included. Data were extracted and synthesized according to the objectives of the review. Twenty six of the 4,975 published articles retrieved were included. All were from high-income countries and covered all cadres of health workers. The regulatory mechanisms and possible effects include 1) organizational-level mechanisms being reported as effective in curbing absenteeism in low- and middle-income countries (LMICs); 2) prohibition of private sector activities in LMICs offering benefits but presenting a challenge for the government to monitor the health workforce; 3) contractual changes from temporary to fixed posts having been associated with no reduction in absenteeism and not being appropriate for LMICs; 4) multifaceted work interventions being implemented in most settings; 5) the possibility of using financial and incentive regulatory mechanisms in LMICs; 6) health intervention mechanisms reducing absenteeism when integrated with exercise programs; and 7) attendance by legislation during emergencies being criticized for violating human rights in the United States and not being effective in curbing absenteeism. Most countries have applied multiple strategies to mitigate health care worker absenteeism. The success of these

  18. Regulatory mechanisms for absenteeism in the health sector: a systematic review of strategies and their implementation

    Science.gov (United States)

    Kisakye, Angela N; Tweheyo, Raymond; Ssengooba, Freddie; Pariyo, George W; Rutebemberwa, Elizeus; Kiwanuka, Suzanne N

    2016-01-01

    Background A systematic review was undertaken to identify regulatory mechanisms aimed at mitigating health care worker absenteeism, to describe where and how they have been implemented as well as their possible effects. The goal was to propose potential policy options for managing the problem of absenteeism among human resources for health in low- and middle-income countries. Mechanisms described in this review are at the local workplace and broader national policy level. Methods A comprehensive online search was conducted on EMBASE, CINAHL, PubMed, Google Scholar, Google, and Social Science Citation Index using MEDLINE search terms. Retrieved studies were uploaded onto reference manager and screened by two independent reviewers. Only publications in English were included. Data were extracted and synthesized according to the objectives of the review. Results Twenty six of the 4,975 published articles retrieved were included. All were from high-income countries and covered all cadres of health workers. The regulatory mechanisms and possible effects include 1) organizational-level mechanisms being reported as effective in curbing absenteeism in low- and middle-income countries (LMICs); 2) prohibition of private sector activities in LMICs offering benefits but presenting a challenge for the government to monitor the health workforce; 3) contractual changes from temporary to fixed posts having been associated with no reduction in absenteeism and not being appropriate for LMICs; 4) multifaceted work interventions being implemented in most settings; 5) the possibility of using financial and incentive regulatory mechanisms in LMICs; 6) health intervention mechanisms reducing absenteeism when integrated with exercise programs; and 7) attendance by legislation during emergencies being criticized for violating human rights in the United States and not being effective in curbing absenteeism. Conclusion Most countries have applied multiple strategies to mitigate health care

  19. Cellular and Molecular Mechanisms in Perioperative Hepatic Protection: A Review of Current Interventions

    Directory of Open Access Journals (Sweden)

    Zahra Talebi

    2017-05-01

    Full Text Available Liver is one of the most important organs needing great concern during the perioperative period. There are a number of different mechanisms that interact with liver cells and might affect their integrity and cell live. Though these mechanisms are not all the same, there is a great common point: all affect the metabolic pathways of the liver. Ischemia, anesthetic drug effects and other perioperative insults may affect the liver. Disturbance in an organ’s blood flow is an inherent part of diverse surgical procedures, which leads to lack of oxygen and nutrient supply. These ischemic periods can be particularly long in case of liver surgeries, such as resection of large hepatic tumors, management of hepatic trauma and liver transplant. Once the blood flow and oxygen supply are restored, the interruption of blood flow affects the oxygen dependent cells in liver, which require mitochondrial oxidative phosphorylation for their metabolism. Molecular mechanisms such as Redox status, ionic interchange disturbances as well as different mediators and cells like KC, SEC, dendritic cells, leukocytes, and lymphocytes, are involved in the process ultimately leading to cell death by apoptosis and necrosis. This review provides an overview on the cellular and molecular mechanisms involved in liver injuries, categorizing these mechanisms in 3 different classes: preoperative mechanisms, intraoperative mechanisms and postoperative mechanisms. Each of them are discussed in a different part of the manuscript

  20. Review of important rock mechanics studies required for underground high level nuclear waste repository program

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S.; Cho, W. J

    2007-01-15

    Disposal concept adapting room and pillar method, which is a confirmed technique in mining and tunnel construction for long time, has advantages at cost, safety, technical feasibility, flexibility, and international cooperation point of views. Then the important rock mechanics principals and in situ and laboratory tests for understanding the behavior of rock, buffer, and backfill as well as their interactions will be reviewed. The accurate understanding of them is important for developing a safe disposal concept and successful operation of underground repository for permanent disposal of radioactive wastes. First of all, In this study, current status of rock mechanics studies for HLW disposal in foreign countries such as Sweden, USA, Canada, Finland, Japan, and France were reviewed. After then the in situ and laboratory tests for site characterization were summarized. Furthermore, rock mechanics studies required during the whole procedure for the disposal project from repository design to the final closure will be reviewed systematically. This study will help for developing a disposal system including site selection, repository design, operation, maintenance, and closure of a repository in deep underground rock. By introducing the required rock mechanics tests at different stages, it would be helpful from the planning stage to the operation stage of a radioactive waste disposal project.

  1. Review of important rock mechanics studies required for underground high level nuclear waste repository program

    International Nuclear Information System (INIS)

    Kwon, S.; Cho, W. J.

    2007-01-01

    Disposal concept adapting room and pillar method, which is a confirmed technique in mining and tunnel construction for long time, has advantages at cost, safety, technical feasibility, flexibility, and international cooperation point of views. Then the important rock mechanics principals and in situ and laboratory tests for understanding the behavior of rock, buffer, and backfill as well as their interactions will be reviewed. The accurate understanding of them is important for developing a safe disposal concept and successful operation of underground repository for permanent disposal of radioactive wastes. First of all, In this study, current status of rock mechanics studies for HLW disposal in foreign countries such as Sweden, USA, Canada, Finland, Japan, and France were reviewed. After then the in situ and laboratory tests for site characterization were summarized. Furthermore, rock mechanics studies required during the whole procedure for the disposal project from repository design to the final closure will be reviewed systematically. This study will help for developing a disposal system including site selection, repository design, operation, maintenance, and closure of a repository in deep underground rock. By introducing the required rock mechanics tests at different stages, it would be helpful from the planning stage to the operation stage of a radioactive waste disposal project

  2. Identification of mechanisms enabling integrated care for patients with chronic diseases: a literature review

    Directory of Open Access Journals (Sweden)

    Denise van der Klauw

    2014-07-01

    Full Text Available Introduction: Notwithstanding care for chronically ill patients requires a shift towards care that is well coordinated and focused on prevention and self-care, the concept of integrated care lacks specificity and clarity. This article presents a literature review to identify mechanisms for achieving integrated care objectives.Theory and methods: Existing models often present a large variety of dimensions, archetypes and categories of integration without specifying them. Models and programmes describing integrated care for chronic diseases were reviewed. Data were extracted related to objectives and clusters of mechanisms of integration.Results: Thirty-four studies presented four objectives: functional, organisational, professional and service integration. We categorised approaches and interventions to achieve these objectives by strategy and clusters of ‘mechanisms of integration’: degree, patient centredness and normative aspects.Conclusions and discussion: The clarification of mechanisms to achieve objectives of integrated care as presented may be used as starting point for the development and refinement of integrated care programmes, including methodological grounding of their evaluation. Given that most studies reviewed lack both empirical data and descriptions of the methods used, future research needs to close these gaps. Validation of the findings by a large panel of experts is suggested as recommendation to work towards a grounded framework.

  3. Factors influencing efficiency of sliding mechanics to close extraction space: a systematic review.

    Science.gov (United States)

    Barlow, M; Kula, K

    2008-05-01

    To review recent literature to determine strength of clinical evidence concerning the influence of various factors on the efficiency (rate of tooth movement) of closing extraction spaces using sliding mechanics. A comprehensive systematic review on prospective clinical trials. An electronic search (1966-2006) of several databases limiting the searches to English and using several keywords was performed. Also a hand search of five key journals specifically searching for prospective clinical trials relevant to orthodontic space closure using sliding mechanics was completed. Outcome Measure - Rate of tooth movement. Ten prospective clinical trials comparing rates of closure under different variables and focusing only on sliding mechanics were selected for review. Of these ten trials on rate of closure, two compared arch wire variables, seven compared material variables used to apply force, and one examined bracket variables. Other articles which were not prospective clinical trials on sliding mechanics, but containing relevant information were examined and included as background information. CONCLUSION - The results of clinical research support laboratory results that nickel-titanium coil springs produce a more consistent force and a faster rate of closure when compared with active ligatures as a method of force delivery to close extraction space along a continuous arch wire; however, elastomeric chain produces similar rates of closure when compared with nickel-titanium springs. Clinical and laboratory research suggest little advantage of 200 g nickel-titanium springs over 150 g springs. More clinical research is needed in this area.

  4. Massage therapy: understanding the mechanisms of action on blood pressure. A scoping review.

    Science.gov (United States)

    Nelson, Nicole L

    2015-10-01

    Massage therapy (MT) has shown potential in reducing blood pressure (BP); however, the psychophysiological pathways and structures involved in this outcome are unclear. The aims of this scoping review were twofold. (1) To summarize the current knowledge of the mechanisms of action of MT on BP. (2) To highlight the research gaps and challenges that researchers must overcome to further elucidate how MT attenuates BP. A scoping review was conducted to examine the evidence regarding the mechanisms of action of MT on BP. This review included the thematic analysis of 27 publications that considered the influence of MT on BP. Based on this analysis, six potential BP mediating pathways were identified Current theories suggest that MT exerts sympatholytic effects through physiologic and psychological mechanisms, improves hypothalamus-pituitary-adrenocortical axis function, and increases in blood flow, which, in turn, may improve endothelial function. Future study is needed, using more scientifically rigorous methodology, to fully elucidate the mechanism of action of MT. Copyright © 2015 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  5. Review of the Mechanisms and Effects of Noninvasive Body Contouring Devices on Cellulite and Subcutaneous Fat

    Science.gov (United States)

    Alizadeh, Zahra; Halabchi, Farzin; Mazaheri, Reza; Abolhasani, Maryam; Tabesh, Mastaneh

    2016-01-01

    Context Today, different kinds of non-invasive body contouring modalities, including cryolipolysis, radiofrequency (RF), low-level laser therapy (LLLT), and high-intensity focused ultrasound (HIFU) are available for reducing the volume of subcutaneous adipose tissue or cellulite. Each procedure has distinct mechanisms for stimulating apoptosis or necrosis adipose tissue. In addition to the mentioned techniques, some investigations are underway for analyzing the efficacy of other techniques such as whole body vibration (WBV) and extracorporeal shockwave therapy (ESWT). In the present review the mechanisms, effects and side effects of the mentioned methods have been discussed. The effect of these devices on cellulite or subcutaneous fat reduction has been assessed. Evidence Acquisition We searched pubmed, google scholar and the cochrane databases for systemic reviews, review articles, meta-analysis and randomized clinical trials up to February 2015. The keywords were subcutaneous fat, cellulite, obesity, noninvasive body contouring, cryolipolysis, RF, LLLT, HIFU, ESWT and WBV with full names and abbreviations. Results We included seven reviews and 66 original articles in the present narrative review. Most of them were applied on normal weight or overweight participants (body mass index cellulite in some body areas. However, the clinical effects are mild to moderate, for example 2 - 4 cm circumference reduction as a sign of subcutaneous fat reduction during total treatment sessions. Overall, there is no definitive noninvasive treatment method for cellulite. Additionally, due to the methodological differences in the existing evidence, comparing the techniques is difficult. PMID:28123436

  6. Mechanical bowel preparation and oral antibiotic prophylaxis in colorectal surgery: Analysis of evidence and narrative review.

    Science.gov (United States)

    Badia, Josep M; Arroyo-García, Nares

    2018-05-14

    The role of oral antibiotic prophylaxis and mechanical bowel preparation in colorectal surgery remains controversial. The lack of efficacy of mechanical preparation to improve infection rates, its adverse effects, and multimodal rehabilitation programs have led to a decline in its use. This review aims to evaluate current evidence on antegrade colonic cleansing combined with oral antibiotics for the prevention of surgical site infections. In experimental studies, oral antibiotics decrease the bacterial inoculum, both in the bowel lumen and surgical field. Clinical studies have shown a reduction in infection rates when oral antibiotic prophylaxis is combined with mechanical preparation. Oral antibiotics alone seem to be effective in reducing infection in observational studies, but their effect is inferior to the combined preparation. In conclusion, the combination of oral antibiotics and mechanical preparation should be considered the gold standard for the prophylaxis of postoperative infections in colorectal surgery. Copyright © 2018 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. On Finsler Geometry and Applications in Mechanics: Review and New Perspectives

    Directory of Open Access Journals (Sweden)

    J. D. Clayton

    2015-01-01

    direction as well as position, and a number of connections emerge associated with various covariant derivatives involving affine and nonlinear coefficients. Finsler geometry encompasses Riemannian, Euclidean, and Minkowskian geometries as special cases, and thus it affords great generality for describing a number of phenomena in physics. Here, descriptions of finite deformation of continuous media are of primary focus. After a review of necessary mathematical definitions and derivations, prior work involving application of Finsler geometry in continuum mechanics of solids is reviewed. A new theoretical description of continua with microstructure is then outlined, merging concepts from Finsler geometry and phase field theories of materials science.

  8. TiO2-based memristors and ReRAM: materials, mechanisms and models (a review)

    International Nuclear Information System (INIS)

    Gale, Ella

    2014-01-01

    The memristor is the fundamental nonlinear circuit element, with uses in computing and computer memory. Resistive Random Access Memory (ReRAM) is a resistive switching memory proposed as a non-volatile memory. In this review we shall summarize the state of the art for these closely-related fields, concentrating on titanium dioxide, the well-utilized and archetypal material for both. We shall cover material properties, switching mechanisms and models to demonstrate what ReRAM and memristor scientists can learn from each other and examine the outlook for these technologies. (invited review)

  9. Regulatory mechanisms for absenteeism in the health sector: a systematic review of strategies and their implementation

    Directory of Open Access Journals (Sweden)

    Kisakye AN

    2016-11-01

    Full Text Available Angela N Kisakye,1 Raymond Tweheyo,1 Freddie Ssengooba,1 George W Pariyo,2 Elizeus Rutebemberwa,1 Suzanne N Kiwanuka1 1Department of Health Policy Planning and Management, Makerere University School of Public Health, Kampala, Uganda; 2Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA Background: A systematic review was undertaken to identify regulatory mechanisms aimed at mitigating health care worker absenteeism, to describe where and how they have been implemented as well as their possible effects. The goal was to propose potential policy options for managing the problem of absenteeism among human resources for health in low- and middle-income countries. Mechanisms described in this review are at the local workplace and broader national policy level. Methods: A comprehensive online search was conducted on EMBASE, CINAHL, PubMed, Google Scholar, Google, and Social Science Citation Index using MEDLINE search terms. Retrieved studies were uploaded onto reference manager and screened by two independent reviewers. Only publications in English were included. Data were extracted and synthesized according to the objectives of the review. Results: Twenty six of the 4,975 published articles retrieved were included. All were from high-income countries and covered all cadres of health workers. The regulatory mechanisms and possible effects include 1 organizational-level mechanisms being reported as effective in curbing absenteeism in low- and middle-income countries (LMICs; 2 prohibition of private sector activities in LMICs offering benefits but presenting a challenge for the government to monitor the health workforce; 3 contractual changes from temporary to fixed posts having been associated with no reduction in absenteeism and not being appropriate for LMICs; 4 multifaceted work interventions being implemented in most settings; 5 the possibility of using financial and incentive regulatory mechanisms

  10. Education on invasive mechanical ventilation involving intensive care nurses: a systematic review.

    Science.gov (United States)

    Guilhermino, Michelle C; Inder, Kerry J; Sundin, Deborah

    2018-03-26

    Intensive care unit nurses are critical for managing mechanical ventilation. Continuing education is essential in building and maintaining nurses' knowledge and skills, potentially improving patient outcomes. The aim of this study was to determine whether continuing education programmes on invasive mechanical ventilation involving intensive care unit nurses are effective in improving patient outcomes. Five electronic databases were searched from 2001 to 2016 using keywords such as mechanical ventilation, nursing and education. Inclusion criteria were invasive mechanical ventilation continuing education programmes that involved nurses and measured patient outcomes. Primary outcomes were intensive care unit mortality and in-hospital mortality. Secondary outcomes included hospital and intensive care unit length of stay, length of intubation, failed weaning trials, re-intubation incidence, ventilation-associated pneumonia rate and lung-protective ventilator strategies. Studies were excluded if they excluded nurses, patients were ventilated for less than 24 h, the education content focused on protocol implementation or oral care exclusively or the outcomes were participant satisfaction. Quality was assessed by two reviewers using an education intervention critical appraisal worksheet and a risk of bias assessment tool. Data were extracted independently by two reviewers and analysed narratively due to heterogeneity. Twelve studies met the inclusion criteria for full review: 11 pre- and post-intervention observational and 1 quasi-experimental design. Studies reported statistically significant reductions in hospital length of stay, length of intubation, ventilator-associated pneumonia rates, failed weaning trials and improvements in lung-protective ventilation compliance. Non-statistically significant results were reported for in-hospital and intensive care unit mortality, re-intubation and intensive care unit length of stay. Limited evidence of the effectiveness of

  11. A review of penetration mechanisms and dynamic properties of tungsten and depleted uranium penetrators

    International Nuclear Information System (INIS)

    Andrew, S.P.; Caligiuri, R.D.; Eiselstein, L.E.

    1991-01-01

    Over the last decade, depleted uranium (DU) and tungsten alloys have been the materials of choice for kinetic energy penetrators. However, despite improvements in mechanical properties in recent years, the penetration performance of tungsten still lags behind that of DU. One possible reason is the difference in deformation mechanisms- DU alloys tend to shear band as they penetrate the target material, whereas tungsten penetrators tend to mushroom. As a first step to determining whether shear banding is truly the reason for superior DU performance, a review and summary of the available information was performed. This paper presents a state-of-the-art review of the formulation, high strain- rate properties, and penetration phenomena of penetrators manufactured from both tungsten and DU alloys. Specifically, the effects of composition, processing, and heat treatment on mechanical properties and penetration mechanisms of these alloys are discussed. Penetration data and models for penetration mechanisms (in particular shear banding) are also presented, as well as the applicability of these models and their salient features

  12. Using Vector Projection Method to evaluate maintainability of mechanical system in design review

    International Nuclear Information System (INIS)

    Chen Lu; Cai Jianguo

    2003-01-01

    Maintainability of a mechanical system is one of the system design parameters that has a great impact in terms of ease of maintenance. In this article, based on the definition of the terms of maintenance and maintainability, an important tool of Design for Maintenance is developed as a way to improve maintainability through design. A set of standard and organized guidelines is provided and maintainability factors in terms of physical design, logistics support and ergonomics are identified. As a specific application of design review, a methodology so called Vector Projection Method is developed to evaluate the maintainability of the mechanical system. Lastly, an example is discussed

  13. Mechanical Properties of Magnesium-Rare Earth Alloy Systems: A Review

    Directory of Open Access Journals (Sweden)

    Sravya Tekumalla

    2014-12-01

    Full Text Available Magnesium-rare earth based alloys are increasingly being investigated due to the formation of highly stable strengthening phases, activation of additional deformation modes and improvement in mechanical properties. Several investigations have been done to study the effect of rare earths when they are alloyed to pure magnesium and other Mg alloys. In this review, the mechanical properties of the previously investigated different magnesium-rare earth based binary alloys, ternary alloys and other higher alloys with more than three alloying elements are presented.

  14. Atomistic modeling of BN nanofillers for mechanical and thermal properties: a review.

    Science.gov (United States)

    Kumar, Rajesh; Parashar, Avinash

    2016-01-07

    Due to their exceptional mechanical properties, thermal conductivity and a wide band gap (5-6 eV), boron nitride nanotubes and nanosheets have promising applications in the field of engineering and biomedical science. Accurate modeling of failure or fracture in a nanomaterial inherently involves coupling of atomic domains of cracks and voids as well as a deformation mechanism originating from grain boundaries. This review highlights the recent progress made in the atomistic modeling of boron nitride nanofillers. Continuous improvements in computational power have made it possible to study the structural properties of these nanofillers at the atomistic scale.

  15. A review of Green's function methods in computational fluid mechanics: Background, recent developments and future directions

    International Nuclear Information System (INIS)

    Dorning, J.

    1981-01-01

    The research and development over the past eight years on local Green's function methods for the high-accuracy, high-efficiency numerical solution of nuclear engineering problems is reviewed. The basic concepts and key ideas are presented by starting with an expository review of the original fully two-dimensional local Green's function methods developed for neutron diffusion and heat conduction, and continuing through the progressively more complicated and more efficient nodal Green's function methods for neutron diffusion, heat conduction and neutron transport to establish the background for the recent development of Green's function methods in computational fluid mechanics. Some of the impressive numerical results obtained via these classes of methods for nuclear engineering problems are briefly summarized. Finally, speculations are proffered on future directions in which the development of these types of methods in fluid mechanics and other areas might lead. (orig.) [de

  16. Science review: Mechanisms of impaired adrenal function in sepsis and molecular actions of glucocorticoids

    OpenAIRE

    Prigent, Hélène; Maxime, Virginie; Annane, Djillali

    2004-01-01

    This review describes current knowledge on the mechanisms that underlie glucocorticoid insufficiency in sepsis and the molecular action of glucocorticoids. In patients with severe sepsis, numerous factors predispose to glucocorticoid insufficiency, including drugs, coagulation disorders and inflammatory mediators. These factors may compromise the hypothalamic–pituitary axis (i.e. secondary adrenal insufficiency) or the adrenal glands (i.e. primary adrenal failure), or may impair glucocorticoi...

  17. Applied structural and solid mechanics section: 1983 review and 1984 programs

    International Nuclear Information System (INIS)

    Chadha, J.A.

    1984-01-01

    This report reviews briefly the applied research and problem solving work carried out by the Applied Structural and Solid Mechanics Section during 1983. In 1983 there was a strong demand for services in the areas of theroretical and experimental stress analysis, heat transfer analysis, nonlinear analysis, and general structural analyses related to nuclear and thermal power plant, and transmission line components. Development of capabilities in these areas progressed well. Proposed work programs for 1984 are outlined in this report

  18. How Does Paying Attention Improve Sexual Functioning in Women? A Review of Mechanisms.

    Science.gov (United States)

    Arora, Nikita; Brotto, Lori A

    2017-07-01

    Female sexual dysfunction (FSD), consisting of a constellation of distressing sexual symptoms, is highly prevalent worldwide. Given the central role played by psychological factors in the development of FSD, psychologically and in particular mindfulness-based interventions have arisen as potential treatment options for women. Although mindfulness-based interventions have been evaluated in samples of women with gynecologic cancer; a history of sexual abuse; multiple sclerosis; and spinal cord injury; and provoked vestibulodynia, the mechanisms by which mindfulness leads to improvements in sexual functioning are largely unstudied. To summarize the literature on mechanisms of mindfulness interventions in general and to hypothesize which mechanisms most likely apply to samples of women with FSD. Medline was searched with terms such as mindfulness, meditation, mediator, mode, moderator, mechanism, sex, and sexual dysfunction. Only studies that conducted a formal mediation or moderation analysis were included. We also conducted a broader review on mechanisms in other populations, with slightly modified inclusion criteria: the terms sex and sexual dysfunction were removed and only studies from 2012 to 2016 and studies that included an active mindfulness intervention were included. In general populations, trait mindfulness and decentering were the most common mechanisms identified for the efficacy of mindfulness. In four studies that examined mediators of improvement in samples with FSD, the following mediators were found to be significant: relationship satisfaction, genital self-image, interoceptive awareness, depressed mood, anxiety, and trait mindfulness, of which interoceptive awareness had the most supporting evidence. Clinicians and researchers can use the identified mediators of improvement (ie, interoceptive awareness, depression, and trait mindfulness) when making decisions about which patient might be more likely to benefit from a mindfulness-based approach to

  19. Mechanics of the Delayed Fracture of Viscoelastic Bodies with Cracks: Theory and Experiment (Review)

    Science.gov (United States)

    Kaminsky, A. A.

    2014-09-01

    Theoretical and experimental studies on the deformation and delayed fracture of viscoelastic bodies due to slow subcritical crack growth are reviewed. The focus of this review is on studies of subcritical growth of cracks with well-developed fracture process zones, the conditions that lead to their critical development, and all stages of slow crack growth from initiation to the onset of catastrophic growth. Models, criteria, and methods used to study the delayed fracture of viscoelastic bodies with through and internal cracks are analyzed. Experimental studies of the fracture process zones in polymers using physical and mechanical methods as well as theoretical studies of these zones using fracture mesomechanics models that take into account the structural and rheological features of polymers are reviewed. Particular attention is given to crack growth in anisotropic media, the effect of the aging of viscoelastic materials on their delayed fracture, safe external loads that do not cause cracks to propagate, the mechanism of multiple-flaw fracture of viscoelastic bodies with several cracks and, especially, processes causing cracks to coalesce into a main crack, which may result in a break of the body. Methods and results of solving two- and three-dimensional problems of the mechanics of delayed fracture of aging and non-aging viscoelastic bodies with cracks under constant and variable external loads, wedging, and biaxial loads are given

  20. Systematic Reviews of Mechanisms for Financing Family Planning: Findings, Implications, and Future Agenda.

    Science.gov (United States)

    Lissner, Craig L; Ali, Moazzam

    2016-12-01

    The article describes an international collaboration that systematically reviewed the evidence on financing mechanisms for family planning/contraception, assessed the strength of and summarized the evidence, identified research gaps, and proposed a new research agenda to address the gaps. The review found that the evidence base is weak owing to the paucity of studies, diversity in findings, and variations in intervention, study design, and outcome measures. Of more than 17,000 papers reviewed only 38 met the eligibility criteria. A number of general recommendations on the directions and areas of future research can be drawn. There is a strong need for more robust study designs on the effectiveness of financial incentives in family planning. © 2016 The Population Council, Inc.

  1. L-Area STS MTR/NRU/NRX Grapple Assembly Closure Mechanics Review

    International Nuclear Information System (INIS)

    Huizenga, D. J.

    2016-01-01

    A review of the closure mechanics associated with the Shielded Transfer System (STS) MTR/NRU/NRX grapple assembly utilized at the Savannah River Site (SRS) was performed. This review was prompted by an operational event which occurred at the Canadian Nuclear Laboratories (CNL) utilizing a DTS-XL grapple assembly which is essentially identical to the STS MTR/NRU/NRX grapple assembly used at the SRS. The CNL operational event occurred when a NRU/NRX fuel basket containing spent nuclear fuel assemblies was inadvertently released by the DTS-XL grapple assembly during a transfer. The SM review of the STS MTR/NRU/NRX grapple assembly will examine the operational aspects of the STS and the engineered features of the STS which prevent such an event at the SRS. The design requirements for the STS NRU/NRX modifications and the overall layout of the STS are provided in other documents.

  2. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    Science.gov (United States)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  3. Effect of process parameters on microstructure and mechanical properties of friction stir welded joints: A review

    Science.gov (United States)

    Wanare, S. P.; Kalyankar, V. D.

    2018-04-01

    Friction stir welding is emerging as a promising technique for joining of lighter metal alloys due to its several advantages over conventional fusion welding processes such as low thermal distortion, good mechanical properties, fine weld joint microstructure, etc. This review article mainly focuses on analysis of microstructure and mechanical properties of friction stir welded joints. Various microstructure characterization techniques used by previous researchers such as optical microscopes, x-ray diffraction, electron probe microscope, transmission electron microscope, scanning electron microscopes with electron back scattered diffraction, electron dispersive microscopy, etc. are thoroughly overviewed and their results are discussed. The effects of friction stir welding process parameters such as tool rotational speed, welding speed, tool plunge depth, axial force, tool shoulder diameter to tool pin diameter ratio, tool geometry etc. on microstructure and mechanical properties of welded joints are studied and critical observations are noted down. The microstructure examination carried out by previous researchers on various zones of welded joints such as weld zone, heat affected zone and base metal are studied and critical remarks have been presented. Mechanical performances of friction stir welded joints based on tensile test, micro-hardness test, etc. are discussed. This article includes exhaustive literature review of standard research articles which may become ready information for subsequent researchers to establish their line of action.

  4. Silver (Ag) Transport Mechanisms in TRISO coated particles: A Critical Review

    Energy Technology Data Exchange (ETDEWEB)

    I J van Rooyen; J H Neethling; J A A Engelbrecht; P M van Rooyen; G Strydom

    2012-10-01

    Transport of 110mAg in the intact SiC layer of TRISO coated particles has been studied for approximately 30 years without arriving at a satisfactory explanation of the transport mechanism. In this paper the possible mechanisms postulated in previous experimental studies, both in-reactor and out-of reactor research environment studies are critically reviewed and of particular interest are relevance to very high temperature gas reactor operating and accident conditions. Among the factors thought to influence Ag transport are grain boundary stoichiometry, SiC grain size and shape, the presence of free silicon, nano-cracks, thermal decomposition, palladium attack, transmutation products, layer thinning and coated particle shape. Additionally new insight to nature and location of fission products has been gained via recent post irradiation electron microscopy examination of TRISO coated particles from the DOE’s fuel development program. The combined effect of critical review and new analyses indicates a direction for investigating possible the Ag transport mechanism including the confidence level with which these mechanisms may be experimentally verified.

  5. Mechanisms of action of fungi and bacteria used as biofertilizers in agricultural soils : a systematic review

    Directory of Open Access Journals (Sweden)

    Sara Paulina Restrepo-Correa

    2017-05-01

    Full Text Available Phosphorus, nitrogen, iron and potassium are some compounds necessary for plant growth and development; chemical fertilizers used to increase concentration significantly affect the environment and soil ecosystems. According to the scientific literature, microorganisms with biofertilizer potential have demonstrated various mechanisms of action to solubilize these compounds and thus meet the requirements of plants. This systematic review collects scientific information that describes the mechanisms of action of microbial fertilizers in agricultural soils, published between 2004 and 2014, in three different databases; ScienceDirect, SpringerLink and Scopus,using the search path (biofertilizer AND (bacteria OR fungi AND (effect OR action OR mechanism. After using different inclusion and exclusion criteria, the search displayed a total of 63 original articles, including six unindexed documents. As a result of the systematic review, it indicates that the production of various organic acids allows soil acidification, facilitating absorption of elements. It was also observed that solubilization of P is the most described mechanism, by obtaining a solubilizing of 726.5 mg/L of P due to P. pseudoalcaligenes

  6. Silver (Ag) transport mechanisms in TRISO coated particles: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Rooyen, I.J. van, E-mail: isabella.vanrooyen@inl.gov [Idaho National Laboratory, Idaho Falls, ID 83415-6188 (United States); Dunzik-Gougar, M.L. [Department of Nuclear Engineering, Idaho State University, ID (United States); Rooyen, P.M. van [Philip M. van Rooyen Network Consultants, Midlands Estates (South Africa)

    2014-05-01

    Transport of {sup 110m}Ag in the intact SiC layer of TRISO coated particles has been studied for approximately 30 years without arriving at a satisfactory explanation of the transport mechanism. In this paper the possible mechanisms postulated in previous experimental studies, both in-reactor and out-of reactor research environment studies are critically reviewed and of particular interest are relevance to very high temperature gas reactor operating and accident conditions. Among the factors thought to influence Ag transport are grain boundary stoichiometry, SiC grain size and shape, the presence of free silicon, nano-cracks, thermal decomposition, palladium attack, transmutation products, layer thinning and coated particle shape. Additionally new insight to nature and location of fission products has been gained via recent post irradiation electron microscopy examination of TRISO coated particles from the DOE's fuel development program. The combined effect of critical review and new analyses indicates a direction for investigating possible the Ag transport mechanism including the confidence level with which these mechanisms may be experimentally verified.

  7. Mechanisms of Acupuncture Therapy in Ischemic Stroke Rehabilitation: A Literature Review of Basic Studies.

    Science.gov (United States)

    Chavez, Lina M; Huang, Shiang-Suo; MacDonald, Iona; Lin, Jaung-Geng; Lee, Yu-Chen; Chen, Yi-Hung

    2017-10-28

    Acupuncture is recommended by the World Health Organization (WHO) as an alternative and complementary strategy for stroke treatment and for improving stroke care. Clinical trial and meta-analysis findings have demonstrated the efficacy of acupuncture in improving balance function, reducing spasticity, and increasing muscle strength and general well-being post-stroke. The mechanisms underlying the beneficial effects of acupuncture in stroke rehabilitation remain unclear. The aim of this study was to conduct a literature review, summarize the current known mechanisms in ischemic stroke rehabilitation through acupuncture and electroacupuncture (EA) therapy, and to detail the frequently used acupoints implicated in these effects. The evidence in this review indicates that five major different mechanisms are involved in the beneficial effects of acupuncture/EA on ischemic stroke rehabilitation: (1) Promotion of neurogenesis and cell proliferation in the central nervous system (CNS); (2) Regulation of cerebral blood flow in the ischemic area; (3) Anti-apoptosis in the ischemic area; (4) Regulation of neurochemicals; and, (5) Improvement of impaired long-term potentiation (LTP) and memory after stroke. The most frequently used acupoints in basic studies include Baihui (GV20), Zusanli (ST36), Quchi (LI11), Shuigou (GV26), Dazhui (GV14), and Hegu (LI4). Our findings show that acupuncture exerts a beneficial effect on ischemic stroke through modulation of different mechanisms originating in the CNS.

  8. Advances in classical and analytical mechanics: A reviews of author’s results

    Directory of Open Access Journals (Sweden)

    Hedrih-Stevanović Katica R.

    2013-01-01

    Full Text Available A review, in subjective choice, of author’s scientific results in area of: classical mechanics, analytical mechanics of discrete hereditary systems, analytical mechanics of discrete fractional order system vibrations, elastodynamics, nonlinear dynamics and hybrid system dynamics is presented. Main original author’s results were presented through the mathematical methods of mechanics with examples of applications for solving problems of mechanical real system dynamics abstracted to the theoretical models of mechanical discrete or continuum systems, as well as hybrid systems. Paper, also, presents serries of methods and scientific results authored by professors Mitropolyski, Andjelić and Rašković, as well as author’s of this paper original scientific research results obtained by methods of her professors. Vector method based on mass inertia moment vectors and corresponding deviational vector components for pole and oriented axis, defined in 1991 by K. Hedrih, is presented. Results in construction of analytical dynamics of hereditary discrete system obtained in collaboration with O. A. Gorosho are presented. Also, some selections of results author’s postgraduate students and doctorantes in area of nonlinear dynamics are presented. A list of scientific projects headed by author of this paper is presented with a list of doctoral dissertation and magister of sciences thesis which contain scientific research results obtained under the supervision by author of this paper or their fist doctoral candidates. [Projekat Ministarstva nauke Republike Srbije, br. ON174001: Dynamics of hybrid systems with complex structures

  9. Review on Molecular Mechanisms of Antifouling Compounds: An Update since 2012.

    Science.gov (United States)

    Chen, Lianguo; Qian, Pei-Yuan

    2017-08-28

    Better understanding of the mechanisms of antifouling compounds is recognized to be of high value in establishing sensitive biomarkers, allowing the targeted optimization of antifouling compounds and guaranteeing environmental safety. Despite vigorous efforts to find new antifouling compounds, information about the mechanisms of antifouling is still scarce. This review summarizes the progress into understanding the molecular mechanisms underlying antifouling activity since 2012. Non-toxic mechanisms aimed at specific targets, including inhibitors of transmembrane transport, quorum sensing inhibitors, neurotransmission blockers, adhesive production/release inhibitors and enzyme/protein inhibitors, are put forward for natural antifouling products or shelf-stable chemicals. Several molecular targets show good potential for use as biomarkers in future mechanistic screening, such as acetylcholine esterase for neurotransmission, phenoloxidase/tyrosinase for the formation of adhesive plaques, N -acyl homoserine lactone for quorum sensing and intracellular Ca 2+ levels as second messenger. The studies on overall responses to challenges by antifoulants can be categorized as general targets, including protein expression/metabolic activity regulators, oxidative stress inducers, neurotransmission blockers, surface modifiers, biofilm inhibitors, adhesive production/release inhibitors and toxic killing. Given the current situation and the knowledge gaps regarding the development of alternative antifoulants, a basic workflow is proposed that covers the indispensable steps, including preliminary mechanism- or bioassay-guided screening, evaluation of environmental risks, field antifouling performance, clarification of antifouling mechanisms and the establishment of sensitive biomarkers, which are combined to construct a positive feedback loop.

  10. Mechanical characteristics of hardened concrete with different mineral admixtures: a review.

    Science.gov (United States)

    Ayub, Tehmina; Khan, Sadaqat Ullah; Memon, Fareed Ahmed

    2014-01-01

    The available literature identifies that the addition of mineral admixture as partial replacement of cement improves the microstructure of the concrete (i.e., porosity and pore size distribution) as well as increasing the mechanical characteristics such as drying shrinkage and creep, compressive strength, tensile strength, flexural strength, and modulus of elasticity; however, no single document is available in which review and comparison of the influence of the addition of these mineral admixtures on the mechanical characteristics of the hardened pozzolanic concretes are presented. In this paper, based on the reported results in the literature, mechanical characteristics of hardened concrete partially containing mineral admixtures including fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA) are discussed and it is concluded that the content and particle size of mineral admixture are the parameters which significantly influence the mechanical properties of concrete. All mineral admixtures enhance the mechanical properties of concrete except FA and GGBS which do not show a significant effect on the strength of concrete at 28 days; however, gain in strength at later ages is considerable. Moreover, the comparison of the mechanical characteristics of different pozzolanic concretes suggests that RHA and SF are competitive.

  11. A critical review of the arsenic uptake mechanisms and phytoremediation potential of Pteris vittata.

    Science.gov (United States)

    Danh, Luu Thai; Truong, Paul; Mammucari, Raffaella; Foster, Neil

    2014-01-01

    The discovery of the arsenic hyperaccumulator, Pteris vittata (Chinese brake fern), has contributed to the promotion of its application as a means of phytoremediation for arsenic removal from contaminated soils and water. Understanding the mechanisms involved in arsenic tolerance and accumulation of this plant provides valuable tools to improve the phytoremediation efficiency. In this review, the current knowledge about the physiological and molecular mechanisms of arsenic tolerance and accumulation in P. vittata is summarized, and an attempt has been made to clarify some of the unresolved questions related to these mechanisms. In addition, the capacity of P. vittata for remediation of arsenic-contaminated soils is evaluated under field conditions for the first time, and possible solutions to improve the remediation capacity of Pteris vittata are also discussed.

  12. Biophysical Stimuli: A Review of Electrical and Mechanical Stimulation in Hyaline Cartilage.

    Science.gov (United States)

    Vaca-González, Juan J; Guevara, Johana M; Moncayo, Miguel A; Castro-Abril, Hector; Hata, Yoshie; Garzón-Alvarado, Diego A

    2017-09-01

    Objective Hyaline cartilage degenerative pathologies induce morphologic and biomechanical changes resulting in cartilage tissue damage. In pursuit of therapeutic options, electrical and mechanical stimulation have been proposed for improving tissue engineering approaches for cartilage repair. The purpose of this review was to highlight the effect of electrical stimulation and mechanical stimuli in chondrocyte behavior. Design Different information sources and the MEDLINE database were systematically revised to summarize the different contributions for the past 40 years. Results It has been shown that electric stimulation may increase cell proliferation and stimulate the synthesis of molecules associated with the extracellular matrix of the articular cartilage, such as collagen type II, aggrecan and glycosaminoglycans, while mechanical loads trigger anabolic and catabolic responses in chondrocytes. Conclusion The biophysical stimuli can increase cell proliferation and stimulate molecules associated with hyaline cartilage extracellular matrix maintenance.

  13. Mechanical Stimulation Protocols of Human Derived Cells in Articular Cartilage Tissue Engineering - A Systematic Review.

    Science.gov (United States)

    Khozoee, Baktash; Mafi, Pouya; Mafi, Reza; Khan, Wasim S

    2017-01-01

    Mechanical stimulation is a key factor in articular cartilage generation and maintenance. Bioreactor systems have been designed and built in order to deliver specific types of mechanical stimulation. The focus has been twofold, applying a type of preconditioning in order to stimulate cell differentiation, and to simulate in vivo conditions in order to gain further insight into how cells respond to different stimulatory patterns. Due to the complex forces at work within joints, it is difficult to simulate mechanical conditions using a bioreactor. The aim of this review is to gain a deeper understanding of the complexities of mechanical stimulation protocols by comparing those employed in bioreactors in the context of tissue engineering for articular cartilage, and to consider their effects on cultured cells. Allied and Complementary Medicine 1985 to 2016, Ovid MEDLINE[R] 1946 to 2016, and Embase 1974 to 2016 were searched using key terms. Results were subject to inclusion and exclusion criteria, key findings summarised into a table and subsequently discussed. Based on this review it is overwhelmingly clear that mechanical stimulation leads to increased chondrogenic properties in the context of bioreactor articular cartilage tissue engineering using human cells. However, given the variability and lack of controlled factors between research articles, results are difficult to compare, and a standardised method of evaluating stimulation protocols proved challenging. With improved standardisation in mechanical stimulation protocol reporting, bioreactor design and building processes, along with a better understanding of joint behaviours, we hope to perform a meta-analysis on stimulation protocols and methods. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Interim guidance on the Standard Review Plan for the review of financial assurance mechanisms for decommissioning under 10 CFR Parts 30, 40, and 70

    International Nuclear Information System (INIS)

    1988-12-01

    Interim Guidance on the Standard Review Plan (SRP) for the Review of Financial Assurance Mechanisms for Decommissioning under 10 CFR Parts 30, 40, and 70 is prepared for the guidance of Nuclear Regulatory Commission staff reviewers in performing reviews of applications from material licensees affected by the decommissioning regulations established June 27, 1988 (53FR24018). The principal purpose of the SRP is to assure the quality and uniformity of staff reviews and to present a base from which to evaluate the financial assurance aspects of the applications. NUREG-1337, identifies who performs the review, the matters that are reviewed, the basis of the review, how the review is performed, and the conclusions that are sought. 3 refs

  15. Efficacy of homecare regimens for mechanical plaque removal in managing gingivitis a meta review.

    Science.gov (United States)

    Van der Weijden, Fridus A; Slot, Dagmar E

    2015-04-01

    Based on evidence as presented in systematic reviews what is the efficacy and safety of available homecare toothbrush regimens for mechanical plaque removal on plaque and gingivitis in adults? Three Internet sources were used (up to and including August 2014) to search for appropriate papers that satisfied the study purpose. Plaque scores and gingivitis scores were considered to be the primary parameter of interest. Safety was considered an important facet in relation to efficacy. Data and conclusions as presented in the selected papers were extracted. The potential risk of bias was estimated and the emerging evidence was graded. Independent screening of 176 unique reviews resulted in 10 published and eligible systematic reviews. They were categorized into one review evaluating the effect of an oral hygiene instruction with a toothbrush on plaque and gingivitis scores, five evaluating the efficacy of manual and power toothbrushes and three reviews evaluating toothbrush safety and one evaluating toothbrush contamination. Tooth brushing is effective in reducing levels of dental plaque. With respect to gingivitis power toothbrushes have a benefit over manual toothbrushes. The greatest body of evidence was available for oscillating-rotating brushes. Tooth brushing generally can be considered safe for the teeth and their investing tissues. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Mechanical properties of provisional dental materials: A systematic review and meta-analysis.

    Science.gov (United States)

    Astudillo-Rubio, Daniela; Delgado-Gaete, Andrés; Bellot-Arcís, Carlos; Montiel-Company, José María; Pascual-Moscardó, Agustín; Almerich-Silla, José Manuel

    2018-01-01

    Provisional restorations represent an important phase during the rehabilitation process, knowledge of the mechanical properties of the available materials allows us to predict their clinical performance. At present, there is no systematic review, which supports the clinicians' criteria, in the selection of a specific material over another for a particular clinical situation. The purpose of this systematic review and meta-analysis was to assess and compare the mechanical properties of dimethacrylates and monomethacrylates used in fabricating direct provisional restorations, in terms of flexural strength, fracture toughness and hardness. This review followed the PRISMA guidelines. The searches were conducted in PubMed, Embase, Web of Science, Scopus, the New York Academy of Medicine Grey Literature Report and were complemented by hand-searching, with no limitation of time or language up to January 10, 2017. Studies that assess and compare the mechanical properties of dimethacrylate- and monomethacrylate-based provisional restoration materials were selected. A quality assessment of full-text articles were performed according to modified ARRIVE and CONSORT criteria and modified Cochrane Collaboration's tool for in vitro studies. Initially, 256 articles were identified. After removing the duplicates and applying the selection criteria, 24 articles were included in the qualitative synthesis and 7 were included in the quantitative synthesis (meta-analysis). It may be concluded that dimethacrylate-based provisional restorations presented better mechanical behavior than monomethacrylate-based ones in terms of flexural strength and hardness. Fracture toughness showed no significant differences. Within the monomethacrylate group, polymethylmethacrylate showed greater flexural strength than polyethylmethacrylate.

  17. Mechanical properties of provisional dental materials: A systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Daniela Astudillo-Rubio

    Full Text Available Provisional restorations represent an important phase during the rehabilitation process, knowledge of the mechanical properties of the available materials allows us to predict their clinical performance. At present, there is no systematic review, which supports the clinicians' criteria, in the selection of a specific material over another for a particular clinical situation. The purpose of this systematic review and meta-analysis was to assess and compare the mechanical properties of dimethacrylates and monomethacrylates used in fabricating direct provisional restorations, in terms of flexural strength, fracture toughness and hardness. This review followed the PRISMA guidelines. The searches were conducted in PubMed, Embase, Web of Science, Scopus, the New York Academy of Medicine Grey Literature Report and were complemented by hand-searching, with no limitation of time or language up to January 10, 2017. Studies that assess and compare the mechanical properties of dimethacrylate- and monomethacrylate-based provisional restoration materials were selected. A quality assessment of full-text articles were performed according to modified ARRIVE and CONSORT criteria and modified Cochrane Collaboration's tool for in vitro studies. Initially, 256 articles were identified. After removing the duplicates and applying the selection criteria, 24 articles were included in the qualitative synthesis and 7 were included in the quantitative synthesis (meta-analysis. It may be concluded that dimethacrylate-based provisional restorations presented better mechanical behavior than monomethacrylate-based ones in terms of flexural strength and hardness. Fracture toughness showed no significant differences. Within the monomethacrylate group, polymethylmethacrylate showed greater flexural strength than polyethylmethacrylate.

  18. The Antihyperglycemic Effects of Rhizoma Coptidis and Mechanism of Actions: A Review of Systematic Reviews and Pharmacological Research

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2014-01-01

    Full Text Available Rhizoma Coptidis (Huang Lian in Chinese pinyin is among the most widely used traditional Chinese herbal medicines and has a profound history of more than 2000 years of being used as a therapeutic herb. The antidiabetic effects of Rhizoma Coptidis have been extensively investigated in animal experiments and clinical trials and its efficacy as a promising antihyperglycemic agent has been widely discussed. In the meantime, findings from modern pharmacological studies have contributed the majority of its bioactivities to berberine, the isoquinoline alkaloids component of the herb, and a number of experiments testing the antidiabetic effects of berberine have been initiated. Therefore, we conducted a review of the current evidence profile of the antihyperglycemic effects of Rhizoma Coptidis as well as its main component berberine and the possible mechanism of actions, in order to summarize research evidence in this area and identify future research directions.

  19. A Comparison of Over-the-Counter Mechanical Nasal Dilators: A Systematic Review.

    Science.gov (United States)

    Kiyohara, Nicole; Badger, Christopher; Tjoa, Tjoson; Wong, Brian

    2016-09-01

    The internal nasal valve is the narrowest part of the nasal airway and a common site of inspiratory collapse and obstruction of nasal airflow. Over-the-counter mechanical nasal dilators are an alternative to surgical intervention that attempts to improve airflow through the internal nasal valve. To determine the efficacy of over-the-counter mechanical nasal dilators and classify these products by mechanism. A database of 33 available over-the-counter mechanical nasal dilators was generated via a PubMed search as well as an internet search via Amazon.com and Google, conducted from April 1, 2013, through December 31, 2015. Products determined to be unavailable or discontinued were excluded from the database. Of the devices examined in published literature, efficacy was based on objective measures, such as measured airflow, the cross-sectional area of the nasal valve, and changes in resistance. Measures of reported sleep quality or patient perception were excluded. An analysis of each product's mechanism revealed 4 broad classes: external nasal dilator strips, nasal stents, nasal clips, and septal stimulators. A review demonstrated 5 studies supporting the use of external nasal dilator strips, 4 studies supporting the use of nasal clips, 1 study supporting the use of nasal stents, and no studies supporting the use of septal stimulators. Our findings suggest that external nasal dilator strips and nasal clips effectively relieve obstruction of the internal nasal valve and may be an alternative to surgical intervention in some patients.

  20. Various bio-mechanical factors affecting heat generation during osteotomy preparation: A systematic review.

    Science.gov (United States)

    Chauhan, Chirag J; Shah, Darshana N; Sutaria, Foram B

    2018-01-01

    As implant site preparation and bone are critical precursors to primary healing, thermal and mechanical damage to the bone must be minimized during the preparation of the implant site. Moreover, excessively traumatic surgery can adversely affect the maturation of bone tissue at the bone/implant interface and consequently diminish the predictability of osseointegration. So, this study was carried out to evaluate the various biological and mechanical factors responsible for heat generation during osteotomy site preparation to reduce the same for successful osseointegration of dental implants. A broad search of the dental literature in PubMed added by manual search was performed for articles published between 1992 and December 2015. Various bio-mechanical factors related to dental implant osteotomy preparation such as dental implant drill designs/material/wear, drilling methods, type of irrigation, and bone quality were reviewed. Titles and abstracts were screened and articles which fulfilled the inclusion criteria were selected for a full-text reading. The initial database search yielded 123 titles, of which 59 titles were discarded after reading the titles and abstracts, 30 articles were again excluded based on inclusion and exclusion criteria, and finally 34 articles were selected for data extraction. Many biological and mechanical factors responsible for heat generation were found. Literatures of this review study have indicated that there are various bio-mechanical reasons, which affect the temperature rise during osteotomy and suggest that the amount of heat generation is a multifactorial in nature and it should be minimized for better primary healing of the implant site.

  1. Mechanical behaviour of degradable phosphate glass fibres and composites-a review.

    Science.gov (United States)

    Colquhoun, R; Tanner, K E

    2015-12-23

    Biodegradable materials are potentially an advantageous alternative to the traditional metallic fracture fixation devices used in the reconstruction of bone tissue defects. This is due to the occurrence of stress shielding in the surrounding bone tissue that arises from the absence of mechanical stimulus to the regenerating bone due to the mismatch between the elastic modulus of bone and the metal implant. However although degradable polymers may alleviate such issues, these inert materials possess insufficient mechanical properties to be considered as a suitable alternative to current metallic devices at sites of sufficient mechanical loading. Phosphate based glasses are an advantageous group of materials for tissue regenerative applications due to their ability to completely degrade in vivo at highly controllable rates based on the specific glass composition. Furthermore the release of the glass's constituent ions can evoke a therapeutic stimulus in vivo (i.e. osteoinduction) whilst also generating a bioactive response. The processing of these materials into fibres subsequently allows them to act as reinforcing agents in degradable polymers to simultaneously increase its mechanical properties and enhance its in vivo response. However despite the various review articles relating to the compositional influences of different phosphate glass systems, there has been limited work summarising the mechanical properties of different phosphate based glass fibres and their subsequent incorporation as a reinforcing agent in degradable composite materials. As a result, this review article examines the compositional influences behind the development of different phosphate based glass fibre compositions intended as composite reinforcing agents along with an analysis of different potential composite configurations. This includes variations in the fibre content, matrix material and fibre architecture as well as other novel composites designs.

  2. Clinical Efficacy of Acupuncture on Rheumatoid Arthritis and Associated Mechanisms: A Systemic Review

    Directory of Open Access Journals (Sweden)

    Pei-Chi Chou

    2018-01-01

    Full Text Available Objective. The objective of this review is to investigate the detailed existing scientific information about the clinical efficacy of acupuncture on rheumatoid arthritis (RA conditions and to reveal the proposed mechanisms. Methods. We searched the PubMed, EMBASE, Cochrane, AMED (Allied and Complementary Medicine, NCCAM (The National Center for Complementary and Alternative Medicine, and CNKI (China National Knowledge Infrastructure databases to identify relevant monographs and related references from 1974 to 2018. Chinese journals and theses/dissertations were hand searched. Results. 43 studies were recruited. Each research was analyzed for study design, subject characteristics, intervention, selected acupoints, assessment parameters, proposed mechanisms, and results/conclusions. Conclusions. In our review, we concluded that acupuncture alone or combined with other treatment modalities is beneficial to the clinical conditions of RA without adverse effects reported and can improve function and quality of life and is worth trying. Several important possible mechanisms were summarized including anti-inflammatory effect, antioxidative effect, and regulation of immune system function. However, there is still inconsistency regarding the clinical efficacy and lack of well-designed human/animal double-blinded RCTs. Future discussion for further agreement on taking traditional Chinese medicine (TCM theory into consideration as much as possible is a top priority.

  3. Quantum mechanics of excitation transport in photosynthetic complexes: a key issues review.

    Science.gov (United States)

    Levi, Federico; Mostarda, Stefano; Rao, Francesco; Mintert, Florian

    2015-07-01

    For a long time microscopic physical descriptions of biological processes have been based on quantum mechanical concepts and tools, and routinely employed by chemical physicists and quantum chemists. However, the last ten years have witnessed new developments on these studies from a different perspective, rooted in the framework of quantum information theory. The process that more, than others, has been subject of intense research is the transfer of excitation energy in photosynthetic light-harvesting complexes, a consequence of the unexpected experimental discovery of oscillating signals in such highly noisy systems. The fundamental interdisciplinary nature of this research makes it extremely fascinating, but can also constitute an obstacle to its advance. Here in this review our objective is to provide an essential summary of the progress made in the theoretical description of excitation energy dynamics in photosynthetic systems from a quantum mechanical perspective, with the goal of unifying the language employed by the different communities. This is initially realized through a stepwise presentation of the fundamental building blocks used to model excitation transfer, including protein dynamics and the theory of open quantum system. Afterwards, we shall review how these models have evolved as a consequence of experimental discoveries; this will lead us to present the numerical techniques that have been introduced to quantitatively describe photo-absorbed energy dynamics. Finally, we shall discuss which mechanisms have been proposed to explain the unusual coherent nature of excitation transport and what insights have been gathered so far on the potential functional role of such quantum features.

  4. A review of toxicity and mechanisms of individual and mixtures of heavy metals in the environment.

    Science.gov (United States)

    Wu, Xiangyang; Cobbina, Samuel J; Mao, Guanghua; Xu, Hai; Zhang, Zhen; Yang, Liuqing

    2016-05-01

    The rational for the study was to review the literature on the toxicity and corresponding mechanisms associated with lead (Pb), mercury (Hg), cadmium (Cd), and arsenic (As), individually and as mixtures, in the environment. Heavy metals are ubiquitous and generally persist in the environment, enabling them to biomagnify in the food chain. Living systems most often interact with a cocktail of heavy metals in the environment. Heavy metal exposure to biological systems may lead to oxidation stress which may induce DNA damage, protein modification, lipid peroxidation, and others. In this review, the major mechanism associated with toxicities of individual metals was the generation of reactive oxygen species (ROS). Additionally, toxicities were expressed through depletion of glutathione and bonding to sulfhydryl groups of proteins. Interestingly, a metal like Pb becomes toxic to organisms through the depletion of antioxidants while Cd indirectly generates ROS by its ability to replace iron and copper. ROS generated through exposure to arsenic were associated with many modes of action, and heavy metal mixtures were found to have varied effects on organisms. Many models based on concentration addition (CA) and independent action (IA) have been introduced to help predict toxicities and mechanisms associated with metal mixtures. An integrated model which combines CA and IA was further proposed for evaluating toxicities of non-interactive mixtures. In cases where there are molecular interactions, the toxicogenomic approach was used to predict toxicities. The high-throughput toxicogenomics combines studies in genetics, genome-scale expression, cell and tissue expression, metabolite profiling, and bioinformatics.

  5. Fracture mechanics of thin wall cylindrical pressure vessels: an interim review

    International Nuclear Information System (INIS)

    Kurtz, R.J.; Olson, N.J.

    1977-08-01

    The report is a result of activities in the LMFBR Fuel Rod Transient Performance Program sponsored by the LMFBR Branch of the Division of Project Management, U.S. Nuclear Regulatory Commission. One of the objectives is to develop predictions relative to the length, direction, and rate of growth of cladding rips subsequent to (or concurrent with) the initial cladding breach during unprotected transients. To provide a basis for evaluation, Battelle, Pacific Northwest Laboratories has reviewed most available fracture mechanics assessments relative to thin-wall cylindrical pressure vessels. The purpose of the report is to review the various fracture mechanics models and to describe the pertinent fracture parameters. It is intended to provide a formal basis for assessing future analytical predictions of fracture behavior of materials exposed to transient LMFBR thermal and mechanical loading conditions. In addition, the report is expected to provide reference material for evaluating or developing experimental programs required to properly address the problem of predicting fracture behavior of materials during transient events

  6. Fe–Al–Mn–C lightweight structural alloys: a review on the microstructures and mechanical properties

    Directory of Open Access Journals (Sweden)

    Hansoo Kim, Dong-Woo Suh and Nack J Kim

    2013-01-01

    Full Text Available Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe–Al–Mn–C alloys were patented in 1950s for replacement of nickel or chromium in corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest.

  7. Mechanisms and biomaterials in pH-responsive tumour targeted drug delivery: A review.

    Science.gov (United States)

    Kanamala, Manju; Wilson, William R; Yang, Mimi; Palmer, Brian D; Wu, Zimei

    2016-04-01

    As the mainstay in the treatment of various cancers, chemotherapy plays a vital role, but still faces many challenges, such as poor tumour selectivity and multidrug resistance (MDR). Targeted drug delivery using nanotechnology has provided a new strategy for addressing the limitations of the conventional chemotherapy. In the last decade, the volume of research published in this area has increased tremendously, especially with functional nano drug delivery systems (nanocarriers). Coupling a specific stimuli-triggered drug release mechanism with these delivery systems is one of the most prevalent approaches for improving therapeutic outcomes. Among the various stimuli, pH triggered delivery is regarded as the most general strategy, targeting the acidic extracellular microenvironment and intracellular organelles of solid tumours. In this review, we discuss recent advances in the development of pH-sensitive nanocarriers for tumour-targeted drug delivery. The review focuses on the chemical design of pH-sensitive biomaterials, which are used to fabricate nanocarriers for extracellular and/or intracellular tumour site-specific drug release. The pH-responsive biomaterials bring forth conformational changes in these nanocarriers through various mechanisms such as protonation, charge reversal or cleavage of a chemical bond, facilitating tumour specific cell uptake or drug release. A greater understanding of these mechanisms will help to design more efficient drug delivery systems to address the challenges encountered in conventional chemotherapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Review on Synthesis, Thermo-Physical Property, and Heat Transfer Mechanism of Nanofluids

    Directory of Open Access Journals (Sweden)

    Mahesh Suresh Patil

    2016-10-01

    Full Text Available Nanofluids are suspended nano-sized particles in a base fluid. With increasing demand for more high efficiency thermal systems, nanofluids seem to be a promising option for researchers. As a result, numerous investigations have been undertaken to understand the behaviors of nanofluids. Since their discovery, the thermo-physical properties of nanofluids have been under intense research. Inadequate understanding of the mechanisms involved in the heat transfer of nanofluids has been the major obstacle for the development of sophisticated nanofluids with the desired properties. In this comprehensive review paper, investigations on synthesis, thermo-physical properties, and heat transfer mechanisms of nanofluids have been reviewed and presented. Results show that the thermal conductivity of nanofluids increases with the increase of the operating temperature. This can potentially be used for the efficiency enhancement of thermal systems under higher operating temperatures. In addition, this paper also provides details concerning dependency of the thermo-physical properties as well as synthesis and the heat transfer mechanism of the nanofluids.

  9. Numerical Modelling of Mechanical Integrity of the Copper-Cast Iron Canister. A Literature Review

    International Nuclear Information System (INIS)

    Lanru Jing

    2004-04-01

    This review article presents a summary of the research works on the numerical modelling of the mechanical integrity of the composite copper-cast iron canisters for the final disposal of Swedish nuclear wastes, conducted by SKB and SKI since 1992. The objective of the review is to evaluate the outstanding issues existing today about the basic design concepts and premises, fundamental issues on processes, properties and parameters considered for the functions and requirements of canisters under the conditions of a deep geological repository. The focus is placed on the adequacy of numerical modelling approaches adopted in regards to the overall mechanical integrity of the canisters, especially the initial state of canisters regarding defects and the consequences of their evolution under external and internal loading mechanisms adopted in the design premises. The emphasis is the stress-strain behaviour and failure/strength, with creep and plasticity involved. Corrosion, although one of the major concerns in the field of canister safety, was not included

  10. The Immunomodulatory Effects of Macrolides—A Systematic Review of the Underlying Mechanisms

    Directory of Open Access Journals (Sweden)

    Petra Zimmermann

    2018-03-01

    Full Text Available BackgroundThe mechanisms underlying the non-antimicrobial immunomodulatory properties of macrolides are not well understood.ObjectivesTo systematically review the evidence for the immunomodulatory properties of macrolides in humans and to describe the underlying mechanism and extent of their influence on the innate and adaptive immune system.MethodsA systematic literature search was done in MEDLINE using the OVID interface from 1946 to December 2016 according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA. Original articles investigating the influence of four macrolides (azithromycin, clarithromycin, erythromycin, and roxithromycin on immunological markers in humans were included.ResultsWe identified 22 randomized, controlled trials, 16 prospective cohort studies, and 8 case–control studies investigating 47 different immunological markers (186 measurements in 1,834 participants. The most frequently reported outcomes were a decrease in the number of neutrophils, and the concentrations of neutrophil elastase, interleukin (IL-8, IL-6, IL-1beta, tumor necrosis factor (TNF-alpha, eosinophilic cationic protein, and matrix metalloproteinase 9. Inhibition of neutrophil function was reported more frequently than eosinophil function. A decrease in T helper (Th 2 cells cytokines (IL-4, IL-5, IL-6 was reported more frequently than a decrease in Th1 cytokines (IL-2, INF-gamma.ConclusionMacrolides influence a broad range of immunological mechanisms resulting in immunomodulatory effects. To optimize the treatment of chronic inflammatory diseases by macrolides, further studies are necessary, particularly comparing different macrolides and dose effect relationships.

  11. Fe–Al–Mn–C lightweight structural alloys: a review on the microstructures and mechanical properties

    Science.gov (United States)

    Kim, Hansoo; Suh, Dong-Woo; Kim, Nack J

    2013-01-01

    Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe–Al–Mn–C alloys were patented in 1950s for replacement of nickel or chromium in corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest. PMID:27877553

  12. Fe-Al-Mn-C lightweight structural alloys: a review on the microstructures and mechanical properties.

    Science.gov (United States)

    Kim, Hansoo; Suh, Dong-Woo; Kim, Nack J

    2013-02-01

    Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe-Al-Mn-C alloys were patented in 1950s for replacement of nickel or chromium in corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest.

  13. Lifelong bilingualism and neural reserve against Alzheimer's disease: a review of findings and potential mechanisms.

    Science.gov (United States)

    Gold, Brian T

    2015-03-15

    Alzheimer's disease (AD) is a progressive brain disorder that initially affects medial temporal lobe circuitry and memory functions. Current drug treatments have only modest effects on the symptomatic course of the disease. In contrast, a growing body of evidence suggests that lifelong bilingualism may delay the onset of clinical AD symptoms by several years. The purpose of the present review is to summarize evidence for bilingualism as a reserve variable against AD and discuss potential underlying neurocognitive mechanisms. Evidence is reviewed suggesting that bilingualism may delay clinical AD symptoms by protecting frontostriatal and frontoparietal executive control circuitry rather than medial temporal lobe memory circuitry. Cellular and molecular mechanisms that may contribute to bilingual cognitive reserve effects are discussed, including those that may affect neuronal metabolic functions, dynamic neuronal-glial interactions, vascular factors, myelin structure and neurochemical signaling. Future studies that may test some of these potential mechanisms of bilingual CR effects are proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. A review on mechanical considerations for chronically-implanted neural probes

    Science.gov (United States)

    Lecomte, Aziliz; Descamps, Emeline; Bergaud, Christian

    2018-06-01

    This review intends to present a comprehensive analysis of the mechanical considerations for chronically-implanted neural probes. Failure of neural electrical recordings or stimulation over time has shown to arise from foreign body reaction and device material stability. It seems that devices that match most closely with the mechanical properties of the brain would be more likely to reduce the mechanical stress at the probe/tissue interface, thus improving body acceptance. The use of low Young’s modulus polymers instead of hard substrates is one way to enhance this mechanical mimetism, though compliance can be achieved through a variety of means. The reduction of probe width and thickness in comparison to a designated length, the use of soft hydrogel coatings and the release in device tethering to the skull, can also improve device compliance. Paradoxically, the more compliant the device, the more likely it will fail during the insertion process in the brain. Strategies have multiplied this past decade to offer partial or temporary stiffness to the device to overcome this buckling effect. A detailed description of the probe insertion mechanisms is provided to analyze potential sources of implantation failure and the need for a mechanically-enhancing structure. This leads us to present an overview of the strategies that have been put in place over the last ten years to overcome buckling issues. Particularly, great emphasis is put on bioresorbable polymers and their assessment for neural applications. Finally, a discussion is provided on some of the key features for the design of mechanically-reliable, polymer-based next generation of chronic neuroprosthetic devices.

  15. Insights into carbon nanotube and graphene formation mechanisms from molecular simulations: a review

    International Nuclear Information System (INIS)

    Page, A J; Ding, F; Irle, S; Morokuma, K

    2015-01-01

    The discovery of carbon nanotubes (CNTs) and graphene over the last two decades has heralded a new era in physics, chemistry and nanotechnology. During this time, intense efforts have been made towards understanding the atomic-scale mechanisms by which these remarkable nanostructures grow. Molecular simulations have made significant contributions in this regard; indeed, they are responsible for many of the key discoveries and advancements towards this goal. Here we review molecular simulations of CNT and graphene growth, and in doing so we highlight the many invaluable insights gained from molecular simulations into these complex nanoscale self-assembly processes. This review highlights an often-overlooked aspect of CNT and graphene formation—that the two processes, although seldom discussed in the same terms, are in fact remarkably similar. Both can be viewed as a 0D → 1D → 2D transformation, which converts carbon atoms (0D) to polyyne chains (1D) to a complete sp 2 -carbon network (2D). The difference in the final structure (CNT or graphene) is determined only by the curvature of the catalyst and the strength of the carbon–metal interaction. We conclude our review by summarizing the present shortcomings of CNT/graphene growth simulations, and future challenges to this important area. (review article)

  16. A review of proton exchange membrane water electrolysis on degradation mechanisms and mitigation strategies

    Science.gov (United States)

    Feng, Qi; Yuan, Xiao-Zi; Liu, Gaoyang; Wei, Bing; Zhang, Zhen; Li, Hui; Wang, Haijiang

    2017-10-01

    Proton exchange membrane water electrolysis (PEMWE) is an advanced and effective solution to the primary energy storage technologies. A better understanding of performance and durability of PEMWE is critical for the engineers and researchers to further advance this technology for its market penetration, and for the manufacturers of PEM water electrolyzers to implement quality control procedures for the production line or on-site process monitoring/diagnosis. This paper reviews the published works on performance degradations and mitigation strategies for PEMWE. Sources of degradation for individual components are introduced. With degradation causes discussed and degradation mechanisms examined, the review emphasizes on feasible strategies to mitigate the components degradation. To avoid lengthy real lifetime degradation tests and their high costs, the importance of accelerated stress tests and protocols is highlighted for various components. In the end, R&D directions are proposed to move the PEMWE technology forward to become a key element in future energy scenarios.

  17. Enhancement and Optimization Mechanisms of Biogas Production for Rural Household Energy in Developing Countries: A review

    Directory of Open Access Journals (Sweden)

    Yitayal Addis Alemayehu

    2015-10-01

    Full Text Available Anaerobic digestion is common but vital process used for biogas and fertilizer production as well as one method for waste treatment. The process is currently used in developing countries primarily for biogas production in the household level of rural people. The aim of this review is to indicate possible ways of including rural households who own less than four heads of cattle for the biogas programs in developing countries. The review provides different research out puts on using biogas substrates other than cow dung or its mix through different enhancement and optimization mechanisms. Many biodegradable materials have been studied for alternative methane production. Therefore, these substrates could be used for production by addressing the optimum conditions for each factor and each processes for enhanced and optimized biogas production.

  18. Reliability and Measurement Error of Tensiomyography to Assess Mechanical Muscle Function: A Systematic Review.

    Science.gov (United States)

    Martín-Rodríguez, Saúl; Loturco, Irineu; Hunter, Angus M; Rodríguez-Ruiz, David; Munguia-Izquierdo, Diego

    2017-12-01

    Martín-Rodríguez, S, Loturco, I, Hunter, AM, Rodríguez-Ruiz, D, and Munguia-Izquierdo, D. Reliability and measurement error of tensiomyography to assess mechanical muscle function: A systematic review. J Strength Cond Res 31(12): 3524-3536, 2017-Interest in studying mechanical skeletal muscle function through tensiomyography (TMG) has increased in recent years. This systematic review aimed to (a) report the reliability and measurement error of all TMG parameters (i.e., maximum radial displacement of the muscle belly [Dm], contraction time [Tc], delay time [Td], half-relaxation time [½ Tr], and sustained contraction time [Ts]) and (b) to provide critical reflection on how to perform accurate and appropriate measurements for informing clinicians, exercise professionals, and researchers. A comprehensive literature search was performed of the Pubmed, Scopus, Science Direct, and Cochrane databases up to July 2017. Eight studies were included in this systematic review. Meta-analysis could not be performed because of the low quality of the evidence of some studies evaluated. Overall, the review of the 9 studies involving 158 participants revealed high relative reliability (intraclass correlation coefficient [ICC]) for Dm (0.91-0.99); moderate-to-high ICC for Ts (0.80-0.96), Tc (0.70-0.98), and ½ Tr (0.77-0.93); and low-to-high ICC for Td (0.60-0.98), independently of the evaluated muscles. In addition, absolute reliability (coefficient of variation [CV]) was low for all TMG parameters except for ½ Tr (CV = >20%), whereas measurement error indexes were high for this parameter. In conclusion, this study indicates that 3 of the TMG parameters (Dm, Td, and Tc) are highly reliable, whereas ½ Tr demonstrate insufficient reliability, and thus should not be used in future studies.

  19. Annual review of numerical fluid mechanics and heat transfer. Volume 1

    International Nuclear Information System (INIS)

    Chawla, T.C.

    1987-01-01

    Numerical techniqes for the analysis of problems in fluid mechanics and heat transfer are discussed, reviewing the results of recent investigations. Topics addressed include thermal radiation in particulate media with dependent and independent scattering, pressure-velocity coupling in incompressiblefluid flow, new explicit methods for diffusion problems, and one-dimensional reaction-diffusion equations in combustion theory. Consideration is given to buckling flows, multidimensional radiative-transfer analysis in participating media, freezing and melting problems, and complex heat-transfer processes in heat-generating horizontal fluid layers

  20. TiO$_2$-based Memristors and ReRAM: Materials, Mechanisms and Models (a Review)

    OpenAIRE

    Gale, Ella

    2016-01-01

    The memristor is the fundamental non-linear circuit element, with uses in computing and computer memory. ReRAM (Resistive Random Access Memory) is a resistive switching memory proposed as a non-volatile memory. In this review we shall summarise the state of the art for these closely-related fields, concentrating on titanium dioxide, the well-utilised and archetypal material for both. We shall cover material properties, switching mechanisms and models to demonstrate what ReRAM and memristor sc...

  1. MECHANISMS IN ENDOCRINOLOGY: Diabetic cardiomyopathy: pathophysiology and potential metabolic interventions state of the art review.

    Science.gov (United States)

    Levelt, Eylem; Gulsin, Gaurav; Neubauer, Stefan; McCann, Gerry P

    2018-04-01

    Heart failure is a major cause of morbidity and mortality in type 2 diabetes. Type 2 diabetes contributes to the development of heart failure through a variety of mechanisms, including disease-specific myocardial structural, functional and metabolic changes. This review will focus on the contemporary contributions of state of the art non-invasive technologies to our understanding of diabetic cardiomyopathy, including data on cardiac disease phenotype, cardiac energy metabolism and energetic deficiency, ectopic and visceral adiposity, diabetic liver disease, metabolic modulation strategies and cardiovascular outcomes with new classes of glucose-lowering therapies. © 2018 The authors.

  2. The analysis of actuating mechanism and review of concepts for the vortex valve

    International Nuclear Information System (INIS)

    Park, Jong Kyun; Sim, Yun Seop; Joung, Sae Won; Lee, Ki Young; Lee, Jun; Kim, Young In

    1995-12-01

    To understand the basic features of the passive fluidic device, which is increasing available core cooling water from the safety injection tanks in the KNGR, review of the existing vortex valves concepts and analysis of the actuating mechanism of them have been performed and the results are as following: * Preliminary methodology development for parallel two water columns behavior, which is similar to the SIT valve actuation condition * Preliminary methodology for the vortex value actuation features * Analysis of the parallel water columns behavior and vortex valve actuation features using the results of above activities * Further works to be done in the analytical methodology. 16 figs., 2 refs. (Author) .new

  3. Effects and mechanisms of a microcurrent dressing on skin wound healing: a review.

    Science.gov (United States)

    Yu, Chao; Hu, Zong-Qian; Peng, Rui-Yun

    2014-01-01

    The variety of wound types has resulted in a wide range of wound dressings, with new products frequently being introduced to target different aspects of the wound healing process. The ideal wound dressing should achieve rapid healing at a reasonable cost, with minimal inconvenience to the patient. Microcurrent dressing, a novel wound dressing with inherent electric activity, can generate low-level microcurrents at the device-wound contact surface in the presence of moisture and can provide an advanced wound healing solution for managing wounds. This article offers a review of the effects and mechanisms of the microcurrent dressing on the healing of skin wounds.

  4. Serotonin reuptake inhibitors and bone health: A review of clinical studies and plausible mechanisms

    Directory of Open Access Journals (Sweden)

    Ravisha Wadhwa

    2017-06-01

    Full Text Available Selective serotonin reuptake inhibitors (SSRIs are currently the treatment of choice in depression and constitute major portion of prescription in depressive patients. The role of serotonin receptors in bone is emerging, raising certain questions regarding the effect of blockade of serotonin reuptake in the bone metabolism. Clinical studies have reported an association of SSRI antidepressants which with increase in fracture and decrease in bone mineral density. This review focus on recent evidence that evaluate the association of SSRIs with the risk of fracture and bone mineral density and also the probable mechanisms that might be involved in such effects.

  5. TiO2-based memristors and ReRAM: materials, mechanisms and models (a review)

    Science.gov (United States)

    Gale, Ella

    2014-10-01

    The memristor is the fundamental nonlinear circuit element, with uses in computing and computer memory. Resistive Random Access Memory (ReRAM) is a resistive switching memory proposed as a non-volatile memory. In this review we shall summarize the state of the art for these closely-related fields, concentrating on titanium dioxide, the well-utilized and archetypal material for both. We shall cover material properties, switching mechanisms and models to demonstrate what ReRAM and memristor scientists can learn from each other and examine the outlook for these technologies.

  6. Advanced paternal age effects in neurodevelopmental disorders-review of potential underlying mechanisms.

    Science.gov (United States)

    Janecka, M; Mill, J; Basson, M A; Goriely, A; Spiers, H; Reichenberg, A; Schalkwyk, L; Fernandes, C

    2017-01-31

    Multiple epidemiological studies suggest a relationship between advanced paternal age (APA) at conception and adverse neurodevelopmental outcomes in offspring, particularly with regard to increased risk for autism and schizophrenia. Conclusive evidence about how age-related changes in paternal gametes, or age-independent behavioral traits affect neural development is still lacking. Recent evidence suggests that the origins of APA effects are likely to be multidimensional, involving both inherited predisposition and de novo events. Here we provide a review of the epidemiological and molecular findings to date. Focusing on the latter, we present the evidence for genetic and epigenetic mechanisms underpinning the association between late fatherhood and disorder in offspring. We also discuss the limitations of the APA literature. We propose that different hypotheses relating to the origins of the APA effects are not mutually exclusive. Instead, multiple mechanisms likely contribute, reflecting the etiological complexity of neurodevelopmental disorders.

  7. Effect of Nanoparticle Incorporation and Surface Coating on Mechanical Properties of Bone Scaffolds: A Brief Review

    Directory of Open Access Journals (Sweden)

    Jesus Corona-Gomez

    2016-07-01

    Full Text Available Mechanical properties of a scaffold play an important role in its in vivo performance in bone tissue engineering, due to the fact that implanted scaffolds are typically subjected to stress including compression, tension, torsion, and shearing. Unfortunately, not all the materials used to fabricate scaffolds are strong enough to mimic native bones. Extensive research has been conducted in order to increase scaffold strength and mechanical performance by incorporating nanoparticles and/or coatings. An incredible improvement has been achieved; and some outstanding examples are the usage of nanodiamond, hydroxyapatite, bioactive glass particles, SiO2, MgO, and silver nanoparticles. This review paper aims to present the results, to summarize significant findings, and to give perspective for future work, which could be beneficial to future bone tissue engineering.

  8. Mechanical, Thermal, and Electrical Properties of Graphene-Epoxy Nanocomposites—A Review

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    Rasheed Atif

    2016-08-01

    Full Text Available Monolithic epoxy, because of its brittleness, cannot prevent crack propagation and is vulnerable to fracture. However, it is well established that when reinforced—especially by nano-fillers, such as metallic oxides, clays, carbon nanotubes, and other carbonaceous materials—its ability to withstand crack propagation is propitiously improved. Among various nano-fillers, graphene has recently been employed as reinforcement in epoxy to enhance the fracture related properties of the produced epoxy–graphene nanocomposites. In this review, mechanical, thermal, and electrical properties of graphene reinforced epoxy nanocomposites will be correlated with the topographical features, morphology, weight fraction, dispersion state, and surface functionalization of graphene. The factors in which contrasting results were reported in the literature are highlighted, such as the influence of graphene on the mechanical properties of epoxy nanocomposites. Furthermore, the challenges to achieving the desired performance of polymer nanocomposites are also suggested throughout the article.

  9. Concise Review: Bone Marrow for the Treatment of Spinal Cord Injury: Mechanisms and Clinical Applications

    Science.gov (United States)

    Wright, Karina T; Masri, Wagih El; Osman, Aheed; Chowdhury, Joy; Johnson, William E B

    2011-01-01

    Transplantation of bone marrow stem cells into spinal cord lesions enhances axonal regeneration and promotes functional recovery in animal studies. There are two types of adult bone marrow stem cell; hematopoietic stem cells (HSCs), and mesenchymal stem cells (MSCs). The mechanisms by which HSCs and MSCs might promote spinal cord repair following transplantation have been extensively investigated. The objective of this review is to discuss these mechanisms; we briefly consider the controversial topic of HSC and MSC transdifferentiation into central nervous system cells but focus on the neurotrophic, tissue sparing, and reparative action of MSC grafts in the context of the spinal cord injury (SCI) milieu. We then discuss some of the specific issues related to the translation of HSC and MSC therapies for patients with SCI and present a comprehensive critique of the current bone marrow cell clinical trials for the treatment of SCI to date. Stem Cells 2011;29:169–178 PMID:21732476

  10. Review on Characterization and Mechanical Performance of Self-cleaning Concrete

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    Zailan Siti Norsaffirah

    2017-01-01

    Full Text Available Self-cleaning concrete is an effective alternative to provide cleaner environment which contribute to sustainability and towards a green environment. It is in accordance with the requirements of environmental issues on huge energy consumption and air pollution from carbon dioxide (CO2 emissions. Photocatalyst in self-cleaning concrete accelerates the decomposition of organic particulates, hence pollution could be reduced through photocatalytic degradation of gaseous pollutants. Mechanical performances of self-cleaning concrete were improved by adding photocatalytic materials. Self cleaning abilities were evaluated in the photocatalytic activity test under UV light and photocatalytic degradation of gaseous pollutant was measured by depollution test. This review aims to give an overview about the characteristics of photocatalytic materials and mechanical performances of self-cleaning concrete.

  11. The Difference Between Countermovement and Squat Jump Performances: A Review of Underlying Mechanisms With Practical Applications.

    Science.gov (United States)

    Van Hooren, Bas; Zolotarjova, Julia

    2017-07-01

    Van Hooren, B and Zolotarjova, J. The difference between countermovement and squat jump performances: a review of underlying mechanisms with practical applications. J Strength Cond Res 31(7): 2011-2020, 2017-Two movements that are widely used to monitor athletic performance are the countermovement jump (CMJ) and squat jump (SJ). Countermovement jump performance is almost always better than SJ performance, and the difference in performance is thought to reflect an effective utilization of the stretch-shortening cycle. However, the mechanisms responsible for the performance-enhancing effect of the stretch-shortening cycle are frequently undefined. Uncovering and understanding these mechanisms is essential to make an inference regarding the difference between the jumps. Therefore, we will review the potential mechanisms that explain the better performance in a CMJ as compared with a SJ. It is concluded that the difference in performance may primarily be related to the greater uptake of muscle slack and the buildup of stimulation during the countermovement in a CMJ. Elastic energy may also have a small contribution to an enhanced CMJ performance. Therefore, a larger difference between the jumps is not necessarily a better indicator of high-intensity sports performance. Although a larger difference may reflect the utilization of elastic energy in a small-amplitude CMJ as a result of a well-developed capability to co-activate muscles and quickly build up stimulation, a larger difference may also reflect a poor capability to reduce the degree of muscle slack and build up stimulation in the SJ. Because the capability to reduce the degree of muscle slack and quickly build up stimulation in the SJ may be especially important to high-intensity sports performance, training protocols might concentrate on attaining a smaller difference between the jumps.

  12. BASEBALL THROWING MECHANICS AS THEY RELATE TO PATHOLOGY AND PERFORMANCE - A REVIEW

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    Rod Whiteley

    2007-03-01

    Full Text Available It is a commonly held perception amongst biomechanists, sports medicine practitioners, baseball coaches and players, that an individual baseball player's style of throwing or pitching influences their performance and susceptibility to injury. With the results of a series of focus groups with baseball managers and pitching coaches in mind, the available scientific literature was reviewed regarding the contribution of individual aspects of pitching and throwing mechanics to potential for injury and performance. After a discussion of the limitations of kinematic and kinetic analyses, the individual aspects of pitching mechanics are discussed under arbitrary headings: Foot position at stride foot contact; Elbow flexion; Arm rotation; Arm horizontal abduction; Arm abduction; Lead knee position; Pelvic orientation; Deceleration-phase related issues; Curveballs; and Teaching throwing mechanics. In general, popular opinion of baseball coaching staff was found to be largely in concordance with the scientific investigations of biomechanists with several notable exceptions. Some difficulties are identified with the practical implementation of analyzing throwing mechanics in the field by pitching coaches, and with some unquantified aspects of scientific analyses

  13. Mechanisms of spinal cord injury regeneration in zebrafish: a systematic review

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    Zeynab Noorimotlagh

    2017-12-01

    Full Text Available Objective(s:To determine the molecular and cellular mechanisms of spinal cord regeneration in zebrafish. Materials and Methods: Medical databases of PubMed and Scopus were searched with following key words: Zebrafish; spinal cord injuries; regeneration; recovery of function. The map of mechanisms was performed using Xmind software. Results: Wnt/ß-catenin signaling, L1.1, L1.2, Major vault protein (MVP, contactin-2 and High mobility group box1 (HMGB1 had positive promoting effects on axonal re-growth while Ptena had an inhibitory effect. Neurogenesis is stimulated by Wnt/ß-catenin signaling as well as HMGB1, but inhibited by Notch signaling. Glial cells proliferate in response to fibroblast growth factor (fgf signaling and Lysophosphatidic acid (LPA. Furthermore, fgf signaling pathway causes glia bridge formation in favor of axonal regeneration. LPA and HMGB1 in acute phase stimulate inflammatory responses around injury and suppress regeneration. LPA also induces microglia activation and neuronal death in addition to glia cell proliferation, but prevents neurite sprouting. Conclusion: This study provides a comprehensive review of the known molecules and mechanisms in the current literature involved in the spinal cord injury (SCI regeneration in zebrafish, in a time course manner. A better understanding of the whole determining mechanisms for the SCI regeneration should be considered as a main goal for future studies.

  14. Mechanical properties of copper processed by Equal Channel Angular Pressing – a review

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    Ludvík Kunz

    2012-01-01

    Full Text Available The Equal Channel Angular Pressing is a hardening treatment with which ductile metals can be processed to refine their grain and sub-grain structure. This process enhances the mechanical strength of metals in terms of tensile strength, stress-controlled fatigue strength, and fatigue crack growth resistance. In this paper the authors draw a review of the major results of a wide research activity they carried out on a copper microstructure processed by Equal Channel Angular Pressing. The essential results are that tensile and fatigue strengths of the so obtained refined structure are improved by a factor of two with respect to the original coarse-grained metal. The fatigue crack initiation mechanism and the stability of the refined microstructure under cyclic loading are topics also discussed, evidencing the essential role of the process and of the material parameter, as the content of impurities in the microstructure. In this review, the authors also underline some critical aspects that have to be more investigated.

  15. Trauma and the psychosis spectrum: A review of symptom specificity and explanatory mechanisms

    Science.gov (United States)

    Gibson, Lauren E.; Alloy, Lauren B.; Ellman, Lauren M.

    2016-01-01

    Traumatic life events have been robustly associated with various psychosis outcomes, including increased risk of psychotic disorders, the prodrome of psychosis, and dimensional measures of psychotic symptoms, such as attenuated positive psychotic symptoms. However, trauma exposure has been linked to various mental disorders; therefore, the specificity of trauma exposure to psychosis remains unclear. This review focuses on two understudied areas of the trauma and psychosis literature: 1) the specificity between trauma and psychosis in relation to other disorders that often result post-trauma, and 2) proposed mechanisms that uniquely link trauma to psychosis. We begin by discussing the underlying connection between trauma exposure and the entire psychosis spectrum with a focus on the influence of trauma type and specific psychotic symptoms. We then consider how the principles of multifinality and equifinality can be useful in elucidating the trauma-psychosis relationship versus the trauma-other disorder relationship. Next, we discuss several cognitive and neurobiological mechanisms that might uniquely account for the association between trauma and psychosis, as well as the role of gender. Lastly, we review important methodological issues that complicate the research on trauma and psychosis, ending with clinical implications for the field. PMID:27632064

  16. Income inequality and depression: a systematic review and meta‐analysis of the association and a scoping review of mechanisms

    Science.gov (United States)

    Patel, Vikram; Burns, Jonathan K.; Dhingra, Monisha; Tarver, Leslie; Kohrt, Brandon A.; Lund, Crick

    2018-01-01

    Most countries have witnessed a dramatic increase of income inequality in the past three decades. This paper addresses the question of whether income inequality is associated with the population prevalence of depression and, if so, the potential mechanisms and pathways which may explain this association. Our systematic review included 26 studies, mostly from high‐income countries. Nearly two‐thirds of all studies and five out of six longitudinal studies reported a statistically significant positive relationship between income inequality and risk of depression; only one study reported a statistically significant negative relationship. Twelve studies were included in a meta‐analysis with dichotomized inequality groupings. The pooled risk ratio was 1.19 (95% CI: 1.07‐1.31), demonstrating greater risk of depression in populations with higher income inequality relative to populations with lower inequality. Multiple studies reported subgroup effects, including greater impacts of income inequality among women and low‐income populations. We propose an ecological framework, with mechanisms operating at the national level (the neo‐material hypothesis), neighbourhood level (the social capital and the social comparison hypotheses) and individual level (psychological stress and social defeat hypotheses) to explain this association. We conclude that policy makers should actively promote actions to reduce income inequality, such as progressive taxation policies and a basic universal income. Mental health professionals should champion such policies, as well as promote the delivery of interventions which target the pathways and proximal determinants, such as building life skills in adolescents and provision of psychological therapies and packages of care with demonstrated effectiveness for settings of poverty and high income inequality. PMID:29352539

  17. Income inequality and depression: a systematic review and meta-analysis of the association and a scoping review of mechanisms.

    Science.gov (United States)

    Patel, Vikram; Burns, Jonathan K; Dhingra, Monisha; Tarver, Leslie; Kohrt, Brandon A; Lund, Crick

    2018-02-01

    Most countries have witnessed a dramatic increase of income inequality in the past three decades. This paper addresses the question of whether income inequality is associated with the population prevalence of depression and, if so, the potential mechanisms and pathways which may explain this association. Our systematic review included 26 studies, mostly from high-income countries. Nearly two-thirds of all studies and five out of six longitudinal studies reported a statistically significant positive relationship between income inequality and risk of depression; only one study reported a statistically significant negative relationship. Twelve studies were included in a meta-analysis with dichotomized inequality groupings. The pooled risk ratio was 1.19 (95% CI: 1.07-1.31), demonstrating greater risk of depression in populations with higher income inequality relative to populations with lower inequality. Multiple studies reported subgroup effects, including greater impacts of income inequality among women and low-income populations. We propose an ecological framework, with mechanisms operating at the national level (the neo-material hypothesis), neighbourhood level (the social capital and the social comparison hypotheses) and individual level (psychological stress and social defeat hypotheses) to explain this association. We conclude that policy makers should actively promote actions to reduce income inequality, such as progressive taxation policies and a basic universal income. Mental health professionals should champion such policies, as well as promote the delivery of interventions which target the pathways and proximal determinants, such as building life skills in adolescents and provision of psychological therapies and packages of care with demonstrated effectiveness for settings of poverty and high income inequality. © 2018 World Psychiatric Association.

  18. Fundamental mechanisms and reactions in non-catalytic subcritical hydrothermal processes: A review.

    Science.gov (United States)

    Yousefifar, Azadeh; Baroutian, Saeid; Farid, Mohammed M; Gapes, Daniel J; Young, Brent R

    2017-10-15

    The management and disposal of solid waste is of increasing concern across the globe. Hydrothermal processing of sludge has been suggested as a promising solution to deal with the considerable amounts of sludge produced worldwide. Such a process not only degrades organic compounds and reduces waste volume, but also provides an opportunity to recover valuable substances. Hydrothermal processing comprises two main sub-processes: wet oxidation (WO) and thermal hydrolysis (TH), in which the formation of various free radicals results in the production of different intermediates. Volatile fatty acids (VFAs), especially acetic acid, are usually the main intermediates which remain as a by-product of the process. This paper aims to review the fundamental mechanism for hydrothermal processing of sludge, and the formation of different free radicals and intermediates therein. In addition, the proposed kinetic models for the two processes (WO and TH) from the literature are reviewed and the advantages and disadvantages of each model are outlined. The effect of mass transfer as a critical component of the design and development of the processes, which has been neglected in most of these proposed models, is also reviewed, and the effect of influencing parameters on the processes' controlling step (reaction or mass transfer) is discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Efficacy of inter-dental mechanical plaque control in managing gingivitis--a meta-review.

    Science.gov (United States)

    Sälzer, Sonja; Slot, Dagmar E; Van der Weijden, Fridus A; Dörfer, Christof E

    2015-04-01

    What is the effect of mechanical inter-dental plaque removal in addition to toothbrushing, on managing gingivitis using various formats of inter-dental self-care in adults based on evidence gathered from existing systematic reviews? Three Internet sources were searched by a strategy designed to include systematic reviews on inter-dental cleaning devices. Plaque and gingivitis scores were the primary parameters of interest. Characteristics of selected papers were extracted. The potential risk of bias was estimated and the acquired evidence was graded. Screening of 395 papers resulted in six systematic reviews. Two papers evaluated the efficacy of dental floss, two of inter-dental brushes (IDB), one of woodsticks and one of the oral irrigator. Weak evidence of unclear or small magnitude was retrieved that supported dental floss, woodsticks and the oral irrigator to reduce gingivitis in addition to toothbrushing. No concomitant evidence for an effect on plaque emerged. There is moderate evidence that IDBs in combination with toothbrushing reduce both plaque and gingivitis. Evidence suggests that inter-dental cleaning with IDBs is the most effective method for inter-dental plaque removal. The majority of available studies fail to demonstrate that flossing is generally effective in plaque removal. All investigated devices for inter-dental self-care seem to support the management of gingivitis, however, to a varying extend. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Overview of reviews: mechanical interventions for the treatment and management of chronic obstructive pulmonary disease.

    Science.gov (United States)

    Lisy, Karolina; White, Heath; Pearson, Alan

    2014-12-01

    Chronic obstructive pulmonary disease (COPD) is characterized by a progressive and non-reversible airflow limitation and symptoms of breathlessness, sputum production and cough. COPD is the fourth most common cause of mortality worldwide and represents a significant social and economic burden. As such, effective strategies that might be employed to treat COPD and manage symptoms need to be investigated. This overview aimed to summarize the existing evidence available in the Cochrane Library regarding the use of mechanical interventions used for the treatment and management of COPD. Systematic reviews that included adult participants with diagnosed COPD who received a mechanical intervention were included. Five reviews were included, and due to the heterogeneity of these reviews, direct and indirect comparisons of the effects of the intervention were not possible. Instead, data of the effectiveness of each intervention were extracted and summarized in tables and discussed as a narrative summary. Interventions included non-invasive positive pressure ventilation (NPPV), positive airway pressure (PEP) devices and neuromuscular electrical stimulation (NMES). Evidence regarding the effectiveness of NPPV was limited, and available data do not support the use of NPPV for patients with stable COPD. NPPV might, however, be of benefit as a weaning strategy for intubated patients and for patients experiencing respiratory failure; however, more research is required. Although PEP devices are considered as a safe airway clearance technique, data do not reveal a clear clinical benefit to their use. NMES is also regarded as safe for patients with COPD, and might also be beneficial in improving exercise tolerance and improving quality of life for patients with COPD. © 2014 Wiley Publishing Asia Pty Ltd.

  1. Relationship between sleep duration and childhood obesity: Systematic review including the potential underlying mechanisms.

    Science.gov (United States)

    Felső, R; Lohner, S; Hollódy, K; Erhardt, É; Molnár, D

    2017-09-01

    The prevalence of obesity is continually increasing worldwide. Determining risk factors for obesity may facilitate effective preventive programs. The present review focuses on sleep duration as a potential risk factor for childhood obesity. The aim is to summarize the evidence on the association of sleep duration and obesity and to discuss the underlying potential physiological and/or pathophysiological mechanisms. The Ovid MEDLINE, Scopus and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for papers using text words with appropriate truncation and relevant indexing terms. All studies objectively measuring sleep duration and investigating the association between sleep duration and obesity or factors (lifestyle and hormonal) possibly associated with obesity were included, without making restrictions based on study design or language. Data from eligible studies were extracted in tabular form and summarized narratively. After removing duplicates, 3540 articles were obtained. Finally, 33 studies (including 3 randomized controlled trials and 30 observational studies) were included in the review. Sleep duration seems to influence weight gain in children, however, the underlying explanatory mechanisms are still uncertain. In our review only the link between short sleep duration and the development of insulin resistance, sedentarism and unhealthy dietary patterns could be verified, while the role of other mediators, such as physical activity, screen time, change in ghrelin and leptin levels, remained uncertain. There are numerous evidence gaps. To answer the remaining questions, there is a need for studies meeting high methodological standards and including a large number of children. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All

  2. The mechanisms of far transfer from cognitive training: Review and hypothesis.

    Science.gov (United States)

    Greenwood, Pamela M; Parasuraman, Raja

    2016-09-01

    General intelligence is important for success in daily life, fueling interest in developing cognitive training as an intervention to improve fluid ability (Gf). A major obstacle to the design of effective cognitive interventions has been the paucity of hypotheses bearing on mechanisms underlying transfer of cognitive training to Gf. Despite the large amounts of money and time currently being expended on cognitive training, there is little scientific agreement on how, or even whether, Gf can be heightened by such training. We review the relevant strands of evidence on cognitive-training-related changes in (a) cortical mechanisms of distraction suppression, and (b) activation of the dorsal attention network (DAN). We hypothesize that training-related increases in control of attention are important for what is termed far transfer of cognitive training to untrained abilities, notably to Gf. We review the evidence that distraction suppression evident in behavior, neuronal firing, scalp electroencephalography, and hemodynamic change is important for protecting target processing during perception and also for protecting targets held in working memory. Importantly, attentional control also appears to be central to performance on Gf assessments. Consistent with this evidence, forms of cognitive training that increase ability to ignore distractions (e.g., working memory training and perceptual training) not only affect the DAN but also affect transfer to Gf. Our hypothesis is supported by existing evidence. However, to advance the field of cognitive training, it is necessary that competing hypotheses on mechanisms of far transfer of cognitive training be advanced and empirically tested. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  3. A review of mechanical and tribological behaviour of polymer composite materials

    Science.gov (United States)

    Prabhakar, K.; Debnath, S.; Ganesan, R.; Palanikumar, K.

    2018-04-01

    Composite materials are finding increased applications in many industrial applications. A nano-composite is a matrix to which nanosized particles have been incorporated to drastically improve the mechanical performance of the original material. The structural components produced using nano-composites will exhibit a high strength-to-weight ratio. The properties of nano-composites have caused researchers and industries to consider using this material in several fields. Polymer nanocomposites consists of a polymer material having nano-particles or nano-fillers dispersed in the polymer matrix which may be of different shapes with at least one of the dimensions less than 100nm. In this paper, comprehensive review of polymer nanocomposites was done majorly in three different areas. First, mechanical behaviour of polymer nanocomposites which focuses on the mechanical property evaluation such as tensile strength, impact strength and modulus of elasticity based on the different combination of filler materials and nanoparticle inclusion. Second, wear behavior of Polymer composite materials with respect to different impingement angles and variation of filler composition using different processing techniques. Third, tribological (Friction and Wear) behaviour of nanocomposites using various combination of nanoparticle inclusion and time. Finally, it summarized the challenges and prospects of polymer nanocomposites.

  4. Additively Manufactured Scaffolds for Bone Tissue Engineering and the Prediction of their Mechanical Behavior: A Review.

    Science.gov (United States)

    Zhang, Xiang-Yu; Fang, Gang; Zhou, Jie

    2017-01-10

    Additive manufacturing (AM), nowadays commonly known as 3D printing, is a revolutionary materials processing technology, particularly suitable for the production of low-volume parts with high shape complexities and often with multiple functions. As such, it holds great promise for the fabrication of patient-specific implants. In recent years, remarkable progress has been made in implementing AM in the bio-fabrication field. This paper presents an overview on the state-of-the-art AM technology for bone tissue engineering (BTE) scaffolds, with a particular focus on the AM scaffolds made of metallic biomaterials. It starts with a brief description of architecture design strategies to meet the biological and mechanical property requirements of scaffolds. Then, it summarizes the working principles, advantages and limitations of each of AM methods suitable for creating porous structures and manufacturing scaffolds from powdered materials. It elaborates on the finite-element (FE) analysis applied to predict the mechanical behavior of AM scaffolds, as well as the effect of the architectural design of porous structure on its mechanical properties. The review ends up with the authors' view on the current challenges and further research directions.

  5. Mechanisms Underlying the Analgesic Effect of Moxibustion on Visceral Pain in Irritable Bowel Syndrome: A Review

    Directory of Open Access Journals (Sweden)

    Renjia Huang

    2014-01-01

    Full Text Available Irritable bowel syndrome (IBS is a functional bowel disorder that causes recurrent abdominal (visceral pain. Epidemiological data show that the incidence rate of IBS is as high as 25%. Most of the medications may lead to tolerance, addiction and toxic side effects. Moxibustion is an important component of traditional Chinese medicine and has been used to treat IBS-like abdominal pain for several thousand years in China. As a mild treatment, moxibustion has been widely applied in clinical treatment of visceral pain in IBS. In recent years, it has played an irreplaceable role in alternative medicine. Extensive clinical studies have demonstrated that moxibustion for treatment of visceral pain is simple, convenient, and inexpensive, and it is being accepted by an increasing number of patients. There have not been many studies investigating the analgesic mechanisms of moxibustion. Studies exploring the analgesic mechanisms have mainly focused on visceral hypersensitivity, brain-gut axis neuroendocrine system, and immune system. This paper reviews the latest developments in moxibustion use for treatment of visceral pain in IBS from these perspectives. It also evaluates potential problems in relevant studies on the mechanisms of moxibustion therapy to promote the application of moxibustion in the treatment of IBS.

  6. The Role of Malware in Reported Cyber Espionage: A Review of the Impact and Mechanism

    Directory of Open Access Journals (Sweden)

    Gaute Wangen

    2015-05-01

    Full Text Available The recent emergence of the targeted use of malware in cyber espionage versus industry requires a systematic review for better understanding of its impact and mechanism. This paper proposes a basic taxonomy to document major cyber espionage incidents, describing and comparing their impacts (geographic or political targets, origins and motivations and their mechanisms (dropper, propagation, types of operating systems and infection rates. This taxonomy provides information on recent cyber espionage attacks that can aid in defense against cyber espionage by providing both scholars and experts a solid foundation of knowledge about the topic. The classification also provides a systematic way to document known and future attacks to facilitate research activities. Geopolitical and international relations researchers can focus on the impacts, and malware and security experts can focus on the mechanisms. We identify several dominant patterns (e.g., the prevalent use of remote access Trojan and social engineering. This article concludes that the research and professional community should collaborate to build an open data set to facilitate the geopolitical and/or technical analysis and synthesis of the role of malware in cyber espionage.

  7. A review of the effect of vital teeth bleaching on the mechanical properties of tooth enamel.

    Science.gov (United States)

    Elfallah, Hunida M; Swain, Michael V

    2013-09-01

    Tooth whitening is considered the easiest and most cost-effective procedure for treating tooth discoloration. Contemporary bleaching agents contain hydrogen peroxide as the active ingredient. It is either applied directly or produced from its precursor, carbamide peroxide. A review of the published literature was undertaken to investigate the potential adverse effects of whitening products on dental enamel, with a focus on its mechanical properties and the influence of various parameters on study outcomes. There appear to be considerable differences in opinion as to whether changes in mechanical properties occur as a result of tooth whitening. However, the mechanical property findings of those studies appear to be related to the load applied during the indentation tests. Most studies which used loads higher than 500mN to determine enamel hardness showed no effect of bleaching, whereas those using lower loads were able to detect hardness reduction in the surface layer of enamel. In conclusion, bleaching reduces the hardness of the enamel surface of enamel, and that is more readily detected with instrumented low load testing systems. This hardness reduction may arise due to degradation or denaturation of enamel matrix proteins by the peroxide oxidation.

  8. Review article: anti-inflammatory mechanisms of action of Saccharomyces boulardii.

    Science.gov (United States)

    Pothoulakis, C

    2009-10-15

    Saccharomyces boulardii, a well-studied probiotic, can be effective in inflammatory gastrointestinal diseases with diverse pathophysiology, such as inflammatory bowel disease (IBD), and bacterially mediated or enterotoxin-mediated diarrhoea and inflammation. To discuss the mechanisms of action involved in the intestinal anti-inflammatory action of S. boulardii. Review of the literature related to the anti-inflammatory effects of this probiotic. Several mechanisms of action have been identified directed against the host and pathogenic microorganisms. S. boulardii and S. boulardii secreted-protein(s) inhibit production of proinflammatory cytokines by interfering with the global mediator of inflammation nuclear factor kappaB, and modulating the activity of the mitogen-activated protein kinases ERK1/2 and p38. S. boulardii activates expression of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) that protects from gut inflammation and IBD. S. boulardii also suppresses 'bacteria overgrowth' and host cell adherence, releases a protease that cleaves C. difficile toxin A and its intestinal receptor and stimulates antibody production against toxin A. Recent results indicate that S. boulardii may interfere with IBD pathogenesis by trapping T cells in mesenteric lymph nodes. The multiple anti-inflammatory mechanisms exerted by S. boulardii provide molecular explanations supporting its effectiveness in intestinal inflammatory states.

  9. Review article: Anti-inflammatory mechanisms of action of Saccharomyces boulardii

    Science.gov (United States)

    Pothoulakis, C.

    2009-01-01

    SUMMARY Background Saccharomyces boulardii (S. boulardii), a well-studied probiotic, can be effective in inflammatory gastrointestinal diseases with diverse pathophysiology, such as Inflammatory Bowel Disease (IBD), and bacterially – or enterotoxin-mediated diarrhea and inflammation. Aim Discuss the mechanisms of action involved in the intestinal anti-inflammatory action of S. boulardii Methods Review of the literature related to the anti-inflammatory effects of this probiotic. Results Several mechanisms of action have been identified directed against the host and pathogenic microorganisms. S. boulardii and S. boulardii secreted protein(s) inhibit production of proinflammatory cytokines by interfering with the global mediator of inflammation nuclear factor κB, and modulating the activity of the mitogen-activated protein kinases ERK1/2 and p38. S. boulardii activates expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ) that protects from gut inflammation and IBD. S. boulardii also suppresses “bacteria overgrowth” and host cell adherence, releases a protease that cleaves C. difficile toxin A and its intestinal receptor, and stimulates antibody production against toxin A. Recent results indicate that S. boulardii may interfere with IBD pathogenesis by trapping T cells in mesenteric lymph nodes. Conclusions The multiple anti-inflammatory mechanisms exerted by S. boulardii provide molecular explanations supporting its effectiveness in intestinal inflammatory states. PMID:19706150

  10. Effects of Heat Input on Microstructure, Corrosion and Mechanical Characteristics of Welded Austenitic and Duplex Stainless Steels: A Review

    Directory of Open Access Journals (Sweden)

    Ghusoon Ridha Mohammed

    2017-01-01

    Full Text Available The effects of input heat of different welding processes on the microstructure, corrosion, and mechanical characteristics of welded duplex stainless steel (DSS are reviewed. Austenitic stainless steel (ASS is welded using low-heat inputs. However, owing to differences in the physical metallurgy between ASS and DSS, low-heat inputs should be avoided for DSS. This review highlights the differences in solidification mode and transformation characteristics between ASS and DSS with regard to the heat input in welding processes. Specifically, many studies about the effects of heat energy input in welding process on the pitting corrosion, intergranular stress, stresscorrosion cracking, and mechanical properties of weldments of DSS are reviewed.

  11. Hypertrophic scars and keloids in surgery: current concepts.

    Science.gov (United States)

    Song, Colin

    2014-09-01

    Hypertrophic scars and keloids remain a challenge in surgery. We appreciate that our understanding of the process at cellular and molecular level, profound as it is, when it comes to the clinical evidence much is left to be desired. Although the bench to bedside conundrum remains, the science of translational research calls for an even higher level of cooperation between the scientist and the clinician for the impetus to succeed.The clinicians alerted us to the possible theories in the pathogenesis of keloid formation, inter alia, the ischemia theory, mast cell theory, immune theory, transforming growth factor β interaction, mechanical theory, and the melanocyte stimulating hormone theory. All of the above presupposed a stimulus that would result in an uncontrolled upregulation of collagen and extracellular matrix expression in the pathogenesis of the keloid. This bedside to bench initiative, as in true science, realized more ponderables than possibilities.By the same token, research into the epidermal-mesenchymal signaling, molecular biology, genomics, and stem cell research holds much promise in the bench top arena. To assess efficacy, many scar assessment scores exist in the literature. The clinical measurement of scar maturity can aid in determining end points for therapeutics. Tissue oxygen tension and color assessment of scars by standardized photography proved to be useful.In surgery, the use of dermal substitutes holds some promise as we surmise that quality scars that arise from dermal elements, molecular and enzyme behavior, and balance. Although a systematic review shows some benefit for earlier closure and healing of wounds, no such review exists at this point in time for the use of dermal substitutes in scars.Adipose-derived stem cell, as it pertains to scars, will hopefully realize the potential of skin regeneration rather than by repair in which we are familiar with as well as the undesirable scarring as a result of healing through the inflammatory

  12. A comprehensive review on self-healing of asphalt materials: Mechanism, model, characterization and enhancement.

    Science.gov (United States)

    Sun, Daquan; Sun, Guoqiang; Zhu, Xingyi; Guarin, Alvaro; Li, Bin; Dai, Ziwei; Ling, Jianming

    2018-05-09

    Self-healing has great potential to extend the service life of asphalt pavement, and this capability has been regarded as an important strategy when designing a sustainable infrastructure. This review presents a comprehensive summary of the state-of-the-art investigations concerning the self-healing mechanism, model, characterization and enhancement, ranging from asphalt to asphalt pavement. Firstly, the self-healing phenomenon as a general concept in asphalt materials is analyzed including its definition and the differences among self-healing and some viscoelastic responses. Additionally, the development of self-healing in asphalt pavement design is introduced. Next, four kinds of possible self-healing mechanism and corresponding models are presented. It is pointed out that the continuum thermodynamic model, considering the whole process from damage initiation to healing recovery, can be a promising study field. Further, a set of self-healing multiscale characterization methods from microscale to macroscale as well as computational simulation scale, are summed up. Thereinto, the computational simulation shows great potential in simulating the self-healing behavior of asphalt materials from mechanical and molecular level. Moreover, the factors influencing self-healing capability are discussed, but the action mechanisms of some factors remain unclear and need to be investigated. Finally, two extrinsic self-healing technologies, induction heating and capsule healing, are recommended as preventive maintenance applications in asphalt pavement. In future, more effective energy-based healing systems or novel material-based healing systems are expected to be developed towards designing sustainable long-life asphalt pavement. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Market-based mechanisms for biodiversity conservation: a review of existing schemes and an outline for a global mechanism

    NARCIS (Netherlands)

    Alvarado Quesada, I.; Hein, L.G.; Weikard, H.P.

    2014-01-01

    Continuous decline of biodiversity over the past decades suggests that efforts to decrease biodiversity loss have been insufficient. One option to deal with this problem is the use of market-based mechanisms for biodiversity conservation. Several studies have analysed such mechanisms individually,

  14. The Complementary and Alternative Medicine for Endometriosis: A Review of Utilization and Mechanism

    Directory of Open Access Journals (Sweden)

    Sai Kong

    2014-01-01

    Full Text Available Endometriosis (EM is one of the common gynecological conditions causing menstrual and pelvic pain and affects 10%–15% of women of reproductive age. In recent years, the complementary and alternative medical (CAM treatment for EM has become popular due to the few adverse reactions reported. The CAM therapy for EM includes several different treatments such as herbs (herbal prescription, extract, and patent, acupuncture, microwave physiotherapy, and Chinese herb medicine enema (CHM enema. These CAM therapies are effective at relieving dysmenorrhoea, shrinking adnexal masses, and promoting pregnancy, with less unpleasant side effects when compared to hormonal and surgical treatments. In this review, we focus on the status quo of CAM on EM and try to identify therapeutic efficacy and mechanisms based on some clinical and experimental studies. We hope to provide some instructive suggestions for clinical treatment and experimental research in the future.

  15. [Effects of biochar on soil nitrogen cycle and related mechanisms: a review].

    Science.gov (United States)

    Pan, Yi-Fan; Yang, Min; Dong, Da; Wu, Wei-Xiang

    2013-09-01

    Biochar has its unique physical and chemical properties, playing a significant role in soil amelioration, nutrient retention, fertility improvement, and carbon storage, and being a hotspot in the research areas of soil ecosystem, biogeochemical cycling, and agricultural carbon sequestration. As a kind of anthropogenic materials, biochar has the potential in controlling soil nitrogen (N) cycle directly or indirectly, and thus, has profound effects on soil ecological functions. This paper reviewed the latest literatures regarding the effects of biochar applications on soil N cycle, with the focuses on the nitrogen species adsorption and the biochemical processes (nitrification, denitrification, and nitrogen fixation) , and analyzed the related action mechanisms of biochar. The future research areas for better understanding the interactions between biochar and soil N cycle were proposed.

  16. Critical review on the physical and mechanical factors involved in tissue engineering of cartilage.

    Science.gov (United States)

    Gaut, Carrie; Sugaya, Kiminobu

    2015-01-01

    Articular cartilage defects often progress to osteoarthritis, which negatively impacts quality of life for millions of people worldwide and leads to high healthcare expenditures. Tissue engineering approaches to osteoarthritis have concentrated on proliferation and differentiation of stem cells by activation and suppression of signaling pathways, and by using a variety of scaffolding techniques. Recent studies indicate a key role of environmental factors in the differentiation of mesenchymal stem cells to mature cartilage-producing chondrocytes. Therapeutic approaches that consider environmental regulation could optimize chondrogenesis protocols for regeneration of articular cartilage. This review focuses on the effect of scaffold structure and composition, mechanical stress and hypoxia in modulating mesenchymal stem cell fate and the current use of these environmental factors in tissue engineering research.

  17. Knee mechanics during planned and unplanned sidestepping: a systematic review and meta-analysis.

    Science.gov (United States)

    Brown, Scott R; Brughelli, Matt; Hume, Patria A

    2014-11-01

    Knee joint mechanics during sidestepping are associated with anterior cruciate ligament injury. Unplanned sidestepping more closely emulates game scenarios when compared with planned sidestepping by limiting decision time, increasing knee loading and challenging the integrity of soft-tissue structures in the knee. It is important to quantify the loads that may challenge the integrity of the knee during planned and unplanned sidestepping. Our objective was to review literature on knee mechanics during planned and unplanned phases of sidestepping. PubMed, CINAHL, MEDLINE (EBSCO), SPORTDiscus and Web of Science were searched using the terms knee mechanics OR knee kine*, AND plan*, unplan*, anticipat*, unanticipat*, side*, cut* or chang*. A systematic approach was used to evaluate 4,629 records. Records were excluded when not available in English, only available in abstract of conference proceedings, not involving a change-of-direction sidestep, not comparing planned and unplanned or maintaining a running velocity greater than 2 m s(−1). Included studies were evaluated independently by two authors using a custom-designed methodological quality assessment derived from the Physiotherapy Evidence Database (PEDro) scale and then confirmed by a third author. Only six studies met the inclusion criteria and were retained for meta-analysis. Magnitude-based inferences were used to assess the standardised effect of the differences between planned and unplanned sidestepping. Knee angles and knee moments were extracted and reported for flexion/extension, abduction/adduction and internal/external rotation for initial contact, weight acceptance, peak push-off and final push-off phases of sidestepping. For kinematic variables, unplanned sidestepping produced a wide range of small to large increases in knee extension angles, small and moderate increases in knee abduction angles and a small increase in internal rotation angle relative to planned sidestepping during the sidestepping

  18. Causes and Mechanisms of Intrauterine Hypoxia and Its Impact on the Fetal Cardiovascular System: A Review

    Directory of Open Access Journals (Sweden)

    Damian Hutter

    2010-01-01

    Full Text Available Until today the role of oxygen in the development of the fetus remains controversially discussed. It is still believed that lack of oxygen in utero might be responsible for some of the known congenital cardiovascular malformations. Over the last two decades detailed research has given us new insights and a better understanding of embryogenesis and fetal growth. But most importantly it has repeatedly demonstrated that oxygen only plays a minor role in the early intrauterine development. After organogenesis has taken place hypoxia becomes more important during the second and third trimester of pregnancy when fetal growth occurs. This review will briefly adress causes and mechanisms leading to intrauterine hypoxia and their impact on the fetal cardiovascular system.

  19. Consumer sleep tracking devices: a review of mechanisms, validity and utility.

    Science.gov (United States)

    Kolla, Bhanu Prakash; Mansukhani, Subir; Mansukhani, Meghna P

    2016-05-01

    Consumer sleep tracking devices such as fitness trackers and smartphone apps have become increasingly popular. These devices claim to measure the sleep duration of their users and in some cases purport to measure sleep quality and awaken users from light sleep, potentially improving overall sleep. Most of these devices appear to utilize data generated from in-built accelerometers to determine sleep parameters but the exact mechanisms and algorithms are proprietary. The growing literature comparing these devices against polysomnography/actigraphy shows that they tend to underestimate sleep disruptions and overestimate total sleep times and sleep efficiency in normal subjects. In this review, we evaluate the current literature comparing the accuracy of consumer sleep tracking devices against more conventional methods used to measure sleep duration and quality. We discuss the current technology that these devices utilize as well as summarize the value of these devices in clinical evaluations and their potential limitations.

  20. Understanding Central Mechanisms of Acupuncture Analgesia Using Dynamic Quantitative Sensory Testing: A Review

    Directory of Open Access Journals (Sweden)

    Jiang-Ti Kong

    2013-01-01

    Full Text Available We discuss the emerging translational tools for the study of acupuncture analgesia with a focus on psychophysical methods. The gap between animal mechanistic studies and human clinical trials of acupuncture analgesia calls for effective translational tools that bridge neurophysiological data with meaningful clinical outcomes. Temporal summation (TS and conditioned pain modulation (CPM are two promising tools yet to be widely utilized. These psychophysical measures capture the state of the ascending facilitation and the descending inhibition of nociceptive transmission, respectively. We review the basic concepts and current methodologies underlying these measures in clinical pain research, and illustrate their application to research on acupuncture analgesia. Finally, we highlight the strengths and limitations of these research methods and make recommendations on future directions. The appropriate addition of TS and CPM to our current research armamentarium will facilitate our efforts to elucidate the central analgesic mechanisms of acupuncture in clinical populations.

  1. [On-line processing mechanisms in text comprehension: a theoretical review on constructing situation models].

    Science.gov (United States)

    Iseki, Ryuta

    2004-12-01

    This article reviewed research on construction of situation models during reading. To position variety of research in overall process appropriately, an unitary framework was devised in terms of three theories for on-line processing: resonance process, event-indexing model, and constructionist theory. Resonance process was treated as a basic activation mechanism in the framework. Event-indexing model was regarded as a screening system which selected and encoded activated information in situation models along with situational dimensions. Constructionist theory was considered to have a supervisory role based on coherence and explanation. From a view of the unitary framework, some problems concerning each theory were examined and possible interpretations were given. Finally, it was pointed out that there were little theoretical arguments on associative processing at global level and encoding text- and inference-information into long-term memory.

  2. Lead toxicity in rice: effects, mechanisms, and mitigation strategies--a mini review.

    Science.gov (United States)

    Ashraf, Umair; Kanu, Adam Sheka; Mo, Zhaowen; Hussain, Saddam; Anjum, Shakeel Ahmad; Khan, Imran; Abbas, Rana Nadeem; Tang, Xiangru

    2015-12-01

    Lead (Pb) is a major environmental pollutant that affects plant morpho-physiological and biochemical attributes. Its higher levels in the environment are not only toxic to human beings but also harmful for plants and soil microbes. We have reviewed the uptake, translocation, and accumulation mechanisms of Pb and its toxic effects on germination, growth, yield, nutrient relation, photosynthesis, respiration, oxidative damage, and antioxidant defense system of rice. Lead toxicity hampers rice germination, root/shoot length, growth, and final yield. It reduces nutrient uptake through roots, disrupts chloroplastic ultrastructure and cell membrane permeability, induces alterations in leaves respiratory activities, produces reactive oxygen species (ROS), and triggers some enzyme and non-enzymatic antioxidants (as defense to oxidative damage). In the end, biochar amendments and phytoremediation technologies have been proposed as soil remediation approaches for Pb tainted soils.

  3. Diabetic ketoacidosis: risk factors, mechanisms and management strategies in sub-Saharan Africa: a review.

    Science.gov (United States)

    Otieno, C F; Kayima, J K; Omonge, E O; Oyoo, G O

    2005-12-01

    Diabetic ketoacidosis is the most common hyperglycaemic emergency in patients with diabetes mellitus, especially type 1 diabetes. It carries very high mortality in sub-Saharan Africa, both in the treated patients and those who are presenting to hospital with diabetes for the first time. To review the risk factors, mechanisms and management approaches in diabetes ketoacidosis in published literature and to discuss them in the context of why a significant proportion of patients who develop diabetic ketoacidosis in sub-Saharan Africa still have high mortality. Literature review of relevant published literature from both Africa and the rest of the world. The main causes or precipitants of DKA in patients in SSA are newly diagnosed diabetes, missed insulin doses and infections. The major underlying mechanism is insulin deficiency. Treated patients miss insulin doses for various reasons, for example, inaccessibility occasioned by; unavailability and unaffordability of insulin, missed clinics, perceived ill-health and alternative therapies like herbs, prayers and rituals. Infections also occur quite often, but are not overt, like urinary tract, tuberculosis and pneumonia. Due to widespread poverty of individuals and nations alike, the healthcare systems are scarce and the few available centres are unable to adequately maintain a reliable system of insulin supply and exhaustively investigate their hospitalised patients. Consequently, there is little guarantee of successful outcomes. Poor people may also have sub-optimal nutrition, caused or worsened by diabetes, more so, at first presentation to hospital. Intensive insulin therapy in such individuals mimics 're-feeding syndrome', an acute anabolic state whose outcome may be unfavourable during the period of treatment of diabetic ketoacidosis. Although mortality and morbidity from diabetic ketoacidosis remains high in sub-Saharan Africa, improved healthcare systems and reliable insulin supply can reverse the trend, at least

  4. Mechanics

    CERN Document Server

    Hartog, J P Den

    1961-01-01

    First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

  5. Acute Pancreatitis after Percutaneous Mechanical Thrombectomy: Case Report and Review of the Literature

    International Nuclear Information System (INIS)

    Hershberger, Richard C.; Bornak, Arash; Aulivola, Bernadette; Mannava, Krishna

    2011-01-01

    Purpose: We describe a case of severe acute pancreatitis after percutaneous mechanical thrombectomy (PMT) and review the literature for the occurrence of this complication. Materials and Methods: A 53-year-old man with a history of bilateral external iliac artery stent placement sought care for acute onset of lifestyle-limiting left claudication. Angiography confirmed left external iliac stent occlusion, and PMT with the AngioJet Xpeedior catheter (Possis Medical, Minneapolis MN) was performed. Results: After PMT of the occluded external iliac artery, a residual in-stent stenosis required the placement of a second iliac stent. The procedure was complicated by severe acute pancreatitis. Other causes of pancreatitis were eliminated during the patient’s hospital stay. A literature review revealed nine cases of acute pancreatitis after PMT. Conclusion: Although rare, pancreatitis can be a devastating complication of PMT. The development of pancreatitis seems to be related to the products of extensive hemolysis triggering an inflammatory process. To prevent this complication, we recommend that close attention be paid to the duration and extent of PMT, thereby avoiding extensive hemolysis and subsequent complications.

  6. Mechanical resistance of zirconium implant abutments: A review of the literature

    Science.gov (United States)

    Vaquero-Aguilar, Cristina; Torres-Lagares, Daniel; Jiménez-Melendo, Manuel; Gutiérrez-Pérez, José L.

    2012-01-01

    The increase of aesthetic demands, together with the successful outcome of current implants, has renewed interest in the search for new materials with enough mechanical properties and better aesthetic qualities than the materials customarily used in implanto-prosthetic rehabilitation. Among these materials, zirconium has been used in different types of implants, including prosthetic abutments. The aim of the present review is to analyse current scientific evidence supporting the use of this material for the above mentioned purposes. We carried out the review of the literature published in the last ten years (2000 through 2010) of in vitro trials of dynamic and static loading of zirconium abutments found in the databases of Medline and Cochrane using the key words zirconium abutment, fracture resistance, fracture strength, cyclic loading. Although we have found a wide variability of values among the different studies, abutments show favourable clinical behaviour for the rehabilitation of single implants in the anterior area. Such variability may be explained by the difficulty to simulate daily mastication under in vitro conditions. The clinical evidence, as found in our study, does not recommend the use of implanto-prosthetic zirconium abutments in the molar area. Key words: Zirconium abutment, zirconium implant abutment, zirconia abutment, fracture resistance, fracture strength, cyclic loading. PMID:22143702

  7. Mechanical model development of rolling bearing-rotor systems: A review

    Science.gov (United States)

    Cao, Hongrui; Niu, Linkai; Xi, Songtao; Chen, Xuefeng

    2018-03-01

    The rolling bearing rotor (RBR) system is the kernel of many rotating machines, which affects the performance of the whole machine. Over the past decades, extensive research work has been carried out to investigate the dynamic behavior of RBR systems. However, to the best of the authors' knowledge, no comprehensive review on RBR modelling has been reported yet. To address this gap in the literature, this paper reviews and critically discusses the current progress of mechanical model development of RBR systems, and identifies future trends for research. Firstly, five kinds of rolling bearing models, i.e., the lumped-parameter model, the quasi-static model, the quasi-dynamic model, the dynamic model, and the finite element (FE) model are summarized. Then, the coupled modelling between bearing models and various rotor models including De Laval/Jeffcott rotor, rigid rotor, transfer matrix method (TMM) models and FE models are presented. Finally, the paper discusses the key challenges of previous works and provides new insights into understanding of RBR systems for their advanced future engineering applications.

  8. Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms.

    Science.gov (United States)

    Kerley, Conor P; Elnazir, Basil; Faul, John; Cormican, Liam

    2015-06-01

    Vitamin D deficiency (VDD) is highly prevalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms.

    LENUS (Irish Health Repository)

    Kerley, Conor P

    2015-02-27

    Vitamin D deficiency (VDD) is highly prevlalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial\\/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease.

  10. Ginger-Mechanism of action in chemotherapy-induced nausea and vomiting: A review.

    Science.gov (United States)

    Marx, Wolfgang; Ried, Karin; McCarthy, Alexandra L; Vitetta, Luis; Sali, Avni; McKavanagh, Daniel; Isenring, Liz

    2017-01-02

    Despite advances in antiemetic therapy, chemotherapy-induced nausea and vomiting (CINV) still poses a significant burden to patients undergoing chemotherapy. Nausea, in particular, is still highly prevalent in this population. Ginger has been traditionally used as a folk remedy for gastrointestinal complaints and has been suggested as a viable adjuvant treatment for nausea and vomiting in the cancer context. Substantial research has revealed ginger to possess properties that could exert multiple beneficial effects on chemotherapy patients who experience nausea and vomiting. Bioactive compounds within the rhizome of ginger, particularly the gingerol and shogaol class of compounds, interact with several pathways that are directly implicated in CINV in addition to pathways that could play secondary roles by exacerbating symptoms. These properties include 5-HT 3 , substance P, and acetylcholine receptor antagonism; antiinflammatory properties; and modulation of cellular redox signaling, vasopressin release, gastrointestinal motility, and gastric emptying rate. This review outlines these proposed mechanisms by discussing the results of clinical, in vitro, and animal studies both within the chemotherapy context and in other relevant fields. The evidence presented in this review indicates that ginger possesses multiple properties that could be beneficial in reducing CINV.

  11. A review of cutting mechanics and modeling techniques for biological materials.

    Science.gov (United States)

    Takabi, Behrouz; Tai, Bruce L

    2017-07-01

    This paper presents a comprehensive survey on the modeling of tissue cutting, including both soft tissue and bone cutting processes. In order to achieve higher accuracy in tissue cutting, as a critical process in surgical operations, the meticulous modeling of such processes is important in particular for surgical tool development and analysis. This review paper is focused on the mechanical concepts and modeling techniques utilized to simulate tissue cutting such as cutting forces and chip morphology. These models are presented in two major categories, namely soft tissue cutting and bone cutting. Fracture toughness is commonly used to describe tissue cutting while Johnson-Cook material model is often adopted for bone cutting in conjunction with finite element analysis (FEA). In each section, the most recent mathematical and computational models are summarized. The differences and similarities among these models, challenges, novel techniques, and recommendations for future work are discussed along with each section. This review is aimed to provide a broad and in-depth vision of the methods suitable for tissue and bone cutting simulations. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. Physical and mechanical properties of PLA, and their functions in widespread applications - A comprehensive review.

    Science.gov (United States)

    Farah, Shady; Anderson, Daniel G; Langer, Robert

    2016-12-15

    Poly(lactic acid) (PLA), so far, is the most extensively researched and utilized biodegradable aliphatic polyester in human history. Due to its merits, PLA is a leading biomaterial for numerous applications in medicine as well as in industry replacing conventional petrochemical-based polymers. The main purpose of this review is to elaborate the mechanical and physical properties that affect its stability, processability, degradation, PLA-other polymers immiscibility, aging and recyclability, and therefore its potential suitability to fulfill specific application requirements. This review also summarizes variations in these properties during PLA processing (i.e. thermal degradation and recyclability), biodegradation, packaging and sterilization, and aging (i.e. weathering and hygrothermal). In addition, we discuss up-to-date strategies for PLA properties improvements including components and plasticizer blending, nucleation agent addition, and PLA modifications and nanoformulations. Incorporating better understanding of the role of these properties with available improvement strategies is the key for successful utilization of PLA and its copolymers/composites/blends to maximize their fit with worldwide application needs. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Acinetobacter spp. Infections in Malaysia: A Review of Antimicrobial Resistance Trends, Mechanisms and Epidemiology.

    Science.gov (United States)

    Mohd Rani, Farahiyah; A Rahman, Nor Iza; Ismail, Salwani; Alattraqchi, Ahmed Ghazi; Cleary, David W; Clarke, Stuart C; Yeo, Chew Chieng

    2017-01-01

    Acinetobacter spp. are important nosocomial pathogens, in particular the Acinetobacter baumannii - calcoaceticus complex, which have become a global public health threat due to increasing resistance to carbapenems and almost all other antimicrobial compounds. High rates of resistance have been reported among countries in Southeast Asia, including Malaysia. In this review, we examine the antimicrobial resistance profiles of Acinetobacter spp. hospital isolates from Malaysia over a period of nearly three decades (1987-2016) with data obtained from various peer-reviewed publications as well as the Malaysian National Surveillance on Antibiotic Resistance (NSAR). NSAR data indicated that for most antimicrobial compounds, including carbapenems, the peak resistance rates were reached around 2008-2009 and thereafter, rates have remained fairly constant (e.g., 50-60% for carbapenems). Individual reports from various hospitals in Peninsular Malaysia do not always reflect the nationwide resistance rates and often showed higher rates of resistance. We also reviewed the epidemiology and mechanisms of resistance that have been investigated in Malaysian Acinetobacter spp. isolates, particularly carbapenem resistance and found that bla OXA-23 is the most prevalent acquired carbapenemase-encoding gene. From the very few published reports and whole genome sequences that are available, most of the Acinetobacter spp. isolates from Malaysia belonged to the Global Clone 2 (GC2) CC92 group with ST195 being the predominant sequence type. The quality of data and analysis in the national surveillance reports could be improved and more molecular epidemiology and genomics studies need to be carried out for further in-depth understanding of Malaysian Acinetobacter spp. isolates.

  14. Effects and mechanisms of biochar-microbe interactions in soil improvement and pollution remediation: A review.

    Science.gov (United States)

    Zhu, Xiaomin; Chen, Baoliang; Zhu, Lizhong; Xing, Baoshan

    2017-08-01

    Biochars have attracted tremendous attention due to their effects on soil improvement; they enhance carbon storage, soil fertility and quality, and contaminant (organic and heavy metal) immobilization and transformation. These effects could be achieved by modifying soil microbial habitats and (or) directly influencing microbial metabolisms, which together induce changes in microbial activity and microbial community structures. This review links microbial responses, including microbial activity, community structures and soil enzyme activities, with changes in soil properties caused by biochars. In particular, we summarized possible mechanisms that are involved in the effects that biochar-microbe interactions have on soil carbon sequestration and pollution remediation. Special attention has been paid to biochar effects on the formation and protection of soil aggregates, biochar adsorption of contaminants, biochar-mediated transformation of soil contaminants by microorganisms, and biochar-facilitated electron transfer between microbial cells and contaminants and soil organic matter. Certain reactive organic compounds and heavy metals in biochar may induce toxicity to soil microorganisms. Adsorption and hydrolysis of signaling molecules by biochar interrupts microbial interspecific communications, potentially altering soil microbial community structures. Further research is urged to verify the proposed mechanisms involved in biochar-microbiota interactions for soil remediation and improvement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Mechanisms of action underlying the anti-inflammatory and immunomodulatory effects of propolis: a brief review

    Directory of Open Access Journals (Sweden)

    Marcio A. R. Araujo

    2011-09-01

    Full Text Available Many biological properties have been attributed to various types of propolis, including anti-inflammatory, antimicrobial, antioxidant, antitumor, wound healing, and immunomodulatory activities. This article reviewed studies published that investigated the anti-inflammatory activity of propolis of different origins and/or its isolated components, focusing on the mechanisms of action underlying this activity and also addressing some aspects of immunomodulatory effects. The search was performed of the following databases: PubMed, Science Direct, HighWire Press, Scielo, Google Academics, Research Gate and ISI Web of Knowledgement. The anti-inflammatory activity was associated with propolis or compounds such as polyphenols (flavonoids, phenolic acids and their esters, terpenoids, steroids and amino acids. CAPE is the most studied compounds. The main mechanisms underlying the anti-inflammatory activity of propolis included the inhibition of cyclooxygenase and consequent inhibition of prostaglandin biosynthesis, free radical scavenging, inhibition of nitric oxide synthesis, reduction in the concentration of inflammatory cytokines and immunosuppressive activity. Propolis was found to exert an anti-inflammatory activity in vivo and in vitro models of acute and chronic inflammation and others studies, indicating its promising potential as anti-inflammatory agent of natural origin and as a source of chemical compounds for the development of new drugs.

  16. A review of safety-focused mechanical modeling of commercial lithium-ion batteries

    Science.gov (United States)

    Zhu, Juner; Wierzbicki, Tomasz; Li, Wei

    2018-02-01

    We are rapidly approaching an inflection point in the adoption of electric vehicles on the roads. All major automotive companies are having well-funded plans for mass market affordable branded EV product line models, which can open the floodgates. A rapid growth of battery energy density, accompanied by an aggressive progress of reduction of costs of lithium-ion batteries, brings safety concerns. While more energy stored in the battery pack of an EV translates to a longer range, the downside is that accidents will be more violent due to battery inevitable explosion. With today's technology, severe crashes involving intrusion into the battery pack will potentially result in a thermal runaway, fire, and explosion. Most of research on lithium-ion batteries have been concerned with the electrochemistry of cells. However, in most cases failure and thermal runaway is caused by mechanical loading due to crash events. There is a growing need to summarize the already published results on mechanical loading and response of batteries and offer a critical evaluation of work in progress. The objective of this paper is to present such review with a discussion of many outstanding issues and outline of a roadmap for future research.

  17. The mechanisms of heavy metal immobilization by cementitious material treatments and thermal treatments: A review.

    Science.gov (United States)

    Guo, Bin; Liu, Bo; Yang, Jian; Zhang, Shengen

    2017-05-15

    Safe disposal of solid wastes containing heavy metals is a significant task for environment protection. Immobilization treatment is an effective technology to achieve this task. Cementitious material treatments and thermal treatments are two types of attractive immobilization treatments due to that the heavy metals could be encapsulated in their dense and durable wasteforms. This paper discusses the heavy metal immobilization mechanisms of these methods in detail. Physical encapsulation and chemical stabilization are two fundamental mechanisms that occur simultaneously during the immobilization processes. After immobilization treatments, the wasteforms build up a low permeable barrier for the contaminations. This reduces the exposed surface of wastes. Chemical stabilization occurs when the heavy metals transform into more stable and less soluble metal bearing phases. The heavy metal bearing phases in the wasteforms are also reviewed in this paper. If the heavy metals are incorporated into more stable and less soluble metal bearing phases, the potential hazards of heavy metals will be lower. Thus, converting heavy metals into more stable phases during immobilization processes should be a common way to enhance the immobilization effect of these immobilization methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A review of mechanisms of circumvention and modulation of chemotherapeutic drug resistance.

    Science.gov (United States)

    O'Connor, R

    2009-05-01

    Drug resistance is a serious limitation to the effective treatment of a number of common malignancies. Thirty years of laboratory and clinical research have greatly defined the molecular alterations underlying many drug resistance processes in cancer. Based on this knowledge, strategies to overcome the impact of resistance and increase the efficacy of cancer treatment have been translated from laboratory models to clinical trials. This article reviews laboratory and, in particular, clinical attempts at drug resistance circumvention from early forays in the inhibition of cellular efflux pump-mediated drug resistance through to more selective circumvention agent strategies and into inhibition of the other important mechanisms which can allow cancer cells to survive therapy, such as apoptosis resistance. Despite some promising results to date, resistance inhibition strategies have largely failed due to poor understanding of the pharmacology, dynamics and complexity of the resistance phenotype. With the realisation that new molecularly-targeted agents can also be rendered ineffectual by the actions of resistance mechanisms, a major focus is once again emerging on identifying new strategies/pharmaceuticals which can augment the activity of the arsenal of more conventional cytotoxics and newer targeted anti-cancer drugs. Future tactical directions where old and new resistance strategies may merge to overcome this challenge are discussed.

  19. Translating Mechanism-Based Strategies to Break the Obesity-Cancer Link: A Narrative Review.

    Science.gov (United States)

    Smith, Laura A; O'Flanagan, Ciara H; Bowers, Laura W; Allott, Emma H; Hursting, Stephen D

    2018-04-01

    Prevalence of obesity, an established risk factor for many cancers, has increased dramatically over the past 50 years in the United States and across the globe. Relative to normoweight cancer patients, obese cancer patients often have poorer prognoses, resistance to chemotherapies, and are more likely to develop distant metastases. Recent progress on elucidating the mechanisms underlying the obesity-cancer connection suggests that obesity exerts pleomorphic effects on pathways related to tumor development and progression and, thus, there are multiple opportunities for primary prevention and treatment of obesity-related cancers. Obesity-associated alterations, including systemic metabolism, adipose inflammation, growth factor signaling, and angiogenesis, are emerging as primary drivers of obesity-associated cancer development and progression. These obesity-associated host factors interact with the intrinsic molecular characteristics of cancer cells, facilitating several of the hallmarks of cancer. Each is considered in the context of potential preventive and therapeutic strategies to reduce the burden of obesity-related cancers. In addition, this review focuses on emerging mechanisms behind the obesity-cancer link, as well as relevant dietary interventions, including calorie restriction, intermittent fasting, low-fat diet, and ketogenic diet, that are being implemented in preclinical and clinical trials, with the ultimate goal of reducing incidence and progression of obesity-related cancers. Copyright © 2018 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  20. Capability and Mechanisms of Macrofungi in Heavy Metal Accumulation:A Review

    Directory of Open Access Journals (Sweden)

    CHEN Miao-miao

    2017-10-01

    Full Text Available Some macrofungi have the ability to accumulate heavy metals, which is comparable to hyper-accumulator plants. Cordyceps militaris can accumulate Zn up to 20 000 mg·kg-1. Therefore, macrofungi have the potential to be used as an important bioremediation tool for heavy metals. In this review, we summarized the heavy metal resistant capacity of typical macrofungi and known relevant mechanisms. Generally, straw-decay fungi presented better capability for Cu, Ag and Cd enrichment than wood-decay fungi, while wood-decay fungi could accumulate Cr, Mg, Se and Pb. Different macrofungi species, different growth periods(mycelium and fruiting body and different parts of fruiting body showed different capability for heavy metals accumulation. General mechanisms for heavy metals accumulation in macrofungi included extracellular precipitation in the forms of polymeric substances, cell wall adsorption and intracellular absorption. Macrofungi could also detoxify by chelating metal ions by metallothionein(MT, secreting antioxidant enzymes(SOD, CAT, POD and degradating the misfolded proteins by ubiquitin-proteasome system(UPS. We also explored the potential of macrofungi in heavy metal remediation and pollution diagnostics as a biological indicator. Some macrofungi had been applied in the remediation of heavy metal contaminated soils and water. Finally, some future research areas including strain breeding and genetic engineering were discussed, which might provide references for the future studies.

  1. Sirenomelia of an intracytoplasmic sperm injection conceptus: a case report and review of mechanism.

    Science.gov (United States)

    Bakhtar, Omid; Benirschke, Kurt; Masliah, Eliezer

    2006-01-01

    Postmortem dissection of the 18-week male conceptus, product of intracytoplasmic sperm injection (ICSI), demonstrated the hallmark findings of sirenomelia. The lower legs were fused and the left knee was rotated medially. Internal organs showed hypoplastic lungs, a multicystic kidney, and unilateral ureteral hypoplasia. The vitelline artery was absorbed, in a classic fashion, into the umbilical artery and communicated with the aorta at a point proximal to the iliac arteries. The tributaries distal to this point were hypoplastic. This finding is consistent with previously documented cases of sirenomelia and is thought to be the pathogenetic mechanism resulting in a vascular steal from the lower extremities. A rare finding was the presence of a penis on the dorsal side just below a perforate anus. In this case report, we discuss the pertinent clinical history and autopsy findings. A brief review of the mechanism thought to give rise to sirenomelia is provided. To our knowledge, this is the first reported case of sirenomelia in an ICSI conceptus.

  2. Review on mechanisms of dairy summer infertility and implications for hormonal intervention

    Directory of Open Access Journals (Sweden)

    B.U. Wakayo

    2015-02-01

    Full Text Available In dairy cows and buffaloes, summer heat stress (HS reduces milk yield and delays return to pregnancy leading to financial loss. Clues for effective interventions against summer infertility (SI lie in understanding the underlying mechanisms. This article reviews current knowledge on the mechanisms of bovine SI and their implication for hormonal management. Under HS dairy animals encounter anestrous, silent cycles and repeat breeding which extend their open period. These effects are attributed mainly to HS induced disturbances in luteinizing hormone (LH secretion, follicular dominance and estrogen secretion, ovulation and oocyte competence, luteal development and progesterone secretion, utero-placental function and embryo-fetal development. Hormonal timed artificial insemination protocols and LH support around estrous improved summer pregnancy rates by avoiding need for estrus detection, assisting follicular development and ovulation, enhancing quality oocytes and stimulating luteal function. Progesterone supplementation to enhance embryonic development did not produce significant improvement in summer pregnancy rates. There is need for evaluating integrated approaches combining hormones, metabolic modifier and cyto-protective agents.

  3. Mechanisms Underlying Cytotoxicity Induced by Engineered Nanomaterials: A Review of In Vitro Studies

    Science.gov (United States)

    Nogueira, Daniele R.; Mitjans, Montserrat; Rolim, Clarice M. B.; Vinardell, M. Pilar

    2014-01-01

    Engineered nanomaterials are emerging functional materials with technologically interesting properties and a wide range of promising applications, such as drug delivery devices, medical imaging and diagnostics, and various other industrial products. However, concerns have been expressed about the risks of such materials and whether they can cause adverse effects. Studies of the potential hazards of nanomaterials have been widely performed using cell models and a range of in vitro approaches. In the present review, we provide a comprehensive and critical literature overview on current in vitro toxicity test methods that have been applied to determine the mechanisms underlying the cytotoxic effects induced by the nanostructures. The small size, surface charge, hydrophobicity and high adsorption capacity of nanomaterial allow for specific interactions within cell membrane and subcellular organelles, which in turn could lead to cytotoxicity through a range of different mechanisms. Finally, aggregating the given information on the relationships of nanomaterial cytotoxic responses with an understanding of its structure and physicochemical properties may promote the design of biologically safe nanostructures. PMID:28344232

  4. A review of visual perception mechanisms that regulate rapid adaptive camouflage in cuttlefish.

    Science.gov (United States)

    Chiao, Chuan-Chin; Chubb, Charles; Hanlon, Roger T

    2015-09-01

    We review recent research on the visual mechanisms of rapid adaptive camouflage in cuttlefish. These neurophysiologically complex marine invertebrates can camouflage themselves against almost any background, yet their ability to quickly (0.5-2 s) alter their body patterns on different visual backgrounds poses a vexing challenge: how to pick the correct body pattern amongst their repertoire. The ability of cuttlefish to change appropriately requires a visual system that can rapidly assess complex visual scenes and produce the motor responses-the neurally controlled body patterns-that achieve camouflage. Using specifically designed visual backgrounds and assessing the corresponding body patterns quantitatively, we and others have uncovered several aspects of scene variation that are important in regulating cuttlefish patterning responses. These include spatial scale of background pattern, background intensity, background contrast, object edge properties, object contrast polarity, object depth, and the presence of 3D objects. Moreover, arm postures and skin papillae are also regulated visually for additional aspects of concealment. By integrating these visual cues, cuttlefish are able to rapidly select appropriate body patterns for concealment throughout diverse natural environments. This sensorimotor approach of studying cuttlefish camouflage thus provides unique insights into the mechanisms of visual perception in an invertebrate image-forming eye.

  5. A review of penetration mechanisms and dynamic properties of tungsten and depleted uranium penetrators

    International Nuclear Information System (INIS)

    Andrew, S.P.; Caligiuri, R.D.; Eiselstein, L.E.

    1991-01-01

    Kinetic energy penetrators must posses the best possible combination of hardness, stiffness, strength, and fracture toughness characteristics to be effective against modern armor systems. Over the last decade, depleted uranium (DU) and tungsten alloys have been the materials of choice for kinetic energy penetrators. Du and tungsten perform abut the same against semi-infinite targets, and DU outperforms tungsten penetrators in oblique, spaced array targets, but because of environmental and subsequent cost concerns, effort has focused on improving the performance of tungsten penetrators over the last few years. However, despite recent improvements in material properties, the penetration performance of tungsten still lags behind that of DU. One possible reason is the difference in deformation mechanisms at the leading edge of the penetrator during the penetration process-DU alloys tend to shear band and sharpen as they penetrate the target material, whereas tungsten penetrators tend to mushroom and blunt. As a first step to determine whether shear banding is truly the reason for superior DU performance, a review of the fabrication, high strain-rate properties, and penetration phenomena of penetrators manufactured from both tungsten and DU alloys. Specifically, the effects of composition, processing, and heat treatment on material properties and penetration mechanisms of these alloys are discussed

  6. Big data handling mechanisms in the healthcare applications: A comprehensive and systematic literature review.

    Science.gov (United States)

    Pashazadeh, Asma; Jafari Navimipour, Nima

    2018-04-12

    Healthcare provides many services such as diagnosing, treatment, prevention of diseases, illnesses, injuries, and other physical and mental disorders. Large-scale distributed data processing applications in healthcare as a basic concept operates on large amounts of data. Therefore, big data application functions are the main part of healthcare operations, but there was not any comprehensive and systematic survey about studying and evaluating the important techniques in this field. Therefore, this paper aims at providing the comprehensive, detailed, and systematic study of the state-of-the-art mechanisms in the big data related to healthcare applications in five categories, including machine learning, cloud-based, heuristic-based, agent-based, and hybrid mechanisms. Also, this paper displayed a systematic literature review (SLR) of the big data applications in the healthcare literature up to the end of 2016. Initially, 205 papers were identified, but a paper selection process reduced the number of papers to 29 important studies. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. A review of potential neurotoxic mechanisms among three chlorinated organic solvents

    International Nuclear Information System (INIS)

    Bale, Ambuja S.; Barone, Stan; Scott, Cheryl Siegel; Cooper, Glinda S.

    2011-01-01

    The potential for central nervous system depressant effects from three widely used chlorinated solvents, trichloroethylene (TCE), perchloroethylene (PERC), and dichloromethane (DCM), has been shown in human and animal studies. Commonalities of neurobehavioral and neurophysiological changes for the chlorinated solvents in in vivo studies suggest that there is a common mechanism(s) of action in producing resultant neurotoxicological consequences. The purpose of this review is to examine the mechanistic studies conducted with these chlorinated solvents and to propose potential mechanisms of action for the different neurological effects observed. Mechanistic studies indicate that this solvent class has several molecular targets in the brain. Additionally, there are several pieces of evidence from animal studies indicating this solvent class alters neurochemical functions in the brain. Although earlier evidence indicated that these three chlorinated solvents perturb the lipid bilayer, more recent data suggest an interaction between several specific neuronal receptors produces the resultant neurobehavioral effects. Collectively, TCE, PERC, and DCM have been reported to interact directly with several different classes of neuronal receptors by generally inhibiting excitatory receptors/channels and potentiating the function of inhibitory receptors/channels. Given this mechanistic information and available studies for TCE, DCM, and PERC, we provide hypotheses on primary targets (e.g. ion channel targets) that appear to be most influential in producing the resultant neurological effects. - Research highlights: → Comparison of neurological effects among TCE, PERC, and DCM. → Correlation of mechanistic findings to neurological effects. → Data support that TCE, PERC, and DCM interact with several ion channels to produce neurological changes.

  8. Mechanical properties of crossed-lamellar structures in biological shells: A review.

    Science.gov (United States)

    Li, X W; Ji, H M; Yang, W; Zhang, G P; Chen, D L

    2017-10-01

    The self-fabrication of materials in nature offers an alternate and powerful solution towards the grand challenge of designing advanced structural materials, where strength and toughness are always mutually exclusive. Crossed-lamellar structures are the most common microstructures in mollusks that are composed of aragonites and a small amount of organic materials. Such a distinctive composite structure has a fracture toughness being much higher than that of pure carbonate mineral. These structures exhibiting complex hierarchical microarchitectures that span several sub-level lamellae from microscale down to nanoscale, can be grouped into two types, i.e., platelet-like and fiber-like crossed-lamellar structures based on the shapes of basic building blocks. It has been demonstrated that these structures have a great potential to strengthen themselves during deformation. The observed underlying toughening mechanisms include microcracking, channel cracking, interlocking, uncracked-ligament bridging, aragonite fiber bridging, crack deflection and zig-zag, etc., which play vital roles in enhancing the fracture resistance of shells with the crossed-lamellar structures. The exploration and utilization of these important toughening mechanisms have attracted keen interests of materials scientists since they pave the way for the development of bio-inspired advanced composite materials for load-bearing structural applications. This article is aimed to review the characteristics of hierarchical structures and the mechanical properties of two kinds of crossed-lamellar structures, and further summarize the latest advances and biomimetic applications based on the unique crossed-lamellar structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Structural, mechanical and chemical evaluation of molar-incisor hypomineralization-affected enamel: A systematic review.

    Science.gov (United States)

    Elhennawy, Karim; Manton, David John; Crombie, Felicity; Zaslansky, Paul; Radlanski, Ralf J; Jost-Brinkmann, Paul-Georg; Schwendicke, Falk

    2017-11-01

    To systematically assess and contrast reported differences in microstructure, mineral density, mechanical and chemical properties between molar-incisor-hypomineralization-affected (MIH) enamel and unaffected enamel. Studies on extracted human teeth, clinically diagnosed with MIH, reporting on the microstructure, mechanical properties or the chemical composition and comparing them to unaffected enamel were reviewed. Electronic databases (PubMed, Embase and Google Scholar) were screened; hand searches and cross-referencing were also performed. Twenty-two studies were included. Fifteen studies on a total of 201 teeth investigated the structural properties, including ten (141 teeth) on microstructure and seven (60 teeth) on mineral density; six (29 teeth) investigated the mechanical properties and eleven (87 teeth) investigated the chemical properties of MIH-affected enamel and compared them to unaffected enamel. Studies unambiguously found a reduction in mineral quantity and quality (reduced Ca and P content), reduction of hardness and modulus of elasticity (also in the clinically sound-appearing enamel bordering the MIH-lesion), an increase in porosity, carbon/carbonate concentrations and protein content compared to unaffected enamel. were ambiguous with regard to the extent of the lesion through the enamel to the enamel-dentin junction, the Ca/P ratio and the association between clinical appearance and defect severity. There is an understanding of the changes related to MIH-affected enamel. The association of these changes with the clinical appearance and resulting implications for clinical management are unclear. MIH-affected enamel is greatly different from unaffected enamel. This has implications for management strategies. The possibility of correlating the clinical appearance of MIH-affected enamel with the severity of enamel changes and deducing clinical concepts (risk stratification etc.) is limited. Crown Copyright © 2017. Published by Elsevier Ltd. All

  10. Mechanisms of action of brief alcohol interventions remain largely unknown – A narrative review

    Directory of Open Access Journals (Sweden)

    Jacques eGaume

    2014-08-01

    Full Text Available A growing body of evidence has shown efficacy of brief intervention (BI for hazardous and harmful alcohol use in primary health care settings. Evidence for efficacy in other settings, and effectiveness when implemented at larger scale is disappointing. Indeed, BI comprises varying content, and exploring BI content and mechanisms of action may be a promising way to enhance efficacy and effectiveness.We searched Medline and PsychInfo, as well as references of retrieved publications for original research or reviews on active ingredients (or components, or mechanisms of face-to-face BIs (and its subtypes, including brief advice and brief motivational interviewing [BMI] for alcohol. Overall, BI active ingredients have been scarcely investigated, almost only within BMI, and mostly among Emergency Room patients, young adults, and US college students. This body of research has shown that personalized feedback may be an effective component; specific MI techniques showed mixed findings; decisional balance findings tended to suggest a potential detrimental effect; while change plan exercises, advice to reduce or stop drinking, presenting alternative change options, and moderation strategies are promising but need further study. Client change talk is a potential mediator of BMI effects; change in norm perceptions and enhanced discrepancy between current behavior and broader life goals and values have received preliminary support; readiness to change was only partially supported as a mediator; while enhanced awareness of drinking, perceived risks/benefits of alcohol use, alcohol treatment seeking, and self-efficacy were seldom studied and have as yet found no significant support as such.Research is obviously limited and has provided no clear and consistent evidence on the mechanisms of alcohol BI. How BI achieves the effects seen in randomized trials remains mostly unknown and should be investigated to inform the development of more effective interventions.

  11. Mechanisms of action of brief alcohol interventions remain largely unknown - a narrative review.

    Science.gov (United States)

    Gaume, Jacques; McCambridge, Jim; Bertholet, Nicolas; Daeppen, Jean-Bernard

    2014-01-01

    A growing body of evidence has shown the efficacy of brief intervention (BI) for hazardous and harmful alcohol use in primary health care settings. Evidence for efficacy in other settings and effectiveness when implemented at larger scale are disappointing. Indeed, BI comprises varying content; exploring BI content and mechanisms of action may be a promising way to enhance efficacy and effectiveness. Medline and PsychInfo, as well as references of retrieved publications were searched for original research or review on active ingredients (components or mechanisms) of face-to-face BIs [and its subtypes, including brief advice and brief motivational interviewing (BMI)] for alcohol. Overall, BI active ingredients have been scarcely investigated, almost only within BMI, and mostly among patients in the emergency room, young adults, and US college students. This body of research has shown that personalized feedback may be an effective component; specific MI techniques showed mixed findings; decisional balance findings tended to suggest a potential detrimental effect; while change plan exercises, advice to reduce or stop drinking, presenting alternative change options, and moderation strategies are promising but need further study. Client change talk is a potential mediator of BMI effects; change in norm perceptions and enhanced discrepancy between current behavior and broader life goals and values have received preliminary support; readiness to change was only partially supported as a mediator; while enhanced awareness of drinking, perceived risks/benefits of alcohol use, alcohol treatment seeking, and self-efficacy were seldom studied and have as yet found no significant support as such. Research is obviously limited and has provided no clear and consistent evidence on the mechanisms of alcohol BI. How BI achieves the effects seen in randomized trials remains mostly unknown and should be investigated to inform the development of more effective interventions.

  12. Parent-related mechanisms underlying the social gradient of childhood overweight and obesity: a systematic review.

    Science.gov (United States)

    Mech, P; Hooley, M; Skouteris, H; Williams, J

    2016-09-01

    Low socio-economic status (SES) is a significant risk factor for childhood overweight and obesity (COWOB) in high-income countries. Parents to young children buffer and accentuate social and cultural influences, and are central to the development of this disease. An understanding of the parent-related mechanisms that underlie the SES-COWOB relationship is needed to improve the efficacy of prevention and intervention efforts. A systematic review of relevant literature was conducted to investigate the mechanisms by which levels of SES (low, middle and high) are associated to COWOB, by exploring mediation and interaction effects. Six electronic databases were searched yielding 5155 initial records, once duplicates were removed. Studies were included if they investigated COWOB, SES, parent-related factors and the multivariate relationship between these factors. Thirty studies were included. Factors found to be mediating the SES-COWOB relationship or interacting with SES to influence COWOB were categorized according to an ecological systems framework, at child, parent, household and social system level factors. High parent body mass index, ethnicity, child-care attendance, high TV time (mother and child), breastfeeding (early weaning), food intake behaviours and birthweight potentially mediate the relationship between SES and COWOB. Different risk factors for COWOB in different SES groups were found. For low SES families, parental obesity and maternal depressive symptoms were strong risk factors for COWOB, whereas long maternal working hours and a permissive parenting style were risk factors for higher SES families. None of the studies investigated parental psychological attributes such as attitudes, beliefs, self-esteem and so on as potential mechanisms/risk factors. Families from different SES groups have different risk and protective factors for COWOB. Prevention and intervention efforts may have improved efficacy if they are tailored to address specific risk factors

  13. Clinical decision - making review on magnetic attachments versus mechanical attachments in dental prosthetics

    Directory of Open Access Journals (Sweden)

    Francesca Fabiano

    2017-11-01

    Full Text Available Background Conventional dentures in edentulous patients show some limitations due to the lack of retention, support and stability thus resulting in difficulty to chew. The modern implantology allows to use different implant overdentures and different attachment systems. The selection of the attachment by practitioners is mainly influenced by the clinical experience or technical preferences. Aims The aim of the present review is to provide an adequate background to the clinicians, in order to select the prosthetic attachments according to the current literature. The mechanical attachments have been compared to the magnetic devices, with the aim to guide the decision of the practitioners. Methods Articles topics selection was based on the use of magnetic attachments in dentistry and the comparison between them and mechanical connectors. The databases used were PubMed/MEDLINE, Google Scholar and ISI Web of Science. A critical evaluation of the selected paper has been made to choose the ones that matched the inclusion criteria. Results Nowadays, few studies have compared different attachments in a manner useful for clinical decision-making. The main problem limiting long-term durability of magnetic attachments in the oral fluid is the poor corrosion resistance of permanent magnets and the consequent leaching of cytotoxic ions. Conclusion Magnetic attachments in comparison with other attaching systems can be useful in patients with special needs, in patients with limited interocclusal space, or in patients with neuromuscular limitations, thanks to the automatic reseating properties. However, it’s important to highlight that the mechanical attachments still represent the best choice in common conditions requiring dental prostheses.

  14. Practice patterns and outcomes associated with early sedation depth in mechanically ventilated patients: a systematic review protocol.

    Science.gov (United States)

    Stephens, Robert J; Dettmer, Matthew R; Roberts, Brian W; Fowler, Susan A; Fuller, Brian M

    2017-06-09

    Mechanical ventilation is a commonly performed intervention in critically ill patients. Frequently, these patients experience deep sedation early in their clinical course. Emerging data suggest that the practice of early deep sedation may negatively impact patient outcomes. The purpose of this review is to assess the world's literature to describe and determine the impact of early deep sedation on the outcomes of mechanically ventilated patients. Randomised controlled trials and non-randomised studies will be eligible for inclusion in this systematic review. With the assistance of a medical librarian, we will comprehensively search MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews and Effects, and Cochrane Database of Systematic Reviews for peer-reviewed literature. Grey literature from appropriate professional society conferences, held from 2010 to 2017, will be reviewed manually. Two authors will independently review all search results, and disagreements will be resolved through arbitration by a third author. If appropriate, meta-analysis will be used for quantitative analysis of the data. Heterogeneity between studies will be assessed using the I 2 statistic. The proposed systematic review will not collect data that are associated with individual patients and does not require ethical approval. Results of this study will contribute to the understanding of early sedation, identify future research targets and guide early care in mechanically ventilated patients. This systematic review has been registered in the international prospective register of systematic reviews (PROSPERO #CRD42017057264). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. Vitamins in Pancreatic Cancer: A Review of Underlying Mechanisms and Future Applications12

    Science.gov (United States)

    Davis-Yadley, Ashley H; Malafa, Mokenge P

    2015-01-01

    Although there is increasing evidence that vitamins influence pancreatic adenocarcinoma biology and carcinogenesis, a comprehensive review is lacking. In this study, we performed a PubMed literature search to review the anticancer mechanisms and the preclinical and clinical studies that support the development of the bioactive vitamins A, C, D, E, and K in pancreatic cancer intervention. Preclinical studies have shown promising results for vitamin A in pancreatic cancer prevention, with clinical trials showing intriguing responses in combination with immunotherapy. For vitamin C, preclinical studies have shown slower tumor growth rates and/or increased survival when used alone or in combination with gemcitabine, with clinical trials with this combination revealing decreased primary tumor sizes and improved performance status. Preclinical studies with vitamin D analogues have shown potent antiproliferative effects and repression of migration and invasion of pancreatic cancer cells, with a clinical trial showing increased time to progression when calciferol was added to docetaxel. For vitamin E, preclinical studies have shown that δ-tocotrienol and γ-tocotrienol inhibited tumor cell growth and survival and augmented gemcitabine activity. Early-phase clinical trials with δ-tocotrienol are ongoing. Vitamin K demonstrates activation of apoptosis and inhibition of cellular growth in pancreatic tumor cells; however, there are no clinical studies available for further evaluation. Although preclinical and clinical studies are encouraging, randomized controlled trials with endpoints based on insights gained from mechanistic and preclinical studies and early-phase clinical trials are required to determine the efficacy of bioactive vitamin interventions in pancreatic cancer. PMID:26567201

  16. A systematic review on potential mechanisms of minocycline in kidney diseases.

    Science.gov (United States)

    Haghi-Aminjan, Hamed; Asghari, Mohammad Hossein; Goharbari, Mohammad Hadi; Abdollahi, Mohammad

    2017-08-01

    Kidney diseases need specialized health care and still are a reason of death. There is a large body of evidence that indicates minocycline possesses some cytoprotective effects beside of antibacterial properties. In this review, we aimed to explain cytoprotective mechanisms and kidney protection of minocycline. In order to find the effects of minocycline on kidney diseases a systematic literature search was performed, according to the guidelines proposed at the PRISMA statement in the electronic databases, including: PubMed, Scopus, and Web of Science up to August 2016, using the term 'minocycline' combined either by 'kidney' or 'renal' and published in English language. The following criteria were included: (1) studies that used minocycline in renal diseases; (2) full-text articles; (3) English language; (4) no limitation in publications with in-vivo or in-vitro and human or animal subjects. Our search provided a total of 1056 articles which 1045 of them were discarded due to not meeting the inclusion criteria. It has been clear that several factors, including apoptosis, oxidative stress, mitochondrial dysfunction and inflammation have pivotal roles in the development and progression of kidney diseases. Minocycline protective properties are via several ways, including anti-apoptotic, free radical scavenging, anti-inflammatory, effect on mitochondrial functions and inhibition of matrix metalloproteinase. This systematic review confirmed that minocycline could have significant effects on treatment of renal malfunctions. However, regarding any possible adverse effects of antibiotics, it appears that more investigation is still needed in this context. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  17. Stress, burnout and depression: A systematic review on DNA methylation mechanisms.

    Science.gov (United States)

    Bakusic, Jelena; Schaufeli, Wilmar; Claes, Stephan; Godderis, Lode

    2017-01-01

    Despite that burnout presents a serious burden for modern society, there are no diagnostic criteria. Additional difficulty is the differential diagnosis with depression. Consequently, there is a need to dispose of a burnout biomarker. Epigenetic studies suggest that DNA methylation is a possible mediator linking individual response to stress and psychopathology and could be considered as a potential biomarker of stress-related mental disorders. Thus, the aim of this review is to provide an overview of DNA methylation mechanisms in stress, burnout and depression. In addition to state-of-the-art overview, the goal of this review is to provide a scientific base for burnout biomarker research. We performed a systematic literature search and identified 25 pertinent articles. Among these, 15 focused on depression, 7 on chronic stress and only 3 on work stress/burnout. Three epigenome-wide studies were identified and the majority of studies used the candidate-gene approach, assessing 12 different genes. The glucocorticoid receptor gene (NR3C1) displayed different methylation patterns in chronic stress and depression. The serotonin transporter gene (SLC6A4) methylation was similarly affected in stress, depression and burnout. Work-related stress and depressive symptoms were associated with different methylation patterns of the brain derived neurotrophic factor gene (BDNF) in the same human sample. The tyrosine hydroxylase (TH) methylation was correlated with work stress in a single study. Additional, thoroughly designed longitudinal studies are necessary for revealing the cause-effect relationship of work stress, epigenetics and burnout, including its overlap with depression. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. A review of porosity-generating mechanisms in crustal shear zones

    Science.gov (United States)

    Fusseis, F.; Regenauer-Lieb, K.; Revets, S.

    2009-04-01

    Knowledge of the spatiotemporal characteristics of permeability is critical for the understanding of fluid migration in rocks. In diagenetic and metamorphic rocks different porosity-generating mechanisms contribute to permeability and so influence fluid migration and fluid/rock interaction. However, little is known about their relative contributions to the porosity architecture of a rock in a tectono-metamorphic environment. This presentation reviews porosity-generating mechanisms that affect fluid migration in shear zones, the most important crustal fluid conduits, in the context of the tectonometamorphic evolution of rocks. Mechanisms that generate porosity can be classified in a) those that involve the direct action of a fluid, b) processes in which a fluid partakes or that are supported by a fluid or c) mechanism that do not involve a fluid. a) Hydraulic fracturing, where it happens through the formation of tensile fractures, occurs where pore fluid pressures equalize the combined lithostatic pressure and strength of the rock (Etheridge et al., 1984, Cox & Etheridge, 1989, Oliver, 1996). Here an internally released (devolatilisation reactions, e.g., Rumble, 1994, Hacker, 1997, Yardley, 1997 and references therein) or externally derived (infiltrating from metamorphic, magmatic or meteoric sources, Baumgartner et al., 1997, Jamtveit et al., 1997, Thompson, 1997, Gleeson et al., 2003) fluid directly causes the mechanical failure of a rock. Where a fluid is in chemical disequilibrium with a rock (undersaturated with regard to a chemical species) minerals will be dissolved, generating dissolution porosity. Rocks ‘leached' by the removal of chemical components by vast amounts of fluid are reported to lose up to 60% of their original volume (e.g., Kerrich et al., 1984, McCaig 1988). Dissolution porosity is probably an underrated porosity-generating mechanism. It can be expected along the entire metamorphic evolution, including diagenesis (Higgs et al., 2007) and

  19. Intestinal uptake of bone seeking radiotracer: possible mechanisms and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. W.; Kim, C. G.; Park, S. A.; Chang, J. A. [WonKwang University Hospital, Iksan (Korea, Republic of)

    2007-07-01

    This study was undertaken to investigate the frequency of intestinal accumulation of Tc-99m 3, 3-diphosphono-1, 2-propanedicarboxylic acid (DPD) on bone scans, describe the patterns of intestinal Tc-99m DPD uptake and discuss the possible mechanisms of this unusual finding. Three thousand, one hundred and ninety-four consecutive patients have been evaluated for intestinal Tc-99m DPD uptake on bone scans. A whole-body bone scan and various spot views were obtained to evaluate the location and intensity of intestinal uptake. Delayed scan and SPECT study were performed to define characteristics of intestinal uptake in some of patients. Available reports of co-relative radiologic imaging, endoscopic studies and laboratory tests were also reviewed to explain the intestinal uptake. Eighteen (9 female, 9 male) patients out of 3194 with a mean age of 57 years showed intestinal Tc-99m DPD uptake. The locations of intestinal uptake were well dispersed throughout the abdomen. The majority of the cases showed lower intensity than iliac spine (12/18, 67%). Eight patients didn't show significant change of uptake characteristics on the delayed images, while intestinal uptake traveled distally in nine patients. Two cases were revealed uptake of peritoneal carcinomatosis with small amount ascites and three cases were revealed tumoral uptake of intestine. Four patients with gastritis showed similar characteristic of intestinal uptake. Six cases of distally traveled intestinal uptake suggested intraluminal Tc-99m DPD activity such as gastrointestinal bleeding. However, stool occult blood tests were negative in three patients, and there is no clinical evidence of gastrointestinal bleeding in other three patients. Intestinal Tc-99m DPD uptake can be observed in 0.5% of bone scans. The mechanism of intestinal uptake is still unclear in some of the patients. Delayed imaging additional spot views and SPECT studies help in the differentiation of this finding from possible

  20. Pembrolizumab-Induced Thyroiditis: Comprehensive Clinical Review and Insights Into Underlying Involved Mechanisms.

    Science.gov (United States)

    Delivanis, Danae A; Gustafson, Michael P; Bornschlegl, Svetlana; Merten, Michele M; Kottschade, Lisa; Withers, Sarah; Dietz, Allan B; Ryder, Mabel

    2017-08-01

    Thyroid immune-related adverse events (irAEs) in patients treated with programmed death receptor-1 (PD-1) blockade are increasingly recognized as one of the most common adverse effects. Our aim was to determine the incidence and examine the potential mechanisms of anti-PD-1-induced thyroid irAEs. Single-center, retrospective cohort study. We studied 93 patients with advanced cancer (ages 24 to 82 years; 60% males) who received at least one infusion of pembrolizumab. Thyroid test results and thyroid imaging modalities were reviewed. Comprehensive 10-color flow cytometry of peripheral blood was performed. Thirteen (14%) thyroid irAEs were observed. Thyroiditis occurred in seven patients (54%), from which four recovered. New onset of hypothyroidism overt/subclinical developed in three patients. Levothyroxine dosing required doubling in three patients with a known history of hypothyroidism. Thyroperoxidase antibodies were positive in the minority of the patients [4/13 (31%)] and diffuse increased 18fludeoxyglucose uptake of the thyroid gland was observed in the majority [7/11 (64%)] of patients. We observed more circulating CD56+CD16+ natural killer (NK) cells and an elevated HLA-DR surface expression in the inflammatory intermediate CD14+CD16+ monocytes in anti-PD-1-treated patients. Thyroid dysfunction is common in cancer patients treated with pembrolizumab. Reversible destructive thyroiditis and overt hypothyroidism are the most common clinical presentations. The mechanism of thyroid destruction appears independent of thyroid autoantibodies and may include T cell, NK cell, and/or monocyte-mediated pathways. Because the thyroid is a frequent target of anti-PD-1 therapies, patients with therapeutically refractory thyroid cancer may be ideal candidates for this treatment. Copyright © 2017 Endocrine Society

  1. Mechanisms of silver diamine fluoride on arresting caries: a literature review.

    Science.gov (United States)

    Zhao, Irene Shuping; Gao, Sherry Shiqian; Hiraishi, Noriko; Burrow, Michael Francis; Duangthip, Duangporn; Mei, May Lei; Lo, Edward Chin-Man; Chu, Chun-Hung

    2018-04-01

    To review the evidence regarding the mechanisms of silver diamine fluoride (SDF) for arresting caries. A literature search was conducted using the keywords silver diamine fluoride, and its alternative names, in seven databases: PubMed, Embase and Scopus (English); China National Knowledge Infrastructure (Chinese); Bilioteca Virtual em Saude (Portuguese); Biblioteca Virtual en Salud Espana (Spanish); and Ichushi-Web (Japanese). The titles and abstracts were screened. Full texts were retrieved for publications that studied mechanisms of actions of SDF, including its effects on remineralisation of carious lesions and on cariogenic bacteria. A total of 1,123 publications were identified. Twenty-nine articles were included and they investigated the effect of SDF on cariogenic bacteria and dental hard tissues. Eleven studies investigated the antibacterial properties of SDF. They found that SDF was bactericidal to cariogenic bacteria, mainly Streptococcus mutans. It inhibited the growth of cariogenic biofilms on teeth. Twenty studies reported the remineralisation of demineralised enamel or dentine by SDF. They found that mineral loss of demineralised enamel and dentine was reduced after SDF treatment. A highly mineralised surface rich in calcium and phosphate was formed on arrested carious lesions. Four studies examined the effect of SDF on dentine collagen. They found that SDF inhibited collagenases (matrix metalloproteinases and cysteine cathepsins) and protected dentine collagen from destruction. SDF is a bactericidal agent and reduces the growth of cariogenic bacteria. It inhibits demineralisation and promotes the remineralisation of demineralised enamel and dentine. It also hampers degradation of the dentine collagen. © 2017 FDI World Dental Federation.

  2. A Review of Consequences of Poverty on Economic Decision-Making: A Hypothesized Model of a Cognitive Mechanism

    OpenAIRE

    Adamkovič, Matúš; Martončik, Marcel

    2017-01-01

    This review focuses on the issue of poverty affecting economic decision-making. By critically evaluating existing studies, the authors propose a structural model detailing the cognitive mechanism involved in how poverty negatively impacts economic decision-making, and explores evidence supporting the basis for the formation of this model. The suggested mechanism consists of a relationship between poverty and four other factors: (1) cognitive load (e.g., experiencing negative affect and stress...

  3. Mixing enhancement strategies and their mechanisms in supersonic flows: A brief review

    Science.gov (United States)

    Huang, Wei

    2018-04-01

    Achieving efficient fuel-air mixing is a crucial issue in the design of the scramjet engine due to the compressibility effect on the mixing shear layer growth and the stringent flow residence time limitation induced by the high-speed crossflow, and the potential solution is to enhance mixing between air and fuel by introducing of streamwise vortices in the flow field. In this survey, some mixing enhancement strategies based on the traditional transverse injection technique proposed in recent years, as well as their mixing augmentation mechanisms, were reviewed in detail, namely the pulsed transverse injection scheme, the traditional transverse injection coupled with the vortex generator, and the dual transverse injection system with a front porthole and a rear air porthole arranged in tandem. The streamwise vortices, through the large-scale stirring motion that they introduce, are responsible for the extraction of large amounts of energy from the mean flow that can be converted into turbulence, ultimately leading to increased mixing effectiveness. The streamwise vortices may be obtained by taking advantage of the shear layer between a jet and the cross stream or by employing intrusive physical devices. Finally, a promising mixing enhancement strategy in supersonic flows was proposed, and some remarks were provided.

  4. Parallel computing in experimental mechanics and optical measurement: A review (II)

    Science.gov (United States)

    Wang, Tianyi; Kemao, Qian

    2018-05-01

    With advantages such as non-destructiveness, high sensitivity and high accuracy, optical techniques have successfully integrated into various important physical quantities in experimental mechanics (EM) and optical measurement (OM). However, in pursuit of higher image resolutions for higher accuracy, the computation burden of optical techniques has become much heavier. Therefore, in recent years, heterogeneous platforms composing of hardware such as CPUs and GPUs, have been widely employed to accelerate these techniques due to their cost-effectiveness, short development cycle, easy portability, and high scalability. In this paper, we analyze various works by first illustrating their different architectures, followed by introducing their various parallel patterns for high speed computation. Next, we review the effects of CPU and GPU parallel computing specifically in EM & OM applications in a broad scope, which include digital image/volume correlation, fringe pattern analysis, tomography, hyperspectral imaging, computer-generated holograms, and integral imaging. In our survey, we have found that high parallelism can always be exploited in such applications for the development of high-performance systems.

  5. Flavonoids Active Against Osteosarcoma: A Review of the Molecular Mechanisms Involved.

    Science.gov (United States)

    Liu, Hui; Gao, Yutong; Dong, Yonghui; Cheng, Peng; Chen, Anmin; Huang, Hui

    2017-01-01

    Osteosarcoma is the most frequent primitive malignant bone tumor affecting adolescents and young adults worldwide. The tumor exhibits aggressive growth in the primary site and readily metastasizes to other organs. There has been no significant improvement in the 5-year survival rate since the 1970s and the figure remains at 60-70%. In addition, the side effects of chemotherapeutic drugs and resistance to chemotherapy compromise the effects of treatment for osteosarcoma. In recent years, the development of flavonoids drugs inhibiting carcinogenesis is attracting great interest in the scientific community. Flavonoids are one kind of polyphenolic compounds widely found in vegetables and fruits. Moreover, flavonoids have become popular compounds, exhibiting comprehensive antitumor activities, while being safe and inexpensive. Here, the literature on the benefits afforded by flavonoids in terms of osteosarcoma treatment is reviewed and certain flavonoids and their effects on osteosarcoma are discussed. These compounds can perturb the cell cycle, induce apoptosis, inhibit tumor cell invasion and metastasis, potentiate the actions of chemotherapeutic agents, trigger autophagy, and stimulate antitumor activity in vivo. In summary, we highlight the currently well-accepted flavonoid compounds and detail the molecular mechanisms by which flavonoids may treat osteosarcoma, and thus the flavonoids exhibit great promise as anti-osteosarcoma agents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. Perceptual and affective mechanisms in facial expression recognition: An integrative review.

    Science.gov (United States)

    Calvo, Manuel G; Nummenmaa, Lauri

    2016-09-01

    Facial expressions of emotion involve a physical component of morphological changes in a face and an affective component conveying information about the expresser's internal feelings. It remains unresolved how much recognition and discrimination of expressions rely on the perception of morphological patterns or the processing of affective content. This review of research on the role of visual and emotional factors in expression recognition reached three major conclusions. First, behavioral, neurophysiological, and computational measures indicate that basic expressions are reliably recognized and discriminated from one another, albeit the effect may be inflated by the use of prototypical expression stimuli and forced-choice responses. Second, affective content along the dimensions of valence and arousal is extracted early from facial expressions, although this coarse affective representation contributes minimally to categorical recognition of specific expressions. Third, the physical configuration and visual saliency of facial features contribute significantly to expression recognition, with "emotionless" computational models being able to reproduce some of the basic phenomena demonstrated in human observers. We conclude that facial expression recognition, as it has been investigated in conventional laboratory tasks, depends to a greater extent on perceptual than affective information and mechanisms.

  7. Transcranial alternating current stimulation: A review of the underlying mechanisms and modulation of cognitive processes

    Directory of Open Access Journals (Sweden)

    Christoph S Herrmann

    2013-06-01

    Full Text Available Brain oscillations of different frequencies have been associated with a variety of cognitive functions. Convincing evidence supporting those associations has been provided by studies using intracranial stimulation, pharmacological interventions and lesion studies. The emergence of novel non-invasive brain stimulation techniques like repetitive transcranial magnetic stimulation (rTMS and transcranial alternating current stimulation (tACS now allows to modulate brain oscillations directly. Particularly, tACS offers the unique opportunity to causally link brain oscillations of a specific frequency range to cognitive processes, because it uses sinusoidal currents that are bound to one frequency only. Using tACS allows to modulate brain oscillations and in turn to influence cognitive processes, thereby demonstrating the causal link between the two. Here, we review findings about the physiological mechanism of tACS and studies that have used tACS to modulate basic motor and sensory processes as well as higher cognitive processes like memory, ambiguous perception, and decision making.

  8. Exploring the Molecular Mechanisms of Nickel-Induced Genotoxicity and Carcinogenicity: A Literature Review

    Science.gov (United States)

    Cameron, Keyuna S.; Buchner, Virginia; Tchounwou, Paul B.

    2011-01-01

    Nickel, a naturally occurring element that exists in various mineral forms, is mainly found in soil and sediment, and its mobilization is influenced by the physicochemical properties of the soil. Industrial sources of nickel include metallurgical processes such as electroplating, alloy production, stainless steel, and nickel-cadmium batteries. Nickel industries, oil- and coal-burning power plants, and trash incinerators have been implicated in its release into the environment. In humans, nickel toxicity is influenced by the route of exposure, dose, and solubility of the nickel compound. Lung inhalation is the major route of exposure for nickel-induced toxicity. Nickel may also be ingested or absorbed through the skin. The primary target organs are the kidneys and lungs. Other organs such as the liver, spleen, heart and testes may also be affected to a lesser extent. Although the most common health effect is an allergic reaction, research has also demonstrated that nickel is carcinogenic to humans. The focus of the present review is on recent research concerning the molecular mechanisms of nickel-induced genotoxicity and carcinogenicity. We first present a background on the occurrence of nickel in the environment, human exposure, and human health effects. PMID:21905451

  9. Epigenetic Mechanisms Shape the Biological Response to Trauma and Risk for PTSD: A Critical Review

    Directory of Open Access Journals (Sweden)

    Morgan Heinzelmann

    2013-01-01

    Full Text Available Posttraumatic stress disorder (PTSD develops in approximately one-quarter of trauma-exposed individuals, leading us and others to question the mechanisms underlying this heterogeneous response to trauma. We suggest that the reasons for the heterogeneity relate to a complex interaction between genes and the environment, shaping each individual’s recovery trajectory based on both historical and trauma-specific variables. Epigenetic modifications provide a unique opportunity to elucidate how preexisting risk factors may contribute to PTSD risk through changes in the methylation of DNA. Preexisting risks for PTSD, including depression, stress, and trauma, result in differential DNA methylation of endocrine genes, which may then result in a different biological responses to trauma and subsequently a greater risk for PTSD onset. Although these relationships are complex and currently inadequately described, we provide a critical review of recent studies to examine how differences in genetic and proteomic biomarkers shape an individual’s vulnerability to PTSD development, thereby contributing to a heterogeneous response to trauma.

  10. Gadolinium-based contrast agent toxicity: a review of known and proposed mechanisms.

    Science.gov (United States)

    Rogosnitzky, Moshe; Branch, Stacy

    2016-06-01

    Gadolinium chelates are widely used as contrast media for magnetic resonance imaging. The approved gadolinium-based contrast agents (GBCAs) have historically been considered safe and well tolerated when used at recommended dosing levels. However, for nearly a decade, an association between GBCA administration and the development of nephrogenic systemic fibrosis (NSF) has been recognized in patients with severe renal impairment. This has led to modifications in clinical practices aimed at reducing the potential and incidence of NSF development. Newer reports have emerged regarding the accumulation of gadolinium in various tissues of patients who do not have renal impairment, including bone, brain, and kidneys. Despite the observations of gadolinium accumulation in tissues regardless of renal function, very limited clinical data regarding the potential for and mechanisms of toxicity is available. This significant gap in knowledge warrants retrospective cohort study efforts, as well as prospective studies that involve gadolinium ion (Gd(3+)) testing in patients exposed to GBCA. This review examines the potential biochemical and molecular basis of gadolinium toxicity, possible clinical significance of gadolinium tissue retention and accumulation, and methods that can limit gadolinium body burden.

  11. Ultrasound assisted extraction of food and natural products. Mechanisms, techniques, combinations, protocols and applications. A review.

    Science.gov (United States)

    Chemat, Farid; Rombaut, Natacha; Sicaire, Anne-Gaëlle; Meullemiestre, Alice; Fabiano-Tixier, Anne-Sylvie; Abert-Vian, Maryline

    2017-01-01

    This review presents a complete picture of current knowledge on ultrasound-assisted extraction (UAE) in food ingredients and products, nutraceutics, cosmetic, pharmaceutical and bioenergy applications. It provides the necessary theoretical background and some details about extraction by ultrasound, the techniques and their combinations, the mechanisms (fragmentation, erosion, capillarity, detexturation, and sonoporation), applications from laboratory to industry, security, and environmental impacts. In addition, the ultrasound extraction procedures and the important parameters influencing its performance are also included, together with the advantages and the drawbacks of each UAE techniques. Ultrasound-assisted extraction is a research topic, which affects several fields of modern plant-based chemistry. All the reported applications have shown that ultrasound-assisted extraction is a green and economically viable alternative to conventional techniques for food and natural products. The main benefits are decrease of extraction and processing time, the amount of energy and solvents used, unit operations, and CO 2 emissions. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Molecular mechanisms of obesity induced osteoporosis and muscle atrophy: A Review

    Directory of Open Access Journals (Sweden)

    Bipradas Roy

    2016-09-01

    Full Text Available Obesity and osteoporosis are two alarming health disorders prominent among middle and old age populations, and the numbers of those affected by these two disorders are increasing. It is estimated that more than 600 million adults are obese and over 200 million people have osteoporosis worldwide. Interestingly, both of these abnormalities share some common features including a genetic predisposition, and a common origin: bone marrow mesenchymal stromal cells. Obesity is characterized by the expression of leptin, adiponectin, interleukin 6 (IL-6, interleukin 10 (IL-10, monocyte chemotactic protein-1 (MCP-1, tumor necrosis factor-alpha (TNF-α, macrophage colony stimulating factor (M-CSF, growth hormone (GH, parathyroid hormone (PTH, angiotensin II (Ang II, 5-hydroxy-tryptamine (5-HT, Advance glycation end products (AGE, and myostatin, which exert their effects by modulating the signaling pathways within bone and muscle. Chemical messengers (eg. TNF-α, IL-6, AGE, leptins that are upregulated or downregulated as a result of obesity have been shown to act as negative regulators of osteoblasts, osteocytes and muscles, as well as positive regulators of osteoclasts. These additive effects of obesity ultimately increase the risk for osteoporosis and muscle atrophy. The aim of this review is to identify the potential cellular mechanisms through which obesity may facilitate osteoporosis, muscle atrophy and bone fractures.

  13. From evidence based medicine to mechanism based medicine. Reviewing the role of pharmacogenetics.

    Science.gov (United States)

    Wilffert, Bob; Swen, Jesse; Mulder, Hans; Touw, Daan; Maitland-Van der Zee, Anke-Hilse; Deneer, Vera

    2013-06-01

    The translation of evidence based medicine to a specific patient presents a considerable challenge. We present by means of the examples nortriptyline, tramadol, clopidogrel, coumarins, abacavir and antipsychotics the discrepancy between available pharmacogenetic information and its implementation in daily clinical practice. Literature review. A mechanism based approach may be helpful to personalize medicine for the individual patient to which pharmacogenetics may contribute significantly. The lack of consistency in what we accept in bioequivalence and in pharmacogenetics of drug metabolising enzymes is discussed and illustrated with the example of nortriptyline. The impact of pharmacogenetics on examples like tramadol, clopidogrel, coumarins and abacavir is described. Also the present status of the polymorphisms of 5-HT2A and C receptors in antipsychotic-induced weight gain is presented as a pharmacodynamic example with until now a greater distance to clinical implementation. The contribution of pharmacogenetics to tailor-made pharmacotherapy, which especially might be of value for patients deviating from the average, has not yet reached the position it seems to deserve.

  14. A Review of Continuing Professional Development (CPD of Training Competencies for Malaysian Mechanical Industries

    Directory of Open Access Journals (Sweden)

    Kasman Zeti

    2018-01-01

    Full Text Available The aim of this paper is to review issues in continuing professional development of vocational training to the mechanical industries. The spectacle of individuals entering the labour market without relevant qualifications is common in Malaysia. There are many who choose to work instead of pursuing further education after secondary school. In the labour market, these individuals are considered to be low-skilled workers because they had no training prior to employment. The role of employers in providing training and education to employees is vital in establishing career development of employees. Employers who contributed to their employees' training funds through Human Resources Development Council would provide opportunities to increase the skills of workers. Based on the Malaysia's Development Plan of Occupational Skill, the issues and challenges that have been identified in producing skilled workers in interpersonal and technical skills. This paper provided an opportunity to examine an enterprise-based approach to skill formation for workers with basic academic qualifications. It presents an alternative scenario to institution-based Technical and Vocational Education and Training (TVET, which many Malaysians are familiar with. A structured curriculum development of human resources learning needs according to the job profile of the typical individual and group work which will provide a clearer perspective on knowledge, competence and skill levels of employee behavior in performing tasks will be discussed. The biggest impact on this study is to produce high skill employees concerning customer satisfaction and increased organizational productivity towards high income nations.

  15. SEURAT-1 liver gold reference compounds: a mechanism-based review.

    Science.gov (United States)

    Jennings, Paul; Schwarz, Michael; Landesmann, Brigitte; Maggioni, Silvia; Goumenou, Marina; Bower, David; Leonard, Martin O; Wiseman, Jeffrey S

    2014-12-01

    There is an urgent need for the development of alternative methods to replace animal testing for the prediction of repeat dose chemical toxicity. To address this need, the European Commission and Cosmetics Europe have jointly funded a research program for 'Safety Evaluation Ultimately Replacing Animal Testing.' The goal of this program was the development of in vitro cellular systems and associated computational capabilities for the prediction of hepatic, cardiac, renal, neuronal, muscle, and skin toxicities. An essential component of this effort is the choice of appropriate reference compounds that can be used in the development and validation of assays. In this review, we focus on the selection of reference compounds for liver pathologies in the broad categories of cytotoxicity and lipid disorders. Mitochondrial impairment, oxidative stress, and apoptosis are considered under the category of cytotoxicity, while steatosis, cholestasis, and phospholipidosis are considered under the category of lipid dysregulation. We focused on four compound classes capable of initiating such events, i.e., chemically reactive compounds, compounds with specific cellular targets, compounds that modulate lipid regulatory networks, and compounds that disrupt the plasma membrane. We describe the molecular mechanisms of these compounds and the cellular response networks which they elicit. This information will be helpful to both improve our understanding of mode of action and help in the selection of appropriate mechanistic biomarkers, allowing us to progress the development of animal-free models with improved predictivity to the human situation.

  16. How do Small Groups Promote Behaviour Change? An Integrative Conceptual Review of Explanatory Mechanisms.

    Science.gov (United States)

    Borek, Aleksandra J; Abraham, Charles

    2018-03-01

    Small groups are used to promote health, well-being, and personal change by altering members' perceptions, beliefs, expectations, and behaviour patterns. An extensive cross-disciplinary literature has articulated and tested theories explaining how such groups develop, function, and facilitate change. Yet these theoretical understandings are rarely applied in the development, description, and evaluation of health-promotion, group-based, behaviour-change interventions. Medline database, library catalogues, search engines, specific journals and reference lists were searched for relevant texts. Texts were reviewed for explanatory concepts or theories describing change processes in groups, which were integrated into the developing conceptual structure. This was designed to be a parsimonious conceptual framework that could be applied to design and delivery. Five categories of interacting processes and concepts were identified and defined: (1) group development processes, (2) dynamic group processes, (3) social change processes, (4) personal change processes, and (5) group design and operating parameters. Each of these categories encompasses a variety of theorised mechanisms explaining individual change in small groups. The final conceptual model, together with the design issues and practical recommendations derived from it, provides a practical basis for linking research and theory explaining group functioning to optimal design of group-based, behaviour-change interventions. © 2018 The Authors. Applied Psychology: Health and Well-Being published by John Wiley & Sons Ltd on behalf of International Association of Applied Psychology.

  17. Alpha-2 agonists for sedation of mechanically ventilated adults in intensive care units: a systematic review.

    Science.gov (United States)

    Cruickshank, Moira; Henderson, Lorna; MacLennan, Graeme; Fraser, Cynthia; Campbell, Marion; Blackwood, Bronagh; Gordon, Anthony; Brazzelli, Miriam

    2016-03-01

    Care of critically ill patients in intensive care units (ICUs) often requires potentially invasive or uncomfortable procedures, such as mechanical ventilation (MV). Sedation can alleviate pain and discomfort, provide protection from stressful or harmful events, prevent anxiety and promote sleep. Various sedative agents are available for use in ICUs. In the UK, the most commonly used sedatives are propofol (Diprivan(®), AstraZeneca), benzodiazepines [e.g. midazolam (Hypnovel(®), Roche) and lorazepam (Ativan(®), Pfizer)] and alpha-2 adrenergic receptor agonists [e.g. dexmedetomidine (Dexdor(®), Orion Corporation) and clonidine (Catapres(®), Boehringer Ingelheim)]. Sedative agents vary in onset/duration of effects and in their side effects. The pattern of sedation of alpha-2 agonists is quite different from that of other sedatives in that patients can be aroused readily and their cognitive performance on psychometric tests is usually preserved. Moreover, respiratory depression is less frequent after alpha-2 agonists than after other sedative agents. To conduct a systematic review to evaluate the comparative effects of alpha-2 agonists (dexmedetomidine and clonidine) and propofol or benzodiazepines (midazolam and lorazepam) in mechanically ventilated adults admitted to ICUs. We searched major electronic databases (e.g. MEDLINE without revisions, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE and Cochrane Central Register of Controlled Trials) from 1999 to 2014. Evidence was considered from randomised controlled trials (RCTs) comparing dexmedetomidine with clonidine or dexmedetomidine or clonidine with propofol or benzodiazepines such as midazolam, lorazepam and diazepam (Diazemuls(®), Actavis UK Limited). Primary outcomes included mortality, duration of MV, length of ICU stay and adverse events. One reviewer extracted data and assessed the risk of bias of included trials. A second reviewer cross-checked all the data extracted. Random-effects meta

  18. Mechanics

    CERN Document Server

    Chester, W

    1979-01-01

    When I began to write this book, I originally had in mind the needs of university students in their first year. May aim was to keep the mathematics simple. No advanced techniques are used and there are no complicated applications. The emphasis is on an understanding of the basic ideas and problems which require expertise but do not contribute to this understanding are not discussed. How­ ever, the presentation is more sophisticated than might be considered appropri­ ate for someone with no previous knowledge of the subject so that, although it is developed from the beginning, some previous acquaintance with the elements of the subject would be an advantage. In addition, some familiarity with element­ ary calculus is assumed but not with the elementary theory of differential equations, although knowledge of the latter would again be an advantage. It is my opinion that mechanics is best introduced through the motion of a particle, with rigid body problems left until the subject is more fully developed. Howev...

  19. A review of recent studies on the mechanisms and analysis methods of sub-synchronous oscillation in wind farms

    Science.gov (United States)

    Wang, Chenggen; Zhou, Qian; Gao, Shuning; Luo, Jia; Diao, Junchao; Zhao, Haoran; Bu, Jing

    2018-04-01

    This paper reviews the recent studies of Sub-Synchronous Oscillation(SSO) in wind farms. Mechanisms and analysis methods are the main concerns of this article. A classification method including new types of oscillation occurred between wind farms and HVDC systems and oscillation caused by Permanent Magnet Synchronous Generators(PMSG) is proposed. Characteristics of oscillation analysis techniques are summarized.

  20. A review of the chemical and physical mechanisms of the storage stability of fast pyrolysis bio-oils

    Energy Technology Data Exchange (ETDEWEB)

    Diebold, J.P.

    1999-01-27

    Understanding the fundamental chemical and physical aging mechanisms is necessary to learn how to produce a bio-oil that is more stable during shipping and storage. This review provides a basis for this understanding and identifies possible future research paths to produce bio-oils with better storage stability.

  1. The effect of grinding on the mechanical behavior of Y-TZP ceramics: A systematic review and meta-analyses

    NARCIS (Netherlands)

    Pereira, G.K.R.; Fraga, S.; Montagner, A.F.; Soares, F.Z.M.; Kleverlaan, C.J.; Valandro, L.F.

    2016-01-01

    The aim of this study was to systematically review the literature to assess the effect of grinding on the mechanical properties, structural stability and superficial characteristics of Y-TZP ceramics. The MEDLINE via PubMed and Web of Science (ISI – Web of Knowledge) electronic databases were

  2. Book review: ALMOG, J. Referential Mechanics: Direct Reference and the Foundations of Semantics (Oxford University Press, 2014

    Directory of Open Access Journals (Sweden)

    Filipe Martone

    Full Text Available Abstract: In this review I discuss Joseph Almog's book "Referential Mechanics". The book discusses direct reference as conceived by three of its founding fathers, Kripke, Kaplan and Donnellan, and introduces Almog's ambitious project of providing a referential semantics to all subject-phrases. I offer a brief overview of its four chapters and point out some of their virtues and shortcomings.

  3. Applied mechanics and mechatronics special topic volume with invited peer reviewed papers only

    CERN Document Server

    Trebuňa, František

    2014-01-01

    The issue ""Applied Mechanics and Mechatronics"" contains results of research from researchers and designers from several prominent universities and research institutes of Central Europe.The publication is divided into three following chapters: Modeling and Simulation of Mechanic and Mechatronic SystemsAnalysis and Design of Mechanic and Mechatronic SystemsExperimental methods in Mechanics and Mechatronics. The submitted publication provides insight on modern approaches and methods in designing, modeling and experimental analyzing of mechanic and mechatronics systems.

  4. Lifelong Bilingualism and Neural Reserve against Alzheimer’s disease: A Review of Findings and Potential Mechanisms

    Science.gov (United States)

    Gold, Brian T.

    2014-01-01

    Alzheimer’s disease (AD) is a progressive brain disorder that initially affects medial temporal lobe circuitry and memory functions. Current drug treatments have only modest effects on the symptomatic course of the disease. In contrast, a growing body of evidence suggests that lifelong bilingualism may delay the onset of clinical AD symptoms by several years. The purpose of the present review is to summarize evidence for bilingualism as a reserve variable against AD and discuss potential underlying neurocognitive mechanisms. Evidence is reviewed suggesting that bilingualism may delay clinical AD symptoms by protecting frontostriatal and frontoparietal executive control circuitry rather than medial temporal lobe memory circuitry. Cellular and molecular mechanisms that may contribute to bilingual cognitive reserve effects are discussed, including those that may affect neuronal metabolic functions, dynamic neuronal-glial interactions, vascular factors, myelin structure and neurochemical signaling. Future studies that may test some of these potential mechanisms of bilingual CR effects are proposed. PMID:25496781

  5. Plant- and microbial-based mechanisms to improve the agronomic effectiveness of phosphate rock: a review

    Directory of Open Access Journals (Sweden)

    Melissa M. Arcand

    2006-12-01

    Full Text Available Deficiency in plant-available phosphorus is considered to be a major limiting factor to food production in many agricultural soils. Mineral resources are necessary to restore soil phosphorus content. In regions where conventional fertilizers are not used due to cost limitations or to mitigate adverse environmental effects, local sources of phosphate rock are being increasingly recognized for potential use as alternative phosphorus fertilizers. The main obstacle associated with using directly applied ground phosphate rock is that the phosphate released is often unable to supply sufficient plant-available phosphorus for crop uptake. Plantand microbial-based mechanisms are low-cost, appropriate technologies to enhance the solubilization and increase the agronomic effectiveness of phosphate rock. Common mechanisms of phosphate rock dissolution including proton and organic acid production will be reviewed for both plants and microorganisms. This review will also address possibilities for future research directions and applications to agriculture, as well as highlight ongoing research at the University of Guelph, Guelph, Canada.A deficiência de fósforo disponível nas plantas é considerada o maior fator de limitação na produção de alimentos em diversos solos agrícolas. São necessários recursos minerais para restaurar o conteúdo de fósforo no solo. Em regiões onde fertilizantes convencionais nãosão utilizados devido às limitações de custo ou de seus efeitos ambientais adversos, fontes locais de rocha fosfática estão sendo crescentemente reconhecidas por seu uso potencial como alternativa aos fertilizantes solúveis de fósforo. O principal obstáculo associado ao uso daaplicação direta da rocha fosfática no solo é que o fósforo liberado é, muitas vezes, incapaz de suprir as necessidades das plantas de forma a aumentar a produção. Mecanismos baseados no uso de plantas e micro-organismos são consideradas tecnologias

  6. Mechanisms and Model Diversity of Trade-Wind Shallow Cumulus Cloud Feedbacks: A Review

    Science.gov (United States)

    Vial, Jessica; Bony, Sandrine; Stevens, Bjorn; Vogel, Raphaela

    2017-11-01

    Shallow cumulus clouds in the trade-wind regions are at the heart of the long standing uncertainty in climate sensitivity estimates. In current climate models, cloud feedbacks are strongly influenced by cloud-base cloud amount in the trades. Therefore, understanding the key factors controlling cloudiness near cloud-base in shallow convective regimes has emerged as an important topic of investigation. We review physical understanding of these key controlling factors and discuss the value of the different approaches that have been developed so far, based on global and high-resolution model experimentations and process-oriented analyses across a range of models and for observations. The trade-wind cloud feedbacks appear to depend on two important aspects: (1) how cloudiness near cloud-base is controlled by the local interplay between turbulent, convective and radiative processes; (2) how these processes interact with their surrounding environment and are influenced by mesoscale organization. Our synthesis of studies that have explored these aspects suggests that the large diversity of model responses is related to fundamental differences in how the processes controlling trade cumulus operate in models, notably, whether they are parameterized or resolved. In models with parameterized convection, cloudiness near cloud-base is very sensitive to the vigor of convective mixing in response to changes in environmental conditions. This is in contrast with results from high-resolution models, which suggest that cloudiness near cloud-base is nearly invariant with warming and independent of large-scale environmental changes. Uncertainties are difficult to narrow using current observations, as the trade cumulus variability and its relation to large-scale environmental factors strongly depend on the time and/or spatial scales at which the mechanisms are evaluated. New opportunities for testing physical understanding of the factors controlling shallow cumulus cloud responses using

  7. Clinical review: Helmet and non-invasive mechanical ventilation in critically ill patients.

    Science.gov (United States)

    Esquinas Rodriguez, Antonio M; Papadakos, Peter J; Carron, Michele; Cosentini, Roberto; Chiumello, Davide

    2013-04-25

    Non-invasive mechanical ventilation (NIV) has proved to be an excellent technique in selected critically ill patients with different forms of acute respiratory failure. However, NIV can fail on account of the severity of the disease and technical problems, particularly at the interface. The helmet could be an alternative interface compared to face mask to improve NIV success. We performed a clinical review to investigate the main physiological and clinical studies assessing the efficacy and related issues of NIV delivered with a helmet. A computerized search strategy of MEDLINE/PubMed (January 2000 to May 2012) and EMBASE (January 2000 to May 2012) was conducted limiting the search to retrospective, prospective, nonrandomized and randomized trials. We analyzed 152 studies from which 33 were selected, 12 physiological and 21 clinical (879 patients). The physiological studies showed that NIV with helmet could predispose to CO₂ rebreathing and increase the patients' ventilator asynchrony. The main indications for NIV were acute cardiogenic pulmonary edema, hypoxemic acute respiratory failure (community-acquired pneumonia, postoperative and immunocompromised patients) and hypercapnic acute respiratory failure. In 9 of the 21 studies the helmet was compared to a face mask during either continous positive airway pressure or pressure support ventilation. In eight studies oxygenation was similar in the two groups, while the intubation rate was similar in four and lower in three studies for the helmet group compared to face mask group. The outcome was similar in six studies. The tolerance was better with the helmet in six of the studies. Although these data are limited, NIV delivered by helmet could be a safe alternative to the face mask in patients with acute respiratory failure.

  8. An Integrative Review on Role and Mechanisms of Ghrelin in Stress, Anxiety and Depression.

    Science.gov (United States)

    Bali, Anjana; Jaggi, Amteshwar Singh

    2016-01-01

    Ghrelin is orexigenic hormone primarily synthesized by endocrine X/A-like cells of gastric oxyntic mucosa to stimulate appetite and food intake along with regulation of growth hormone and insulin secretion; glucose and lipid metabolism; gastrointestinal motility; blood pressure, heart rate and neurogenesis. Furthermore, peripherally (after crossing the blood brain barrier) as well as centrally synthesized ghrelin (in the hypothalamus) regulates diverse functions of central nervous system including stress-associated behavioral functions. Exposure to stress alters the ghrelin levels and alteration in ghrelin levels significantly affects neuro-endocrinological parameters; metabolism-related physiology, behavior and mood. Studies have shown both anxiolytic and anxiogenic role of ghrelin suggesting its dual role in modulating anxiety-related behavior. However, it is proposed that increase in ghrelin levels during stress condition is an endogenous stress coping behavior and increased ghrelin levels may be required to prevent excessive anxiety. In preclinical and clinical studies, an elevation in ghrelin levels during depression has been correlated with their antidepressant activities. Ghrelin-induced modulation of stress and associated conditions has been linked to alteration in hypothalamic-pituitary-adrenal (HPA) axis; autonomic nervous system (mainly sympathetic nervous system and serotonergic neurotransmission. A reciprocal relationship has been reported between corticotropin-releasing hormone (CRH) and ghrelin as ghrelin increases the release of CRH, ACTH and corticosteroids; while CRH decreases the expression of ghrelin. Similarly, ghrelin increases the serotonin turnover and in turn, serotonin controls ghrelin signaling to modulate anxiety-related behavior. The present review discusses the dual role of ghrelin in stress and related behavioral disorders along with possible mechanisms.

  9. Biological Mechanisms Whereby Social Exclusion May Contribute to the Etiology of Psychosis: A Narrative Review.

    Science.gov (United States)

    Selten, Jean-Paul; Booij, Jan; Buwalda, Bauke; Meyer-Lindenberg, Andreas

    2017-01-03

    The purpose of this review is to examine whether a contribution of social exclusion to the pathogenesis of psychosis is compatible with the dopamine hypothesis and/or the neurodevelopmental hypothesis. Humans experience social exclusion as defeating. An animal model for defeat is the resident-intruder paradigm. The defeated animal shows evidence of an increased sensitivity to amphetamine, increased dopamine release in the nucleus accumbens and prefrontal cortex, and increased firing of dopaminergic neurons in the ventral tegmental area. As for humans, one study showed that amphetamine-induced striatal dopamine release was significantly greater among nonpsychotic young adults with severe hearing impairment than among normal hearing controls. Two other studies reported an association between childhood trauma and increased dopamine function in striatal subregions. Several studies have suggested that the perigenual anterior cingulate cortex (pgACC) may play a role in the processing of social stress. Importantly, the pgACC regulates the activity of the ventral striatum through bidirectional interconnections. We are not aware of studies in humans that examined whether (proxies for) social exclusion contributes to the structural brain changes present at psychosis onset. Animal studies, however, reported that long-term isolation may lead to reductions in volume of the total brain, hippocampus, or medial prefrontal cortex. Other animal studies reported that social defeat can reduce neurogenesis. In conclusion, the answer to the question as to whether there are plausible mechanisms whereby social exclusion can contribute to the pathogenesis of psychosis is cautiously affirmative. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Mechanisms and Model Diversity of Trade-Wind Shallow Cumulus Cloud Feedbacks: A Review

    Science.gov (United States)

    Vial, Jessica; Bony, Sandrine; Stevens, Bjorn; Vogel, Raphaela

    Shallow cumulus clouds in the trade-wind regions are at the heart of the long standing uncertainty in climate sensitivity estimates. In current climate models, cloud feedbacks are strongly influenced by cloud-base cloud amount in the trades. Therefore, understanding the key factors controlling cloudiness near cloud-base in shallow convective regimes has emerged as an important topic of investigation. We review physical understanding of these key controlling factors and discuss the value of the different approaches that have been developed so far, based on global and high-resolution model experimentations and process-oriented analyses across a range of models and for observations. The trade-wind cloud feedbacks appear to depend on two important aspects: (1) how cloudiness near cloud-base is controlled by the local interplay between turbulent, convective and radiative processes; (2) how these processes interact with their surrounding environment and are influenced by mesoscale organization. Our synthesis of studies that have explored these aspects suggests that the large diversity of model responses is related to fundamental differences in how the processes controlling trade cumulus operate in models, notably, whether they are parameterized or resolved. In models with parameterized convection, cloudiness near cloud-base is very sensitive to the vigor of convective mixing in response to changes in environmental conditions. This is in contrast with results from high-resolution models, which suggest that cloudiness near cloud-base is nearly invariant with warming and independent of large-scale environmental changes. Uncertainties are difficult to narrow using current observations, as the trade cumulus variability and its relation to large-scale environmental factors strongly depend on the time and/or spatial scales at which the mechanisms are evaluated. New opportunities for testing physical understanding of the factors controlling shallow cumulus cloud responses using

  11. The Safar Center for Resuscitation Research: Searching for Breakthroughs in the New Millennium

    Directory of Open Access Journals (Sweden)

    P. M. Kochanek

    2006-01-01

    Full Text Available This review, written on the occasion of the 70th anniversary of the Institute for General Reanimatology of the Russian Academy of Medical Sciences, provides an update of recent research in the field of resuscitation medicine carried out at the Safar Center for Resuscitation Research at the University of Pittsburgh School of Medicine. Current and recent studies describing bench to bedside investigation in the areas of traumatic brain injury (TBI, cardiopulmonary arrest, hemorrhagic shock, and ultra-novel approaches to resuscitation are discussed. Investigation in TBI across a variety of topics by many investigators including mechanism of neuronal death, oxidative and nitrative stress, proteomics, adenosine, serotonin, novel magnetic resonance imaging application, inflicted childhood neurotrauma, and TBI rehabilitation is addressed. Research discussed in the program of cardiopulmonary arrest includes optimization of the use of mild hypothermia and novel investigation in experimental asphyxial cardiac arrest. In the program on hemorrhagic shock, our recent work on the application of mild hypothermia to prolong the «golden hour» is presented. Finally, a brief overview of our studies of a novel approach to the resuscitation of exsan-guination cardiac arrest using emergency preservation for resuscitation (EPR is provided.

  12. Migratory potential of transplanted glial progenitors as critical factor for successful translation of glia replacement therapy: The gap between mice and men.

    Science.gov (United States)

    Srivastava, Rohit K; Bulte, Jeff W M; Walczak, Piotr; Janowski, Miroslaw

    2018-05-01

    Neurological disorders are a major threat to public health. Stem cell-based regenerative medicine is now a promising experimental paradigm for its treatment, as shown in pre-clinical animal studies. Initial attempts have been on the replacement of neuronal cells only, but glial progenitors (GPs) are now becoming strong alternative cellular therapeutic candidates to replace oligodendrocytes and astrocytes as knowledge accumulates about their important emerging role in various disease processes. There are many examples of successful therapeutic outcomes for transplanted GPs in small animal models, but clinical translation has proved to be challenging due to the 1,000-fold larger volume of the human brain compared to mice. Human GPs transplanted into the mouse brain migrate extensively and can induce global cell replacement, but a similar extent of migration in the human brain would only allow for local rather than global cell replacement. We review here the mechanisms that govern cell migration, which could potentially be exploited to enhance the migratory properties of GPs through cell engineering pre-transplantation. We furthermore discuss the (dis)advantages of the various cell delivery routes that are available, with particular emphasis on intra-arterial injection as the most suitable route for achieving global cell distribution in the larger brain. Now that therapeutic success has proven to be feasible in small animal models, future efforts will need to be directed to enhance global cell delivery and migration to make bench-to-bedside translation a reality. © 2017 Wiley Periodicals, Inc.

  13. Recent Advances in Monoclonal Antibody Therapies for Multiple Sclerosis

    Science.gov (United States)

    Stavropoulos, Nikolaos; Wittenberg, Nathan J.; Dasari, Harika; Abdelrahim, Murtada A.; Henley, John R.; Oh, Sang-Hyun; Warrington, Arthur E.; Rodriguez, Moses

    2016-01-01

    Introduction Multiple sclerosis (MS) is the most common chronic inflammatory, demyelinating disease of the CNS and results in neurological disability. Existing immunomodulatory and immunosuppressive approaches lower the number of relapses but do not cure or reverse existing deficits nor improve long-term disability in MS patients. Areas Covered Monogenic antibodies were described as treatment options for MS, however the immunogenicity of mouse antibodies hampered the efficacy of potential therapeutics in humans. Availability of improved antibody production technologies resulted in a paradigm shift in MS treatment strategies. In this review, an overview of immunotherapies for MS that use conventional monoclonal antibodies reactive to immune system and their properties and mechanisms of action will be discussed, including recent advances in MS therapeutics and highlight natural autoantibodies (NAbs) that directly target CNS cells. Expert Opinion Recent challenges for MS therapy are the identification of relevant molecular and cellular targets, time frame of treatment, and antibody toxicity profiles to identify safe treatment options for MS patients. The application of monoclonal antibody therapies with better biological efficacy associated with minimum side effects possesses huge clinical potential. Advances in monoclonal antibody technologies that directly target cells of nervous system may promote the CNS regeneration field from bench to bedside. PMID:26914737

  14. Visualizing liver anatomy, physiology and pharmacology using multiphoton microscopy.

    Science.gov (United States)

    Wang, Haolu; Liang, Xiaowen; Gravot, Germain; Thorling, Camilla A; Crawford, Darrell H G; Xu, Zhi Ping; Liu, Xin; Roberts, Michael S

    2017-01-01

    Multiphoton microscopy (MPM) has become increasingly popular and widely used in both basic and clinical liver studies over the past few years. This technology provides insights into deep live tissues with less photobleaching and phototoxicity, which helps us to better understand the cellular morphology, microenvironment, immune responses and spatiotemporal dynamics of drugs and therapeutic cells in the healthy and diseased liver. This review summarizes the principles, opportunities, applications and limitations of MPM in hepatology. A key emphasis is on the use of fluorescence lifetime imaging (FLIM) to add additional quantification and specificity to the detection of endogenous fluorescent species in the liver as well as exogenous molecules and nanoparticles that are applied to the liver in vivo. We anticipate that in the near future MPM-FLIM will advance our understanding of the cellular and molecular mechanisms of liver diseases, and will be evaluated from bench to bedside, leading to real-time histology of human liver diseases. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Review on patents for mechanical stimulation of articular cartilage tissue engineering

    NARCIS (Netherlands)

    Donkelaar, van C.C.; Schulz, R.M.

    2008-01-01

    To repair articular cartilage defects in osteoarthritic patients with three-dimensional tissue engineered chondrocyte grafts, requires the formation of new cartilage with sufficient mechanical properties. The premise is that mechanical stimulation during the culturing process is necessary to reach

  16. Review of the Book “Defense Mechanisms. Coping Strategies. Self-Regulation”

    Directory of Open Access Journals (Sweden)

    Stoil Mavrodiev

    2012-10-01

    Full Text Available This book deals with coping strategies and defense mechanisms as two kinds of self-regulation of human behaviour. The defense mechanisms are described with some examples of fiction books.

  17. Arbuscular mycorrhizal fungi for the biocontrol of plant-parasitic nematodes: a review of the mechanisms involved

    Directory of Open Access Journals (Sweden)

    Nele eSchouteden

    2015-11-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF are obligate root symbionts that can protect their host plant against biotic stress factors such as plant parasitic nematode (PPN infection. PPN consist of a wide range of species with different life styles that can cause major damage in many important crops worldwide. Various mechanisms have been proposed to play a role in the biocontrol effect of AMF against PPN. This review presents an overview of the different mechanisms that have been proposed, and discusses into more detail the plausibility of their involvement in the biocontrol against PPN specifically. The proposed mechanisms include enhanced plant tolerance, direct competition for nutrients and space, induced systemic resistance (ISR and altered rhizosphere interactions. Recent studies have emphasized the importance of ISR in biocontrol and are increasingly placing rhizosphere effects on the foreground as well, both of which will be the focal point of this review. Though AMF are not yet widely used in conventional agriculture, recent data help to develop a better insight into the modes of action, which will eventually lead towards future field applications of AMF against PPN. The scientific community has entered an exciting era that provide the tools to actually unravel the underlying molecular mechanisms, making this a timely opportunity for a review of our current knowledge and the challenges ahead.

  18. Arbuscular Mycorrhizal Fungi for the Biocontrol of Plant-Parasitic Nematodes: A Review of the Mechanisms Involved.

    Science.gov (United States)

    Schouteden, Nele; De Waele, Dirk; Panis, Bart; Vos, Christine M

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate root symbionts that can protect their host plant against biotic stress factors such as plant-parasitic nematode (PPN) infection. PPN consist of a wide range of species with different life styles that can cause major damage in many important crops worldwide. Various mechanisms have been proposed to play a role in the biocontrol effect of AMF against PPN. This review presents an overview of the different mechanisms that have been proposed, and discusses into more detail the plausibility of their involvement in the biocontrol against PPN specifically. The proposed mechanisms include enhanced plant tolerance, direct competition for nutrients and space, induced systemic resistance (ISR) and altered rhizosphere interactions. Recent studies have emphasized the importance of ISR in biocontrol and are increasingly placing rhizosphere effects on the foreground as well, both of which will be the focal point of this review. Though AMF are not yet widely used in conventional agriculture, recent data help to develop a better insight into the modes of action, which will eventually lead toward future field applications of AMF against PPN. The scientific community has entered an exciting era that provides the tools to actually unravel the underlying molecular mechanisms, making this a timely opportunity for a review of our current knowledge and the challenges ahead.

  19. Arbuscular Mycorrhizal Fungi for the Biocontrol of Plant-Parasitic Nematodes: A Review of the Mechanisms Involved

    Science.gov (United States)

    Schouteden, Nele; De Waele, Dirk; Panis, Bart; Vos, Christine M.

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate root symbionts that can protect their host plant against biotic stress factors such as plant-parasitic nematode (PPN) infection. PPN consist of a wide range of species with different life styles that can cause major damage in many important crops worldwide. Various mechanisms have been proposed to play a role in the biocontrol effect of AMF against PPN. This review presents an overview of the different mechanisms that have been proposed, and discusses into more detail the plausibility of their involvement in the biocontrol against PPN specifically. The proposed mechanisms include enhanced plant tolerance, direct competition for nutrients and space, induced systemic resistance (ISR) and altered rhizosphere interactions. Recent studies have emphasized the importance of ISR in biocontrol and are increasingly placing rhizosphere effects on the foreground as well, both of which will be the focal point of this review. Though AMF are not yet widely used in conventional agriculture, recent data help to develop a better insight into the modes of action, which will eventually lead toward future field applications of AMF against PPN. The scientific community has entered an exciting era that provides the tools to actually unravel the underlying molecular mechanisms, making this a timely opportunity for a review of our current knowledge and the challenges ahead. PMID:26635750

  20. A Mini Review on Nanocarbon-Based 1D Macroscopic Fibers:Assembly Strategies and Mechanical Properties

    Institute of Scientific and Technical Information of China (English)

    Liang Kou; Yingjun Liu; Cheng Zhang; Le Shao; Zhanyuan Tian; Zengshe Deng; Chao Gao

    2017-01-01

    Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and twodimensional graphene both possess remarkable mechanical properties. In the past years, a large amount of work have been done by using CNTs or graphene as building blocks for constructing novel, macroscopic, mechanically strong fibrous materials. In this review, we summarize the assembly approaches of CNT-based fibers and graphene-based fibers in chronological order, respectively. The mechanical performances of these fibrous materials are compared, and the critical influences on the mechanical properties are discussed. Personal perspectives on the fabrication methods of CNT-and graphene-based fibers are further presented.

  1. [Possible changes in energy-minimizer mechanisms of locomotion due to chronic low back pain - a literature review].

    Science.gov (United States)

    de Carvalho, Alberito Rodrigo; Andrade, Alexandro; Peyré-Tartaruga, Leonardo Alexandre

    2015-01-01

    One goal of the locomotion is to move the body in the space at the most economical way possible. However, little is known about the mechanical and energetic aspects of locomotion that are affected by low back pain. And in case of occurring some damage, little is known about how the mechanical and energetic characteristics of the locomotion are manifested in functional activities, especially with respect to the energy-minimizer mechanisms during locomotion. This study aimed: a) to describe the main energy-minimizer mechanisms of locomotion; b) to check if there are signs of damage on the mechanical and energetic characteristics of the locomotion due to chronic low back pain (CLBP) which may endanger the energy-minimizer mechanisms. This study is characterized as a narrative literature review. The main theory that explains the minimization of energy expenditure during the locomotion is the inverted pendulum mechanism, by which the energy-minimizer mechanism converts kinetic energy into potential energy of the center of mass and vice-versa during the step. This mechanism is strongly influenced by spatio-temporal gait (locomotion) parameters such as step length and preferred walking speed, which, in turn, may be severely altered in patients with chronic low back pain. However, much remains to be understood about the effects of chronic low back pain on the individual's ability to practice an economic locomotion, because functional impairment may compromise the mechanical and energetic characteristics of this type of gait, making it more costly. Thus, there are indications that such changes may compromise the functional energy-minimizer mechanisms. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

  2. Current understanding of the driving mechanisms for spatiotemporal variations of atmospheric speciated mercury: a review

    Directory of Open Access Journals (Sweden)

    H. Mao

    2016-10-01

    Full Text Available Atmospheric mercury (Hg is a global pollutant and thought to be the main source of mercury in oceanic and remote terrestrial systems, where it becomes methylated and bioavailable; hence, atmospheric mercury pollution has global consequences for both human and ecosystem health. Understanding of spatial and temporal variations of atmospheric speciated mercury can advance our knowledge of mercury cycling in various environments. This review summarized spatiotemporal variations of total gaseous mercury or gaseous elemental mercury (TGM/GEM, gaseous oxidized mercury (GOM, and particulate-bound mercury (PBM in various environments including oceans, continents, high elevation, the free troposphere, and low to high latitudes. In the marine boundary layer (MBL, the oxidation of GEM was generally thought to drive the diurnal and seasonal variations of TGM/GEM and GOM in most oceanic regions, leading to lower GEM and higher GOM from noon to afternoon and higher GEM during winter and higher GOM during spring–summer. At continental sites, the driving mechanisms of TGM/GEM diurnal patterns included surface and local emissions, boundary layer dynamics, GEM oxidation, and for high-elevation sites mountain–valley winds, while oxidation of GEM and entrainment of free tropospheric air appeared to control the diurnal patterns of GOM. No pronounced diurnal variation was found for Tekran measured PBM at MBL and continental sites. Seasonal variations in TGM/GEM at continental sites were attributed to increased winter combustion and summertime surface emissions, and monsoons in Asia, while those in GOM were controlled by GEM oxidation, free tropospheric transport, anthropogenic emissions, and wet deposition. Increased PBM at continental sites during winter was primarily due to local/regional coal and wood combustion emissions. Long-term TGM measurements from the MBL and continental sites indicated an overall declining trend. Limited measurements suggested TGM

  3. Current understanding of the driving mechanisms for spatiotemporal variations of atmospheric speciated mercury: a review

    Science.gov (United States)

    Mao, Huiting; Cheng, Irene; Zhang, Leiming

    2016-10-01

    Atmospheric mercury (Hg) is a global pollutant and thought to be the main source of mercury in oceanic and remote terrestrial systems, where it becomes methylated and bioavailable; hence, atmospheric mercury pollution has global consequences for both human and ecosystem health. Understanding of spatial and temporal variations of atmospheric speciated mercury can advance our knowledge of mercury cycling in various environments. This review summarized spatiotemporal variations of total gaseous mercury or gaseous elemental mercury (TGM/GEM), gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM) in various environments including oceans, continents, high elevation, the free troposphere, and low to high latitudes. In the marine boundary layer (MBL), the oxidation of GEM was generally thought to drive the diurnal and seasonal variations of TGM/GEM and GOM in most oceanic regions, leading to lower GEM and higher GOM from noon to afternoon and higher GEM during winter and higher GOM during spring-summer. At continental sites, the driving mechanisms of TGM/GEM diurnal patterns included surface and local emissions, boundary layer dynamics, GEM oxidation, and for high-elevation sites mountain-valley winds, while oxidation of GEM and entrainment of free tropospheric air appeared to control the diurnal patterns of GOM. No pronounced diurnal variation was found for Tekran measured PBM at MBL and continental sites. Seasonal variations in TGM/GEM at continental sites were attributed to increased winter combustion and summertime surface emissions, and monsoons in Asia, while those in GOM were controlled by GEM oxidation, free tropospheric transport, anthropogenic emissions, and wet deposition. Increased PBM at continental sites during winter was primarily due to local/regional coal and wood combustion emissions. Long-term TGM measurements from the MBL and continental sites indicated an overall declining trend. Limited measurements suggested TGM/GEM increasing from the

  4. The crucifixion of Jesus: review of hypothesized mechanisms of death and implications of shock and trauma-induced coagulopathy.

    Science.gov (United States)

    Bergeron, Joseph W

    2012-04-01

    The crucifixion of Jesus is arguably the most well-known and controversial execution in history. Christian faithful, dating back to the time of Jesus, have believed that Jesus was executed by crucifixion and later returned physically to life again. Others have questioned whether Jesus actually died by crucifixion, at all. From review of medical literature, physicians have failed to agree on a specific mechanism of Jesus' death. A search of Medline/Pubmed was completed with respect to crucifixion, related topics, and proposed mechanisms of Jesus' death. Several hypotheses for the mechanism of Jesus' death have been presented in medical literature, including 1) Pulmonary embolism 2) Cardiac rupture 3) Suspension trauma 4) Asphyxiation 5) Fatal stab wound, and 6) Shock. Each proposed mechanism of Jesus' death will be reviewed. The events of Jesus' execution are described, as they are pertinent to development of shock. Traumatic shock complicated by trauma-induced coagulopathy is proposed as a contributing factor, and possibly the primary mechanism, of Jesus' death by crucifixion. Copyright © 2011 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  5. Research Review: Dopamine Transfer Deficit: A Neurobiological Theory of Altered Reinforcement Mechanisms in ADHD

    Science.gov (United States)

    Tripp, Gail; Wickens, Jeff R.

    2008-01-01

    This review considers the hypothesis that changes in dopamine signalling might account for altered sensitivity to positive reinforcement in children with ADHD. The existing evidence regarding dopamine cell activity in relation to positive reinforcement is reviewed. We focus on the anticipatory firing of dopamine cells brought about by a transfer…

  6. Vanadium alloys for structural applications in fusion systems: A review of vanadium alloy mechanical and physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, B.A.; Smith, D.L.

    1991-12-16

    The current knowledge is reviewed on (1) the effects of neutron irradiation on tensile strength and ductility, ductile-brittle transition temperature, creep, fatigue, and swelling of vanadium-base alloys, (2) the compatibility of vanadium-base alloys with liquid lithium, water, and helium environments, and (3) the effects of hydrogen and helium on the physical and mechanical properties of vanadium alloys that are potential candidates for structural materials applications in fusion systems. Also, physical and mechanical properties issues are identified that have not been adequately investigated in order to qualify a vanadium-base alloy for the structural material in experimental fusion devices and/or in fusion reactors.

  7. Vanadium alloys for structural applications in fusion systems: A review of vanadium alloy mechanical and physical properties

    International Nuclear Information System (INIS)

    Loomis, B.A.; Smith, D.L.

    1991-01-01

    The current knowledge is reviewed on (1) the effects of neutron irradiation on tensile strength and ductility, ductile-brittle transition temperature, creep, fatigue, and swelling of vanadium-base alloys, (2) the compatibility of vanadium-base alloys with liquid lithium, water, and helium environments, and (3) the effects of hydrogen and helium on the physical and mechanical properties of vanadium alloys that are potential candidates for structural materials applications in fusion systems. Also, physical and mechanical properties issues are identified that have not been adequately investigated in order to qualify a vanadium-base alloy for the structural material in experimental fusion devices and/or in fusion reactors

  8. Follow the Money: A Comprehensive Review of the Funding Mechanisms of Voucher Programs in Six Cases. Informing Policy & Improving Practice Research Brief

    Science.gov (United States)

    Stewart, Molly S.; Moon, Jodi S.

    2016-01-01

    This comprehensive review is part of a three-part report, Follow the "Money: A Detailed Analysis of the Funding Mechanisms of Voucher Programs in Six Cases"; this review contains the cross-case analysis and findings of the funding mechanisms of voucher programs across five states (Arizona, Indiana, Louisiana, Ohio, and Wisconsin) and the…

  9. Bioremediation mechanisms of combined pollution of PAHs and heavy metals by bacteria and fungi: A mini review.

    Science.gov (United States)

    Liu, Shao-Heng; Zeng, Guang-Ming; Niu, Qiu-Ya; Liu, Yang; Zhou, Lu; Jiang, Lu-Hua; Tan, Xiao-Fei; Xu, Piao; Zhang, Chen; Cheng, Min

    2017-01-01

    In recent years, knowledge in regard to bioremediation of combined pollution of polycyclic aromatic hydrocarbons (PAHs) and heavy metals by bacteria and fungi has been widely developed. This paper reviews the species of bacteria and fungi which can tackle with various types of PAHs and heavy metals entering into environment simultaneously or successively. Microbial activity, pollutants bioavailability and environmental factors (e.g. pH, temperature, low molecular weight organic acids and humic acids) can all affect the bioremediation of PAHs and heavy metals. Moreover, this paper summarizes the remediation mechanisms of PAHs and heavy metals by microbes via elucidating the interaction mechanisms of heavy metals with heavy metals, PAHs/PAHs metabolites with PAHs and PAHs with heavy metals. Based on the above reviews, this paper also discusses the potential research needs for this field. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Exploring Communication Challenges Between Nurses and Mechanically Ventilated Patients in the Intensive Care Unit: A Structured Review.

    Science.gov (United States)

    Dithole, Kefalotse; Sibanda, Sambulelwe; Moleki, Mary M; Thupayagale-Tshweneagae, Gloria

    2016-06-01

    Mechanical ventilation is a necessary procedure for patients with a range of illnesses and conditions. Mechanical ventilation affects voice production, leaving patients unable to communicate their needs with nurses and family. The communication difficulty causes distress, frustration, and anger if not attended to. This structured review sought to identify communication challenges which exist between nurses and mechanically ventilated patients in intensive care units (ICU) and hence explore possible solutions to improve these communication challenges. A electronic search of MEDLINE, CINAHL, and PsycINFO was conducted to identify relevant literature on nurse-patient communication challenges in the ICU published between January 2005 and December 2014. Studies meeting the inclusion criteria were retrieved in full, reviewed, and study quality assessed. Six studies were identified for inclusion in the review. Analysis identified five core influences on communication in the ICU: patient's consciousness level, nature of nurse-patient interactions, communication methods, staff skills and perceptions, and the intensive care physical environment. An evidence-based and multifactorial communication intervention encompassing staff skills development and training, development of relevant patient materials or devices and collaborations with relevant health professionals like speech and language therapists has the potential to improve nurse-patient communication in the ICU and hence improve patient outcomes. © 2016 Sigma Theta Tau International.

  11. Preliminary experience on early mechanical recanalization of middle cerebral artery for acute ischemic stroke and literature review

    International Nuclear Information System (INIS)

    Bai Weixing; Li Tianxiao; Zhu Liangfu; Xue Jiangyu; Wang Ziliang

    2012-01-01

    Objective: To evaluate the feasibility,efficacy and complication of early middle cerebral artery (MCA) mechanical recanalization (MER) for treatment of acute ischemic stroke. Methods: Seven cases undergone MER of MCA for the treatment of acute cerebral infarct were retrospectively reviewed and analyzed, including the etiology, mechanism, Qureshi grading scale, location and size of infarcts, NIHSS score of pre and post procedure, endovascular technique and complications. Referring to the literature, the indications of MCA recanalization were further identified. Results: A total of 7 cases with mean age of 48 yrs were reviewed, which included 3 cases of atherosclerotic thrombosis and 4 embolic cases with pre NIHSS score ranging from 3 to 22. Mechanical recanalization succeeded in 6 cases, but 2 cases of cardiogenic embolism died of intracranial hemorrhage postoperatively. Favorable clinical outcomes were achieved in 4 cases whereas 1 deteriorated. Overall complications seemed to be consistent with literatures reviewed. Conclusions: Early MER of MCA may benefit to a certain subset of acute ischemia stroke patients, however, embolic cases, elder patients and those with severe neurologic deficits are often accompanied by higher complications and unfavorable outcome. (authors)

  12. Copyrolysis of Biomass and Coal: A Review of Effects of Copyrolysis Parameters, Product Properties, and Synergistic Mechanisms

    Science.gov (United States)

    2016-01-01

    Concerns in the last few decades regarding the environmental and socioeconomic impacts of the dependence on fossil fuels have resulted in calls for more renewable and alternative energy sources. This has led to recent interest in copyrolysis of biomass and coal. Numerous reviews have been found related to individual pyrolysis of coal and biomass. This review deals mainly with the copyrolysis of coal and biomass and then compares their results with those obtained using coal and biomass pyrolysis in detail. It is controversial whether there are synergistic or additive behaviours when coal and biomass are blended during copyrolysis. In this review, the effects of reaction parameters such as feedstock types, blending ratio, heating rate, temperature, and reactor types on the occurrence of synergy are discussed. Also, the main properties of the copyrolytic products are pointed out. Some possible synergistic mechanisms are also suggested. Additionally, several outlooks based on studies in the literature are also presented in this paper. PMID:27722171

  13. The molecular mechanisms of action of PPAR-γ agonists in the treatment of corneal alkali burns (Review)

    Science.gov (United States)

    Zhou, Hongyan; Zhang, Wensong; Bi, Miaomiao; Wu, Jie

    2016-01-01

    Corneal alkali burns (CAB) are characterized by injury-induced inflammation, fibrosis and neovascularization (NV), and may lead to blindness. This review evaluates the current knowledge of the molecular mechanisms responsible for CAB. The processes of cytokine production, chemotaxis, inflammatory responses, immune response, cell signal transduction, matrix metalloproteinase production and vascular factors in CAB are discussed. Previous evidence indicates that peroxisome proliferator-activated receptor γ (PPAR-γ) agonists suppress immune responses, inflammation, corneal fibrosis and NV. This review also discusses the role of PPAR-γ as an anti-inflammatory, anti-fibrotic and anti-angiogenic agent in the treatment of CAB, as well as the potential role of PPAR-γ in the pathological process of CAB. There have been numerous studies evaluating the clinical profiles of CAB, and the aim of this systematic review was to summarize the evidence regarding the treatment of CAB with PPAR-γ agonists. PMID:27499172

  14. Drugs associated with teratogenic mechanisms. Part II : a literature review of the evidence on human risks

    NARCIS (Netherlands)

    van Gelder, Marleen M. H. J.; de Jong-van den Berg, Lolkje T. W.; Roeleveld, Nel

    What is the current state of knowledge on the human risks of drugs suspected to be associated with teratogenic mechanisms? Evidence for the presence or absence of human risks of birth defects is scarce or non-existent for the majority of drugs associated with teratogenic mechanisms. Medical drugs

  15. Critical review: Radionuclide transport, sediment transport, and water quality mathematical modeling; and radionuclide adsorption/desorption mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Y.; Serne, R.J.; Arnold, E.M.; Cowan, C.E.; Thompson, F.L. [Pacific Northwest Lab., Richland, WA (United States)

    1981-01-01

    This report describes the results of a detailed literature review of radionuclide transport models applicable to rivers, estuaries, coastal waters, the Great Lakes, and impoundments. Some representatives sediment transport and water quality models were also reviewed to evaluate if they can be readily adapted to radionuclide transport modeling. The review showed that most available transport models were developed for dissolved radionuclide in rivers. These models include the mechanisms of advection, dispersion, and radionuclide decay. Since the models do not include sediment and radionuclide interactions, they are best suited for simulating short-term radionuclide migration where: (1) radionuclides have small distribution coefficients; (2) sediment concentrations in receiving water bodies are very low. Only 5 of the reviewed models include full sediment and radionuclide interactions: CHMSED developed by Fields; FETRA SERATRA, and TODAM developed by Onishi et al, and a model developed by Shull and Gloyna. The 5 models are applicable to cases where: (1) the distribution coefficient is large; (2) sediment concentrations are high; or (3) long-term migration and accumulation are under consideration. The report also discusses radionuclide absorption/desorption distribution ratios and addresses adsorption/desorption mechanisms and their controlling processes for 25 elements under surface water conditions. These elements are: Am, Sb, C, Ce, Cm, Co, Cr, Cs, Eu, I, Fe, Mn, Np, P, Pu, Pm, Ra, Ru, Sr, Tc, Th, {sup 3}H, U, Zn and Zr.

  16. Extensor Mechanism Disruption after Total Knee Arthroplasty: A Case Series and Review of Literature.

    Science.gov (United States)

    Vaishya, Raju; Agarwal, Amit Kumar; Vijay, Vipul

    2016-02-04

    Extensor mechanism disruption following total knee arthroplasty (TKA) is a rare but devastating complication. These patients may require revision of the implants, but even then, it may not be possible to restore the normal function of the knee after the disruption. The patterns of extensor mechanism disruption can broadly be classified into three types: suprapatellar (quadriceps tendon rupture), transpatellar (patellar fracture), or infrapatellar (patellar tendon rupture). Infrapatellar tendon ruptures are the worst injuries, as they carry maximum morbidity and are challenging to manage. The disruption of the extensor mechanism may occur either intra-operatively or in the immediate postoperative period due to an injury. The treatment of extensor mechanism complications after TKA may include either nonsurgical management or surgical intervention in the form of primary repair or reconstruction with autogenous, allogeneic, or synthetic substitutes. We have provided an algorithm for the management of extensor mechanism disruption after TKA.

  17. Carbon capture in vehicles : a review of general support, available mechanisms, and consumer-acceptance issues.

    Science.gov (United States)

    2012-05-01

    This survey of the feasibility of introducing carbon capture and storage (CCS) into light vehicles : started by reviewing the level of international support for CCS in general. While there have been : encouraging signs that CCS is gaining acceptance ...

  18. From evidence based medicine to mechanism based medicine : Reviewing the role of pharmacogenetics

    NARCIS (Netherlands)

    Wilffert, Bob; Swen, Jesse; Mulder, Hans; Touw, Daan; Maitland-Van der Zee, Anke-Hilse; Deneer, Vera

    Aim of the review The translation of evidence based medicine to a specific patient presents a considerable challenge. We present by means of the examples nortriptyline, tramadol, clopidogrel, coumarins, abacavir and antipsychotics the discrepancy between available pharmacogenetic information and its

  19. From evidence based medicine to mechanism based medicine. Reviewing the role of pharmacogenetics

    NARCIS (Netherlands)

    Wilffert, Bob; Swen, Jesse; Mulder, Hans; Touw, Daan; Maitland-Van der Zee, Anke-Hilse; Deneer, Vera

    Aim of the review The translation of evidence based medicine to a specific patient presents a considerable challenge. We present by means of the examples nortriptyline, tramadol, clopidogrel, coumarins, abacavir and antipsychotics the discrepancy between available pharmacogenetic information and its

  20. Peer Review and Reflective Teaching Practices: An Effective Mechanism for Quality Enhancement in Higher Education

    OpenAIRE

    Raj, Sony Jalarajan; Massey, Susan R.; Jose, Soumya

    2017-01-01

    Quality education and teacher accountability are predominant issues generating apprehension in higher education. Traditional methods of evaluation are giving way to more contemporary methods. One technique that is being implemented in many universities throughout the world that provides feedback and improves pedagogical approaches is a formative and collaborative process known as peer review of teaching (PRT). Review of the literature included 34 studies which identified five themes that offe...

  1. Linking governance mechanisms to health outcomes: a review of the literature in low- and middle-income countries.

    Science.gov (United States)

    Ciccone, Dana Karen; Vian, Taryn; Maurer, Lydia; Bradley, Elizabeth H

    2014-09-01

    We conducted a synthesis of peer-reviewed literature to shed light on links between governance mechanisms and health outcomes in low- and middle-income countries. Our review yielded 30 studies, highlighting four key governance mechanisms by which governance may influence health outcomes in these settings: Health system decentralization that enables responsiveness to local needs and values; health policymaking that aligns and empowers diverse stakeholders; enhanced community engagement; and strengthened social capital. Most, but not all, studies found a positive association between governance and health. Additionally, the nature of the association between governance mechanisms and health differed across studies. In some studies (N = 9), the governance effect was direct and positive, while in others (N = 5), the effect was indirect or modified by contextual factors. In still other studies (N = 4), governance was found to have a moderating effect, indicating that governance mechanisms influenced other system processes or structures that improved health. The remaining studies reported mixed findings about the association between governance and health (N = 6), no association between governance and health (N = 4), or had inconclusive results (N = 2). Further exploration is needed to fully understand the relationship between governance and health and to inform the design and delivery of evidence-based, effective governance interventions around the world. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Improvement of Emergency Management Mechanism of Public Health Crisis in Rural China: A Review Article.

    Science.gov (United States)

    Hu, Jiaxiang; Chen, Chao; Kuai, Tingting

    2018-02-01

    With the rapid development of social economy in China, various public health emergencies frequently occur. Such emergencies cause a serious threat to human health and public safety, especially in rural China. Owing to flaws in emergency management mechanism and policy, the government is not capable to effectively deal with public health emergencies. Therefore, this study aimed to discuss the path to improve the emergency management mechanism for public health emergency in rural China. This study was conducted in 2017 to detect the emergency management mechanism of public health crisis (EMMPHC) in Rural China. Data were collected using the following keywords: Rural China, public health emergency, emergency management mechanism, organization mechanism, operation mechanism in the databases of PubMed, Scopus, Web of Science, and CNKI. EMMPHC in rural China can be enhanced from the following three aspects. First, a permanent institution for rural emergency management with public health management function is established. Second, the entire process of emergency management mechanism, including the stages of pre-disaster, disaster, and post-disaster, is improved. Finally, investment in rural public health is increased, and an adequate reserve system for emergency resources is formed. The new path of EMMPHC in rural China can effectively help the local government accomplish the dispatch capability in public health emergency, and it has important research significance for the protection of public health and social stability of residents in rural China.

  3. Antiplatelet and anticoagulation regimen in patients with mechanical valve undergoing PCI - State-of-the-art review.

    Science.gov (United States)

    Gajanana, Deepakraj; Rogers, Toby; Iantorno, Micaela; Buchanan, Kyle D; Ben-Dor, Itsik; Pichard, Augusto D; Satler, Lowell F; Torguson, Rebecca; Okubagzi, Petros G; Waksman, Ron

    2018-04-02

    A common clinical dilemma regarding treatment of patients with a mechanical valve is the need for concomitant antiplatelet therapy for a variety of reasons, referred to as triple therapy. Triple therapy is when a patient is prescribed aspirin, a P2Y12 antagonist, and an oral anticoagulant. Based on the totality of the available evidence, best practice in 2017 for patients with mechanical valves undergoing percutaneous coronary intervention (PCI) is unclear. Furthermore, the optimal duration of dual antiplatelet therapy after PCI is evolving. With better valve designs that are less thrombogenic, the thromboembolic risks can be reduced at a lower international normalized ratio target, thus decreasing the bleeding risk. This review will offer an in-depth survey of current guidelines, current evidence, suggested approach for PCI in this cohort, and future studies regarding mechanical valve patients undergoing PCI. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Mechanical design and performance specifications of anthropomorphic prosthetic hands: a review.

    Science.gov (United States)

    Belter, Joseph T; Segil, Jacob L; Dollar, Aaron M; Weir, Richard F

    2013-01-01

    In this article, we set forth a detailed analysis of the mechanical characteristics of anthropomorphic prosthetic hands. We report on an empirical study concerning the performance of several commercially available myoelectric prosthetic hands, including the Vincent, iLimb, iLimb Pulse, Bebionic, Bebionic v2, and Michelangelo hands. We investigated the finger design and kinematics, mechanical joint coupling, and actuation methods of these commercial prosthetic hands. The empirical findings are supplemented with a compilation of published data on both commercial and prototype research prosthetic hands. We discuss numerous mechanical design parameters by referencing examples in the literature. Crucial design trade-offs are highlighted, including number of actuators and hand complexity, hand weight, and grasp force. Finally, we offer a set of rules of thumb regarding the mechanical design of anthropomorphic prosthetic hands.

  5. Review of the inverse scattering problem at fixed energy in quantum mechanics

    Science.gov (United States)

    Sabatier, P. C.

    1972-01-01

    Methods of solution of the inverse scattering problem at fixed energy in quantum mechanics are presented. Scattering experiments of a beam of particles at a nonrelativisitic energy by a target made up of particles are analyzed. The Schroedinger equation is used to develop the quantum mechanical description of the system and one of several functions depending on the relative distance of the particles. The inverse problem is the construction of the potentials from experimental measurements.

  6. The effect of grinding on the mechanical behavior of Y-TZP ceramics: A systematic review and meta-analyses.

    Science.gov (United States)

    Pereira, G K R; Fraga, S; Montagner, A F; Soares, F Z M; Kleverlaan, C J; Valandro, L F

    2016-10-01

    The aim of this study was to systematically review the literature to assess the effect of grinding on the mechanical properties, structural stability and superficial characteristics of Y-TZP ceramics. The MEDLINE via PubMed and Web of Science (ISI - Web of Knowledge) electronic databases were searched with included peer-reviewed publications in English language and with no publication year limit. From 342 potentially eligible studies, 73 were selected for full-text analysis, 30 were included in the systematic review with 20 considered in the meta-analysis. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Statistical analyses were performed using RevMan 5.1, with random effects model, at a significance level of 0.05. A descriptive analysis considering phase transformation, Y-TZP grain size, Vickers hardness, residual stress and aging of all included studies were executed. Four outcomes were considered in the meta-analyses (factor: grinding x as-sintered) in global and subgroups analyses (grinding tool, grit-size and cooling) for flexural strength and roughness (Ra) data. A significant difference (pgrinding; subgroup analyses revealed that different parameters also lead to different effects on roughness. High heterogeneity was found in some comparisons. Generally grinding promotes decrease in strength and increase in roughness of Y-TZP ceramics. However, the use of a grinding tool that allows greater accuracy of the movement (i.e. contra angle hand-pieces coupled to slowspeed turbines), small grit size (<50μm) and the use of plenty coolant seem to be the main factors to decrease the defect introduction and allow the occurrence of the toughening transformation mechanism, decreasing the risk of deleterious impact on Y-TZP mechanical properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Review of the physical and mechanical properties and potential applications of the B2 compound NiAl: Unabridged version of a paper published in International materials review

    Science.gov (United States)

    Noebe, Ronald D.; Bowman, Randy R.; Nathal, Michael V.

    1992-01-01

    Considerable work has been performed on NiAl over the last three decades, with an extremely rapid growth in research on this intermetallic occurring in the last few years due to recent interest in this material for electronic and high temperature structural applications. However, many physical properties and the controlling fracture and deformation mechanisms over certain temperature regimes are still in question. Part of this problem lies in the incomplete characterization of many of the alloys previously investigated. Fragmentary data on processing conditions, chemistry, microstructure and the apparent difficulty in accurately measuring composition has made direct comparison between individual studies sometimes tenuous. Therefore, the purpose of this review is to summarize all available mechanical and pertinent physical properties on NiAl, stressing the most recent investigations, in an attempt to understand the behavior of NiAl and its alloys over a broad temperature range.

  8. Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action.

    Science.gov (United States)

    Peck, Rebecca; Rella, Walter; Tudela, Julio; Aznar, Justo; Mozzanega, Bruno

    2016-02-01

    Recent studies have identified that levonorgestrel administered orally in emergency contraception (LNG-EC) is only efficacious when taken before ovulation. However, the drug does not consistently prevent follicular rupture or impair sperm function. The present systematic review is performed to analyze and more precisely define the extent to which pre-fertilization mechanisms of action may explain the drug's efficacy in pregnancy avoidance. We also examine the available evidence to determine if pre-ovulatory drug administration may be associated with post-fertilization effects. The mechanism of action of LNG-EC is reviewed. The drug has no ability to alter sperm function at doses used in vivo and has limited ability to suppress ovulation. Our analysis estimates that the drug's ovulatory inhibition potential could prevent less than 15 percent of potential conceptions, thus making a pre-fertilization mechanism of action significantly less likely than previously thought. Luteal effects (such as decreased progesterone, altered glycodelin levels, and shortened luteal phase) present in the literature may suggest a pre-ovulatory induced post-fertilization drug effect. Plan B is the most widely used emergency contraceptive available. It is important for patients and physicians to clearly understand the drug's mechanism of action (MOA). The drug was originally thought to work by preventing fertilization. Recent research has cast doubt on this. Our review of the research suggests that it could act in a pre-fertilization capacity, and we estimate that it could prevent ovulation in only 15 percent or less of cases. The drug has no ability to alter sperm function and limited ability to suppress ovulation. Further, data suggest that when administered pre-ovulation, it may have a post-fertilization MOA.

  9. A Review of Recovery Mechanisms of Ionically Modified Waterflood in Carbonate Reservoirs

    DEFF Research Database (Denmark)

    Sohal, Muhammad Adeel Nassar; Thyne, Geoffrey; Søgaard, Erik Gydesen

    2016-01-01

    . This process has been evaluated as a wettability-modifying agent in carbonates and captured the global research focus in water-based enhanced oil recovery (EOR) methods. This paper provides a comprehensive review of the published research to speed the process of further investigations in this field. The review......Advanced water flooding is a process in which the ionic strength as well as the ionic composition of the injected water is tuned to improve the oil recovery. It has been observed in field trials and in lab core flooding experiments; advanced water flooding has the potential to recover additional oil...

  10. [Pontomedullary lacerations and concomitant injuries: a review of possible underlying mechanisms].

    Science.gov (United States)

    Živković, Vladimir; Nikolić, Slobodan

    2013-01-01

    Anatomically, brainstem is constituted of medulla oblongata, pons and mesencephalon. Traumatic lesions of brainstem most commonly occur on pontomedullary junction. There are several possible mechanisms of pontomedullary lacerations. The first mechanism includes impact to the chin, with or without a skull base fracture, and most often leads to this fatal injury, due to impact force transmission through the jawbone and temporomandibular joint. The second mechanism includes lateral and posterior head impacts with subsequent hinge fractures, where occurrence of pontomedullary lacerations in these cases may depend on the energy of impact, as well as on the exact position of the fracture line, but less so on the head's movement. The third mechanism includes frontoposterior hyperextension of the head, due to frontal impact, concomitant with fractures or dislocations of upper spine. In the fourth mechanism, there is an absence of direct impact to the head, due to the indirect force of action after feet or buttocks-first impact. Most of these cases are accompanied by ring fractures as well. In situations such as these, the impact force is transmitted up the spinal column and upper vertebrae, and telescopically intruded into the skull, causing brainstem laceration. The jawbone and other facial bones can act as shock absorbers, and their fracture could diminish the energy transfer towards the skull and protect the brain and brainstem from injury. In all the cases with pontomedullary laceration posterior neck dissection should be performed during the autopsy, since upper spine injuries are often associated with this type of injury.

  11. Selection of Antiepileptic Drug Polytherapy Based on Mechanisms of Action: The Evidence Reviewed

    NARCIS (Netherlands)

    Deckers, C.L.P.; Czuczwar, S.J.; Hekster, Y.A.; Keyser, A.J.M.; Kubova, H.; Meinardi, H.; Patsalos, P.N.; Renier, W.O.; Rijn, C.M. van

    2000-01-01

    Purpose: When monotherapy with antiepileptic drugs (AEDs) fails, combination therapy is tried so as to improve effectiveness, by improving either efficacy, or tolerability, or both. We have reviewed the available studies (both animal and human) on AED polytherapy to determine whether AEDs can be

  12. RODENT LEYDIG CELL TUMORIGENESIS: A REVIEW OF THE PHYSIOLOGY, PATHOLOGY, MECHANISMS, AND RELEVANCE TO HUMANS

    Science.gov (United States)

    Leydig cells (LCs) are the cells of the testis that have as their primary function the production of testosterone. LCs are a common target of compounds tested in rodent carcinogenicity bioassays. The number of reviews on Leydig cell tumors (LCTs) has increased in recent years bec...

  13. Engine Tune-up Service. Unit 6: Emission Control Systems. Review Exercise Book. Automotive Mechanics Curriculum.

    Science.gov (United States)

    Bacon, E. Miles

    This book of pretests and review exercises is designed to accompany the Engine Tune-Up Service Student Guide for Unit 6, Emission Control Systems, available separately as CE 031 220. Focus of the exercises and pretests is inspecting, testing, and servicing emission control systems. Pretests and performance checklists are provided for each of the…

  14. Engine Tune-Up Service. Unit 3: Primary Circuit. Review Exercise Book. Automotive Mechanics Curriculum.

    Science.gov (United States)

    Bacon, E. Miles

    This book of pretests and review exercises is designed to accompany the Engine Tune-Up Service Student Guide for Unit 3, Primary Circuit, available separately as CE 031 211. Focus of the exercises and pretests is testing the primary ignition circuit. Pretests and performance checklists are provided for each of the eight performance objectives…

  15. Engine Tune-up Service. Unit 2: Charging System. Review Exercise Book. Automotive Mechanics Curriculum.

    Science.gov (United States)

    Richardson, Roger L.; Bacon, E. Miles

    This book of pretests and review exercises is designed to accompany the Engine Tune-Up Service Student Guide for Unit 2, Charging System, available separately as CE 031 208. Focus of the exercises and pretests is testing the charging system. Pretests and performance checklists are provided for each of the three performance objectives contained in…

  16. Engine Tune-up Service. Unit 4: Secondary Circuit. Review Exercise Book. Automotive Mechanics Curriculum.

    Science.gov (United States)

    Bacon, E. Miles

    This book of pretests and review exercises is designed to accompany the Engine Tune-Up Service Student Guide for Unit 4, Secondary Circuit, available separately as CE 031 214. Focus of the exercises and pretests is testing and servicing the secondary ignition circuit. Pretests and performance checklists are provided for each of the seven…

  17. A review of studies of the activation of the blood coagulation mechanism in chimpanzees (Pan troglodytes)

    NARCIS (Netherlands)

    ten Cate, H.; Schenk, B. E.; Biemond, B. J.; Levi, M. [=Marcel M.; van der Poll, T.; Buller, H. R.; ten Cate, J. W.

    1994-01-01

    This paper reviews our recent studies of blood coagulation activation in the chimpanzee which were carried out employing sensitive immunoassays that measure activation markers of blood coagulation in plasma. Infused factor VIIa activated both factors IX and X in vivo; this reaction depended on the

  18. Mechanisms of Change in the Relationship between Self-Compassion, Emotion Regulation, and Mental Health: A Systematic Review.

    Science.gov (United States)

    Inwood, Elisa; Ferrari, Madeleine

    2018-04-19

    Research suggests that self-compassion may improve mental health by promoting emotion regulation (Berking & Whitley, ). This review aimed to identify studies which investigated the relationship between self-compassion, emotion regulation, and mental health in order to examine the role of emotional regulation as a mechanism of change. Searches were conducted in PsycINFO, CINAHL, Medline complete, Web of Science and Scopus databases. Inclusion criteria required publications to be: peer reviewed, published in English, contain validated measures of self-compassion and emotion regulation, and report a direct analysis on the relationship between these constructs. The search yielded five studies which met inclusion criteria. Emotion regulation significantly mediated the relationship between self-compassion and mental health. This pattern was consistent across community and clinical samples, for a range of mental health symptoms including stress, depression, and post-traumatic stress disorder. A critical limitation of the review was that all included studies used cross-sectional data, limiting interpretations regarding causation. Results provide preliminary evidence that emotion regulation may be a mechanism of change in the relationship between self-compassion and mental health. Self-compassion may be a pertinent preliminary treatment target for individuals who avoid experiences of emotions. © 2018 The International Association of Applied Psychology.

  19. Mechanical characteristic and biological behaviour of implanted and restorative bioglasses used in medicine and dentistry: A systematic review.

    Science.gov (United States)

    Lizzi, F; Villat, C; Attik, N; Jackson, P; Grosgogeat, B; Goutaudier, C

    2017-06-01

    Nowadays bioactive glasses are finding increasing applications in medical practice due to their ability to stimulate re-mineralisation. However, they are intrinsically brittle materials and the study of new compositions will open up new scenarios enhancing their mechanical properties and maintaining the high bioactivity for a broader range of applications. This systematic review aims to identify the relationship between the composition of bioactive glasses used in medical applications and their influence on the mechanical and biological properties. Various electronic databases (PubMed, Science Direct) were used for collecting articles on this subject. This research includes papers from January 2011 to March 2016. PRISMA guidelines for systematic review and meta-analysis have been used. 109 abstracts were collected and screened, 68 articles were read as relevant articles and a total of 22 papers were finally selected for this study. Most of the studies obtained enhanced mechanical properties and the conservation of bioactivity behaviours; although a lack of homogeneity in the characterization methods makes it difficult to compare data. New compositions of bioactive glasses incorporating specific ions and the addition in polymers will be the most important direction for future researches in developing new materials for medical applications and especially for dentistry. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  20. A Review of the As-Built SLM Ti-6Al-4V Mechanical Properties towards Achieving Fatigue Resistant Designs

    Directory of Open Access Journals (Sweden)

    Dylan Agius

    2018-01-01

    Full Text Available Ti-6Al-4V has been widely used in both the biomedical and aerospace industry, due to its high strength, corrosion resistance, high fracture toughness and light weight. Additive manufacturing (AM is an attractive method of Ti-6Al-4V parts’ fabrication, as it provides a low waste alternative for complex geometries. With continued progress being made in SLM technology, the influence of build layers, grain boundaries and defects can be combined to improve further the design process and allow the fabrication of components with improved static and fatigue strength in critical loading directions. To initiate this possibility, the mechanical properties, including monotonic, low and high cycle fatigue and fracture mechanical behaviour, of machined as-built SLM Ti-6Al-4V, have been critically reviewed in order to inform the research community. The corresponding crystallographic phases, defects and layer orientations have been analysed to determine the influence of these features on the mechanical behaviour. This review paper intends to enhance our understanding of how these features can be manipulated and utilised to improve the fatigue resistance of components fabricated from Ti-6Al-4V using the SLM technology.

  1. Invited review article: high-speed flexure-guided nanopositioning: mechanical design and control issues.

    Science.gov (United States)

    Yong, Y K; Moheimani, S O R; Kenton, B J; Leang, K K

    2012-12-01

    Recent interest in high-speed scanning probe microscopy for high-throughput applications including video-rate atomic force microscopy and probe-based nanofabrication has sparked attention on the development of high-bandwidth flexure-guided nanopositioning systems (nanopositioners). Such nanopositioners are designed to move samples with sub-nanometer resolution with positioning bandwidth in the kilohertz range. State-of-the-art designs incorporate uniquely designed flexure mechanisms driven by compact and stiff piezoelectric actuators. This paper surveys key advances in mechanical design and control of dynamic effects and nonlinearities, in the context of high-speed nanopositioning. Future challenges and research topics are also discussed.

  2. Kinetic bed therapy to prevent nosocomial pneumonia in mechanically ventilated patients: a systematic review and meta-analysis.

    Science.gov (United States)

    Delaney, Anthony; Gray, Hilary; Laupland, Kevin B; Zuege, Danny J

    2006-01-01

    Nosocomial pneumonia is the most important infectious complication in patients admitted to intensive care units. Kinetic bed therapy may reduce the incidence of nosocomial pneumonia in mechanically ventilated patients. The objective of this study was to investigate whether kinetic bed therapy reduces the incidence of nosocomial pneumonia and improves outcomes in critically ill mechanically ventilated patients. We searched Medline, EMBASE, CINAHL, CENTRAL, and AMED for studies, as well as reviewed abstracts of conference proceedings, bibliographies of included studies and review articles and contacted the manufacturers of medical beds. Studies included were randomized or pseudo-randomized clinical trials of kinetic bed therapy compared to standard manual turning in critically ill mechanically ventilated adult patients. Two reviewers independently applied the study selection criteria and extracted data regarding study validity, type of bed used, intensity of kinetic therapy, and population under investigation. Outcomes assessed included the incidence of nosocomial pneumonia, mortality, duration of ventilation, and intensive care unit and hospital length of stay. Fifteen prospective clinical trials were identified, which included a total of 1,169 participants. No trial met all the validity criteria. There was a significant reduction in the incidence of nosocomial pneumonia (pooled odds ratio (OR) 0.38, 95% confidence interval (CI) 0.28 to 0.53), but no reduction in mortality (pooled OR 0.96, 95%CI 0.66 to 1.14), duration of mechanical ventilation (pooled standardized mean difference (SMD) -0.14 days, 95%CI, -0.29 to 0.02), duration of intensive care unit stay (pooled SMD -0.064 days, 95% CI, -0.21 to 0.086) or duration of hospital stay (pooled SMD 0.05 days, 95% CI -0.18 to 0.27). While kinetic bed therapy has been purported to reduce the incidence of nosocomial pneumonia in mechanically ventilated patients, the overall body of evidence is insufficient to support this

  3. A review of protective factors and causal mechanisms that enhance the mental health of Indigenous Circumpolar youth

    Directory of Open Access Journals (Sweden)

    Joanna Petrasek MacDonald

    2013-12-01

    Full Text Available Objectives . To review the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. Study design . A systematic literature review of peer-reviewed English-language research was conducted to systematically examine the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. Methods . This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA guidelines, with elements of a realist review. From 160 records identified in the initial search of 3 databases, 15 met the inclusion criteria and were retained for full review. Data were extracted using a codebook to organize and synthesize relevant information from the articles. Results . More than 40 protective factors at the individual, family, and community levels were identified as enhancing Indigenous youth mental health. These included practicing and holding traditional knowledge and skills, the desire to be useful and to contribute meaningfully to one's community, having positive role models, and believing in one's self. Broadly, protective factors at the family and community levels were identified as positively creating and impacting one's social environment, which interacts with factors at the individual level to enhance resilience. An emphasis on the roles of cultural and land-based activities, history, and language, as well as on the importance of social and family supports, also emerged throughout the literature. Conclusions . Healthy communities and families foster and support youth who are resilient to mental health challenges and able to adapt and cope with multiple stressors, be they social, economic, or environmental. Creating opportunities and environments where youth can successfully navigate challenges and enhance their resilience can in turn contribute to fostering healthy Circumpolar communities. Looking at the

  4. A review of protective factors and causal mechanisms that enhance the mental health of Indigenous Circumpolar youth.

    Science.gov (United States)

    MacDonald, Joanna Petrasek; Ford, James D; Willox, Ashlee Cunsolo; Ross, Nancy A

    2013-12-09

    To review the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. A systematic literature review of peer-reviewed English-language research was conducted to systematically examine the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with elements of a realist review. From 160 records identified in the initial search of 3 databases, 15 met the inclusion criteria and were retained for full review. Data were extracted using a codebook to organize and synthesize relevant information from the articles. More than 40 protective factors at the individual, family, and community levels were identified as enhancing Indigenous youth mental health. These included practicing and holding traditional knowledge and skills, the desire to be useful and to contribute meaningfully to one's community, having positive role models, and believing in one's self. Broadly, protective factors at the family and community levels were identified as positively creating and impacting one's social environment, which interacts with factors at the individual level to enhance resilience. An emphasis on the roles of cultural and land-based activities, history, and language, as well as on the importance of social and family supports, also emerged throughout the literature. More than 40 protective factors at the individual, family, and community levels were identified as enhancing Indigenous youth mental health. These included practicing and holding traditional knowledge and skills, the desire to be useful and to contribute meaningfully to one's community, having positive role models, and believing in one's self. Broadly, protective factors at the family and community levels were identified as positively creating and impacting one's social

  5. NEW MOLECULAR MEDICINE-BASED SCAR MANAGEMENT STRATEGIES

    Science.gov (United States)

    Arno, Anna I; Gauglitz, Gerd G; Barret, Juan P; Jeschke, Marc G

    2014-01-01

    Keloids and hypertrophic scars are prevalent disabling conditions with still suboptimal treatments. Basic science and molecular-based medicine research has contributed to unravel new bench-to-bedside scar therapies, and to dissect the complex signaling pathways involved. Peptides such as transforming growth factor beta (TGF-β) superfamily, with SMADs, Ski, SnoN, Fussels, endoglin, DS-Sily, Cav-1p, AZX100, thymosin-β4 and other related molecules may emerge as targets to prevent and treat keloids and hypertrophic scars. The aim of this review is to describe the basic complexity of these new molecular scar management strategies, and point out new fibrosis research lines. PMID:24438742

  6. Drugs associated with teratogenic mechanisms. Part II: a literature review of the evidence on human risks

    NARCIS (Netherlands)

    Gelder, M.M.H.J. van; Jong-van den Berg, L.T. de; Roeleveld, N.

    2014-01-01

    STUDY QUESTION: What is the current state of knowledge on the human risks of drugs suspected to be associated with teratogenic mechanisms? SUMMARY ANSWER: Evidence for the presence or absence of human risks of birth defects is scarce or non-existent for the majority of drugs associated with

  7. The clean development mechanism's contribution to sustainable development: A review of the literature

    DEFF Research Database (Denmark)

    Olsen, Karen Holm

    2007-01-01

    The challenges of how to respond to climate change and ensure sustainable development are currently high on the political agenda among the world's leading nations. The Clean Development Mechanism (CDM) is part of the global carbon market developing rapidly as part of the Kyoto response towards...

  8. Why increased nuchal translucency is associated with congenital heart disease: a systematic review on genetic mechanisms

    NARCIS (Netherlands)

    Burger, N.B.; Bekker, M.N.; Groot, C.J. de; Christoffels, V.M.; Haak, M.C.

    2015-01-01

    This overview provides insight into the underlying genetic mechanism of the high incidence of cardiac defects in fetuses with increased nuchal translucency (NT). Nuchal edema, the morphological equivalent of increased NT, is likely to result from abnormal lymphatic development and is strongly

  9. Mechanical properties of copper processed by Equal Channel Angular Pressing - a review

    Czech Academy of Sciences Publication Activity Database

    Kunz, Ludvík; Collini, L.

    -, č. 19 (2012), s. 61-75 ISSN 1971-8993 R&D Projects: GA ČR GAP108/10/2001 Institutional research plan: CEZ:AV0Z20410507 Keywords : ultrafine-grained structure * equal channel angular pressing * copper * fatigue Subject RIV: JL - Materials Fatigue , Friction Mechanics

  10. Concise Review: Plasma and Nuclear Membranes Convey Mechanical Information to Regulate Mesenchymal Stem Cell Lineage.

    Science.gov (United States)

    Uzer, Gunes; Fuchs, Robyn K; Rubin, Janet; Thompson, William R

    2016-06-01

    Numerous factors including chemical, hormonal, spatial, and physical cues determine stem cell fate. While the regulation of stem cell differentiation by soluble factors is well-characterized, the role of mechanical force in the determination of lineage fate is just beginning to be understood. Investigation of the role of force on cell function has largely focused on "outside-in" signaling, initiated at the plasma membrane. When interfaced with the extracellular matrix, the cell uses integral membrane proteins, such as those found in focal adhesion complexes to translate force into biochemical signals. Akin to these outside-in connections, the internal cytoskeleton is physically linked to the nucleus, via proteins that span the nuclear membrane. Although structurally and biochemically distinct, these two forms of mechanical coupling influence stem cell lineage fate and, when disrupted, often lead to disease. Here we provide an overview of how mechanical coupling occurs at the plasma and nuclear membranes. We also discuss the role of force on stem cell differentiation, with focus on the biochemical signals generated at the cell membrane and the nucleus, and how those signals influence various diseases. While the interaction of stem cells with their physical environment and how they respond to force is complex, an understanding of the mechanical regulation of these cells is critical in the design of novel therapeutics to combat diseases associated with aging, cancer, and osteoporosis. Stem Cells 2016;34:1455-1463. © 2016 AlphaMed Press.

  11. A Review of Biological Communication Mechanisms Applicable to Small Autonomous Systems

    Science.gov (United States)

    2010-09-01

    katydids, grasshoppers, beetles, moths, butterflies , ants, caterpillars, beetle larvae Hitting the ground Band-winged grasshoppers, cockroaches... butterflies and moths (Lepidoptera and Noctuidae). The Agaristid moth (e.g., Hecatesia exultans and Hecatesia thyridion) has castanet-like...Insects. The Ohio J. of Science 1957, 57 (2), 101. Bailey, W. J. The Mechanics of Stridulation in Bush Crickets (Tettigonioidea, Orthoptera): I

  12. Evaluation of wheel/rail contact mechanics : roller rig concept design review.

    Science.gov (United States)

    2014-07-01

    A need exists for a new test rig design with advanced sensing technologies that will allow the railroad industry and regulatory : agencies to better understand the wheel-rail contact dynamics and mechanics, especially as it pertains to high-speed rai...

  13. Mechanism of growth, composition and structure of oxide films formed on ferrous alloys in molten salt electrolytes - a review

    International Nuclear Information System (INIS)

    Tzvetkoff, Tz.; Kolchakov, J.

    2004-01-01

    The growth kinetics, chemical composition and structure of scales formed during corrosion of Fe and its alloys in molten salts are reviewed. Special attention is paid to the effect of the composition of the molten salt mixture and the gas atmosphere on the stability and protective ability of corrosion layers. First, the thermodynamical background of the corrosion and oxidation of Fe-base engineering materials in molten salt media is briefly commented. A concise review of the growth kinetics of passivating oxide films is also presented. These two introductory chapters serve as a guide for the extensive survey of the growth mechanism, nature and properties of oxide and related scales on ferrous alloys in a range of molten electrolytes - chlorides, nitrates, sulphates, carbonates, hydroxides and mixtures thereof in gas atmospheres containing O 2 , CO 2 , SO 2 , SO 3 and HCl

  14. Transgender stigma and health: A critical review of stigma determinants, mechanisms, and interventions.

    Science.gov (United States)

    White Hughto, Jaclyn M; Reisner, Sari L; Pachankis, John E

    2015-12-01

    Transgender people in the United States experience widespread prejudice, discrimination, violence, and other forms of stigma. This critical review aims to integrate the literature on stigma towards transgender people in the U.S. This review demonstrates that transgender stigma limits opportunities and access to resources in a number of critical domains (e.g., employment, healthcare), persistently affecting the physical and mental health of transgender people. The applied social ecological model employed here elucidates that transgender stigma operates at multiple levels (i.e., individual, interpersonal, structural) to impact health. Stigma prevention and coping interventions hold promise for reducing stigma and its adverse health-related effects in transgender populations. Additional research is needed to document the causal relationship between stigma and adverse health as well as the mediators and moderators of stigma in US transgender populations. Multi-level interventions to prevent stigma towards transgender people are warranted. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Transgender Stigma and Health: A Critical Review of Stigma Determinants, Mechanisms, and Interventions

    Science.gov (United States)

    White Hughto, Jaclyn M.; Reisner, Sari L.; Pachankis, John E.

    2015-01-01

    Rationale Transgender people in the United States experience widespread prejudice, discrimination, violence, and other forms of stigma. Objective This critical review aims to integrate the literature on stigma towards transgender people in the US. Results This review demonstrates that transgender stigma limits opportunities and access to resources in a number of critical domains (e.g., employment, healthcare), persistently affecting the physical and mental health of transgender people. The applied social ecological model employed here elucidates that transgender stigma operates at multiple levels (i.e., individual, interpersonal, structural) to impact health. Stigma prevention and coping interventions hold promise for reducing stigma and its adverse health-related effects in transgender populations. Conclusion Additional research is needed to document the causal relationship between stigma and adverse health as well as the mediators and moderators of stigma in US transgender populations. Multi-level interventions to prevent stigma towards transgender people are warranted. PMID:26599625

  16. Pontomedullary lacerations and concomitant injuries: A review of possible underlying mechanisms

    Directory of Open Access Journals (Sweden)

    Živković Vladimir

    2013-01-01

    Full Text Available Anatomically, brainstem is constituted of medulla oblongata, pons and mesencephalon. Traumatic lesions of brainstem most commonly occur on pontomedullary junction. There are several possible mechanisms of pontomedullary lacerations. The first mechanism includes impact to the chin, with or without a skull base fracture, and most often leads to this fatal injury, due to impact force transmission through the jawbone and temporomandibular joint. The second mechanism includes lateral and posterior head impacts with subsequent hinge fractures, where occurrence of pontomedullary lacerations in these cases may depend on the energy of impact, as well as on the exact position of the fracture line, but less so on the head’s movement. The third mechanism includes frontoposterior hyperextension of the head, due to frontal impact, concomitant with fractures or dislocations of upper spine. In the fourth mechanism, there is an absence of direct impact to the head, due to the indirect force of action after feet or buttocks­first impact. Most of these cases are accompanied by ring fractures as well. In situations such as these, the impact force is transmitted up the spinal column and upper vertebrae, and telescopically intruded into the skull, causing brainstem laceration. The jawbone and other facial bones can act as shock absorbers, and their fracture could diminish the energy transfer towards the skull and protect the brain and brainstem from injury. In all the cases with pontomedullary laceration posterior neck dissection should be performed during the autopsy, since upper spine injuries are often associated with this type of injury. [Projekat Ministarstva nauke Republike Srbije, br. 45005

  17. Mechanisms of sports injuries among professional footballers:  a review

    OpenAIRE

    Ibikundle, P.O.; Ani, U.K.; Useh, U.; Akosile, C.O.

    2014-01-01

    Football is an impact collision sport, with injuries occurring in both contact and non-contact situations. Injuries may be caused by complex interactions between internal and external risk factors. The internal factors such as age, sex, and body compositions may influence the risk of sustaining injuries, predisposing the player to injury, and are therefore by definitions risk factors. The main purpose of this study was to review articles and draw attention to the prevalence, severity and mech...

  18. Alkali – activated binders: a review part 1. Historical background, terminology, reaction mechanisms and hydration products

    OpenAIRE

    Torgal, Fernando Pacheco; Gomes, J. P. Castro; Jalali, Said

    2008-01-01

    The disintegration of concrete structures made of ordinary Portland cement (OPC) is a worrying topic of increasing significance. The development of new binders with longer durability is therefore needed. Alkali-activated binders have emerged as an alternative to OPC binders, which seems to have superior durability and environmental impact. This paper reviews current knowledge about alkali-activated binders. The subjects of Part 1 in this paper are historical background, terminology a...

  19. The Physiological Mechanisms of Effect of Vitamins and Amino Acids on Tendon and Muscle Healing: A Systematic Review.

    Science.gov (United States)

    Tack, Christopher; Shorthouse, Faye; Kass, Lindsy

    2018-05-01

    To evaluate the current literature via systematic review to ascertain whether amino acids/vitamins provide any influence on musculotendinous healing and if so, by which physiological mechanisms. EBSCO, PubMed, ScienceDirect, Embase Classic/Embase, and MEDLINE were searched using terms including "vitamins," "amino acids," "healing," "muscle," and "tendon." The primary search had 479 citations, of which 466 were excluded predominantly due to nonrandomized design. Randomized human and animal studies investigating all supplement types/forms of administration were included. Critical appraisal of internal validity was assessed using the Cochrane risk of Bias Tool or the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool for human and animal studies, respectively. Two reviewers performed duel data extraction. Twelve studies met criteria for inclusion: eight examined tendon healing and four examined muscle healing. All studies used animal models, except two human trials using a combined integrator. Narrative synthesis was performed via content analysis of demonstrated statistically significant effects and thematic analysis of proposed physiological mechanisms of intervention. Vitamin C/taurine demonstrated indirect effects on tendon healing through antioxidant activity. Vitamin A/glycine showed direct effects on extracellular matrix tissue synthesis. Vitamin E shows an antiproliferative influence on collagen deposition. Leucine directly influences signaling pathways to promote muscle protein synthesis. Preliminary evidence exists, demonstrating that vitamins and amino acids may facilitate multilevel changes in musculotendinous healing; however, recommendations on clinical utility should be made with caution. All animal studies and one human study showed high risk of bias with moderate interobserver agreement (k = 0.46). Currently, there is limited evidence to support the use of vitamins and amino acids for musculotendinous injury. Both

  20. Stem cell therapy on skin: Mechanisms, recent advances and drug reviewing issues

    Directory of Open Access Journals (Sweden)

    Gong-Yau Chu

    2018-01-01

    Full Text Available Stem cell products and its clinical applications have been widely discussed in recent years, particularly when the Japanese “induced pluripotent stem cells” founder Dr. Yamanaka was awarded as Nobel Prize laureate in 2013. For decades, major progresses have been achieved in the stem cell biology field, and more and more evidence showed that skin stem cells are involved in the process of skin repair. Stem/progenitor cells of the epidermis are recognized to play the most essential role in the tissue regeneration of skin. In this review, we first illustrated basic stem cell characteristics and various stem cell subtypes resided in the skin. Second, we provided several literatures to elucidate how stem/progenitor cells collaborate in the process of skin repair with the evidence from animal model studies and in vitro experiments. Third, we also introduced several examples of skin cell products on the pharmaceutic market and the ongoing clinical trials aiming for unmet medical difficulties of skin. Last but not least, we summarized general reviewing concerns and some disputatious issues on dermatological cell products. With this concise review, we hope to provide further beneficial suggestions for the development of more effective and safer dermatological stem/progenitor cell products in the future.