Sample records for regenerative hyperplasia nrh

  1. Nodular Regenerative Hyperplasia in Common Variable Immunodeficiency

    PubMed Central

    Fuss, Ivan J.; Friend, Julia; Yang, Zhiqong; He, Ping; Hooda, Lubna; Boyer, James; Xi, Liqiang; Raffeld, Mark; Kleiner, David E.; Heller, Theo; Strober, Warren

    2013-01-01

    Purpose Patients with Common Variable Immunodeficiency (CVID) are subject to the development of a liver disease syndrome known as nodular regenerative hyperplasia (NRH). The purpose of this study was to define the characteristics and course of this complication of CVID. Methods CVID patients were evaluated by retrospective and prospective clinical course review. Liver biopsy specimens were evaluated for evidence of NRH and studied via RT-PCR for cytokine analysis. Results NRH in our CVID patient population occurred in approximately 5% of the 261 patients in our total CVID study group, initially presenting in most cases with an elevated alkaline phosphatase level. While in some patients the disease remained static, in a larger proportion a more severe disease developed characterized by portal hypertension, the latter leading to hypersplenism with neutropenia and thrombocytopenia and, in some cases, to ascites. In addition, a substantial proportion of patients either developed or presented initially with an autoimmune hepatitis-like (AIH-like) liver disease that resulted in severe liver dysfunction and, in most cases to death due to infections. The liver histologic findings in these AIH-like patients were characterized by underlying NRH pattern with superimposed interface hepatitis, lymphocytic infiltration and fibrosis. Immunologic studies of biopsies of NRH patients demonstrated the presence of infiltrating T cells producing IFN-?, suggesting that the NRH is due to an autoimmune process. Conclusion Overall, these studies provide evidence that NRH may not be benign but, can be a severe and potentially fatal disease complication of CVID that merits close monitoring and intervention. PMID:23420139

  2. Diagnosing Nodular Regenerative Hyperplasia of the Liver Is Thwarted by Low Interobserver Agreement

    PubMed Central

    Jharap, Bindia; van Asseldonk, Dirk P.; de Boer, Nanne K. H.; Bedossa, Pierre; Diebold, Joachim; Jonker, A. Mieke; Leteurtre, Emmanuelle; Verheij, Joanne; Wendum, Dominique; Wrba, Fritz; Zondervan, Pieter E.; Colombel, Jean-Frédéric; Reinisch, Walter; Mulder, Chris J. J.; Bloemena, Elisabeth; van Bodegraven, Adriaan A.

    2015-01-01

    Background and Aims Nodular regenerative hyperplasia (NRH) of the liver is associated with several diseases and drugs. Clinical symptoms of NRH may vary from absence of symptoms to full-blown (non-cirrhotic) portal hypertension. However, diagnosing NRH is challenging. The objective of this study was to determine inter- and intraobserver agreement on the histopathologic diagnosis of NRH. Methods Liver specimens (n=48) previously diagnosed as NRH, were reviewed for the presence of NRH by seven pathologists without prior knowledge of the original diagnosis or clinical background. The majority of the liver specimens were from thiopurine using inflammatory bowel disease patients. Histopathologic features contributing to NRH were also assessed. Criteria for NRH were modified by consensus and subsequently validated. Interobserver agreement was evaluated by using the standard kappa index. Results After review, definite NRH, inconclusive NRH and no NRH were found in 35% (23-40%), 21% (13-27%) and 44% (38-56%), respectively (median, IQR). The median interobserver agreement for NRH was poor (? = 0.20, IQR 0.14-0.28). The intraobserver variability on NRH ranged between 14% and 71%. After modification of the criteria and exclusion of biopsies with technical shortcomings, the interobserver agreement on the diagnosis NRH was fair (? = 0.45). Conclusions The interobserver agreement on the histopathologic diagnosis of NRH was poor, even when assessed by well-experienced liver pathologists. Modification of the criteria of NRH based on consensus effort and exclusion of biopsies of poor quality led to a fairly increased interobserver agreement. The main conclusion of this study is that NRH is a clinicopathologic diagnosis that cannot reliably be based on histopathology alone. PMID:26054009

  3. Nodular regenerative hyperplasia of the liver: case report of a 13-year-old girl and review of the literature

    Microsoft Academic Search

    Gertrud M. Trenschel; Astrid Schubert; Volker Dries; Gabriele Benz-Bohm

    2000-01-01

    Background. Nodular regenerative hyperplasia (NRH) of the liver is a multi-acinar regenerative nodular lesion in a non-cirrhotic liver.\\u000a It is a rare entity, especially in children, and remains of unknown aetiology.¶Objective. NRH is often seen in association with other diseases or drug intake. In half of patients it is complicated by portal hypertension.\\u000a Radiologically, its nodular appearance may look like

  4. Nodular regenerative hyperplasia of the liver: diagnosis by liver biopsy.

    PubMed Central

    Qizilbash, A. H.; Castelli, M.

    1980-01-01

    Specimens of liver obtained by needle biopsy from two patients with rheumatoid arthritis showed features of nodular regenerative hyperplasia. In one patient the nodularity was apparent on gross examination of the specimen. Portal hypertension was present in the other patient. The cause and pathogenesis of the disorder are poorly understood. Images FIG. 1 FIG. 2 FIG. 3 PMID:7388707

  5. Nodular regenerative hyperplasia of the liver, CREST syndrome and primary biliary cirrhosis: an overlap syndrome?

    PubMed Central

    McMahon, R F; Babbs, C; Warnes, T W

    1989-01-01

    Nodular regenerative hyperplasia of the liver (NRHL) has been found in association with collagen vascular diseases, after drug therapy, with autoimmune disease, and with a variety of haematological disorders. The association of NRHL with the syndrome of Calcinosis cutis, Raynaud's phenomenon, oesophageal dysfunction, sclerodactyly and telangiectasia (CREST syndrome) has only been reported on two previous occasions. The liver disease usually associated with CREST syndrome is primary biliary cirrhosis (PBC) and recently nodular hyperplasia of the liver has been reported in patients with early stage PBC. We present a case of NRHL with CREST syndrome and serological and biochemical features of PBC, a newly recognised overlap syndrome. Images Figure PMID:2583572

  6. Regenerative Hyperplasia Is Not Required for Liver Tumor Induction in Female B6C3F 1Mice Exposed to Trihalomethanes

    Microsoft Academic Search

    Ronald L. Melnick; Michael C. Kohn; June K. Dunnick; Joel R. Leininger

    1998-01-01

    Chloroform (TCM), a water disinfection by-product, induced liver tumors in female mice when administered by gavage in corn oil but not when given in drinking water at comparable daily doses. Because short-term studies showed that the gavage doses also induced liver toxicity, it has been suggested that the liver tumor response occurs secondary to cytotoxicity and consequent regenerative hyperplasia induced

  7. Coexpression of IL-6 and soluble IL-6R causes nodular regenerative hyperplasia and adenomas of the liver.

    PubMed Central

    Maione, D; Di Carlo, E; Li, W; Musiani, P; Modesti, A; Peters, M; Rose-John, S; Della Rocca, C; Tripodi, M; Lazzaro, D; Taub, R; Savino, R; Ciliberto, G

    1998-01-01

    Studies with tumor necrosis factor p55 receptor- and interleukin-6 (IL-6)-deficient mice have shown that IL-6 is required for hepatocyte proliferation and reconstitution of the liver mass after partial hepatectomy. The biological activities of IL-6 are potentiated when this cytokine binds soluble forms of its specific receptor subunit (sIL-6R) and the resulting complex interacts with the transmembrane signaling chain gp130. We show here that double transgenic mice expressing high levels of both human IL-6 and sIL-6R under the control of liver-specific promoters spontaneously develop nodules of hepatocellular hyperplasia around periportal spaces and present signs of sustained hepatocyte proliferation. The resulting picture is identical to that of human nodular regenerative hyperplasia, a condition frequently associated with immunological and myeloproliferative disorders. In high expressors, hyperplastic lesions progress with time into discrete liver adenomas. These data strongly suggest that the IL-6/sIL-6R complex is both a primary stimulus to hepatocyte proliferation and a pathogenic factor of hepatocellular transformation. PMID:9755159

  8. Regenerative hyperplasia is not required for liver tumor induction in female B6C3F1 mice exposed to trihalomethanes.

    PubMed

    Melnick, R L; Kohn, M C; Dunnick, J K; Leininger, J R

    1998-01-01

    Chloroform (TCM), a water disinfection by-product, induced liver tumors in female mice when administered by gavage in corn oil but not when given in drinking water at comparable daily doses. Because short-term studies showed that the gavage doses also induced liver toxicity, it has been suggested that the liver tumor response occurs secondary to cytotoxicity and consequent regenerative hyperplasia induced by oxidative metabolism of TCM to the toxic dihalocarbonyl intermediate. This study compares dose-response relationships of gavage-administered chlorinated/brominated trihalomethanes for hepatotoxicity, replicative DNA synthesis, and hepatocarcinogenicity in female B6C3F1 mice. The liver tumor data were obtained from previously published studies. Because bromine is a better leaving group than chlorine, metabolism of bromodichloromethane (BDCM) should produce the same intermediates as would be formed from TCM. Hence, the toxicity and carcinogenicity of BDCM was expected to be qualitatively similar to that of TCM. Dose responses for liver weight, serum sorbitol dehydrogenase and alanine aminotransferase (ALT) activities, hepatocyte degeneration, and hepatocyte labeling index (LI, a measure of replicative DNA synthesis) in female mice were similar following 3 weeks of gavage administration (once per day, 5 days per week) with TCM, BDCM, or chlorodibromomethane (CDBM). Fits of composite data for these trihalomethanes to a Hill equation model revealed sigmoidal dose responses for ALT activity and hepatocyte LI and a nearly linear low-dose response for liver tumor incidence. For this family of chemicals, the mouse liver tumor response was not associated with an elevated hepatocyte LI at doses of approximately 1 mmol/kg or less. High incidences of liver tumors were observed with BDCM and CDBM at doses that had a marginal effect or no effect on the hepatocyte LI. Thus, the carcinogenic effects of trihalomethanes are not simply a consequence of cytotoxicity and regenerative hyperplasia. The possible contributions from other activation pathways, including GSH conjugation and reductive metabolism, need to be considered in assessments of the carcinogenicity of the trihalomethanes. PMID:9465273

  9. NRH:quinone oxidoreductase 2 (NQO2) catalyzes metabolic activation of quinones and anti-tumor drugs.

    PubMed

    Celli, Claudia M; Tran, Namphuong; Knox, Richard; Jaiswal, Anil K

    2006-07-28

    NRH:quinone oxidoreductase 2 (NQO2) is a cytosolic flavoprotein that utilizes NRH as electron donor. The present studies investigate the role of NQO2 in metabolic detoxification/activation of quinones and quinone based anti-tumor drugs. Chinese hamster ovary (CHO) cells stably overexpressing cDNA derived mouse NQO2 and mouse keratinocytes from DMBA-induced skin tumors in wild-type and NQO2-null mice were generated. The CHO cells overexpressing NQO2 and mouse keratinocytes expressing or deficient in NQO2 were treated with varying concentrations of mitomycin C (MMC), CB1954, MMC analog BMY25067, EO9, menadione and BP-3,6-quinone, in the absence and presence of NRH. The cytotoxicity of the drugs was evaluated by colony formation. The CHO cells overexpressing higher levels of mouse NQO2 showed significantly increased cytotoxicity to menadione, BP-3,6-quinone and to the anti-tumor drugs MMC and CB1954 when compared to CHO cells expressing endogenous NQO2. The cytotoxicity increased in presence of NRH. Similar results were also observed with BMY25067 and EO9 treatments, but to a lesser extent. The results on keratinocytes deficient in NQO2 supported the data from CHO cells. The inclusion of NRH had no effect on cytotoxicity of quinones and drugs in keratinocytes deficient in NQO2. Mouse NQO2 protein was expressed in bacteria, purified and used to study the role of NQO2 in MMC-induced DNA cross-linking. Bacterially expressed and purified NQO2 efficiently catalyzed MMC activation that led to DNA cross-linking. These results concluded that NQO2 plays a significant role in the metabolic activation of both quinones and anti-tumor drugs leading to cytotoxicity and cell death. PMID:16765324

  10. The two common polymorphic forms of human NRH-quinone oxidoreductase 2 (NQO2) have different biochemical properties

    PubMed Central

    Megarity, Clare F.; Gill, James R.E.; Clare Caraher, M.; Stratford, Ian J.; Nolan, Karen A.; Timson, David J.

    2014-01-01

    There are two common forms of NRH-quinone oxidoreductase 2 (NQO2) in the human population resulting from SNP rs1143684. One has phenylalanine at position 47 (NQO2-F47) and the other leucine (NQO2-L47). Using recombinant proteins, we show that these variants have similar steady state kinetic parameters, although NQO2-L47 has a slightly lower specificity constant. NQO2-L47 is less stable towards proteolytic digestion and thermal denaturation than NQO2-F47. Both forms are inhibited by resveratrol, but NQO2-F47 shows negative cooperativity with this inhibitor. Thus these data demonstrate, for the first time, clear biochemical differences between the variants which help explain previous biomedical and epidemiological findings. PMID:24631540

  11. Regenerative Aerobraking

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    2004-01-01

    NASA's exploration goals for Mars and Beyond will require new power systems and in situ resource utilization technologies. Regenerative aerobraking may offer a revolutionary approach for in situ power generation and oxygen harvesting during these exploration missions. In theory, power and oxygen can be collected during aerobraking and stored for later use in orbit or on the planet. This technology would capture energy and oxygen from the plasma field that occurs naturally during hypersonic entry using well understood principles of magnetohydrodynamics and oxygen filtration. This innovative approach generates resources upon arrival at the operational site, and thus greatly differs from the traditional approach of taking everything you need with you from Earth. Fundamental analysis, computational fluid dynamics, and some testing of experimental hardware have established the basic feasibility of generating power during a Mars entry. Oxygen filtration at conditions consistent with spacecraft entry parameters at Mars has been studied to a lesser extent. Other uses of the MHD power are presented. This paper illustrates how some features of regenerative aerobraking may be applied to support human and robotic missions at Mars.

  12. Benign prostate hyperplasia (BPH) - resources

    MedlinePLUS

    Resources - benign prostatic hyperplasia (BPH); Prostate enlargement resources; BPH resources ... organizations provide information on benign prostatic hyperplasia ( prostate enlargement ): National Kidney and Urologic Diseases Information Clearinghouse - www. ...

  13. Research Councils UK Regenerative

    E-print Network

    Berzins, M.

    and nanotechnology, and Energy and its storage. Regenerative medicine #12;BasicBiology Translational MedicineResearch Councils UK Regenerative medicine #12;Regenerative medicine, the approach that seeks testing to make safer medicines. Success in this research field has also led to economic growth for the UK

  14. MRC CENTRE FOR REGENERATIVE

    E-print Network

    HIGHLIGHTS MRC CENTRE FOR REGENERATIVE MEDICINE www.crm.ed.ac.uk Boosting cell production could developments in the MRC Centre for Regenerative Medicine (CRM). We have continued to strengthen our for Regenerative Medicine (SCRM) building, bringing together all our teams into a single state-of-the-art facility

  15. CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE

    E-print Network

    Ford, James

    CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE INSTITUTE FOR STEM CELL BIOLOGY & SCHOLAR TRAINING GRANT REGENERATIVE MEDICINE Postdoctoral Scholar Application Deadline: August 31, 2011 Instructions cell biology/regenerative medicine, and letters of recommendation. d) Applications must be complete

  16. Indolequinone inhibitors of NRH:quinone oxidoreductase 2. Characterization of the mechanism of inhibition in both cell-free and cellular systems.

    PubMed

    Yan, Chao; Dufour, Marine; Siegel, David; Reigan, Philip; Gomez, Joe; Shieh, Biehuoy; Moody, Christopher J; Ross, David

    2011-08-01

    We describe a series of indolequinones as efficient mechanism-based inhibitors of NRH:quinone oxidoreductase 2 (NQO2) for use either in cellular or cell-free systems. Compounds were designed to be reduced in the active site of the enzyme leading to loss of a substituted phenol leaving group and generation of a reactive iminium electrophile. Inhibition of NQO2 activity was assessed in both cell-free systems and the human leukemia K562 cell line. Inhibition of recombinant human NQO2 by the indolequinones was NRH-dependent, with kinetic parameters characteristic of mechanism-based inhibition and partition ratios as low as 2.0. Indolequinones inhibited NQO2 activity in K562 cells at nanomolar concentrations that did not inhibit NQO1 and were nontoxic to cells. Computation-based molecular modeling simulations demonstrated favorable conformations of indolequinones positioned directly above and in parallel with the isoalloxazine ring of FAD, and mass spectrometry extended our previous finding of adduction of the FAD in the active site of NQO2 by an indolequinone-derived iminium electrophile to the wider series of indolequinone inhibitors. Modeling combined with biochemical testing identified key structural parameters for effective inhibition, including a 5-aminoalkylamino side chain. Hydrogen bonding of the terminal amine nitrogen in the aminoalkylamino side chain was found to be critical for the correct orientation of the inhibitors in the active site. These indolequinones were irreversible inhibitors and were found to be at least 1 order of magnitude more potent than any previously documented competitive inhibitors of NQO2 and represent the first mechanism-based inhibitors of NQO2 to be characterized in cellular systems. PMID:21718050

  17. Indolequinone Inhibitors of NRH:Quinone Oxidoreductase 2 (NQO2). Characterization of Mechanism of Inhibition in both Cell-free and Cellular Systems. †

    PubMed Central

    Yan, Chao; Dufour, Marine; Siegel, David; Reigan, Philip; Gomez, Joe; Shieh, Biehuoy; Moody, Christopher J.; Ross, David

    2011-01-01

    We describe a series of indolequinones as efficient mechanism-based inhibitors of NRH:quinone oxidoreductase 2 (NQO2) for use either in cellular or cell-free systems. Compounds were designed to be reduced in the active site of the enzyme leading to loss of a substituted phenol leaving group and generation of a reactive iminium electrophile. Inhibition of NQO2 activity was assessed in both cell-free systems and in the human leukemia K562 cell line. Inhibition of recombinant human NQO2 by the indolequinones was NRH-dependent with kinetic parameters characteristic of mechanism-based inhibition and partition ratios as low as 2.0. Indolequinones inhibited NQO2 activity in K562 cells at nanomolar concentrations which did not inhibit NQO1 and were non-toxic to cells. Computational-based molecular modeling simulations demonstrated favorable conformations of indolequinones positioned directly above and in parallel to the isoalloxazine ring of FAD and mass spectrometry extended our previous finding of adduction of the FAD in the active site of NQO2 by an indolequinone-derived iminium electrophile to the wider series of indolequinone inhibitors. Modeling combined with biochemical testing identified key structural parameters for effective inhibition including a 5-aminoalkyamino side chain. Hydrogen bonding of the terminal amine nitrogen in the aminoalkylamino side chain was found to be critical for correct orientation of the inhibitors in the active site. These indolequinones were irreversible inhibitors and were found to be at least an order of magnitude more potent than any previously documented competitive inhibitors of NQO2 and represent the first mechanism-based inhibitors of NQO2 to be characterized in cellular systems. PMID:21718050

  18. Morphogenesis & Regenerative Medicine

    E-print Network

    Brodie III, Edmund D.

    Morphogenesis Symposium & Regenerative Medicine May 27-29, 2009 Registration & Abstract submission will showcase some of the best research performed in morphogenesis and regenerative medicine. A wide range Francisco Haifan Lin Yale University Ruth Lehmann The Skirball Institute of Biomolecular Medicine #12;

  19. Regenerative fuel cells

    Microsoft Academic Search

    L. A. Kvasnikov; R. G. Tazetdinov

    1978-01-01

    The working processes in power plants using regenerative fuel cells are studied. The main types of regenerative fuel cells are characterized. Special attention is devoted to systems with thermal regeneration of the components by means of thermoelectrochemical converters of heat into electrical energy. Expressions for the principal parameters in the working processes are obtained by making use of the apparatus

  20. Regenerative Hydride Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  1. The Nonclassic Adrenal Hyperplasias

    Microsoft Academic Search

    Didier Dewailly; Ricardo Azziz

    Nonclassic adrenal hyperplasia (NCAH) resulting from 11?-hydroxylase or 3?-hydroxysteroid dehydrogenase is very rare and may\\u000a not even exist in women presenting with hyperandrogenism in adulthood. Consequently, screening for these disorders in hyperandrogenic\\u000a patients is not generally necessary. Alternatively, 21-hydroxylase (21-OH)-deficient NCAH has been increasingly recognized\\u000a in adolescent or adult hyperandrogenic patients. It is now widely accepted that neither clinical presentation

  2. Regenerative catalytic oxidation

    SciTech Connect

    Gribbon, S.T. [Engelhard Process Emission Systems, South Lyon, MI (United States)

    1996-12-31

    Currently Regenerative Thermal Oxidizers (R.T.O.`s) are an accepted technology for the control of volatile organic compounds (VOC`s) and hazardous air pollutants (HAP`s). This control technology, when introduced, offered substantial reductions in operating costs, especially auxiliary fuel requirements when compared to existing control technologies such as recuperative thermal and recuperative catalytic oxidizers. While these savings still exist, there is a demand for control of new and/or hybrid technologies, one of which is Regenerative Catalytic Oxidizers (R.C.O.`s). This paper will explore the development of regenerative catalytic oxidation from the theoretical stage through pilot testing through a commercial installation. The operating cost of R.C.O.`s will be compared to R.T.O.`s to verify the savings that are achievable through the use of regenerative catalytic oxidation. In the development of this technology, which is a combination of two (2) existing technologies, R.T.O.`s and catalysis, a second hybrid technology was explored and pilot tested. This is a combination R.C.O. for VOC and HAP control and simultaneous SCR (Selective Catalytic Reduction) for NOx (Oxides of Nitrogen) control. Based on the pilot and full scale testing, both regenerative catalytic oxidizers and systems which combine R.C.O. with SCR for both VOC and NOx reduction are economically viable and are in fact commercially available. 6 figs., 2 tabs.

  3. Nonclassic Congenital Adrenal Hyperplasia

    PubMed Central

    Witchel, Selma Feldman; Azziz, Ricardo

    2010-01-01

    Nonclassic congenital adrenal hyperplasia (NCAH) due to P450c21 (21-hydroxylase deficiency) is a common autosomal recessive disorder. This disorder is due to mutations in the CYP21A2 gene which is located at chromosome 6p21. The clinical features predominantly reflect androgen excess rather than adrenal insufficiency leading to an ascertainment bias favoring diagnosis in females. Treatment goals include normal linear growth velocity and “on-time” puberty in affected children. For adolescent and adult women, treatment goals include regularization of menses, prevention of progression of hirsutism, and fertility. This paper will review key aspects regarding pathophysiology, diagnosis, and treatment of NCAH. PMID:20671993

  4. Oral focal epithelial hyperplasia.

    PubMed

    López-Jornet, Pía; Camacho-Alonso, Fabio; Berdugo, Lucero

    2010-01-01

    Focal epithelial hyperplasia (FEH) is a benign, asymptomatic disease. It appears as papules, principally on the lower lip, although it can also be found on the retro-commissural mucosa and tongue and, less frequently, on the upper lip, gingiva and palate. FEH is caused by human papillomavirus subtype 13 or 32. The condition occurs in many populations and ethnic groups. We present the clinical case of a 31-year-old male with lesions that clinically and histologically corresponded to FEH. PMID:20863043

  5. Diffuse intrapulmonary neuroendocrine cell hyperplasia

    PubMed Central

    McGuire, Anna L; Maziak, Donna E; Sekhon, Harman S

    2013-01-01

    Diffuse intrapulmonary neuroendocrine cell hyperplasia is a rare, potential precursor lesion to typical pulmonary carcinoid tumours. Fewer than 50 cases have been reported in the literature. Their pathogenesis, clinical significance and management is controversial. A patient who presented with diffuse intrapulmonary neuroendocrine cell hyperplasia associated with a primary typical carcinoid tumour of the lung is reported. PMID:24032122

  6. Regenerative Life Support Evaluation

    NASA Technical Reports Server (NTRS)

    Kleiner, G. N.; Thompson, C. D.

    1977-01-01

    This paper describes the development plan and design concept of the Regenerative Life Support Evaluation (RLSE) planned for flight testing in the European Space Agency Spacelab. The development plan encompasses the ongoing advanced life support subsystem and a systems integration effort to evolve concurrently subsystem concepts that perform their function and can be integrated with other subsystems in a flight demonstration of a regenerative life support system. The design concept for RLSE comprises water-electrolysis O2 generation, electrochemically depolarized CO2 removal, and Sabatier CO2 reduction for atmosphere regeneration, urine vapor-compression distillation, and wash-water hyperfiltration for waste-water recovery. The flight demonstration by RLSE is an important step in qualifying the regenerative concepts for life support in space stations.

  7. Cavity optoelectromechanical regenerative amplification

    E-print Network

    Taylor, Michael A; Knittel, Joachim; Lee, Kwan H; McRae, Terry G; Bowen, Warwick P

    2011-01-01

    Regenerative amplification is demonstrated in a cavity optoelectromechanical system using electrical gradient forces and optomechanical transduction. Mechanical linewidth narrowing to $6.6 \\pm 1.4$ mHz was observed at a frequency of 27.3 MHz, corresponding to an effective mechanical quality factor of $4 \\times 10^9$. A theoretical model of the system was formulated, showing that the delay in electrical feedback allows additional linewidth narrowing compared to purely optomechanical regenerative amplification. The linewidth was confirmed experimentally to scale inversely with the mechanical energy as predicted by the model.

  8. CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE

    E-print Network

    Quake, Stephen R.

    CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE INSTITUTE FOR STEM CELL BIOLOGY & SCHOLAR TRAINING GRANT REGENERATIVE MEDICINE Postdoctoral Scholar Application Deadline: September 10, 2012 Instructions on their interest in a research career in stem cell biology and regenerative medicine. c) All applicants awarded

  9. Regenerative Composition Structures Alexander Gnedin

    E-print Network

    Sekhon, Jasjeet S.

    Regenerative Composition Structures Alexander Gnedin and Jim Pitman Technical Report No. 644 of Kingman's partition structures) is defined by a regenerative description of component sizes. Each regenerative composition structure is represented by a process of random sampling of points from an exponential

  10. CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE

    E-print Network

    Quake, Stephen R.

    CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE INSTITUTE FOR STEM CELL BIOLOGY & SCHOLAR TRAINING GRANT REGENERATIVE MEDICINE Pre-doctoral Scholar Application Deadline: September 6, 2013 Instructions on their interest in a research career in stem cell biology and regenerative medicine. c) All applicants awarded

  11. CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE

    E-print Network

    Quake, Stephen R.

    CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE INSTITUTE FOR STEM CELL BIOLOGY & SCHOLAR TRAINING PROGRAM REGENERATIVE MEDICINE MD Research Scholar Application Deadline: August 24, 2012 Instructions in a research career in stem cell biology and regenerative medicine. c) This application is for a research

  12. CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE

    E-print Network

    Quake, Stephen R.

    CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE INSTITUTE FOR STEM CELL BIOLOGY & SCHOLAR TRAINING PROGRAM REGENERATIVE MEDICINE MD Research Scholar Application Deadline: August 23, 2013 Instructions in a research career in stem cell biology and regenerative medicine. c) This application is for a research

  13. CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE

    E-print Network

    Quake, Stephen R.

    CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE INSTITUTE FOR STEM CELL BIOLOGY & SCHOLAR TRAINING GRANT REGENERATIVE MEDICINE Pre-doctoral Scholar Application Deadline: August 24, 2012 Instructions on their interest in a research career in stem cell biology and regenerative medicine. c) All applicants awarded

  14. PEM regenerative fuel cells

    Microsoft Academic Search

    Larry L. Swette; Anthony B. Laconti; Stephen A. McCatty

    1993-01-01

    This paper will update the progress in developing electrocatalyst systems and electrode structures primarily for the positive electrode of single-unit solid polymer proton exchange membrane (PEM) regenerative fuel cells. The work was done with DuPont Nafion 117 in complete fuel cells (40 sq cm electrodes). The cells were operated alternately in fuel cell mode and electrolysis mode at 80 C.

  15. Thermally regenerative fuel cells

    Microsoft Academic Search

    F. A. Ludwig; A. Kindler; J. McHardy

    1991-01-01

    The three phase project was undertaken to investigate solventless ionic liquids as possible working fluids for a new type of thermally regenerative fuel cell (TRFC). The heart of the new device, invented at Hughes Aircraft Company in 1983, is an electrochemical concentration cell where acid and base streams react to produce electrical energy. Thermal energy is then used to decompose

  16. Regenerative fuel cell study

    NASA Technical Reports Server (NTRS)

    Wynveen, R. A.; Schubert, F. H.

    1972-01-01

    The completion of the study is reported for the regenerative fuel cell subsystem (RFCS) as an energy storage process for use aboard the space shuttle launched modular space station (MSS). The MSS mission requirements, and RFCS are discussed, and a comparison between RFCS and a nickel cadmium battery subsystem is presented. Development costs are also discussed.

  17. Regenerative feedback resonant circuit

    SciTech Connect

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  18. Regenerative fuel cells

    Microsoft Academic Search

    Larry L. Swette; Nancy D. Kackley; Anthony B. Laconti

    1992-01-01

    A development status evaluation is presented for moderate-temperature, single-unit, regenerative fuel cells using either alkaline or solid polymer proton-exchange membrane (PEM) electrolytes. Attention is given to the results thus far obtained for Pt, Ir, Rh, and Na(x)Pt3O4 catalysts. Alkaline electrolyte tests have been performed on a half-cell basis with a floating-electrode cell; PEM testing has been with complete fuel cells,

  19. Cavity optoelectromechanical regenerative amplification

    E-print Network

    Michael A. Taylor; Alex Szorkovszky; Joachim Knittel; Kwan H. Lee; Terry G. McRae; Warwick P. Bowen

    2012-06-29

    Cavity optoelectromechanical regenerative amplification is demonstrated. An optical cavity enhances mechanical transduction, allowing sensitive measurement even for heavy oscillators. A 27.3 MHz mechanical mode of a microtoroid was linewidth narrowed to 6.6\\pm1.4 mHz, 30 times smaller than previously achieved with radiation pressure driving in such a system. These results may have applications in areas such as ultrasensitive optomechanical mass spectroscopy.

  20. Cardiac regenerative medicine.

    PubMed

    Yuasa, Shinsuke; Fukuda, Keiichi

    2008-01-01

    Severe heart failure is associated with damage to the myocardium that is irreversible with current medical therapies. Recent experimental and clinical studies, however, have opened the possibility of solving many of the associated problems, making this an exciting and tangible goal. There are many potential cell sources for regenerative cardiac medicine, including bone marrow stem cells, endothelial progenitor cells, skeletal myocytes, adult cardiac stem cells, and embryonic stem (ES) cells. Although ES cells are highly proliferative and suitable for mass production, they are not autologous, and an efficient protocol is yet to be established to ensure selective cardiomyocyte induction. Recent studies have successfully established inducible pluripotent stem (iPS) cells from mouse and human fibroblasts by the gene transfer of 4 transcription factors that are strongly expressed in ES cells: Oct3/4, Sox2, Klf4 and c-Myc. iPS cells can differentiate into all 3 germ layer-derived cells and are syngeneic, indicating that they can become an ideal cell source for regenerative medicine. Despite these successes, the accumulating evidence from fields as diverse as developmental biology, stem cell biology and tissue engineering must be integrated to achieve the full potential of cardiac regenerative medicine. PMID:18772528

  1. Regenerative medicine strategies.

    PubMed

    Atala, Anthony

    2012-01-01

    Applications of regenerative medicine technology may offer novel therapies for patients with injuries, end-stage organ failure, or other clinical problems. Currently, patients suffering from diseased and injured organs can be treated with transplanted organs. However, there is a severe shortage of donor organs that is worsening yearly as the population ages and new cases of organ failure increase. Scientists in the field of regenerative medicine and tissue engineering are now applying the principles of cell transplantation, material science, and bioengineering to construct biological substitutes that will restore and maintain normal function in diseased and injured tissues. The stem cell field is also advancing rapidly, opening new avenues for this type of therapy. For example, therapeutic cloning and cellular reprogramming may one day provide a potentially limitless source of cells for tissue engineering applications. While stem cells are still in the research phase, some therapies arising from tissue engineering endeavors have already entered the clinical setting successfully, indicating the promise regenerative medicine holds for the future. PMID:22244387

  2. Focal nodular hyperplasia (FNH).

    PubMed

    Nat, Laura; Poant?, Laura Irina

    2014-01-01

    Focal nodular hyperplasia (FNH) is a benign tumour of the liver (hepatic tumour), which is the second most prevalent tumour of the liver (the first is hepatic hemangioma). It has a higher incidence in females, 20-40 years old, but also occurs in men and even in children. It is usually asymptomatic, rarely grows or bleeds, and has no malignant potential. This tumour was once often resected because it was difficult to distinguish from hepatic adenoma, but with modem multiphase imaging it is now diagnosed strictly by imaging criteria, and not resected. We present the case of a 78 years old man who presented to emergency room (ER) with a history of dry cough, chest pain and mild dyspnea. Chest X-ray showed ascension of the right hemidiaphragm, and a homogeneous round opacity of 6/6.2 cm in the right cardiophrenic angle. The first suspicion was of pulmonary tumor, but the final diagnosis was FNH, confirmed by CT scan. We discuss the differential diagnosis and prognosis of this entity. The particularities of the case are the presentation with respiratory symptoms and pulmonary mass, and the age of the patient. PMID:25000678

  3. Congenital lipoid adrenal hyperplasia

    PubMed Central

    2014-01-01

    Congenital lipoid adrenal hyperplasia (lipoid CAH) is the most fatal form of CAH, as it disrupts adrenal and gonadal steroidogenesis. Most cases of lipoid CAH are caused by recessive mutations in the gene encoding steroidogenic acute regulatory protein (StAR). Affected patients typically present with signs of severe adrenal failure in early infancy and 46,XY genetic males are phenotypic females due to disrupted testicular androgen secretion. The StAR p.Q258X mutation accounts for about 70% of affected alleles in most patients of Japanese and Korean ancestry. However, it is more prevalent (92.3%) in the Korean population. Recently, some patients have been showed that they had late and mild clinical findings. These cases and studies constitute a new entity of 'nonclassic lipoid CAH'. The cholesterol side-chain cleavage enzyme, P450scc (CYP11A1), plays an essential role converting cholesterol to pregnenolone. Although progesterone production from the fetally derived placenta is necessary to maintain a pregnancy to term, some patients with P450scc mutations have recently been reported. P450scc mutations can also cause lipoid CAH and establish a recently recognized human endocrine disorder. PMID:25654062

  4. Regenerative simulation of TES processes

    Microsoft Academic Search

    Søren Asmussen; Benjamin Melamed

    1994-01-01

    Regenerative simulation has become a familiar and established tool for simulation-based estimation. However, many applications (e.g., traffic in high-speed communications networks) call for autocorrelated stochastic models to which traditional regenerative theory is not directly applicable. Consequently, extensions of regenerative simulation to dependent time series is increasingly gaining in theoretical and practical interest, with Markov chains constituting an important case. Fortunately,

  5. NRH:Quinone Oxidoreductase 2 (NQO2) Protein Competes with the 20 S Proteasome to Stabilize Transcription Factor CCAAT Enhancer-binding Protein ? (C/EBP?), Leading to Protection against ? Radiation-induced Myeloproliferative Disease*

    PubMed Central

    Xu, Junkang; Patrick, Brad Allen; Jaiswal, Anil K.

    2013-01-01

    NRH:quinone oxidoreductase 2 (NQO2) is a flavoprotein that protects cells against radiation and chemical-induced oxidative stress. Disruption of the NQO2 gene in mice leads to ? radiation-induced myeloproliferative diseases. In this report, we showed that the 20 S proteasome and NQO2 both interact with myeloid differentiation factor CCAAT-enhancer-binding protein ? (C/EBP?). The interaction of the 20 S proteasome with C/EBP? led to the degradation of C/EBP?. NQO2, in the presence of its cofactor NRH, protected C/EBP? against 20 S degradation. Deletion and site-directed mutagenesis demonstrated that NQO2 and 20 S competed for the same binding region of S(268)GAGAGKAKKSV(279) in C/EBP?. Exposure of mice and HL-60 cells to ? radiation enhanced the levels of NQO2, which led to an increased NQO2 interaction with C/EBP? and decreased 20 S interaction with C/EBP?. NQO2 stabilization of C/EBP? was independent of NQO1, even though both interacted with the same C/EBP? domain. NQO2?/? mice, deficient in NQO2, failed to stabilize C/EBP?. This contributed to the development of ? radiation-induced myeloproliferative disease in NQO2?/? mice. PMID:24142791

  6. Central Limit Theorems for Permuted Regenerative Estimators

    E-print Network

    Nakayama, Marvin K.

    Central Limit Theorems for Permuted Regenerative Estimators James M. Calvin and Marvin K. Nakayama for some permuted estimators from regenerative simulations. These limit theorems provide the basis: efficiency, statistical analysis. Probability: regenerative processes. 1 Introduction In Calvin and Nakayama

  7. Regenerative air heater

    DOEpatents

    Hasselquist, Paul B. (Maple Grove, MN); Baldner, Richard (Minnetonka, MN)

    1982-01-01

    A gas-cooled steel skirt is used to support a refractory cored brick matrix and dome structure in a high temperature regenerative air heater useful in magnetohydrodynamic power generation. The steel skirt thermally expands to accommodate the thermal expansion of the dome structure despite substantial temperature differential thereby reducing relative movement between the dome bricks. Gas cooling of the steel skirt allows the structure to operate above its normal temperature during clean-out cycles and also allows for the control of the thermal expansion of the steel skirt.

  8. Regenerative Sorption Refrigerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Wen, Liang-Chi; Bard, Steven

    1991-01-01

    Two-stage sorption refrigerator achieves increased efficiency via regenerative-heating concept in which waste heat from praseodymium/cerium oxide (PCO) chemisorption compressor runs charcoal/krypton (C/Kr) sorption compressor. Waste heat from each PCO sorption compressor used to power surrounding C/Kr sorption compressor. Flows of heat in two compressor modules controlled by gas-gap thermal switches. Has no wearing moving parts other than extremely long life, room-temperature check valves operating about twice per hour. Virtually no measurable vibration, and has potential operating life of at least ten years.

  9. Regenerative air heater

    DOEpatents

    Hasselquist, P.B.; Baldner, R.

    1980-11-26

    A gas-cooled steel skirt is used to support a refractory cored brick matrix and dome structure in a high temperature regenerative air heater useful in magnetohydrodynamic power generation. The steel skirt thermally expands to accommodate the thermal expansion of the dome structure despite substantial temperature differential thereby reducing relative movement between the dome bricks. Gas cooling of the steel skirt allows the structure to operate above its normal temperature during clean-out cycles and also allows for the control of the thermal expansion of the steel skirt.

  10. Regenerative adsorbent heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  11. [Focal nodular hyperplasia (author's transl)].

    PubMed

    Schild, H; Thelen, M; Paquet, K J; Biersack, H J; Janson, R; Bücheler, E; Hansen, H H; Grönniger, J

    1980-10-01

    Focal nodular hyperplasia was diagnosed angiographically in 14 patients and confirmed histologically. Differentiation of this benign lesion from other space-occupying diseases of the liver can be very difficult, since focal nodular hyperplasia produces a variable angiographic appearance. The typical angiogram showing radial vessels in the arterial phase and sharply demarcated foci in the parenchyma phase is found in only one third of patients. Angiographic differential diagnosis includes adenomas and carcinomas of the liver. Resection of the tumours in case of malignant tumours is not indicated. Foci at the margin of the liver, or if they are pedunculated, should be removed in case of spontaneous perforation. Tumours in the centre of the liver should be observed (computer tomography). Oral contraceptives stimulate the growth of these foci. They may diminish in size after stopping these drugs. 70% of cases of focal nodular hyperplasia remain clinically silent and were discovered accidentally or at autopsy. PMID:6263766

  12. Nanosensors for regenerative medicine.

    PubMed

    Yeo, David C; Wiraja, Christian; Mantalaris, Athanasios; Xu, Chenjie

    2014-10-01

    Assessing biodistribution, fate, and function of implanted therapeutic cells in preclinical animal experiments is critical to realize safe, effective and efficient treatments for subsequent implementation within the clinic. Currently, tissue histology, the most prevalent analytical technique to meet this need, is limited by end-point analysis, high cost and long preparation time. Moreover, it is disadvantaged by an inability to monitor in real-time, qualitative interpretation and ethical issues arising from animal sacrifice. While genetic engineering techniques allow cells to express molecules with detectable signals (e.g., fluorescence, luminescence, T1 (spin-lattice)/T2 (spin-spin) contrast in magnetic resonance imaging, radionuclide), concerns arise regarding technical complexity, high-cost of genetic manipulation, as well as mutagenic cell dysfunction. Alternatively, cells can be labeled using nanoparticle-sensors-nanosensors that emit signals to identify cell location, status and function in a simple, cost-effective, and non-genetic manner. This review article provides the definition, classification, evolution, and applications of nanosensor technology and focuses on how they can be utilized in regenerative medicine. Several examples of direct applications include: (1) monitoring post-transplantation cell behavior, (2) revealing host response following foreign biomaterial implantation, and (3) optimization of cell bioprocess operating conditions. Incorporating nanosensors is expected to expedite the development of cell-based regenerative medicine therapeutics. PMID:25992416

  13. Parathyroid hyperplasia associated with thymoma.

    PubMed Central

    Byrne, D. J.; Gunn, A.; Davidson, D. L.; Paterson, C. R.

    1989-01-01

    The case of a 65 year old female with myasthenia gravis and hypercalcaemia is presented. Failure of medical control of the myasthenia necessitated thymectomy at which time parathyroid exploration was also carried out. This revealed parathyroid hyperplasia and a thymoma. This association has not been previously documented in the literature. PMID:2608566

  14. The Pharmacology of Regenerative Medicine

    PubMed Central

    Saul, Justin M.; Furth, Mark E.; Andersson, Karl-Erik

    2013-01-01

    Regenerative medicine is a rapidly evolving multidisciplinary, translational research enterprise whose explicit purpose is to advance technologies for the repair and replacement of damaged cells, tissues, and organs. Scientific progress in the field has been steady and expectations for its robust clinical application continue to rise. The major thesis of this review is that the pharmacological sciences will contribute critically to the accelerated translational progress and clinical utility of regenerative medicine technologies. In 2007, we coined the phrase “regenerative pharmacology” to describe the enormous possibilities that could occur at the interface between pharmacology, regenerative medicine, and tissue engineering. The operational definition of regenerative pharmacology is “the application of pharmacological sciences to accelerate, optimize, and characterize (either in vitro or in vivo) the development, maturation, and function of bioengineered and regenerating tissues.” As such, regenerative pharmacology seeks to cure disease through restoration of tissue/organ function. This strategy is distinct from standard pharmacotherapy, which is often limited to the amelioration of symptoms. Our goal here is to get pharmacologists more involved in this field of research by exposing them to the tools, opportunities, challenges, and interdisciplinary expertise that will be required to ensure awareness and galvanize involvement. To this end, we illustrate ways in which the pharmacological sciences can drive future innovations in regenerative medicine and tissue engineering and thus help to revolutionize the discovery of curative therapeutics. Hopefully, the broad foundational knowledge provided herein will spark sustained conversations among experts in diverse fields of scientific research to the benefit of all. PMID:23818131

  15. Regenerative braking device

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1982-01-12

    Disclosed are several embodiments of a regenerative braking device for an automotive vehicle. The device includes a plurality of rubber rollers (24, 26) mounted for rotation between an input shaft (14) connectable to the vehicle drivetrain and an output shaft (16) which is drivingly connected to the input shaft by a variable ratio transmission (20). When the transmission ratio is such that the input shaft rotates faster than the output shaft, the rubber rollers are torsionally stressed to accumulate energy, thereby slowing the vehicle. When the transmission ratio is such that the output shaft rotates faster than the input shaft, the rubber rollers are torsionally relaxed to deliver accumulated energy, thereby accelerating or driving the vehicle.

  16. Hydrogels in Regenerative Medicine

    PubMed Central

    Slaughter, Brandon V.; Khurshid, Shahana S.; Fisher, Omar Z.; Khademhosseini, Ali

    2015-01-01

    Hydrogels, due to their unique biocompatibility, flexible methods of synthesis, range of constituents, and desirable physical characteristics, have been the material of choice for many applications in regenerative medicine. They can serve as scaffolds that provide structural integrity to tissue constructs, control drug and protein delivery to tissues and cultures, and serve as adhesives or barriers between tissue and material surfaces. In this work, the properties of hydrogels that are important for tissue engineering applications and the inherent material design constraints and challenges are discussed. Recent research involving several different hydrogels polymerized from a variety of synthetic and natural monomers using typical and novel synthetic methods are highlighted. Finally, special attention is given to the microfabrication techniques that are currently resulting in important advances in the field. PMID:20882499

  17. THE BLIND SIMULATION PROBLEM and REGENERATIVE PROCESSES

    E-print Network

    Bucklew, James Antonio

    THE BLIND SIMULATION PROBLEM and REGENERATIVE PROCESSES JAMES BUCKLEW November 6, 2000 Abstract and hence to a general consideration of regenerative processes. We derive several new large deviation for many regenerative processes. KEYWORDS: Monte Carlo Simulation, Large Deviation Theory, Regener­ ative

  18. Study on regenerative braking of electric vehicle

    Microsoft Academic Search

    Zhang Chuanwei; Bai Zhifeng; Cao Binggang; Li Jingcheng

    2004-01-01

    This paper discusses the regenerative braking system for electric vehicle (EV) that performs regenerative energy recovery based on analytical deduction of several regenerative braking systems with the microscopic view of pulse width modulation (PWM) driving, a constant regenerative current control scheme is proposed, thereby providing improved performance and the energy recovery efficiency at minimum cost. Experimental results of EV show

  19. Carbon Nanotubes in Regenerative Medicine

    Microsoft Academic Search

    Bhavna S. Paratala; Balaji Sitharaman

    \\u000a This chapter focuses on the latest developments in applications of carbonnanotubes (CNTs) for regenerative medicine. Regenerative\\u000a Medicine focuses on technologies to create functional tissues to repair or replace tissues or organs lost due to trauma or\\u000a disease. Carbon nonotubes (CNTs) have been under investigation in the past decade for an array of applications due to their\\u000a unique and versatile properties.

  20. Adenomatous hyperplasia of the liver.

    PubMed

    Gindhart, T D; Cimis, R J; Mosenthal, W T; Longnecker, D S

    1979-01-01

    An unusual case of adenomatous hyperplasia of the liver arose spontaneously in an 82-year-old woman. Massive fatal ascites developed during an eight-week period in the absence of cirrhosis. No drug, chemical, or hormone could be identified as the causative agent. Estrogens may play a role as possible promoters in the growth of hepatic tumors. Identifying liver tumors in women that are not associated with oral contraceptive use is valuable. PMID:215102

  1. Prostatic stromal hyperplasia with atypia.

    PubMed

    Hutchinson, Ryan C; Wu, Kevin J; Cheville, John C; Thiel, David D

    2013-01-01

    Prostatic stromal hyperplasia with atypia (PSHA) is a rare histologic finding diagnosed incidentally on prostate biopsies, transurethral resection specimens, and radical prostatectomy specimens. PSHA has a bizarre histologic appearance and these lesions often raise concern for sarcoma; however, their clinical course is indolent and does not include extraprostatic progression. We discuss a case of PHSA discovered on prostate biopsy performed for an abnormal digital rectal examination and review the literature on this rare pathologic finding. PMID:23781384

  2. Phytotherapy for benign prostatic hyperplasia

    Microsoft Academic Search

    Glenn S. Gerber

    2002-01-01

    Phytotherapy has become a more popular treatment option among American men with benign prostatic hyperplasia (BPH). The most\\u000a popular herbal agent is saw palmetto (Serenoa repens), which is derived from the berry of the American dwarf palm tree. Pygeum africanum and beta-sitosterol are also used by many patients with BPH, either alone or in combination with saw palmetto. A significant

  3. Hypoglycaemia in congenital adrenal hyperplasia.

    PubMed Central

    Mackinnon, J; Grant, D B

    1977-01-01

    Two young children with salt-losing congenital adrenal hyperplasia developed profound hypoglycaemia. In one child hypoglycaemia occurred after a prolonged fast and in the other it was precipitated by infection. This complication may be more common than the literature suggests, and emergency treatment with glucose or hydrocortisone, given by injection, should be given to any child with the disorder who suddenly or unexpectedly collapses. PMID:879852

  4. Thermally regenerative fuel cells

    NASA Astrophysics Data System (ADS)

    Ludwig, F. A.; Kindler, A.; McHardy, J.

    1991-10-01

    The three phase project was undertaken to investigate solventless ionic liquids as possible working fluids for a new type of thermally regenerative fuel cell (TRFC). The heart of the new device, invented at Hughes Aircraft Company in 1983, is an electrochemical concentration cell where acid and base streams react to produce electrical energy. Thermal energy is then used to decompose the resulting salts and regenerate the cell reactants. In principle, a TRFC can be matched to any source of thermal energy simply by selecting working fluids with the appropriate regeneration temperature. However, aqueous working fluids (the focus of previous studies) impose limitations on both the operating temperatures and the achievable energy densities. It was the need to overcome these limitations that prompted the present investigation. Specific aims were to identify possible working fluids for TRFC systems with both low and high regeneration temperatures. A major advantage of our aqueous-fluid TRFC systems has been the ability to use hydrogen electrodes. The low activation and mass transfer losses of these electrodes contribute substantially to overall system efficiency.

  5. Regenerative switching CMOS system

    DOEpatents

    Welch, James D. (10328 Pinehurst Ave., Omaha, NE 68124)

    1998-01-01

    Complementary Metal Oxide Semiconductor (CMOS) Schottky barrier Field Effect Transistor systems, which are a seriesed combination of N and P-Channel MOSFETS, in which Source Schottky barrier junctions of the N and P-Channel Schottky barrier MOSFETS are electically interconnected, (rather than the Drains as in conventional diffused junction CMOS), which Schottky barrier MOSFET system demonstrates Regenerative Inverting Switching Characteristics in use are disclosed. Both the N and P-Channel Schottky barrier MOSFET devices are unique in that they provide operational Drain Current vs. Drain to Source voltage as a function of Gate voltage only where the polarities of the Drain voltage and Gate voltage are opposite, referenced to the Source as a common terminal, and where the polarity of the voltage applied to the Gate is appropriate to cause Channel inversion. Experimentally derived results which demonstrate and verify the operation of N and P-Channel Schottky barrier MOSFETS actually fabricated on P and N-type Silicon respectively, by a common procedure using vacuum deposited Chromium as a Schottky barrier forming metal, are also provided.

  6. Regenerative switching CMOS system

    DOEpatents

    Welch, J.D.

    1998-06-02

    Complementary Metal Oxide Semiconductor (CMOS) Schottky barrier Field Effect Transistor systems, which are a series combination of N and P-Channel MOSFETS, in which Source Schottky barrier junctions of the N and P-Channel Schottky barrier MOSFETS are electrically interconnected, (rather than the Drains as in conventional diffused junction CMOS), which Schottky barrier MOSFET system demonstrates Regenerative Inverting Switching Characteristics in use are disclosed. Both the N and P-Channel Schottky barrier MOSFET devices are unique in that they provide operational Drain Current vs. Drain to Source voltage as a function of Gate voltage only where the polarities of the Drain voltage and Gate voltage are opposite, referenced to the Source as a common terminal, and where the polarity of the voltage applied to the Gate is appropriate to cause Channel inversion. Experimentally derived results which demonstrate and verify the operation of N and P-Channel Schottky barrier MOSFETS actually fabricated on P and N-type Silicon respectively, by a common procedure using vacuum deposited Chromium as a Schottky barrier forming metal, are also provided. 14 figs.

  7. Regenerative Strategies for Craniofacial Disorders

    PubMed Central

    Garland, Catharine B.; Pomerantz, Jason H.

    2012-01-01

    Craniofacial disorders present markedly complicated problems in reconstruction because of the complex interactions of the multiple, simultaneously affected tissues. Regenerative medicine holds promise for new strategies to improve treatment of these disorders. This review addresses current areas of unmet need in craniofacial reconstruction and emphasizes how craniofacial tissues differ from their analogs elsewhere in the body. We present a problem-based approach to illustrate current treatment strategies for various craniofacial disorders, to highlight areas of need, and to suggest regenerative strategies for craniofacial bone, fat, muscle, nerve, and skin. For some tissues, current approaches offer excellent reconstructive solutions using autologous tissue or prosthetic materials. Thus, new “regenerative” approaches would need to offer major advantages in order to be adopted. In other tissues, the unmet need is great, and we suggest the greatest regenerative need is for muscle, skin, and nerve. The advent of composite facial tissue transplantation and the development of regenerative medicine are each likely to add important new paradigms to our treatment of craniofacial disorders. PMID:23248598

  8. Biomaterials for Bone Regenerative Engineering.

    PubMed

    Yu, Xiaohua; Tang, Xiaoyan; Gohil, Shalini V; Laurencin, Cato T

    2015-06-01

    Strategies for bone tissue regeneration have been continuously evolving for the last 25 years since the introduction of the "tissue engineering" concept. The convergence of the life, physical, and engineering sciences has brought in several advanced technologies available to tissue engineers and scientists. This resulted in the creation of a new multidisciplinary field termed as "regenerative engineering". In this article, the role of biomaterials in bone regenerative engineering is systematically reviewed to elucidate the new design criteria for the next generation of biomaterials for bone regenerative engineering. The exemplary design of biomaterials harnessing various materials characteristics towards successful bone defect repair and regeneration is highlighted. Particular attention is given to the attempts of incorporating advanced materials science, stem cell technologies, and developmental biology into biomaterials design to engineer and develop the next generation bone grafts. PMID:25846250

  9. Medical management of benign prostatic hyperplasia

    Microsoft Academic Search

    Andrew Chacon; Manoj Monga

    1999-01-01

    The management of benign prostatic hyperplasia has undergone a rapid evolution over the past decade from a surgical emphasis to a medical emphasis. Great strides in the development of a-adrenergic blockers, 5a-reductase inhibitors and a variety of phytotherapeutics have fueled this evolution. This article reviews the past, present and future of the medical management of benign prostatic hyperplasia.

  10. Venous neointimal hyperplasia in polytetrafluoroethylene dialysis grafts

    Microsoft Academic Search

    Prabir Roy-Chaudhury; Burnett S. Kelly; Mary Ann Miller; Anita Reaves; Janice Armstrong; Nuwan Nanayakkara; Sue C. Heffelfinger

    2001-01-01

    Venous neointimal hyperplasia in polytetrafluoroethylene dialysis grafts.BackgroundVascular access dysfunction is the most important cause of morbidity and hospitalization in the hemodialysis population in the United States at a cost of $1 billion per annum. Venous neointimal hyperplasia (VNH) characterized by stenosis and subsequent thrombosis accounts for the overwhelming majority of pathology resulting in polytetrafluoroethylene (PTFE) dialysis graft failure. Despite the

  11. Regenerative cascade homotopies for solving polynomial systems

    E-print Network

    Sommese, Andrew J.

    Regenerative cascade homotopies for solving polynomial systems Jonathan D. Hauenstein Andrew J that combining regen- eration with the dimension-by-dimension algorithm was significantly faster than naively witness supersets. This regener- ative cascade is superior in practice to all known methods. Department

  12. TEST ON REGENERATIVE PROCESS THROUGH -DIVERGENCE

    E-print Network

    Paris-Sud XI, Université de

    TEST ON REGENERATIVE PROCESS THROUGH -DIVERGENCE Jacques TOUBOUL Jack to reject the hypothesis saying that a process is a regenerative process. This condition is based: Regenerative Process; Renewal Process; minimum -divergence; Point Process. 2000 MSC: 60K20 62H15 62H12 60G51

  13. Regenerative Medicine: Past and Present

    Microsoft Academic Search

    Anthony Atala

    2009-01-01

    Novel therapies resulting from regenerative medicine and tissue engineering technology may offer new hope for patients with injuries, end-stage organ failure, degenerative disorders and many other clinical issues. Currently, patients suffering from diseased and injured organs are treated with transplanted organs. However, there is a shortage of donor organs that is worsening yearly as the population ages and new cases

  14. Regenerative flywheel energy storage system

    Microsoft Academic Search

    E. L. Lustanader; I. H. Edelfelt; D. W. Jones; A. B. Plunkett; E. Richter; F. G. Turnbull

    1979-01-01

    The development, fabrication, and testing of a regenerative flywheel energy storage and recovery system for a battery\\/flywheel electric vehicle of the 3000 lb class are described. The vehicle propulsion system was simulated on a digital computer in order to determine the optimum system operating strategies and establish a calculated range improvement over a nonregenerative, all-electric vehicle. Fabrication of the inductor

  15. Regenerative flywheel energy storage system

    Microsoft Academic Search

    E. L. Lustanader; I. H. Edelfelt; D. W. Jones; A. B. Plunkett; E. Richter; F. G. Turnbull

    2008-01-01

    The development, fabrication, and testing of a regenerative flywheel energy storage and recovery system for a battery\\/flywheel electric vehicle of the 3000 lb class are described. The vehicle propulsion system was simulated on a digital computer in order to determine the optimum system operating strategies and establish a calculated range improvement over a nonregenerative, all-electric vehicle. Fabrication of the inductor

  16. CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE

    E-print Network

    Quake, Stephen R.

    , Hispanic, Native American Indian, Alaskan Native, Hawaiian) #12;CIRM Scholar Training Grant Pre GRANT REGENERATIVE MEDICINE Pre-doctoral Scholar Application Deadline: June 30, 2011 Instructions will not be considered. e) The length of support will be for one year. #12;CIRM Scholar Training Grant Pre

  17. Focal epithelial hyperplasia - an update.

    PubMed

    Said, Ahmed K; Leao, Jair C; Fedele, Stefano; Porter, Stephen R

    2013-07-01

    Focal epithelial hyperplasia (FEH) is an asymptomatic benign mucosal disease, which is mostly observed in specific groups in certain geographical regions. FEH is usually a disease of childhood and adolescence and is generally associated with people who live in poverty and of low socioeconomic status. Clinically, FEH is typically characterized by multiple, painless, soft, sessile papules, plaques or nodules, which may coalesce to give rise to larger lesions. Human papillomavirus (HPV), especially genotypes 13 and 32, have been associated and detected in the majority of FEH lesions. The clinical examination and social history often allow diagnosis, but histopathological examination of lesional tissue is usually required to confirm the exact diagnosis. FEH sometimes resolves spontaneously however, treatment is often indicated as a consequence of aesthetic effects or any interference with occlusion. There remains no specific therapy for FEH, although surgical removal, laser excision or possibly topical antiviral agents may be of benefit. There remains no evidence that FEH is potentially malignant. PMID:23061874

  18. Electrospun Nanofibers for Regenerative Medicine**

    PubMed Central

    Liu, Wenying; Thomopoulos, Stavros

    2013-01-01

    This article reviews recent progress in applying electrospun nanofibers to the emerging field of regenerative medicine. We begin with a brief introduction to electrospinning and nanofibers, with a focus on issues related to the selection of materials, incorporation of bioactive molecules, degradation characteristics, control of mechanical properties, and facilitation of cell infiltration. We then discuss a number of approaches to fabrication of scaffolds from electrospun nanofibers, including techniques for controlling the alignment of nanofibers and for producing scaffolds with complex architectures. We also highlight applications of the nanofiber-based scaffolds in four areas of regenerative medicine that involve nerves, dural tissues, tendons, and the tendon-to-bone insertion site. We conclude this review with perspectives on challenges and future directions for design, fabrication, and utilization of scaffolds based on electrospun nanofibers. PMID:23184683

  19. Heat regenerative external combustion engine

    NASA Astrophysics Data System (ADS)

    Duva, Anthony W.

    1993-03-01

    It is an object of the invention to provide an external combustion expander-type engine having improved efficiency. It is another object of the invention to provide an external combustion engine in which afterburning in the exhaust channel is substantially prevented. Yet another object of the invention is to provide an external combustion engine which is less noisy than an external combustion engine of conventional design. These and other objects of the invention will become more apparent from the following description. The above objects of the invention are realized by providing a heat regenerative external combustion engine. The heat regenerative external combustion engine of the invention comprises a combustion chamber for combusting a monopropellant fuel in order to form an energized gas. The energized gas is then passed through a rotary valve to a cylinder having a reciprocating piston disposed therein. The gas is spent in moving the piston, thereby driving a drive shaft.

  20. Angiolymphoid Hyperplasia with Eosinophilia: A Case Report.

    PubMed

    Esteves, Paola; Barbalho, Marcella; Lima, Tiago; Quintella, Leonardo; Niemeyer-Corbellini, João Paulo; Ramos-E-Silva, Marcia

    2015-01-01

    Angiolymphoid hyperplasia with eosinophilia is a rare disease considered as being a vascular malformation resulting from a subjacent arteriovenous shunt. It affects mostly the head of women between 20 and 40 years old and may present spontaneous involution. PMID:26120306

  1. Angiolymphoid Hyperplasia with Eosinophilia: A Case Report

    PubMed Central

    Esteves, Paola; Barbalho, Marcella; Lima, Tiago; Quintella, Leonardo; Niemeyer-Corbellini, João Paulo; Ramos-e-Silva, Marcia

    2015-01-01

    Angiolymphoid hyperplasia with eosinophilia is a rare disease considered as being a vascular malformation resulting from a subjacent arteriovenous shunt. It affects mostly the head of women between 20 and 40 years old and may present spontaneous involution. PMID:26120306

  2. Sebaceous hyperplasia: systemic treatment with isotretinoin*

    PubMed Central

    Tagliolatto, Sandra; Santos, Octavio de Oliveira; Alchorne, Maurício Mota de Avelar; Enokihara, Mauro Yoshiaki

    2015-01-01

    The study aimed to verify the therapeutic action of isotretinoin in the treatment of sebaceous hyperplasia. During two months, 20 patients with sebaceous hyperplasia took isotretinoin at a dosage of 1mg/kg per day. Their skin lesions were counted and photographed before and after treatment and re-evaluated two years later. The average number of sebaceous hyperplasia lesions before treatment was 24 per patient. At the end of two months of therapy, the number of lesions decreased to 2 per patient. The statistically analyzed data showed a reduction in the number of lesions following isotretinoin use (p < 0.05). Two years after the end of the treatment, the average number of sebaceous hyperplasia lesions was 4 per patient. There were no severe side effects. Thus, the data analysis suggests that isotretinoin is a safe and effective drug for treating the disease under study. PMID:25830991

  3. Thermal regenerative cracking (TRC) process

    SciTech Connect

    Bhojwani, A.H.; Gartside, R.J.; Johnson, A.R.; Woebcke, H.N.

    1982-03-09

    An improved thermal regenerative cracking (Trc) apparatus and process includes: (1) an improved low residence time solid-gas separation device and system; and (2) an improved solids feeding device and system; as well as an improved sequential thermal cracking process; an improved solids quench boiler and process; an improved preheat vaporization system; and an improved fuel gas generation system for solids heated. One or more of the improvements may be incorporated in a conventional trc system.

  4. Thermal regenerative cracking (trc) apparatus

    SciTech Connect

    Bhojwani, A.H.; Gartside, R.J.; Johnson, A.R.; Woebcke, H.N.

    1983-01-25

    An improved thermal regenerative cracking (trc) apparatus and process includes: an improved low residence time solid-gas separation device and system; and an improved solids feeding device and system; as well as an improved sequential thermal cracking process; an improved solids quench boiler and process; an improved preheat vaporization system; and an improved fuel gas generation system for solids heated. One or more of the improvements may be incorporated in a conventional trc system.

  5. The unitized regenerative fuel cell

    SciTech Connect

    NONE

    1997-05-01

    Fuel cells can operate on hydrogen fuel and oxygen from air. If the fuel cell is designed to also operate in reverse as an electrolyzer, then electricity can be used to convert the water back into hydrogen and oxygen. This dual function system is known as a reversible or unitized regenerative fuel cell. This is an excellent energy source in situations where weight is a concern.

  6. Regenerative nanomedicine for vision restoration.

    PubMed

    Zarbin, Marco A; Arlow, Timothy; Ritch, Robert

    2013-12-01

    Herein, we discuss recent applications of nanotechnology to ophthalmology, including nanoparticles for drug, gene, and trophic factor delivery; regenerative medicine (in the areas of optogenetics and optic nerve regeneration); and diagnostics (eg, minimally invasive biometric monitoring). Specific applications for the management of choroidal neovascularization, retinal neovascularization, oxidative damage, optic nerve damage, and retinal degenerative disease are considered. Nanotechnology will play an important role in early- and late-stage interventions in the management of blinding diseases. PMID:24290123

  7. Gingival enlargement in partial hemifacial hyperplasia

    PubMed Central

    Jagtap, Rasika Ravindra; Deshpande, Gaurav Shekhar

    2014-01-01

    Hemifacial hypertrophy is a rare developmental disorder, characterized by unilateral enlargement of facial tissues. The hemifacial hyperplasia is classified as true hemifacial hypertrophy and partial hemifacial hypertrophy. It is unilateral enlargement of viscerocranial condition in which not all structures are enlarged. We present a rare case of gingival enlargement in partial hemifacial hyperplasia highlighting the clinical and radiological findings with the corrective treatment offered for gingival enlargement. PMID:25624636

  8. Current research on regenerative systems.

    PubMed

    Shapira, J; Mandel, A D; Quattrone, P D; Bell, N L

    1969-01-01

    Multiple studies directed toward the development of a regenerative life support system have shown that easily synthesized organic compounds and microbiological materials are potentially capable of being used as foods for long-duration space missions. Animal feeding studies have supported these views. The organic compounds presently believed to offer the greatest potential are glycerol, simple glycerol derivatives such as triacetin, and formose sugars. Laboratory studies indicate that glycerol can be synthesized from formaldehyde which in turn is obtained by the direct catalytic oxidation of methane, a by-product of the Sabatier reaction used in spacecraft atmosphere control system. Formose sugars are derived from the self-condensation of formaldehyde. Mixtures of glycerol and triacetin have been shown to be suitable as a major component of diets fed to weanling rats for prolonged periods. These compounds do not exist as stereoisomers and therefore offer advantages over the formose sugars. Hydrogenomonas eutropha is the microbiological system under investigation. An automated system for the continuous autotrophic production of Hydrogenomonas bacteria is in operation, and the nutritional requirements for growth in the system using urea as a nitrogen source are being studied. Nutritional evaluation of Hydrogenomonas bacteria has shown they are capable of supplying the total protein requirement of growing rats for prolonged periods. The potential and problems of these regenerative systems and the prospects for the accomplishment of a totally regenerative food system will be discussed. PMID:12197534

  9. Congenital absence of portal vein with nodular regenerative hyperplasia of the liver

    Microsoft Academic Search

    L. Grazioli; D. Alberti; L. Olivetti; W. Rigamonti; F. Codazzi; L. Matricardi; C. Fugazzola; A. Chiesa

    2000-01-01

    .   Congenital absence of the portal vein is a very rare anomaly. The intestinal and splenic venous drainage bypasses the liver\\u000a and drain into the inferior vena cava (IVC). Two cases of such anomaly are described. Both cases were investigated by US coupled\\u000a with echo-colour Doppler examination, CT and MR imaging, followed by digital subtraction angiography (DSA) and liver biopsy.

  10. Regenerative fuel cell engineering - FY99

    Microsoft Academic Search

    Michael A. Inbody; Rodney L. Borup; James C. Hedstrom; Jose Tafoya; Byron Morton; Lois Zook; Nicholas E. Vanderborgh

    2000-01-01

    The authors report the work conducted by the ESA-EPE Fuel Cell Engineering Team at Los Alamos National Laboratory during FY99 on regenerative fuel cell system engineering. The work was focused on the evaluation of regenerative fuel cell system components obtained through the RAFCO program. These components included a 5 kW PEM electrolyzer, a two-cell regenerative fuel cell stack, and samples

  11. Genetics of congenital adrenal hyperplasia.

    PubMed

    Krone, Nils; Arlt, Wiebke

    2009-04-01

    Congenital adrenal hyperplasia (CAH) is one of the most common inherited metabolic disorders. It comprises a group of autosomal recessive disorders caused by the deficiency of one of four steroidogenic enzymes involved in cortisol biosynthesis or in the electron donor enzyme P450 oxidoreductase (POR) that serves as electron donor to steroidogenic cytochrome P450 (CYP) type II enzymes. The biochemical and clinical phenotype depends on the specific enzymatic defect and the impairment of specific enzyme activity. Defects of steroid 21-hydroxylase (CYP21A2) and 11beta-hydroxylase (CYP11B1) only affect adrenal steroidogenesis, whereas 17alpha-hydroxylase (CYP17A1) and 3beta-hydroxysteroid dehydrogenase type 2 (HSD3B2) deficiency also impact on gonadal steroid biosynthesis. Inactivating POR gene mutations are the cause of CAH manifesting with apparent combined CYP17A1-CYP21A2 deficiency. P450 oxidoreductase deficiency (ORD) has a complex phenotype including two unique features not observed in any other CAH variant: skeletal malformations and severe genital ambiguity in both sexes. PMID:19500762

  12. Bromodeoxyuridine Specifically Labels the Regenerative Stem Cells of Planarians

    E-print Network

    Alvarado, Alejandro Sánchez

    Bromodeoxyuridine Specifically Labels the Regenerative Stem Cells of Planarians Phillip A. Newmark1 University Parkway, Baltimore, Maryland 21210 The singular regenerative abilities of planarians require to label specifically the regenerative stem cells, combined with the recently described use of double

  13. Developmental Cell Regenerative Growth in Drosophila Imaginal Discs

    E-print Network

    Gibson, Matt

    Developmental Cell Article Regenerative Growth in Drosophila Imaginal Discs Is Regulated results in localized regenerative proliferation characterized by altered expression of patterning genes are induced by tissue damage and are important for regenerative growth. Furthermore, ectopic Myc enhances

  14. Tenure Track Assistant Professor Cluster Hire in Regenerative Medicine

    E-print Network

    Stormo, Gary

    Tenure Track Assistant Professor Cluster Hire in Regenerative Medicine The Departments of regenerative medicine, including the genetic and epigenetic control of embryonic, adult, or cancer stem cells organisms to explore fundamental and translational questions in regenerative medicine. We anticipate

  15. Optimal packing for cascaded regenerative transmission based on

    E-print Network

    Turitsyn, Sergei K.

    Optimal packing for cascaded regenerative transmission based on phase sensitive amplifiers Mariia performance of advanced modulation formats in nonlinear regenerative channels based on cascaded phase nonlinear regenerative channels for ultra-high capacity transmission. © 2013 Optical Society of America OCIS

  16. Advanced regenerative absorption refrigeration cycles

    DOEpatents

    Dao, Kim (14 Nace Ave., Piedmont, CA 94611)

    1990-01-01

    Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

  17. Heat regenerative external combustion engine

    NASA Astrophysics Data System (ADS)

    Duva, Anthony W.

    1993-10-01

    A heat regenerative external combustion engine is disclosed. The engine includes fuel inlet means which extends along the exhaust passage and/or combustion chamber in order to preheat the fuel, To provide for preheating by gases in both the combustion chamber and the exhaust passage, the combustion chamber is arranged annularly around the drive shaft and between the cylinders. This configuration also is advantageous in that it reduces the noise of combustion. The engine of the invention is particularly well-suited for use in a torpedo.

  18. ``HYTEC''-A thermally regenerative fuel cell

    Microsoft Academic Search

    Prodyot Roy; Samir A. Salamah; Jerry Maldonado; Regina S. Narkiewicz

    1993-01-01

    HYTEC (Hydrogen Thermo-Electrochemical Converter) is a thermally regenerative fuel cell for direct conversion of heat into electricity. The principles of basic cell operation involve ionic transport of hydrogen through a hydride-ion (H-) conducting, molten electrolyte, and reaction with alkali metals, oxygen, or air. In order to operate HYTEC in a thermally regenerative mode, pure Li and Na, or a mixture

  19. ‘‘HYTEC’’—A thermally regenerative fuel cell

    Microsoft Academic Search

    Prodyot Roy; Samir A. Salamah; Jerry Maldonado; Regina S. Narkiewicz

    1993-01-01

    HYTEC (Hydrogen Thermo-Electrochemical Converter) is a thermally regenerative fuel cell for direct conversion of heat into electricity. The principles of basic cell operation involve ionic transport of hydrogen through a hydride-ion (H?) conducting, molten electrolyte, and reaction with alkali metals, oxygen, or air. In order to operate HYTEC in a thermally regenerative mode, pure Li and Na, or a mixture

  20. Regenerative braking strategy for electric vehicles

    Microsoft Academic Search

    Jingang Guo; Junping Wang; Binggang Cao

    2009-01-01

    Regenerative braking is an effective approach for electric vehicles to extend their driving range. The control strategy of regenerative braking plays an important role in maintaining the vehicle's stability and recovering energy. In this paper, the main properties that have influence on brake energy regeneration are analyzed. Mathematical model of brake energy regenerating electric vehicles is established. By analyzing the

  1. Optimization of parallel regenerative braking control strategy

    Microsoft Academic Search

    Zhang Jingming; Song Baoyu; Niu Xiaojing

    2008-01-01

    Regenerative braking system is the own system of electric and hybrid electric vehicle. The system can restore the kinetic energy and potential energy, used during start and accelerating, into battery through electrical machine. The total brake force is composed of friction brake force on front axel, friction brake force on rear axel and regenerative brake force when a vehicle equipped

  2. Studies of regenerative braking in electric vehicle

    Microsoft Academic Search

    M. K. Yoong; Y. H. Gan; G. D. Gan; C. K. Leong; Z. Y. Phuan; B. K. Cheah; K. W. Chew

    2010-01-01

    Generally the braking system for a car is based on hydraulic braking technology. However, this traditional braking methodology causes a lot of energy wastage since it produces unwanted heat during braking. Thus, the invention of regenerative braking in electric car has overcome these disadvantages moreover it helps in save energy and provides higher efficiency for a car. In regenerative mode,

  3. Regenerative Medicine in Alzheimer's Disease

    PubMed Central

    Felsenstein, Kevin M.; Candelario, Kate M.; Steindler, Dennis A.; Borchelt, David R.

    2013-01-01

    Identifying novel, effective therapeutics for Alzheimer's disease (AD) is one of the major unmet medical needs for the coming decade. Because the current paradigm for developing and testing disease modifying AD therapies is protracted and likely to be even longer with the shift towards earlier intervention in pre-clinical AD, it is an open question whether we can develop, test, and widely deploy a novel therapy in time to help the current at-risk generation if we continue to follow the standard paradigms of discovery and drug development. There is an imperative need to find safe and effective preventative measures that can be rapidly deployed to stem the coming wave of AD that will potentially engulf the next generation. We can broadly define regenerative medicine as approaches that use stem-cell-based therapies or approaches that seek to modulate inherent neurogenesis. Neurogenesis, though most active during pre-natal development has been shown to continue in several small parts of the brain, which includes the hippocampus and the subventricular zone, suggesting its potential to reverse cognitive deficits. If AD pathology impacts neurogenesis then it follows that conditions that stimulate endogenous neurogenesis (e.g., environmental stimuli, physical activity, trophic factors, cytokines, and drugs) may help to promote the regenerative and recovery process. Herein, we review the complex logistics of potentially implementing neurogenesis-based therapeutic strategies for the treatment of AD. PMID:24286919

  4. Optimal performance of regenerative cryocoolers

    NASA Astrophysics Data System (ADS)

    de Boer, P. C. T.

    2011-02-01

    The key component of a regenerative cryocooler is its regenerative heat exchanger. This device is subject to losses due to imperfect heat transfer between the regenerator material and the gas, as well as due to viscous dissipation. The relative magnitudes of these losses can be characterized by the ratio of the Stanton number St to the Fanning friction factor f. Using available data for the ratio St/ f, results are developed for the optimal cooling rate and Carnot efficiency. The variations of pressure and temperature are taken to be sinusoidal in time, and to have small amplitudes. The results are applied to the case of the Stirling cryocooler, with flow being generated by pistons at both sides of the regenerator. The performance is found to be close to optimal at large ratio of the warm space volume to the regenerator void volume. The results are also applied to the Orifice Pulse Tube Refrigerator. In this case, optimal performance additionally requires a large ratio of the regenerator void volume to the cold space volume.

  5. Premature sebaceous hyperplasia in an adolescent boy.

    PubMed

    Wang, Qian; Liu, Jing-Mu; Zhang, Yi-Zhi

    2011-01-01

    Sebaceous hyperplasia is a common, benign condition of the sebaceous glands in adults of middle age or older, occurring primarily on the face and neck. In adolescent or young adult patients, it is a rare entity called premature sebaceous hyperplasia (PSH). Previous reports indicate that the onset of PSH occurs during or shortly after puberty, with an average age-at-onset of 19 years. Here we present an extremely rare prepubescent case of PSH that developed on the right side of a boy's neck when he was 8 years old. PMID:21371111

  6. Modeling regenerative braking and storage for vehicles

    SciTech Connect

    Wicks, F.; Donnelly, K. [Union Coll., Schenectady, NY (United States)

    1997-12-31

    The fuel savings benefits of regenerative braking and storage for vehicles are often described but not quantified. For example, the federal government and automobile manufacturers are sponsoring a Program for a New Generation of Vehicles (PGNV) with a goal of obtaining a performance of 80 mpg in a family size car. It is typically suggested that such a vehicle will be a hybrid engine and electric drive with regenerative braking. The authors note that while regenerative braking has the potential of saving fuel, it may also do more harm than good as a result of additional weight, less than ideal charge/discharge efficiency on the batteries or storage flywheels and the limited portion of the entire driving cycle when regenerative braking can be utilized. The authors also noted that if regenerative braking can have a net benefit, it would be on a heavy vehicle such as a municipal bus because of the frequent stop and go requirements for both traffic light and passengers. Thus the authors initiated a study of regenerative braking on such a vehicle. The resulting analysis presented in this paper includes data following municipal buses to define the driving cycle, modeling the bus power requirements from weight, aerodynamics and rolling resistance, and then calculating the fuel saving that could result from an ideal regenerative braking system.

  7. Variable ratio regenerative braking device

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1981-12-15

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  8. Unitized regenerative fuel cell systems

    SciTech Connect

    Mitlitsky, F; Molter, T M; Myers, B; Weisberg, A H

    1998-09-10

    Energy storage systems with extremely high specific energy (>400 Wh/kg) have been designed that use lightweight pressure vessels to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs).[1] URFC systems are being designed and developed for a variety of applications, including high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEVs), hybrid energy storage/propulsion systems for spacecraft, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications.[1-10] Energy storage for HALE SRA was the original application for this set of innovations, and a prototype solar powered aircraft (Pathfinder-Plus) recently set another altitude record for all propeller-driven aircraft on August 6, 1998, when it flew to 80,285 feet (24.47 km).[11

  9. Regenerative braking system for a hybrid electric vehicle

    Microsoft Academic Search

    S. R. Cikanek; K. E. Bailey

    2002-01-01

    This paper discusses a regenerative braking system (RBS) for a parallel hybrid electric vehicle (PHEV) that performs regenerative energy recovery based on vehicle attributes, thereby providing improved performance, efficiency and reliability at minimal additional cost. A detailed description of the regenerative braking algorithm is presented along with simulation results from a dynamic model of the PHEV exhibiting the regenerative braking

  10. Hydrogen\\/chlorine regenerative fuel cell

    Microsoft Academic Search

    Maricle

    1978-01-01

    A regenerative fuel cell is described in which the reactive gases are hydrogen and chlorine and the electrolyte is an aqueous solution of a conductive salt or acid in which hydrogen chloride gas is soluble.

  11. Regenerative medicine applications in combat casualty care.

    PubMed

    Fleming, Mark E; Bharmal, Husain; Valerio, Ian

    2014-03-01

    The purpose of this report is to describe regenerative medicine applications in the management of complex injuries sustained by service members injured in support of the wars in Afghanistan and Iraq. Improvements in body armor, resuscitative techniques and faster transport have translated into increased patient survivability and more complex wounds. Combat-related blast injuries have resulted in multiple extremity injuries, significant tissue loss and amputations. Due to the limited availability and morbidity associated with autologous tissue donor sites, the introduction of regenerative medicine has been critical in managing war extremity injuries with composite massive tissue loss. Through case reports and clinical images, this report reviews the application of regenerative medicine modalities employed to manage combat-related injuries. It illustrates that the novel use of hybrid reconstructions combining traditional and regenerative medicine approaches are an effective tool in managing wounds. Lessons learned can be adapted to civilian care. PMID:24750059

  12. A regenerative cycle reciprocating internal combustion engine

    Microsoft Academic Search

    C. J. Rallis

    1989-01-01

    A regenerative constant-volume internal combustion engine cycle is presented and analyzed. It is shown how a reciprocating piston-in-cylinder version can be achieved in practice by using separate compression (cold) and expansion (hot) cylinders interconnected by a transfer port packed with a regenerative matrix. By injecting a volatile liquid, such as water, during compression it is possible to achieve a measure

  13. Global strategic partnerships in regenerative medicine.

    PubMed

    French, Anna; Suh, Jane Y; Suh, Carol Y; Rubin, Lee; Barker, Richard; Bure, Kim; Reeve, Brock; Brindley, David A

    2014-09-01

    The approach to research and development in biomedical science is changing. Increasingly, academia and industry seek to collaborate, and share resources and expertise, by establishing partnerships. Here, we explore the co-development partnership landscape in the field of regenerative medicine, focusing on agreements involving one or more private entities. A majority of the largest biopharmaceutical companies have announced strategic partnerships with a specific regenerative medicine focus, signifying the growth and widening appeal of this emerging sector. PMID:25150363

  14. Spectrum of carcinoembryonic antigen immunoreactivity from isolated ductal hyperplasias to atypical hyperplasias associated with infiltrating ductal breast cancer.

    PubMed Central

    Schmitt, F C; Andrade, L

    1995-01-01

    AIMS--To study the immunohistochemical expression of carcinoembryonic antigen (CEA) in ductal hyperplasia of the breast and to investigate its putative relation with atypia and co-existing infiltrating ductal carcinoma. METHODS--Paraffin wax embedded tissue from 37 cases of isolated ductal hyperplasia (five with atypia and 32 without atypia) and 25 cases of ductal hyperplasia associated infiltrating ductal carcinoma (IDC) (seven with atypia and 18 without atypia) was stained with a monoclonal anti-CEA antibody using a standard avidin biotin immunoperoxidase method. RESULTS--CEA immunoreactivity was observed in eight (12.8%) ductal hyperplasia cases. The percentage of CEA positivity in ductal hyperplasia cases with atypia (33.3%) was substantially higher than that observed in cases of ductal hyperplasia without atypia (8.0%). Six cases of ductal hyperplasia associated IDC reacted with CEA; in these six cases the neoplastic cells of the co-existing carcinoma were also CEA positive. The percentage of CEA immunoreactivity in ductal hyperplasia associated IDC was higher than that observed in isolated ductal hyperplasia (24.0 v 5.4%). The percentage of CEA immunoreactivity in atypical ductal hyperplasia associated IDC was similar to that observed in IDC alone (42.9 v 40.0%). CONCLUSIONS--The presence of CEA immunoreactivity has been confirmed in benign proliferative breast lesions. The prevalence of such immunoreactivity increases from 3.1% in isolated, nonatypical ductal hyperplasia to 42.9% in atypical ductal hyperplasia associated IDC. This finding and the similarity of the frequency of CEA positivity in atypical ductal hyperplasia associated IDC and in IDC alone suggests that there is a pathogenetic link between ductal hyperplasia and some types of breast cancer. Images PMID:7706519

  15. Regenerative fuel cell engineering - FY99

    SciTech Connect

    Michael A. Inbody; Rodney L. Borup; James C. Hedstrom; Jose Tafoya; Byron Morton; Lois Zook; Nicholas E. Vanderborgh

    2000-01-01

    The authors report the work conducted by the ESA-EPE Fuel Cell Engineering Team at Los Alamos National Laboratory during FY99 on regenerative fuel cell system engineering. The work was focused on the evaluation of regenerative fuel cell system components obtained through the RAFCO program. These components included a 5 kW PEM electrolyzer, a two-cell regenerative fuel cell stack, and samples of the electrolyzer membrane, anode, and cathode. The samples of the electrolyzer membrane, anode, and cathode were analyzed to determine their structure and operating characteristics. Tests were conducted on the two-cell regenerative fuel cell stack to characterize its operation as an electrolyzer and as a fuel cell. The 5 kW PEM electrolyzer was tested in the Regenerative Fuel Cell System Test Facility. These tests served to characterize the operation of the electrolyzer and, also, to verify the operation of the newly completed test facility. Future directions for this work in regenerative fuel cell systems are discussed.

  16. Current overview on challenges in regenerative endodontics

    PubMed Central

    Bansal, Ramta; Jain, Aditya; Mittal, Sunandan

    2015-01-01

    Introduction: Regenerative endodontics provides hope of converting the non-vital tooth into vital once again. It focuses on substituting traumatized and pathological pulp with functional pulp tissue. Current regenerative procedures successfully produce root development but still fail to re-establish real pulp tissue and give unpredictable results. There are several drawbacks that need to be addressed to improve the quality and efficiency of the treatment. Aim: The aim of this review article is to discuss major priorities that ought to be dealt before applications of regenerative endodontics flourish the clinical practice. Materials and Methods: A web-based research on MEDLINE was done using filter terms Review, published in the last 10 years and Dental journals. Keywords used for research were “regenerative endodontics,” “dental stem cells,” “growth factor regeneration,” “scaffolds,” and “challenges in regeneration.” This review article screened about 150 articles and then the relevant information was compiled. Results: Inspite of the impressive growth in regenerative endodontic field, there are certain loopholes in the existing treatment protocols that might sometimes result in undesired and unpredictable outcomes. Conclusion: Considerable research and development efforts are required to improve and update existing regenerative endodontic strategies to make it an effective, safe, and biological mode to save teeth. PMID:25657518

  17. High power regenerative laser amplifier

    DOEpatents

    Miller, John L. (Livermore, CA); Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Dublin, CA); Zapata, Luis E. (Livermore, CA)

    1994-01-01

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse.

  18. High power regenerative laser amplifier

    SciTech Connect

    Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

    1994-02-08

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

  19. Staged regenerative sorption heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1995-01-01

    A regenerative adsorbent heat pump process and system for cooling and heating a space. A sorbent is confined in a plurality of compressors of which at least four are first stage and at least four are second stage. The first stage operates over a first pressure region and the second stage over a second pressure region which is higher than the first. Sorbate from the first stage enters the second stage. The sorbate loop includes a condenser, expansion valve, evaporator and the compressors. A single sorbate loop can be employed for single-temperature-control such as air conditioning and heating. Two sorbate loops can be used for two-temperature-control as in a refrigerator and freezer. The evaporator temperatures control the freezer and refrigerator temperatures. Alternatively the refrigerator temperature can be cooled by the freezer with one sorbate loop. A heat transfer fluid is circulated in a closed loop which includes a radiator and the compressors. Low temperature heat is exhausted by the radiator. High temperature heat is added to the heat transfer fluid entering the compressors which are desorbing vapor. Heat is transferred from compressors which are sorbing vapor to the heat transfer fluid, and from the heat transfer fluid to the compressors which are desorbing vapor. Each compressor is subjected to the following phases, heating to its highest temperature, cooling down from its highest temperature, cooling to its lowest temperature, and warming up from its lowest temperature. The phases are repeated to complete a cycle and regenerate heat.

  20. JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE RESEARCH ARTICLE J Tissue Eng Regen Med (2011).

    E-print Network

    Linhardt, Robert J.

    2011-01-01

    JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE RESEARCH ARTICLE J Tissue Eng Regen Med, Robert Maidhof1, Leo Wan1, Hyoungshin Park2 and Gordana Vunjak-Novakovic1 * 1 Department of Biomedical and the best-developed contractile behaviour. These findings contribute to defining bioreactor design

  1. Fertility in patients with congenital adrenal hyperplasia.

    PubMed

    Reichman, David E; White, Perrin C; New, Maria I; Rosenwaks, Zev

    2014-02-01

    Congenital adrenal hyperplasia (CAH) is the most frequently encountered genetic steroid disorder affecting fertility. Steroid hormones play a crucial role in sexual development and reproductive function; patients with either 21- hydroxylase or 11?-hydroxylase deficiency thus face immense challenges to their fertility. Given the relevance of CAH in reproductive medicine as well as the diagnostic challenges posed by the phenotypic overlap with polycystic ovary syndrome, we review the reproductive pahophysiology of both classic and nonclassic CAH and present contemporary treatment options. PMID:24355046

  2. Giant hepatic angiomyolipoma simulating focal nodular hyperplasia

    Microsoft Academic Search

    Masaki Miyahara; Michio Kobayashi; Izuru Tada; Kazunari Okada; Koichi Sato; Yang Kim; Tadayasu Hiraoka; Shigeo Yokoyama

    1988-01-01

    A case of hepatic angiomyolipoma occurring in a 41-year-old woman, the eighteenth case in literature, is reported herein.\\u000a The radiographic imagings of the tumor simulated those of focal nodular hyperplasia; namely, the tumor was hyperechoic on\\u000a ultrasound, hypodense on computed tomography, hypervascular on angiography, and exhibited an uptake of technetium (Tc)-99m\\u000a phytate. The diagnosis was established after successful removal of

  3. Medical Treatment of Benign Prostatic Hyperplasia

    PubMed Central

    Lepor, Herbert

    2011-01-01

    Medical therapy for the treatment of benign prostatic hyperplasia (BPH) became an accepted standard of care in the 1990s following the reports of randomized, double-blind, placebo-controlled studies showing that finasteride, a 5-? reductase inhibitor, and terazosin, an ?-blocker, significantly improved lower urinary tract symptoms and increased peak urinary flow rates in men with BPH. This article reviews novel approaches to the pharmacological treatment of BPH. PMID:21826125

  4. Saw Palmetto for Benign Prostatic Hyperplasia

    Microsoft Academic Search

    Stephen Bent; Christopher Kane; Katsuto Shinohara; John Neuhaus; Esther S. Hudes; Harley Goldberg; Andrew L. Avins

    2006-01-01

    In this double-blind trial, we randomly assigned 225 men over the age of 49 years who had moderate-to-severe symptoms of benign prostatic hyperplasia to one year of treatment with saw palmetto extract (160 mg twice a day) or placebo. The pri- mary outcome measures were changes in the scores on the American Urological Association Symptom Index (AUASI) and the maximal

  5. Congenital adrenal hyperplasia: management during critical illness

    Microsoft Academic Search

    E Charmandari; E J Lichtarowicz-Krynska; P C Hindmarsh; A Johnston; A Aynsley-Green; C G D Brook

    2001-01-01

    BACKGROUNDLittle is known of the optimal dose and administration schedule of hydrocortisone in critically ill patients with congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency.AIMTo determine plasma cortisol concentrations after intravenous administration of hydrocortisone in children with CAH and to relate these to plasma cortisol concentrations achieved by endogenous secretion in the stress of critical illness in previously healthy children.METHODSPlasma

  6. Laser treatment of benign prostatic hyperplasia

    Microsoft Academic Search

    Rainer M. Kuntz

    2007-01-01

    To evaluate the role of lasers that allow acute removal of obstructing tissue in the surgical treatment of benign prostatic\\u000a hyperplasia (BPH). A MEDLINE search over the last 6 years focused on randomized trials, large case series and review articles.\\u000a A total of more than 4,000 patients were analyzed with respect to the morbidity and outcome, and the advantages and disadvantages

  7. The ultrastructure of transmissible murine colonic hyperplasia.

    PubMed Central

    Johnson, E.; Barthold, S. W.

    1979-01-01

    Transmissible murine colonic hyperplasia was examined ultrastructurally by sequential sampling after inoculation with the etiologic agent, Citobacter freundii. Light-microscopic changes in the descending colon of inoculated mice were correlated with scanning and transmission electron-microsopic findings. Bacteria were attached to the surface of the mucosa between 4 and 10 days after inoculation. Hyperplasia was most severe at 16 days and thereafter underwent regression. Regression was preceded by extrusion of infected cells from the surface mucosa and replacement by immature hyperplasia epithelium. Hyperplastic epithelium throughtout the crypt resembled undifferentiated crypt cells of controls. By 45 days, the mucosa had reverted to near normal structure. The results suggest that severe mucosal proliferation with minimal inflammatory change resulted from attachment of bacteria to the surface mucosal epithelium. The hyperplastic response appeared to be a defense mechanism of replacing infected cells with newly migrated, uninfected epithelium. Images Figure 15 Figure 16 Figure 4 Figure 5 Figure 6 Figure 1 Figure 2 Figure 3 Figure 8 Figure 12 Figure 13 Figure 14 Figure 9 Figure 10 Figure 11 Figure 7 PMID:525674

  8. European Doctoral Academy in Regenerative Engineering Marie Curie Initial Training Network

    E-print Network

    Cesare, Bernardo

    European Doctoral Academy in Regenerative Engineering Marie Curie Initial Training Network TECAS) and Regenerative Medicine (RM) though the establishment of a European Doctoral Academy in Regenerative Engineering/cell combinations. Research Field: Cardiovascular tissue engineering and regenerative medicine Keywords

  9. Overcoming immunological barriers in regenerative medicine

    PubMed Central

    Zakrzewski, Johannes L; van den Brink, Marcel R M; Hubbell, Jeffrey A

    2015-01-01

    Regenerative therapies that use allogeneic cells are likely to encounter immunological barriers similar to those that occur with transplantation of solid organs and allogeneic hematopoietic stem cells (HSCs). Decades of experience in clinical transplantation hold valuable lessons for regenerative medicine, offering approaches for developing tolerance-induction treatments relevant to cell therapies. Outside the field of solid-organ and allogeneic HSC transplantation, new strategies are emerging for controlling the immune response, such as methods based on biomaterials or mimicry of antigen-specific peripheral tolerance. Novel biomaterials can alter the behavior of cells in tissue-engineered constructs and can blunt host immune responses to cells and biomaterial scaffolds. Approaches to suppress autoreactive immune cells may also be useful in regenerative medicine. The most innovative solutions will be developed through closer collaboration among stem cell biologists, transplantation immunologists and materials scientists. PMID:25093888

  10. Overcoming immunological barriers in regenerative medicine.

    PubMed

    Zakrzewski, Johannes L; van den Brink, Marcel R M; Hubbell, Jeffrey A

    2014-08-01

    Regenerative therapies that use allogeneic cells are likely to encounter immunological barriers similar to those that occur with transplantation of solid organs and allogeneic hematopoietic stem cells (HSCs). Decades of experience in clinical transplantation hold valuable lessons for regenerative medicine, offering approaches for developing tolerance-induction treatments relevant to cell therapies. Outside the field of solid-organ and allogeneic HSC transplantation, new strategies are emerging for controlling the immune response, such as methods based on biomaterials or mimicry of antigen-specific peripheral tolerance. Novel biomaterials can alter the behavior of cells in tissue-engineered constructs and can blunt host immune responses to cells and biomaterial scaffolds. Approaches to suppress autoreactive immune cells may also be useful in regenerative medicine. The most innovative solutions will be developed through closer collaboration among stem cell biologists, transplantation immunologists and materials scientists. PMID:25093888

  11. Combined hydraulic and regenerative braking system

    DOEpatents

    Venkataperumal, Rama R. (Troy, MI); Mericle, Gerald E. (Mount Clemens, MI)

    1981-06-02

    A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  12. Combined hydraulic and regenerative braking system

    SciTech Connect

    Mericle, G.E.; Venkataperumal, R.R.

    1981-06-02

    A combined hydraulic and regenerative braking system and method is disclosed for an electric vehicle. The braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  13. Functionalized Nanostructures with Application in Regenerative Medicine

    PubMed Central

    Perán, Macarena; García, María A.; López-Ruiz, Elena; Bustamante, Milán; Jiménez, Gema; Madeddu, Roberto; Marchal, Juan A.

    2012-01-01

    In the last decade, both regenerative medicine and nanotechnology have been broadly developed leading important advances in biomedical research as well as in clinical practice. The manipulation on the molecular level and the use of several functionalized nanoscaled materials has application in various fields of regenerative medicine including tissue engineering, cell therapy, diagnosis and drug and gene delivery. The themes covered in this review include nanoparticle systems for tracking transplanted stem cells, self-assembling peptides, nanoparticles for gene delivery into stem cells and biomimetic scaffolds useful for 2D and 3D tissue cell cultures, transplantation and clinical application. PMID:22489186

  14. Cell sheets engineering for esophageal regenerative medicine

    PubMed Central

    Kanai, Nobuo; Yamato, Masayuki

    2014-01-01

    Recently, cell-based therapies, regenerative medicine, and tissue engineering have been progressing rapidly. We have developed a novel strategy for regenerative medicine to recover tissue functions using temperature-responsive cell culture surfaces. To overcome of conventional methods such as the usage of single-cell suspension injection, we have applied transplantable cell sheets fabricated with temperature-responsive culture surfaces for cell delivery. In the field of gastroenterology, transplantable cell sheets from autologous oral mucosal epithelial cells can prevent esophageal stricture following extensive endoscopic mucosal resection. PMID:25333004

  15. Improved Regenerative Sorbent-Compressor Refrigerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1992-01-01

    Conceptual regenerative sorbent-compressor refrigerator attains regeneration efficiency and, therefore, overall power efficiency and performance greater than conventional refrigerators. Includes two fluid loops. In one, CH2FCF3 (R134a) ciculates by physical adsorption and desorption in four activated-charcoal sorption compressors. In other, liquid or gas coolant circulated by pump. Wave of regenerative heating and cooling propagates cyclically like peristatic wave among sorption compressors and associated heat exchangers. Powered by electricity, oil, gas, solar heat, or waste heat. Used as air conditioners, refrigerators, and heat pumps in industrial, home, and automotive applications.

  16. Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children

    E-print Network

    Chapman, Michael S.

    Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder intestinal abnormalities, ranging from lymphoid nodular hyperplasia to aphthoid ulceration. Histology showed

  17. Bit Error Rate Comparison of Repeater and Regenerative Communication Satellites

    Microsoft Academic Search

    T. Huang; J. Omura; L. Biederman

    1980-01-01

    We evaluate and compare bit error rates for conventional (linear and nonlinear) repeater satellites and regenerative satellites. This work is based on a new formulation for error rates using the generalized moment technique for numerical evaluation of error rates. Both coherent MPSK and noncoherent MFSK modulations are considered with regenerative satellites. The results show that regenerative satellites are especially effective

  18. Using Permutations in Regenerative Simulations to Reduce Variance

    E-print Network

    Nakayama, Marvin K.

    Using Permutations in Regenerative Simulations to Reduce Variance James M. Calvin and Marvin K of performance measures obtained from a regenerative simulation of a system having two distinct sequences fixed number of cycles from the first regenerative sequence, our new estimator has smaller mean squared

  19. Steady State Analysis of Markov Regenerative with Age Memory Policy

    E-print Network

    Telek, Miklós

    Steady State Analysis of Markov Regenerative SPN with Age Memory Policy Mikl#19;os Telek 1 , Andrea marking process belongs to the class of Markov Regenerative Processes (MRGP). We refer to this class of models as Markov Regenerative SPN (MRSPN). In this paper, we describe a computationally e#11;ective algo

  20. The mission of the UW Stem Cell and Regenerative Medi-

    E-print Network

    SCRMCNotes The mission of the UW Stem Cell and Regenerative Medi- cine Center is to advance the science of stem cell biology and foster breakthroughs in regenerative medicine through faculty. They include Stem Cell Bioengineering, Cardiovascular Regeneration, Musculoskeletal Regen- eration, Molecular

  1. The Semi-Regenerative Method of Simulation Output Analysis

    E-print Network

    Nakayama, Marvin K.

    The Semi-Regenerative Method of Simulation Output Analysis JAMES M. CALVIN New Jersey Institute develop a class of techniques for analyzing the output of simulations of a semi-regenerative process. Called the semi-regenerative method, the approach is a generalization of the regenera- tive method

  2. SHARED MEMORY PARALLEL REGENERATIVE QUEUING NETWORK Panajotis Katsaros

    E-print Network

    Katsaros, Panagiotis

    SHARED MEMORY PARALLEL REGENERATIVE QUEUING NETWORK SIMULATION Panajotis Katsaros Constantine Lazos simulations. The simulation results are statistically processed, by applying the classical regenerative method'' of the time intervals, match each other. In this sense, the regenerative method provides a safe way

  3. Expected Impulse Rewards in Markov Regenerative Stochastic Petri Nets ?

    E-print Network

    Newcastle upon Tyne, University of

    Expected Impulse Rewards in Markov Regenerative Stochastic Petri Nets ? Reinhard German1, Aad P. A regenerative stochastic Petri nets, which allow for transitions with non-exponentially distributed ring times system with service breakdowns. Key words: Markov regenerative stochastic Petri nets, method of sup

  4. Regenerative Block-Bootstrap Confidence Intervals for the Extremal Index

    E-print Network

    Boyer, Edmond

    Regenerative Block-Bootstrap Confidence Intervals for the Extremal Index Patrice Bertail1 , St to show how the regenerative block-bootstrap methodology (RBB), proved asymptotically valid in the case of sample means and U-statistics based on data drawn from a regenerative Markov chain X = {Xn}nN in Bertail

  5. The mission of the UW Stem Cell and Regenerative Medi-

    E-print Network

    SCRMCNotes The mission of the UW Stem Cell and Regenerative Medi- cine Center is to advance the science of stem cell biology and foster breakthroughs in regenerative medicine through faculty Wilmut, Director of the Edinburgh University Regenerative Medicine Centre, helped launch the center

  6. The mission of the UW Stem Cell and Regenerative Medi-

    E-print Network

    SCRMCNotes The mission of the UW Stem Cell and Regenerative Medi- cine Center is to advance the science of stem cell biology and foster breakthroughs in regenerative medicine through faculty:Wan-Ju Li 2 Milestones 3 2010 FellowshipWinners 4 SSSCR Update 4 Tuesday Seminar Series 5 Regenerative

  7. NON-REGENERATIVE MIMO RELAYING WITH CHANNEL STATE INFORMATION

    Microsoft Academic Search

    Olga Muñoz; Josep Vidal; Adrián Agustín

    This paper deals with the design of non-regenerative relays in cooperative transmission schemes. The conventional non- regenerative approach is the amplify and forward (AF) approach, where the signal received at the relay is simply amplified and retransmitted. In this paper, we propose an alternative design which maximizes the capacity for non- regenerative cooperative transmission, when channel state information is available

  8. Regenerative Steady-State Simulation of Discrete-Event Systems

    E-print Network

    Henderson, Shane

    Regenerative Steady-State Simulation of Discrete-Event Systems Shane G. Henderson University of Michigan, and Peter W. Glynn Stanford University The regenerative method possesses certain asymptotic. Therefore, applying the regenerative method to steady-state discrete-event system simulations is of great

  9. Markov Regenerative Stochastic Petri Nets with Age Type General Transitions

    E-print Network

    Telek, Miklós

    Markov Regenerative Stochastic Petri Nets with Age Type General Transitions Mikl#19;os Telek 1 Abstract. Markov Regenerative Stochastic Petri Nets (MRSPN) have been recently introduced in the literature with preemp- tive resume (prs) service policy. Key words: Markov regenerative processes, Stochastic Petri Nets

  10. Energy Management for Regenerative Brakes on a DC Feeding System

    Microsoft Academic Search

    Yuruki Okada; Takafumi Koseki; Satoru Sone

    Recently, regenerative brakes are implemented in trains at DC fed electric railways in Japan. Regenerative braking system converts kinetic energy to electrical energy. And other powering trains at the identical feeding circuit must consume the electrical energy. Therefore, when the electrical loads are not sufficient at feeding circuit, braking trains must squeeze regenerative power. The problem is that such braking

  11. Focal epithelial hyperplasia in a Turkish family.

    PubMed

    Gökahmeto?lu, Selma; Ferahba?, Ayten; Canöz, Özlem

    2014-12-01

    Focal epithelial hyperplasia (FEH) is a benign proliferative condition that is more frequently found in children of certain ethnic groups. Human papillomavirus (HPV) 13 and 32 genotypes has been consistently detected in these lesions. In this study a daughter, mother and father had FEH, and HPV 13 was shown by sequence analysis in the lesions of these patients. Cryotherapy was applied to the lesions and the lesions improved, but did not recover properly. In conclusion, HPV genotyping should be performed in FEH cases. PMID:25551850

  12. Telangiectatic focal nodular hyperplasia: a variant of hepatocellular adenoma

    Microsoft Academic Search

    Valerie Paradis; Asmae Benzekri; Delphine Dargère; Ivan Bièche; Ingrid Laurendeau; Valerie Vilgrain; Jacques Belghiti; Michel Vidaud; Claude Degott; Pierre Bedossa

    2004-01-01

    Background & Aims: “Telangiectatic focal nodular hyperplasia” designate atypical lesions considered as variants of focal nodular hyperplasia (FNH). However, because “telangiectatic FNH” share several morphologic patterns with hepatocellular adenomas, classification of such lesions deserve further clarification. Therefore, the aim of the present study was to reconsider the classification of telangiectatic FNH with the help of a molecular approach. Methods: Ten

  13. Hepatic focal nodular hyperplasia: angiography, CT, sonography, and scintigraphy

    Microsoft Academic Search

    J. V. Rogers; L. A. Mack; P. C. Freeny; M. L. Johnson; P. J. Sones

    1981-01-01

    Eleven patients with focal nodular hyperplasia of the liver underwent a combination of radiologic procedures, including sonography, computed tomography (CT), hepatic scintigraphy, and angiography. This paper describes the radiologic findings in this group of patients and reviews the current literature. In the present series, sonography was the most sensitive (100%) method for detection of focal nodular hyperplasia, while CT was

  14. Regenerative Studies: College Community and Community College.

    ERIC Educational Resources Information Center

    Woltz, Mary G.

    This case study applies principles derived from the Center for Regenerative Studies (CRS) to a community college in North Carolina. CRS, on the campus of California State Polytechnic Institute (California), is dedicated to the education, demonstration, and research of degenerative systems in the areas of shelter, food production, energy, water and…

  15. Regenerative Morphing Eli Shechtman1,3

    E-print Network

    Shapiro, Ehud

    Regenerative Morphing Eli Shechtman1,3 Alex Rav-Acha2 Michal Irani2 Steve Seitz3,4 1 Adobe Systems morphing approach in which the output sequence is regenerated from small pieces of the two source (input the images are of very different objects (e.g., a cloud and a face). We pose the morphing task as an optimiza

  16. New Regenerative Cycle for Vapor Compression Refrigeration

    Microsoft Academic Search

    Mark J. Bergander

    2005-01-01

    The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available

  17. Regenerative fuel cell systems for project pathfinder

    NASA Technical Reports Server (NTRS)

    Huff, J. R.; Hedstrom, J.; Vanderborgh, N. E.; Prokopius, P.

    1989-01-01

    The objectives of a surface power program, an element of the exploration thrust of the Pathfinder project, and plans for meeting them are outlined. Technological assessment and tradeoff studies of fuel cell and electrolyzer technologies suitable for use in a regenerative fuel cell are described. The viability of proton exchange membranes (PEM) in meeting the system requirements is discussed.

  18. Regenerative nanomedicine: current perspectives and future directions

    PubMed Central

    Chaudhury, Koel; Kumar, Vishu; Kandasamy, Jayaprakash; RoyChoudhury, Sourav

    2014-01-01

    Nanotechnology has considerably accelerated the growth of regenerative medicine in recent years. Application of nanotechnology in regenerative medicine has revolutionized the designing of grafts and scaffolds which has resulted in new grafts/scaffold systems having significantly enhanced cellular and tissue regenerative properties. Since the cell–cell and cell-matrix interaction in biological systems takes place at the nanoscale level, the application of nanotechnology gives an edge in modifying the cellular function and/or matrix function in a more desired way to mimic the native tissue/organ. In this review, we focus on the nanotechnology-based recent advances and trends in regenerative medicine and discussed under individual organ systems including bone, cartilage, nerve, skin, teeth, myocardium, liver and eye. Recent studies that are related to the design of various types of nanostructured scaffolds and incorporation of nanomaterials into the matrices are reported. We have also documented reports where these materials and matrices have been compared for their better biocompatibility and efficacy in supporting the damaged tissue. In addition to the recent developments, future directions and possible challenges in translating the findings from bench to bedside are outlined. PMID:25214780

  19. Bifunctional electrodes for unitised regenerative fuel cells

    Microsoft Academic Search

    Sebastian Altmann; Till Kaz; Kaspar Andreas Friedrich

    2011-01-01

    The effects of different configurations and compositions of platinum and iridium oxide electrodes for the oxygen reaction of unitised regenerative fuel cells (URFC) are reported. Bifunctional oxygen electrodes are important for URFC development because favourable properties for the fuel cell and the electrolysis modes must be combined into a single electrode. The bifunctional electrodes were studied under different combinations of

  20. Thermally regenerative fuel cells. Final report

    Microsoft Academic Search

    F. A. Ludwig; A. Kindler; J. McHardy

    1991-01-01

    The three phase project was undertaken to investigate solventless ionic liquids as possible working fluids for a new type of thermally regenerative fuel cell (TRFC). The heart of the new device, invented at Hughes Aircraft Company in 1983, is an electrochemical concentration cell where acid and base streams react to produce electrical energy. Thermal energy is then used to decompose

  1. Regenerative fuel cell systems for space station

    Microsoft Academic Search

    M. A. Hoberecht; D. W. Sheibley

    1985-01-01

    Regenerative fuel cell (RFC) systems are the leading energy storage candidates for Space Station. Key design features are the advanced state of technology readiness and high degree of system level design flexibility. Technology readiness was demonstrated through testing at the single cell, cell stack, mechanical ancillary component, subsystem, and breadboard levels. Design flexibility characteristics include independent sizing of power and

  2. Anhydrous Hâ\\/Clâ regenerative fuel cell

    Microsoft Academic Search

    Maricle

    1978-01-01

    A regenerative fuel cell is described in which the reactive gases are hydrogen and chlorine and the electrolyte is a conductive anhydrous solvent in which the chlorine gas and the hydrogen chloride gas are soluble, this electrolyte readily releasing the gaseous hydrogen chloride for storage during discharge of the cell.

  3. Regenerative fuel cells for space applications

    NASA Astrophysics Data System (ADS)

    Appleby, A. John

    1987-09-01

    After several years of development of the regenerative fuel cell (RFC) as the electrochemical storage system to be carried by the future space station, the official stance has now been adopted that nickel hydrogen batteries would be a better system choice. RFCs are compared with nickel hydrogen and other battery systems for space platform applications.

  4. An improved theory for regenerative pump performance

    E-print Network

    Kim, Yong Jung

    and it can be used for the design of twisted blades that would increase the pump head and efficiency. A new, impeller angles, CFD 1 INTRODUCTION Regenerative flow pumps and compressors have found many applications of publications existing in the literature is comparatively less than papers dealing with centrifugal and axial

  5. Some Recent Developments of Regenerative Circuits

    Microsoft Academic Search

    E. H. Armstrong

    1922-01-01

    A system of circuits is described whereby the effective resistance of a regenerative circuit is periodically made positive and negative, tho predominantly positive. Such a circuit will respond to impressed electromotive forces by setting up free oscillations during the negative resistance period, which oscillations are proportional to the exciting emf. The forced oscillations produced by the exciting emf. will be

  6. Coordinated control for regenerative braking system

    Microsoft Academic Search

    Zhang Junzhi; Lu Xin; Chen Shanglou; Zhang Pengjun

    2008-01-01

    This paper presents a design of regenerative braking system (RBS) for hybrid electric vehicles using hierarchical control structure and method. The hierarchical model is mainly composed of three modules for driver intent identification, energy management and coordinated control based on components control. As a consequence, RBS, a complicated hybrid dynamic system, is successfully decomposed by several simple modules. The control

  7. Modeling regenerative braking and storage for vehicles

    Microsoft Academic Search

    F. Wicks; K. Donnelly

    1997-01-01

    The fuel saving benefits of regenerative braking and storage for vehicles are often described but not quantified. For example, the federal government and automobile manufacturers are sponsoring a Program for a New Generation of Vehicles (PGNV) with a goal of obtaining a performance of 80 mpg in a family size car. It is typically suggested that such a vehicle will

  8. Cutting vehicle emissions with regenerative braking

    Microsoft Academic Search

    Peter Clarke; Tariq Muneer; Kevin Cullinane

    2010-01-01

    This paper presents an analysis of vehicle regenerative braking systems as a quick and relatively easy means of achieving higher overall fuel efficiency and lowering carbon emissions. The system involves the installation of an additional electric motor\\/generator in parallel to the vehicle’s internal combustion engine and is used in conjunction with a DCDC converter and ultracapacitor. The system is used

  9. Use of elastomers in regenerative braking systems

    NASA Astrophysics Data System (ADS)

    The storage of potential energy as strain energy in elastomers was investigated. The evolution of the preferred stressing scheme is described, and test results on full-size elastomeric energy storage units sized for an automotive regenerative braking system application are presented. The need for elastomeric material improvements is also discussed.

  10. Polycystic Ovaries Associated with Congenital Adrenal Hyperplasia

    PubMed Central

    Lucis, O. J.; Hobkirk, R.; Hollenberg, C. H.; MacDonald, S. A.; Blahey, P.

    1966-01-01

    Polycystic ovaries were found in a 16-year-old female with congenital absence of vagina, male-like external genitalia, and congenital adrenal hyperplasia. Masculinization was sufficiently severe to cause the patient to be reared as a male. Biochemical studies of ovarian tissue revealed hyperactivity and an imbalance of enzyme systems concerned with steroid-hormone biosynthesis, which led to production of large amounts of androgens. The pathway towards estrogens was preserved but less efficient than normal. Urinary steroid metabolites before and after hysterectomy and bilateral salpingo-oophorectomy revealed an absence of Porter-Silber chromogens and tetrahydrocortisone. Excretion of aldosterone was normal and that of corticosterone slightly higher than normal. The patterns of urinary 17-ketosteroids, pregnanediol, pregnanetriol and pregnanetriolone were similar to those commonly seen in congenital adrenal hyperplasia with steroid 21-hydroxylase deficiency. Urinary estrogens after panhysterectomy were low, being in the post-menopausal range. The pathogenesis of polycystic ovaries and their possible contribution to masculinization are discussed. ImagesFig. 1Fig. 2Fig. 3 PMID:5901591

  11. Congenital adrenal hyperplasia: biochemical and molecular perspectives.

    PubMed

    Maitra, Anurupa; Shirwalkar, Heena

    2003-07-01

    Congenital adrenal hyperplasia is a disorder occurring in both sexes and is the commonest cause of ambiguous genitalia. It is a group of autosomal recessive disorders in which, on the basis of an enzyme defect the bulk of steroid hormone production by adrenal cortex shifts from corticosteroids to androgens. Autosomal recessive mutations in the CYP21, CYP17, CYP11B1 and 3betaHSD genes that encode steroidogenic enzymes, in addition to mutations in the gene encoding the intracellular cholesterol transport protein steroidogenic acute regulatory protein StAR can cause CAH. Each of the defects causes different biochemical consequences and clinical features. Deficiencies in 21 hydroxylase (21-OH) and 11beta-Hydroxylase (11beta-OH) are the two most frequent causes of CAH. All the biochemical defects impair cortisol secretion, resulting into compensatory hypersecretion of ACTH and consequent hyperplasia of the adrenal cortex. Research in recent years has clarified clinical, biochemical and genetic problems in diagnosis and treatment of the disorders. Expanding knowledge of the gene mutations associated with each of these disorders is providing valuable diagnostic tools in addition to the biochemical profile and phenotype. Genotyping is useful in selecting instances to provide genetic counseling and to clarify ambiguous cases. PMID:15255373

  12. [Regenerative medicine: applications and development in urology.

    PubMed

    Pinto, F; Calarco, A; Brescia, A; Sacco, E; D'Addessi, A; Racioppi, M; Bassi, P F

    2007-01-01

    PURPOSE. Congenital abnormalities and acquired disorders can lead to organ damage and loss. Nowadays, transplantation represents the only effective treatment option. However, there is a marked decrease in the number of organ donors, which is even yearly worsening due to the population aging. The regenerative medicine represents a realistic option that allows to restore and maintain the normal functions of tissues and organs. This article reviews the principles of regenerative medicine and the recent advances with regard to its application to the genitourinary tract. RECENT FINDINGS. The field of regenerative medicine involves different areas of technology, such as tissue engineering, stem cells and cloning. Tissue engineering involves the field of cell transplantation, materials science and engineering in order to create functional replacement tissues. Stem cells and cloning permit the extraction of pluripotent, embryonic stem cells offering a potentially limitless source of cells for tissue engineering applications. Most current strategies for tissue engineering depend upon a sample of autologous cells from the patient's diseased organ. Biopsies from patients with extensive end-stage organ failure, however, may not yield enough normal cells. In these situations, stem cells are envisaged as being an alternative source. Stem cells can be derived from discarded human embryos (human embryonic stem cells), from fetal tissue or from adult sources (bone marrow, fat, skin). Therapeutic cloning offers a potentially limitless source of cells for tissue engineering applications. Regenerative medicine and tissue engineering scientists have increasingly applied the principles of cell transplantation, materials science and bioengineering to construct biological substitutes that will restore and maintain normal function in urological diseased and injured tissues such as kidney, ureter, bladder, urethra and penis. CONCLUSIONS. Regenerative medicine offers several applications in acquired and congenital genito-urinary diseases. Tissue engineering, stem cells and, mostly, cloning have been applied in experimental studies with excellent results. Few preliminary human applications have been developed with promising results. PMID:21086380

  13. Congenital adrenal hyperplasia: Treatment and outcomes

    PubMed Central

    Kamoun, Mahdi; Feki, Mouna Mnif; Sfar, Mohamed Habib; Abid, Mohamed

    2013-01-01

    Congenital adrenal hyperplasia (CAH) describes a group of autosomal recessive disorders where there is impairment of cortisol biosynthesis. CAH due to 21-hydroxylase deficiency accounts for 95% of cases and shows a wide range of clinical severity. Glucocorticoid and mineralocorticoid replacement therapies are the mainstays of treatment of CAH. The optimal treatment for adults with CAH continues to be a challenge. Important long-term health issues for adults with CAH affect both men and women. These issues may either be due to the disease or to steroid treatment and may affect final height, fertility, cardiometabolic risk, bone metabolism, neuro-cognitive development and the quality-of-life. Patients with CAH should be regularly followed-up from childhood to adulthood by multidisciplinary teams who have knowledge of CAH. Optimal replacement therapy, close clinical and laboratory monitoring, early life-style interventions, early and regular fertility assessment and continuous psychological management are needed to improve outcome. PMID:24251136

  14. Optimizing the management of benign prostatic hyperplasia

    PubMed Central

    Elterman, Dean S.; Kaplan, Steven A.

    2012-01-01

    One of the challenges facing primary care physicians and specialists as the population ages is the management of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). While as many as 18% of men in their 40s report bother from an enlarged prostate, that figure rises dramatically, whereby 50% of men in their 50s and 90% of men in their 90s will complain of bothersome symptoms related to an enlarged prostate. Studies have shown that BPH is a progressive disease, which if left untreated can result in worsening of symptoms, acute urinary retention and renal failure. Until about 20 years ago the only management option available to urologists was surgery. In the early 1990s medical therapy emerged as the predominant treatment for BPH. Therapy may be tailored to target symptoms and progression of disease. PMID:22496710

  15. Phytotherapy of benign prostatic hyperplasia. A minireview.

    PubMed

    Pagano, Ester; Laudato, Massimiliano; Griffo, Michele; Capasso, Raffaele

    2014-07-01

    Benign prostate hyperplasia (BPH) is a common condition affecting older men, with an incidence that is age-dependent. Histological BPH, which typically develops after the age of 40 years, ranges in prevalence from >50% at 60 years to as high as 90% by 85 years of age. Typical symptoms include increased frequency of urination, nocturia, urgency, hesitancy, and weak urine stream. Conventional medicines used for the treatment of BPH include alpha blockers and 5-alpha reductase inhibitors. This articles review the mode of action, the efficacy, and the safety, including herb-drug interactions of the most common botanicals (Serenoa repens, Pygeum africanum, Urtica dioica, and Cucurbita pepo) and nutraceuticals (isoflavones, lycopene, selenium, and ?-Sitosterol) in controlling the lower urinary tract symptoms associated to BPH. PMID:25165780

  16. Langerhans Cell Hyperplasia From Molluscum Contagiosum.

    PubMed

    Hatter, Alyn D; Zhou, Xin; Honda, Kord; Popkin, Daniel L

    2015-08-01

    Langerhans cell histiocytosis (LCH) carries a prognosis, which ranges from benign to potentially fatal. There is currently little framework to decipher metrics, which predict the benign versus aggressive nature of LCH. We wanted to determine whether molluscum contagiosum virus (MCV) DNA could be isolated from a cutaneous lesion, demonstrating Langerhans cell hyperplasia resembling LCH in a patient with both. Polymerase chain reaction on biopsy-proven MCV and the hyperplastic lesion has been performed. Two specific regions within the MCV genome were detected from both biopsies. The authors report our findings and suggest that some MCV can produce histological lesions resembling LCH, similar to the literature on scabies mimicking LCH. Efforts to find a reactive "driver" in LCH may significantly inform the clinical scenario. PMID:25140667

  17. Researches on regenerative medicine-current state and prospect.

    PubMed

    Wang, Zheng-Guo; Xiao, Kai

    2012-01-01

    Since 1980s, the rapid development of tissue engineering and stem cell research has pushed regenerative medicine to a new fastigium, and regenerative medicine has become a noticeable research field in the international biology and medicine. In China, about 100 million patients need repair and regeneration treatment every year, while the number is much larger in the world. Regenerative medicine could provide effective salvation for these patients. Both Chinese Academy of Sciences and Chinese Academy of Engineering have made roadmaps of 2010-2050 and 2011-2030 for regenerative medicine. The final goal of the two roadmaps is to make China go up to leading position in most research aspects of regenerative medicine. In accord with this strategy, the government and some enterprises have invested 3-5 billion RMB (0.5-0.8 billion USD) for the research on regenerative medicine. In order to push the translation of regenerative medicine forward-from bench to bedside, a strategic alliance has been established, and it includes 27 top-level research institutes, medical institutes, colleges, universities and enterprises in the field of stem cell and regeneration medicine. Recently the journal, Science, has published a special issue-Regenerative Medicine in China, consisting of 35 papers dealing with stem cell and regeneration, tissue engineering and regeneration, trauma and regeneration and bases for tissue repair and regenerative medicine. It is predicated that a greater breakthrough in theory and practice of regenerative medicine will be achieved in the near future (20 to 30 years). PMID:23069095

  18. [Tissue engineered skin and regenerative wound repair].

    PubMed

    Han, Chun-mao; Wang, Xin-gang

    2013-04-01

    Various skin defects resulting from mechanical injury, burns, chronic ulcers, and resection of tumor etc. are very common in clinic. The traditional treatment measure, such as grafting of autologous split-thickness skin remains the gold standard. However, its limitations are obvious, such as shortage of donor sites, creation of new injury, and scar formation. To realize regenerative or scarless repair of tissue defects has always been the dream of human being. The advent of tissue engineered skin (TES) provides an ideal access to tissue regeneration. After decades of development, several kinds of TES products have been developed and used in clinic, with promising effects. However, a large number of basic scientific problems regarding TES, as well as difficulties in translation of basic research to bedside should be taken into serious consideration. This article presents a comprehensive overview of strategies of construction of TES, the role of TES in regenerative wound repair, and its opportunities and challenges. PMID:23985197

  19. Induced Pluripotent Stem Cells for Regenerative Medicine

    PubMed Central

    Hirschi, Karen K.; Li, Song; Roy, Krishnendu

    2014-01-01

    With the discovery of induced pluripotent stem (iPS) cells, it is now possible to convert differentiated somatic cells into multipotent stem cells that have the capacity to generate all cell types of adult tissues. Thus, there is a wide variety of applications for this technology, including regenerative medicine, in vitro disease modeling, and drug screening/discovery. Although biological and biochemical techniques have been well established for cell reprogramming, bioengineering technologies offer novel tools for the reprogramming, expansion, isolation, and differentiation of iPS cells. In this article, we review these bioengineering approaches for the derivation and manipulation of iPS cells and focus on their relevance to regenerative medicine. PMID:24905879

  20. Bioactive supramolecular peptide nanofibers for regenerative medicine.

    PubMed

    Arslan, Elif; Garip, I Ceren; Gulseren, Gulcihan; Tekinay, Ayse B; Guler, Mustafa O

    2014-09-01

    Recent advances in understanding of cell-matrix interactions and the role of the extracellular matrix (ECM) in regulation of cellular behavior have created new perspectives for regenerative medicine. Supramolecular peptide nanofiber systems have been used as synthetic scaffolds in regenerative medicine applications due to their tailorable properties and ability to mimic ECM proteins. Through designed bioactive epitopes, peptide nanofiber systems provide biomolecular recognition sites that can trigger specific interactions with cell surface receptors. The present Review covers structural and biochemical properties of the self-assembled peptide nanofibers for tissue regeneration, and highlights studies that investigate the ability of ECM mimetic peptides to alter cellular behavior including cell adhesion, proliferation, and/or differentiation. PMID:24574311

  1. Electrospun Silk Biomaterial Scaffolds for Regenerative Medicine

    PubMed Central

    Zhang, Xiaohui; Reagan, Michaela R; Kaplan, David L.

    2009-01-01

    Electrospinning is a versatile technique that enables the development of nanofiber-based biomaterial scaffolds. Scaffolds can be generated that are useful for tissue engineering and regenerative medicine since they mimic the nanoscale properties of certain fibrous components of the native extracellular matrix in tissues. Silk is a natural protein with excellent biocompatibility, remarkable mechanical properties as well as tailorable degradability. Integrating these protein polymer advantages with electrospinning results in scaffolds with combined biochemical, topographical and mechanical cues with versatility for a range of biomaterial, cell and tissue studies and applications. This review covers research related to electrospinning of silk, including process parameters, post treatment of the spun fibers, functionalization of nanofibers, and the potential applications for these material systems in regenerative medicine. Research challenges and future trends are also discussed. PMID:19643154

  2. Unitized Regenerative Fuel Cell System Model Development

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jakupca, Ian

    2003-01-01

    A Unitized Regenerative Fuel Cell (URFC) Energy Storage System is being developed at the NASA Glenn Research Center. This URFC system is unique in that it uses the surface area of the hydrogen and oxygen storage tanks as radiating heat surfaces for overall thermal control of the system. The tank surfaces also play an important role in the temperature control of regenerative gas dryers/humidifiers used to dry the hydrogen and oxygen gases produced by electrolysis during the charging and also used to humidify the hydrogen and oxygen gases used by fuel cell during the discharging of the URFCS. A bi- directional pressure controller is used to control the pressure of the oxygen and hydrogen gas inside the URFC stack during both charging and discharging of the URFC system. A water storage accumulator is used to store water reactant and control water pressure inside the URFC stack.

  3. Regenerative Endodontics: A Road Less Travelled

    PubMed Central

    Bansal, Ramta; Mittal, Sunandan; Kumar, Tarun; Kaur, Dilpreet

    2014-01-01

    Although traditional approaches like root canal therapy and apexification procedures have been successful in treating diseased or infected root canals, but these modalities fail to re-establish healthy pulp tissue in treated teeth. Regeneration-based approaches aims to offer high levels of success by replacing diseased or necrotic pulp tissues with healthy pulp tissue to revitalize teeth. The applications of regenerative approaches in dental clinics have potential to dramatically improve patients’ quality of life. This review article offers a detailed overview of present regenerative endodontic approaches aiming to revitalize teeth and also outlines the problems to be dealt before this emerging field contributes to clinical treatment protocols. It conjointly covers the basic trilogy elements of tissue engineering. PMID:25478476

  4. Endometrial stem cells in regenerative medicine.

    PubMed

    Verdi, Javad; Tan, Aaron; Shoae-Hassani, Alireza; Seifalian, Alexander M

    2014-01-01

    First described in 2004, endometrial stem cells (EnSCs) are adult stem cells isolated from the endometrial tissue. EnSCs comprise of a population of epithelial stem cells, mesenchymal stem cells, and side population stem cells. When secreted in the menstrual blood, they are termed menstrual stem cells or endometrial regenerative cells. Mounting evidence suggests that EnSCs can be utilized in regenerative medicine. EnSCs can be used as immuno-modulatory agents to attenuate inflammation, are implicated in angiogenesis and vascularization during tissue regeneration, and can also be reprogrammed into induced pluripotent stem cells. Furthermore, EnSCs can be used in tissue engineering applications and there are several clinical trials currently in place to ascertain the therapeutic potential of EnSCs. This review highlights the progress made in EnSC research, describing their mesodermal, ectodermal, and endodermal potentials both in vitro and in vivo. PMID:25097665

  5. Regenerative endodontics: a road less travelled.

    PubMed

    Bansal, Ramta; Jain, Aditya; Mittal, Sunandan; Kumar, Tarun; Kaur, Dilpreet

    2014-10-01

    Although traditional approaches like root canal therapy and apexification procedures have been successful in treating diseased or infected root canals, but these modalities fail to re-establish healthy pulp tissue in treated teeth. Regeneration-based approaches aims to offer high levels of success by replacing diseased or necrotic pulp tissues with healthy pulp tissue to revitalize teeth. The applications of regenerative approaches in dental clinics have potential to dramatically improve patients' quality of life. This review article offers a detailed overview of present regenerative endodontic approaches aiming to revitalize teeth and also outlines the problems to be dealt before this emerging field contributes to clinical treatment protocols. It conjointly covers the basic trilogy elements of tissue engineering. PMID:25478476

  6. Graphene-Based Materials in Regenerative Medicine.

    PubMed

    Ding, Xili; Liu, Haifeng; Fan, Yubo

    2015-07-01

    Graphene possesses many unique properties such as two-dimensional planar structure, super conductivity, chemical and mechanical stability, large surface area, and good biocompatibility. In the past few years, graphene-based materials have risen as a shining star on the path of researchers seeking new materials for future regenerative medicine. Herein, the recent research advances made in graphene-based materials mostly utilizing the mechanical and electrical properties of graphene are described. The most exciting findings addressing the impact of graphene-based materials on regenerative medicine are highlighted, with particular emphasis on their applications including nerve, bone, cartilage, skeletal muscle, cardiac, skin, adipose tissue regeneration, and their effects on the induced pluripotent stem cells. Future perspectives and emerging challenges are also addressed in this Review article. PMID:26037920

  7. Turbo Decoder Development in Regenerative Communications Satellites

    Microsoft Academic Search

    B. Lestriez; E. R. Perez

    2006-01-01

    For regenerative telecom satellite systems, the turbo decoder has become a basic component of the on-board processing (OBP). This paper presents the algorithm selection choices and the test bench policy during the design process of a communication system critical block such as a turbo decoder compliant with the DVB-RCS standard (digital video broadcast-return channel satellite). The architecture, based on the

  8. Optimization of an irreversible Stirling regenerative cycle

    NASA Astrophysics Data System (ADS)

    Aragón-González, G.; Cano-Bianco, M.; León-Galicia, A.; Rivera-Camacho, J. M.

    2015-01-01

    In this work a Stirling regenerative cycle with some irreversibilities is analyzed. The analyzed irreversibilities are located at the heat exchangers. They receive a finite amount of heat and heat leakage occurs between both reservoirs. Using this model, power and the efficiency at maximum power are obtained. Some optimal design parameters for the exchanger heat areas and thermal conductances are presented. The relation between the power, efficiency and the results obtained are shown graphically.

  9. A solar regenerative thermoelectrochemical converter (RTEC)

    SciTech Connect

    Townsend, C.W.; McHardy, J. (Hughes Aircraft Co., El Segundo, CA (United States))

    1992-02-01

    This is an executive summary of a final subcontract report that describes the successful completion of a closed-loop demonstration of a regenerative thermoelectromechanical device using solar heat input for the production of electricity. The full report, which contains a detailed description of the two-year effort, is currently subject to a government secrecy order which precludes public release of the information. Copies of the full report will be made available for general release whenever the secrecy order is lifted.

  10. REGENERATIVE FUEL CELL SYSTEMS FOR SATELLITES

    Microsoft Academic Search

    Asbjørn Strand; Helge Weydahl

    Next generation telecommunication satellites will demand increasingly more power. Power levels of 30 kW or more are foreseen for the next 10 years. Battery technology that can sustain 30 kW for eclipse lengths of up to 72 minutes will represent a major impact on the total mass of the satellite, even with new Li-ion battery technologies. Regenerative fuel cell systems

  11. Regenerative Hydrogen-Oxygen Fuel Cell

    Microsoft Academic Search

    S. E. Voltz; M. D. Read

    1962-01-01

    The regenerative hydrogen-oxygen ion-exchange membrane fuel cell is especially suitable for use in space power systems. During discharge, the anode reaction is H2+20H-¿2H2O+2e. The electrons pass out of the fuel cell at the anode to the load, then re-enter at the cathode. The cathode reaction is ½02+H2O+2e ¿20H-. The hydroxyl ions pass through the membrane to the anode; the electrical

  12. Shannon capacity of nonlinear regenerative channels

    E-print Network

    Sorokina, M A

    2013-01-01

    We compute Shannon capacity of nonlinear channels with regenerative elements. Conditions are found under which capacity of such nonlinear channels is higher than the Shannon capacity of the classical linear additive white Gaussian noise channel. We develop a general scheme for designing the proposed channels and apply it to the particular nonlinear sine-mapping. The upper bound for regeneration efficiency is found and the asymptotic behavior of the capacity in the saturation regime is derived.

  13. Short wavelength regenerative amplifier free electron lasers

    E-print Network

    Dunning, D J; Thompson, N R

    2008-01-01

    In this paper we discuss extending the operating wavelength range of tunable Regenerative Amplifier FELs to shorter wavelengths than current design proposals, notably into the XUV regions of the spectrum and beyond where the reflectivity of broadband optics is very low. Simulation studies are presented which demonstrate the development of good temporal coherence in generic systems with a broadband radiation feedback of less than one part in ten thousand.

  14. Stem cell sources for regenerative medicine.

    PubMed

    Riazi, Ali M; Kwon, Sarah Y; Stanford, William L

    2009-01-01

    Tissue-resident stem cells or primitive progenitors play an integral role in homeostasis of most organ systems. Recent developments in methodologies to isolate and culture embryonic and somatic stem cells have many new applications poised for clinical and preclinical trials, which will enable the potential of regenerative medicine to be realized. Here, we overview the current progress in therapeutic applications of various stem cells and discuss technical and social hurdles that must be overcome for their potential to be realized. PMID:19089350

  15. Common ethical issues in regenerative medicine.

    PubMed

    Awaya, Tsuyoshi

    2005-01-01

    One of the common ethical issues in regenerative medicine is progress in 'componentation' (= being treated as parts) of the human body, and the enhancement of the view of such "human body parts." 'Componentation' of the human body represents a preliminary step toward commodification of the human body. The process of commodification of the human body follows the steps of 'materialization' (= being treated as a material object) [first step] -- 'componentation' [second step] -- 'resourcialization' (= being treated as resources) [third step] -- commodification [fourth step]. Transplantation medicine and artificial organ developments have dramatically exposed the potential of organs and tissues as parts, and regenerative medicine has a role in advancing 'componentation' of the human body and further enhancing the view of human body parts. The 'componentation' of the human body, regardless of the degree of regenerative medicine's contribution to it, is considered as a challenge to the traditional view of human bodies and the abstract value of "Human Dignity" in the same way or alongside the 'resourcialization' and commodification. However, in the future, a new perspective of human bodies that means "a perspective whereby human bodies, organs, tissues, and even the bodies themselves are perceived as disposable tools like disposable cameras, syringes, or contact lens" and therefore a new ethical view, suitable for a new reality, may emerge. PMID:16637131

  16. Application of Regenerative Medicine for Kidney Diseases

    PubMed Central

    Fukui, Akira; Kobayashi, Eiji

    2007-01-01

    Following recent advancements of stem cell research, the potential for organ regeneration using somatic stem cells as an ultimate therapy for organ failure has increased. However, anatomically complicated organs such as the kidney and liver have proven more refractory to stem cell-based regenerative techniques. At present, kidney regeneration is considered to require one of two approaches depending on the type of renal failure, namely acute renal failure (ARF) and chronic renal failure (CRF). The kidney has the potential to regenerate itself provided that the damage is not too severe and the kidney's structure remains intact. Regenerative medicine for ARF should therefore aim to activate or support this potent. In cases of the irreversible damage to the kidney, which is most likely in patients with CRF undergoing long-term dialysis, self-renewal is totally lost. Thus, regenerative medicine for CRF will likely involve the establishment of a functional whole kidney de novo. This article reviews the challenges and recent advances in both approaches and discusses the potential approach of these novel strategies for clinical application. PMID:19279698

  17. Regenerative Braking Algorithm for a HEV with CVT Ratio Control During Deceleration

    Microsoft Academic Search

    Hoon Yeo; Donghyun Kim; Sungho Hwang; Hyunsoo Kim

    A regenerative braking algorithm is proposed to make maximum use of regenerative brake for improvement of fuel consumption. In the regenerative braking algorithm, the regenerative torque is determined by considering the motor capacity, battery SOC and vehicle velocity. The regenerative braking force is calculated from the brake control unit by comparing the demanded brake force(torque) and the motor torque available.

  18. Condylar Hyperplasia and Facial Asymmetry: Report of Five Cases

    Microsoft Academic Search

    Divya Mehrotra; Satish Dhasmana; Mala Kamboj; Gautam Gambhir

    2011-01-01

    Condylar hyperplasia of mandible is overdevelopment of condyle, unilaterally or bilaterally, leading to facial asymmetry,\\u000a mandibular deviation, malocclusion and articular dysfunction. This is a series of five such patients managed at our centre.

  19. Foveolar hyperplasia at the gastric cardia: prevalence and associations

    Microsoft Academic Search

    M Voutilainen; M Juhola; M Fa?rkkila?; P Sipponen

    2002-01-01

    Aims: In the gastric antrum and body, foveolar hyperplasia is a feature of reactive gastritis resulting from—for example, duodenogastric bile reflux and the use of non-steroidal anti-inflammatory drugs (NSAIDs). The aim of this study was to examine the occurrence and clinical relevance of gastric cardiac foveolar hyperplasia.Methods: The study population was drawn from a consecutive series of 1698 patients sent

  20. Platelet rich fibrin - a novel acumen into regenerative endodontic therapy

    PubMed Central

    Sharma, Krishna

    2014-01-01

    Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF) has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy. PMID:24516822

  1. The Impact of Biomechanics in Tissue Engineering and Regenerative Medicine

    E-print Network

    Butler, David L.

    Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue ...

  2. 07.10.1407.10.14 Jochen Mecke, Ursula Regener, Anne Zwierlein.Jochen Mecke, Ursula Regener, Anne Zwierlein. EinfhrungEinfhrung

    E-print Network

    Schubart, Christoph

    07.10.1407.10.14 Jochen Mecke, Ursula Regener, Anne Zwierlein.Jochen Mecke, Ursula Regener, AnneBlutkreuz, Brudermord: Jiddische Literatur und der 1. Weltkriegund der 1. Weltkrieg 02.12.1402.12.14 Ursula Regener.Ursula. Dr. Jochen Mecke (Romanistik)Prof. Dr. Jochen Mecke (Romanistik) Prof. Dr. Ursula Regener

  3. Allopregnanolone as regenerative therapeutic for Alzheimer's disease: Translational development and clinical promise

    E-print Network

    Brinton, Roberta Diaz

    Allopregnanolone as regenerative therapeutic for Alzheimer's disease: Translational development Keywords: Neurogenesis Neurosteroid Regenerative medicine Treatment regimen Pharmacokinetics to the clinic as a regenerative therapeutic for neurodegenerative diseases, in particular Alzheimer

  4. Regenerative Estimation Variants of Response Times in Closed Networks of Queues

    E-print Network

    Katsaros, Panagiotis

    Regenerative Estimation Variants of Response Times in Closed Networks of Queues PANAJOTIS KATSAROS regenerative estimation variants of response times, in multivariate simulations of closed queuing networks. Key-Words: - Queuing networks, Regenerative method, Simulation output analysis, Sequential control

  5. Extreme values statistics for Markov chains via the (pseudo-) regenerative method

    E-print Network

    Paris-Sud XI, Université de

    Extreme values statistics for Markov chains via the (pseudo-) regenerative method Patrice Bertail events in the markovian setup, based on the regenerative method and the Nummelin technique. Exploiting: regenerative Markov chain, Nummelin splitting technique, extreme value statistics, cycle submaximum, Hill

  6. Analysis of arterial intimal hyperplasia: review and hypothesis

    PubMed Central

    2007-01-01

    Background Despite a prodigious investment of funds, we cannot treat or prevent arteriosclerosis and restenosis, particularly its major pathology, arterial intimal hyperplasia. A cornerstone question lies behind all approaches to the disease: what causes the pathology? Hypothesis I argue that the question itself is misplaced because it implies that intimal hyperplasia is a novel pathological phenomenon caused by new mechanisms. A simple inquiry into arterial morphology shows the opposite is true. The normal multi-layer cellular organization of the tunica intima is identical to that of diseased hyperplasia; it is the standard arterial system design in all placentals at least as large as rabbits, including humans. Formed initially as one-layer endothelium lining, this phenotype can either be maintained or differentiate into a normal multi-layer cellular lining, so striking in its resemblance to diseased hyperplasia that we have to name it "benign intimal hyperplasia". However, normal or "benign" intimal hyperplasia, although microscopically identical to pathology, is a controllable phenotype that rarely compromises blood supply. It is remarkable that each human heart has coronary arteries in which a single-layer endothelium differentiates early in life to form a multi-layer intimal hyperplasia and then continues to self-renew in a controlled manner throughout life, relatively rarely compromising the blood supply to the heart, causing complications requiring intervention only in a small fraction of the population, while all humans are carriers of benign hyperplasia. Unfortunately, this fundamental fact has not been widely appreciated in arteriosclerosis research and medical education, which continue to operate on the assumption that the normal arterial intima is always an "ideal" single-layer endothelium. As a result, the disease is perceived and studied as a new pathological event caused by new mechanisms. The discovery that normal coronary arteries are morphologically indistinguishable from deadly coronary arteriosclerosis continues to elicit surprise. Conclusion Two questions should inform the priorities of our research: (1) what controls switch the single cell-layer intimal phenotype into normal hyperplasia? (2) how is normal (benign) hyperplasia maintained? We would be hard-pressed to gain practical insights without scrutinizing our premises. PMID:17974015

  7. Tumoral pseudoangiomatous stromal hyperplasia of the breast.

    PubMed

    Wieman, Stephanie M; Landercasper, Jeffrey; Johnson, Jeanne M; Ellis, Richard L; Wester, Susan M; Lambert, Pamela J; Ross, Lauren A

    2008-12-01

    Tumoral pseudoangiomatous stromal hyperplasia (PASH) is a rare benign proliferative disease of the breast. The majority of the literature reports of PASH have not contained detailed descriptions of the imaging characteristics of PASH. A 10-year retrospective study of patients with tumoral PASH and a 20-year Ovid MEDLINE search were performed to determine whether specific imaging and needle biopsy results could characterize PASH preoperatively. We identified 22 patients with tumoral PASH. Seventeen (77%) of 22 women had a palpable lump and 14 (72%) of 21 had a density on mammography. Ultrasound (US) findings included mixed or hypoechoic echogenicity in 83 per cent and ill-defined borders in 62 per cent. Eight (36%) patients had lesions with a Breast Imaging Reporting and Data System (BI-RADS) classification of 4 or 5. The sensitivity of preoperative core needle biopsy (CNB) to identify PASH was 83 per cent. A review of the literature revealed that 90 per cent of patients with PASH had some malignant imaging characteristics and 95 per cent had a mass on mammography. The imaging characteristics of PASH exhibited marked variability. Excision of PASH after CNB may be considered for patients with symptoms, enlarging lesions, or lesions classified as BI-RADS 4 or 5. PASH diagnosed by CNB allows selected patients to avoid excision. PMID:19097540

  8. A Case of Congenital Lipoid Adrenal Hyperplasia

    PubMed Central

    Hashemipour, Mahin; Ghasemi, Mahmoud; Hovsepian, Silva

    2012-01-01

    Lipoid congenital adrenal hyperplasia (lipoid CAH), a rare disorder of steroid biosynthesis, is the most severe form of CAH. In this disorder the synthesis of glucocorticoids, mineralocorticoids and sex steroids is impaired which result in adrenal failure, severe salt wasting crisis and hyperpigmentation in phenotypical female infants irrespective of genetic sex. In this report, we presented a 28-day-old phenotypic female infant, which referred with lethargy, failure to thrive and electrolyte abnormalities. Considering the clinical and biochemical findings, lipoid CAH was diagnosed and replacement therapy with standard doses of glucocorticoid and mineralocorticoid and sodium chloride was initiated. During follow-up, she had good clinical condition, but at 6 years of age, she refers with hypertension and adrenal insufficiency because of arbitrary drug discontinuation by mother. In ultrasonography an abdominal mass (the testicles) was reported. Chromosome study showed 46XY pattern. Orchiectomy was performed. We recommended that in cases with clinical presentation of adrenal insufficiency if there is not the facility to determine the karyotype, repeated ultrasonography perform during follow-up. In addition, investigating the genetic bases of the disorder would help us to determine the pathogenesis of lipoid CAH in our community. It would be helpful in prenatal diagnosis and treatment of the disorder to prevent its related comorbidities. PMID:22891154

  9. Neointimal hyperplasia associated with synthetic hemodialysis grafts

    PubMed Central

    Li, Li; Terry, Christi M.; Shiu, Yan-Ting E.; Cheung, Alfred K.

    2008-01-01

    Stenosis is a major cause of failure of hemodialysis vascular grafts and is primarily caused by neointimal hyperplasia (NH) at the anastomoses. The objective of this article is to provide a scientific review of the biology underlying this disorder and a critical review of the state-of-the-art investigational preventive strategies in order to stimulate further research in this exciting area. The histology of the NH shows myofibroblasts (that are probably derived from adventitial fibroblasts), extracellular matrices, pro-inflammatory cells including foreign-body giant cells, a variety of growth factors and cytokines, and neovasculature. The contributing factors of the pathogenesis of NH include surgical trauma, bioincompatibility of the synthetic graft, and the various mechanical stresses that result from luminal hypertension and compliance mismatch between the vessel wall and graft. These mechanical stimuli are focal in nature and may have a significant influence on the preferential localization of the NH. Novel mechanical graft designs and local drug delivery strategies show promise in animal models in preventing graft NH development. Successful prevention of graft stenosis would provide a superior alternative to the native fistula as hemodialysis vascular access. PMID:18668026

  10. Transurethral microwave thermotherapy for benign prostatic hyperplasia.

    PubMed

    Rubeinstein, Jonathan N; McVary, Kevin T

    2003-01-01

    Transurethral resection of the prostate (TURP) remains the gold standard for treatment of benign prostatic hyperplasia (BPH). In general, while this procedure is safe, patients require a spinal, epidural, or general anesthesia and often several days of hospital stay; the potential morbidity and mortality limits the use of TURP in high-risk patients. Pharmacotherapy has been recommended as a first-line therapy for all patients with mild to moderate symptoms. Patients are often times enthusiastic if they are offered a one-time method to treat lower urinary tract symptoms secondary to BPH, provided that the method offers reduced risk and allows an efficacy equal to that of medical therapy. One such method is transurethral microwave thermotherapy (TUMT). TUMT involves the insertion of a specially designed urinary catheter with a microwave antenna, which heats the prostate and destroys hyperplastic prostate tissue. TUMT allows the avoidance of general or regional anesthesia, and results in minimal blood loss and fluid absorption. In this review, the authors discussed the current indications and outcome of TUMT, including the history of the procedure, the mechanism of action, the indications for TUMT, the pre-operative considerations, the patient selection, the results in terms of efficacy, by comparing TUMT vs. Sham, TUMT vs. Alpha-blocker and TUMT vs. TURP. Finally, the complications are presented, as well as other uses and future directions of the procedure. The authors concluded that TUMT is a safe and effective minimally invasive alternative to treatment of symptomatic BPH. PMID:15745533

  11. The strong financial case for regenerative medicine and the regen industry.

    PubMed

    Mason, Chris; Dunnill, Peter

    2008-05-01

    Although the therapeutic promise of regenerative medicine is immensely exciting, the cost of product development, and particularly of clinical trials, for the more demanding applications will be high. For this reason it is vital for scientists and start-ups who wish to see their ideas implemented to be able to convince established major pharmaceutical or device companies with the necessary 'deep pockets' that the expenditure can yield an appropriate return. It also means that governments and health insurance companies must see a gain in funding regenerative medicine for patients. To address this issue the costs of five major medical conditions that could benefit from regenerative medicine have been defined for the USA as an illustration. This choice of country was made as potentially the largest initial market and one where the billing system for healthcare allows access to individual direct and some indirect costs. The data are complemented by a number of relevant examples of costs per quality-adjusted life year to indicate where current treatment methods are weak or strong. Finally, the relationship of the nascent regen* industry to the pharma and medical device sectors is summarized to assess the challenge of encouraging their involvement. PMID:18462058

  12. Clinical concepts for regenerative therapy in furcations.

    PubMed

    Sanz, Mariano; Jepsen, Karin; Eickholz, Peter; Jepsen, Søren

    2015-06-01

    Furcation involvements present one of the greatest challenges in periodontal therapy because furcation-involved molar teeth respond less favorably to conventional periodontal therapy compared with noninvolved molar or nonmolar teeth. Various regenerative procedures have been proposed and applied with the aim of eliminating the furcation defect or reducing the furcation depth. An abundance of studies and several systematic reviews have established the effectiveness of membrane therapy (guided tissue regeneration) for buccal Class II furcation involvement of mandibular and maxillary molars compared with open flap surgery. Bone grafts/substitutes may enhance the results of guided tissue regeneration. However, complete furcation closure is not a predictable outcome. Limited data and no meta-analyses are available on the effects of enamel matrix proteins for furcation regeneration. Enamel matrix protein therapy has demonstrated clinical improvements in the treatment of buccal Class II furcation defects in mandibular molars; however, complete closure of the furcation lesion is achieved only in a minority of cases. Neither guided tissue regeneration nor enamel matrix protein therapy have demonstrated predictable results for approximal Class II and for Class III furcations. Promising preclinical data from furcation regeneration studies in experimental animals is available for growth factor- and differentiation factor-based technologies, but very limited data are available from human clinical studies. Although cell-based therapies have received considerable attention in regenerative medicine, their experimental evaluation in the treatment of periodontal furcation lesions is at a very early stage of development. In summary, the indications and the limitations for currently available treatment modalities for furcation defects are well established. New regenerative treatments are clearly needed to improve the predictability of a complete resolution of furcation defects. PMID:25867991

  13. An optically pumped submillimeter wavelength regenerative amplifier

    NASA Technical Reports Server (NTRS)

    Galantowicz, T. A.

    1977-01-01

    An optically pumped regenerative submillimeter laser amplifier is described. The amplifier uses a waveguide cavity resonator, and a Fabry-Perot interferometer composed of two dielectric-coated mirrors serves as input and output port for the submillimeter signal. Use of two mirrors enabled obtaining variations of up to 6:1 in transmission by varying the mirror spacing. When the 373-micron transition in CH3CN is excited in the oscillator by the CO2 laser pump beam, the received signal with amplification is about nine times the unamplified signal.

  14. Small Molecule based Musculoskeletal Regenerative Engineering

    PubMed Central

    Lo, Kevin W.-H.; Jiang, Tao; Gagnon, Keith A.; Nelson, Clarke; Laurencin, Cato T.

    2014-01-01

    Clinicians and scientists working in the field of regenerative engineering are actively investigating a wide range of methods to promote musculoskeletal tissue regeneration. Small molecule-mediated tissue regeneration is emerging as a promising strategy for regenerating various musculoskeletal tissues and a large number of small molecule compounds have been recently discovered as potential bioactive molecules for musculoskeletal tissue repair and regeneration. In this review, we summarize the recent literature encompassing the past four years in the area of small bioactive molecule for promoting repair and regeneration of various musculoskeletal tissues including bone, muscle, cartilage, tendon, and nerve. PMID:24405851

  15. Regenerative nanotechnology in oral and maxillofacial surgery.

    PubMed

    Shakib, Kaveh; Tan, Aaron; Soskic, Vukic; Seifalian, Alexander M

    2014-12-01

    Regenerative nanotechnology is at the forefront of medical research, and translational medicine is a challenge to both scientists and clinicians. Although there has been an exponential rise in the volume of research generated about it for both medical and surgical uses, key questions remain about its actual benefits. Nevertheless, some people think that therapeutics based on its principles may form the core of applied research for the future. Here we give an account of its current use in oral and maxillofacial surgery, and implications and challenges for the future. PMID:25218313

  16. Phosphorous-Containing Polymers for Regenerative Medicine

    PubMed Central

    Watson, Brendan M.; Kasper, F. Kurtis; Mikos, Antonios G.

    2014-01-01

    Disease and injury have resulted in a large, unmet need for functional tissue replacements. Polymeric scaffolds can be used to deliver cells and bioactive signals to address this need for regenerating damaged tissue. Phosphorous-containing polymers have been implemented to improve and accelerate the formation of native tissue both by mimicking the native role of phosphorous groups in the body and by attachment of other bioactive molecules. This manuscript reviews the synthesis, properties, and performance of phosphorous-containing polymers that can be useful in regenerative medicine applications. PMID:24565855

  17. Thermal regenerative cracker: a development update

    SciTech Connect

    Gartside, R.J.; Ellis, A.F.

    1983-03-01

    Reports that significant progress has been achieved in the areas of solids flow, separation, solids heating, and mechanical reliability. Predicts that this technology will be ready for commercial application in the near future. Emphasizes that the thermal regenerative cracker (TRC) is not a new olefins process but a new olefins cracking heater. Explains that it produces a conventional cracked gas and can be easily retrofitted into existing liquids crackers with only minor changes to the downstream compression and fractionation systems. Points out that this ability to be easily retrofitted is extremely important in view of the world-wide ethylene overcapacity situation and likely modernization trends. Presents a diagram of the TRC process.

  18. Avoiding immunological rejection in regenerative medicine.

    PubMed

    Bolton, Eleanor M; Bradley, John Andrew

    2015-05-01

    One of the major goals of regenerative medicine is repair or replacement of diseased and damaged tissues by transfer of differentiated stem cells or stem cell-derived tissues. The possibility that these tissues will be destroyed by immunological rejection remains a challenge that can only be overcome through a better understanding of the nature and expression of potentially immunogenic molecules associated with cell replacement therapy and the mechanisms and pathways resulting in their immunologic rejection. This review draws on clinical experience of organ and tissue transplantation, and on transplantation immunology research to consider practical approaches for avoiding and overcoming the possibility of rejection of stem cell-derived tissues. PMID:25933238

  19. Dynamics of high repetition rate regenerative amplifiers

    NASA Astrophysics Data System (ADS)

    Grishin, M.; Gulbinas, V.; Michailovas, A.

    2007-07-01

    Dynamics features of high repetition rate continuously pumped solid-state regenerative amplifiers were studied numerically. A space independent rate equations and discrete-time dynamical system approach were used for system state evolution analysis. Regular single-energy operation, quasi-periodic pulsing and chaotic behavior regions are distinguished in space of control parameters. Diagrams of dynamical regimes comprehensively exhibiting operation features of the system are presented. Seed energy is shown to be an important parameter determining the stability space. Conditions of stable operation are described quantitatively.

  20. Transpiration And Regenerative Cooling Of Rocket Engine

    NASA Technical Reports Server (NTRS)

    Obrien, Charles J.

    1989-01-01

    Transpiration cooling extends limits of performance. Addition of transpiration cooling to regeneratively-cooled rocket-engine combustion chamber proposed. Modification improves performance of engine by allowing use of higher chamber pressure. Throat section of combustion-chamber wall cooled by transpiration, while chamber and nozzle sections cooled by fluid flowing in closed channels. Concept applicable to advanced, high-performance terrestrial engines or some kinds of industrial combustion chambers. With proper design, cooling scheme makes possible to achieve higher chamber pressure and higher overall performance in smaller engine.

  1. Nonlinear dynamics of a regenerative cutting process

    E-print Network

    Grzegorz Litak; Sven Schubert; Guenter Radons

    2012-01-24

    We examine the regenerative cutting process by using a single degree of freedom non-smooth model with a friction component and a time delay term. Instead of the standard Lyapunov exponent calculations, we propose a statistical 0-1 test analysis for chaos detection. This approach reveals the nature of the cutting process signaling regular or chaotic dynamics. For the investigated deterministic model we are able to show a transition from chaotic to regular motion with increasing cutting speed. For two values of time delay showing the different response the results have been confirmed by the means of the spectral density and the multiscaled entropy.

  2. Johnson Space Center's Regenerative Life Support Systems Test Bed

    Microsoft Academic Search

    D. J. Barta; D. L. Henninger

    1996-01-01

    The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with

  3. PROGRESS AND PROBLEMS IN THE THEORY OF REGENERATIVE PHENOMENA

    E-print Network

    PROGRESS AND PROBLEMS IN THE THEORY OF REGENERATIVE PHENOMENA J.F.C. Kingman Abstract Regenerative in Chung's magisterial account [2] of Markov processes with a countable state space, and this was provided in [23] and [24]. For Chung the fundamental objects are the transition functions pij(t) = P {X(t) = j|X(0

  4. PROGRESS AND PROBLEMS IN THE THEORY OF REGENERATIVE PHENOMENA

    E-print Network

    PROGRESS AND PROBLEMS IN THE THEORY OF REGENERATIVE PHENOMENA J.F.C. Kingman Abstract Regenerative, but a major milestone was the publication in 1960 by K.L. Chung of a magisterial account [3] of the theory second edition [4] is also worth study.) For Chung the fundamental quantities are the transition

  5. DESIGNING HUMAN 2.0 (TRANSHUMAN) – REGENERATIVE EXISTENCE

    Microsoft Academic Search

    Natasha Vita-More

    2008-01-01

    This paper explores regenerative existence for Human 2.0 – the transhuman. In building this focus, the author addresses the use of emerging technologies as propitious in designing the amended, extended, and suspended human body. Here, a first focus covers emerging biotechnologies for regenerative existence, which play a large role in extreme life extension. A second focus covers the digital technologies

  6. State of the art: stem cells in equine regenerative medicine.

    PubMed

    Lopez, M J; Jarazo, J

    2015-03-01

    According to Greek mythology, Prometheus' liver grew back nightly after it was removed each day by an eagle as punishment for giving mankind fire. Hence, contrary to popular belief, the concept of tissue and organ regeneration is not new. In the early 20th century, cell culture and ex vivo organ preservation studies by Alexis Carrel, some with famed aviator Charles Lindbergh, established a foundation for much of modern regenerative medicine. While early beliefs and discoveries foreshadowed significant accomplishments in regenerative medicine, advances in knowledge within numerous scientific disciplines, as well as nano- and micromolecular level imaging and detection technologies, have contributed to explosive advances over the last 20 years. Virtually limitless preparations, combinations and applications of the 3 major components of regenerative medicine, namely cells, biomaterials and bioactive molecules, have created a new paradigm of future therapeutic options for most species. It is increasingly clear, however, that despite significant parallels among and within species, there is no 'one-size-fits-all' regenerative therapy. Likewise, a panacea has yet to be discovered that completely reverses the consequences of time, trauma and disease. Nonetheless, there is no question that the promise and potential of regenerative medicine have forever altered medical practices. The horse is a relative newcomer to regenerative medicine applications, yet there is already a large body of work to incorporate novel regenerative therapies into standard care. This review focuses on the current state and potential future of stem cells in equine regenerative medicine. PMID:24957845

  7. Preemptive Repeat Identical Transitions in Markov Regenerative Stochastic Petri Nets

    E-print Network

    Telek, Miklós

    ­ tic Petri Nets (MRSPN) assumes that the random firing time associated to each transition is resampledPreemptive Repeat Identical Transitions in Markov Regenerative Stochastic Petri Nets Andrea Bobbio words: Stochastic Petri Nets, Semi­Markov Reward Models, Markov regenerative processes, pre­ emptive

  8. Development of a dynamic regenerative fuel cell system

    Microsoft Academic Search

    Alvin Bergen; Thomas Schmeister; Lawrence Pitt; Andrew Rowe; Nedjib Djilali; Peter Wild

    2007-01-01

    The development of a regenerative Integrated Renewable Energy Experiment (IRENE) is presented. IRENE is a laboratory-scale distributed energy system with a modular structure which can be re-configured to test newly developed components for generic regenerative systems integrating renewable energy, electrolysis, hydrogen and electricity storage and fuel cells. A special design feature of this test bed is the ability to accept

  9. Review on the Unitized Regenerative Fuel Cells Materials

    Microsoft Academic Search

    SALWAN S. DIHRAB; K. SOPIAN; A. ZAHARIM

    Unitized regenerative fuel cell is a unique fuel cell can work in both electrolyser and fuel cell in one cell at different mode, its useful in some application in which the weight is an important issue. This article reviews current literatures with the objective of identifying the latest development in membrane and bipolar plate materials for the Unitized Regenerative Fuel

  10. A novel unitized regenerative proton exchange membrane fuel cell

    Microsoft Academic Search

    O. J. Murphy; A. J. Cisar; A. Gonzalez-Martin; C. E. Salinas; S. F. Simpson

    1995-01-01

    A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed

  11. Theory of regenerative frequency dividers using double-balanced mixers

    Microsoft Academic Search

    R. G. Harrison

    1989-01-01

    Regenerative frequency halvers using double-balanced mixers are analyzed in terms of modified Bessel functions. Particular attention is given to a regenerative divide using a zero-memory double-balanced Schottky diode mixer. Closed-form solutions predict the threshold of turn on, the steady-state input-output amplitude relationship, and the operational bandwidth. Experimental results are also presented

  12. Research on control for regenerative braking of electric vehicle

    Microsoft Academic Search

    Binggang Cao; Zhifeng Bai; Wei Zhang

    2005-01-01

    The limitation of driving range is the key restriction for the development of EV (electric vehicle), and regenerative braking is an effective approach to extend the driving range of electric vehicle. To protect the battery from broken caused by large charging current during regenerative braking, the control strategy that makes the charging current as control object is proposed in this

  13. Bioethical aspects of regenerative and reproductive medicine.

    PubMed

    Yoshimura, Yasunori

    2006-05-01

    The birth announced in 1997 of Dolly, the lamb cloned from the somatic mammary cells of an adult ewe, and the discovery of human embryonic stem cells in 1998 have been the most exciting developments in the biological sciences in the past decade. Reproductive somatic cell nuclear transfer (SCNT) in additional species has been inefficient in that relatively few births, harmful side effects and high fetal and neonatal death rates have resulted from many attempts. Ongoing debates about the ethics of reproductive SCNT have revealed that some researchers regard human reproductive SCNT as morally unacceptable in all circumstances, others see merit in reproductive SCNT in certain circumstances and others await more information before making judgment about the ethical status of the procedure. Regenerative medicine and emerging biotechnologies started to revolutionize the practice of medicine. Advances in stem cell biology, including embryonic and postnatal somatic stem cells, have made the prospect of tissue regeneration a potential reality. Mammal cloning experiments have provided new impetus to the prospect of regenerative medicine through stem cell research. The procedure of SCNT could be used to create the raw material to replace defective or senescent tissue as a natural extension of the biology of stem cells. Researchers working in reproductive medicine should consider the potential hope given to many patients against the requisite and ethically contentious creation of human blastocysts for therapeutic intent. PMID:16879561

  14. Regenerative fuel cell systems R and D

    SciTech Connect

    Mitlitsky, F.; Myers, B.; Weisberg, A.H. [Lawrence Livermore National Lab., Livermore, CA (United States)

    1998-08-01

    Regenerative fuel cell (RFC) systems produce power and electrolytically regenerate their reactants using stacks of electrochemical cells. Energy storage systems with extremely high specific energy (> 400 Wh/kg) have been designed that use lightweight pressure vessels to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs). Progress is reported on the development, integration, and operation of rechargeable energy storage systems with such high specific energy. Lightweight pressure vessels that enable high specific energies have been designed with performance factors (burst pressure/internal volume/tank weight) > 50 km (2.0 million inches), and a vessel with performance factor of 40 km (1.6 million inches) was fabricated. New generations of both advanced and industry-supplied hydrogen tankage are under development. A primary fuel cell test rig with a single cell (46 cm{sup 2} active area) has been modified and operated reversibly as a URFC (for up to 2010 cycles on a single cell). This URFC uses bifunctional electrodes (oxidation and reduction electrodes reverse roles when switching from charge to discharge, as with a rechargeable battery) and cathode feed electrolysis (water is fed from the hydrogen side of the cell). Recent modifications also enable anode feed electrolysis (water is fed from the oxygen side of the cell). Hydrogen/halogen URFCs, capable of higher round-trip efficiency than hydrogen/oxygen URFCs, have been considered, and will be significantly heavier. Progress is reported on higher performance hydrogen/oxygen URFC operation with reduced catalyst loading.

  15. Analysis of Regen Cooling in Rocket Combustors

    NASA Technical Reports Server (NTRS)

    Harper, Brent (Technical Monitor); Merkle, C. L.; Li, D.; Sankaran, V.

    2004-01-01

    The use of detailed CFD modeling for the description of cooling in rocket chambers is discussed. The overall analysis includes a complete three-dimensional analysis of the flow in the regenerative cooling passages, conjugate heat transfer in the combustor walls, and the effects of film cooling on the inside chamber. The results in the present paper omit the effects of film cooling and include only regen cooling and the companion conjugate heat transfer. The hot combustion gases are replaced by a constant temperature wall boundary condition. Load balancing for parallel cluster computations is ensured by using single-block unstructured grids for both fluids and solids, and by using a 'multiple physical zones' to account for differences in the number of equations. Validation of the method is achieved by comparing simple two-dimensional solutions with analytical results. Representative results for cooling passages are presents showing the effects of heat conduction in the copper walls with tube aspect ratios of 1.5:l.

  16. Multiple excitation regenerative amplifier inertial confinement system

    DOEpatents

    George, Victor E. [Livermore, CA; Haas, Roger A. [Pleasanton, CA; Krupke, William F. [Pleasanton, CA; Schlitt, Leland G. [Livermore, CA

    1980-05-27

    The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation.

  17. Multiple excitation regenerative amplifier inertial confinement system

    DOEpatents

    George, V.E.; Haas, R.A.; Krupke, W.F.; Schlitt, L.G.

    1980-05-27

    The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation. 11 figs.

  18. [Pathophysiology and therapy of benign prostatic hyperplasia].

    PubMed

    Sampson, Natalie; Madersbacher, Stephan; Berger, Peter

    2008-01-01

    Benign prostatic hyperplasia (BPH) and benign prostatic enlargement (BPE) are among the most frequent medical disorders of elderly men and cause a number of annoying symptoms of the lower urinary tract (LUTS), leading to reduced quality of life and severe complications, including acute urinary retention. Nodular overgrowth of the epithelium and in particular the fibromuscular tissue is observed in the transition zone and periurethral areas. In particular, functional and phenotypic transdifferentiation of fibroblasts into myofibroblasts is a hallmark of the tissue remodeling in the benign hyperplastic prostate. BPH/BPE have a complex pathophysiology with a multitude of endocrine and local factors involved. Two risk factors, namely aging and circulating androgens, contribute significantly to risk of BPH/BPE. One of the primary initiating mechanisms appears to be a consequence of age-related changes in systemic sex steroid hormone levels accompanied by alterations in local androgen metabolism. This results in the disruption of the delicate balance of interacting growth factor signaling pathways and stromal/epithelial interactions generating a growth promoting and tissue remodeling microenvironment that leads to an increase in prostate volume. Secondarily, altered cytokine and chemoattractant production by the remodeled stroma promotes local inflammation that may further contribute to disease progression via lymphocyte-derived inflammatory cytokines and reactive oxygen/nitrogen species. Local hypoxia as a result of increased oxygen demands of proliferating cells may induce low levels of reactive oxygen species promoting neovascularization and fibroblast-to-myofibroblast transdifferentiation. Medical therapies for LUTS due to BPH/BPE have changed little over the past 15 years with mainstay treatments being alpha-adrenoreceptor blockade and 5alpha-reductase inhibitors. We provide an in depth view of the mechanisms underlying BPH/BPE and relate new research findings to the clinical picture with the prospect of novel therapeutic targets, including selective hormone antagonists/agonists, anti-stromal therapy, vitamin-D analogues and approaches to redress the redox imbalance. PMID:18726663

  19. Prostate . Author manuscript Inflammation in benign prostatic hyperplasia: a 282 patients'

    E-print Network

    Boyer, Edmond

    Prostate . Author manuscript Page /1 7 Inflammation in benign prostatic hyperplasia: a 282 patients Taille Abstract Introduction and objectives Prostatic inflammation could be a key component in prostate enlargement and benign prostatic hyperplasia (BPH) progression. Our aim

  20. ``HYTEC''—A thermally regenerative fuel cell

    NASA Astrophysics Data System (ADS)

    Roy, Prodyot; Salamah, Samir A.; Maldonado, Jerry; Narkiewicz, Regina S.

    1993-01-01

    HYTEC (Hydrogen Thermo-Electrochemical Converter) is a thermally regenerative fuel cell for direct conversion of heat into electricity. The principles of basic cell operation involve ionic transport of hydrogen through a hydride-ion (H-) conducting, molten electrolyte, and reaction with alkali metals, oxygen, or air. In order to operate HYTEC in a thermally regenerative mode, pure Li and Na, or a mixture of Li/Na alloy, is used for reaction with hydrogen, to form metal hydride which is subsequently decomposed to metal and hydrogen at higher temperatures. The reactants are then separated and redirected to the electrochemical cell. In the cell the molten, H--conducting electrolyte is immobilized between two thin hydrogen-permeable, solid, metallic electrodes which also act as current collectors. The H2 gas first diffuses through the cathode electrode and forms a hydride ion (H+e?H-) at the cathode-electrolyte interface. The H- ion subsequently migrated through the electrolyte under a chemical potential gradient created by the presence of the alkali metal in the anode chamber. The H- ion releases the electron to form hydrogen atoms (H-?H+e) at the anode-electrolyte interface. The hydrogen atom diffuses through the anode electrode and reacts with the alkali metal to form metal hydride. The electron released passes through the load circuit to complete the cycle. In the regeneration scheme, the fuel cell is operated at temperature T1. The metal hydride formed at the anode is pumped to the decomposition chamber through a recuperator. The metal hydride is decomposed at a higher temperature, T2, by an external heat source. The H2 gas is separated from the alkali metal by a H2-permeable, solid, metallic membrane and fed into the anode chamber of the cell. The hydrogen-depleted alkali metal is directed to the cathode chamber of the cell, via the recuperator, to complete the cycle. To date, electrochemical feasibility of the concept has been experimentally demonstrated. A system analysis indicates that a HYTEC system can reach efficiencies as high as 30%. The paper describes the unique features of the HYTEC concept as compared to other thermally regenerative fuel cells. The current developmental status is also included.

  1. Rebouissou et al 1 Molecular pathogenesis of focal nodular hyperplasia and

    E-print Network

    Paris-Sud XI, Université de

    ,version1 #12;Rebouissou et al 3 Focal nodular hyperplasia and hepatocellular adenomas are benign liver hyperplasia (FNH), first described by Edmondson, are the second most frequent benign liver tumors afterRebouissou et al 1 Molecular pathogenesis of focal nodular hyperplasia and hepatocellular adenoma

  2. Heating system for regenerative coke oven batteries

    SciTech Connect

    Weber, H.; Morgenstern, M.; Stalherm, D.; Urbye, K.

    1984-02-14

    A heating system for regenerative coke oven batteries having a plurality of coke oven chambers separated by heating walls and a plurality of regenerators extending the length of the coke oven for preheating air and cooling hot waste gases comprises a plurality of spaced heating ducts extending upwardly in the heating walls which are grouped into two adjacent pairs of heating ducts. The ducts in each group of four heating ducts are separated by first and second binder walls with the first binder walls carrying one binder duct for supplying air and discharging hot waste to and from adjacent heat ducts in one of the pairs in the group. The second wall is either provided with no heating ducts or a pair of heating ducts. A horizontal channel connects the tops of all four heating ducts in each group and the lower end of each heating duct is provided with a rich gas supply nozzle.

  3. Regenerative system for a gas turbine

    SciTech Connect

    Wadsworth, W.

    1987-04-28

    A regenerative system is described for a gas turbine, wherein the turbine has a single shaft on which are mounted a compressor section and a work section, comprising: an air heater mounted adjacent the exit of the work section, the hot exit gas and pressurized air passing through passages formed in the air heater; combustor housings surrounding the compressor section, each containing a combustor mounted within it and extending coaxially thereof, each combustor having a transition section extending to the entrance to the work section; an annular connector housing extending between the combustor housing and the exit of the compressor section to carry the compressed air radially; an outer duct leading from the connector housing to one end of the air heater; and an inner duct attached to the other end of the air heater.

  4. Regenerative block empirical likelihood for Markov chains

    E-print Network

    Harari-Kermadec, Hugo

    2011-01-01

    Empirical likelihood is a powerful semi-parametric method increasingly investigated in the literature. However, most authors essentially focus on an i.i.d. setting. In the case of dependent data, the classical empirical likelihood method cannot be directly applied on the data but rather on blocks of consecutive data catching the dependence structure. Generalization of empirical likelihood based on the construction of blocks of increasing nonrandom length have been proposed for time series satisfying mixing conditions. Following some recent developments in the bootstrap literature, we propose a generalization for a large class of Markov chains, based on small blocks of various lengths. Our approach makes use of the regenerative structure of Markov chains, which allows us to construct blocks which are almost independent (independent in the atomic case). We obtain the asymptotic validity of the method for positive recurrent Markov chains and present some simulation results.

  5. Power Management in Regenerative Life Support Systems

    NASA Technical Reports Server (NTRS)

    Crawford, Sekou; Pawlowski, Christopher; Finn, Cory; Mead, Susan C. (Technical Monitor)

    1999-01-01

    Effective management of power can reduce the cost of launch and operation of regenerative life support systems. Variations in power may be quite severe and may manifest as surges or spikes, While the power plant may have some ability to deal with these variations, with batteries for example, over-capacity is expensive and does nothing to address the fundamental issue of excessive demand. Because the power unit must be sized to accommodate the largest demand, avoiding power spikes has the potential to reduce the required size of the power plant while at the same time increasing the dependability of the system. Scheduling of processors can help to reduce potential power spikes. However, not all power-consuming equipment is easily scheduled. Therefore, active power management is needed to further decrease the risk of surges or spikes. We investigate the use of a hierarchical scheme to actively manage power for a model of a regenerative life support system. Local level controllers individually determine subsystem power usage. A higher level controller monitors overall system power and detects surges or spikes. When a surge condition is detected, the higher level controller conducts an 'auction' and describes subsystem power usage to re-allocate power. The result is an overall reduction in total power during a power surge. The auction involves each subsystem making a 'bid' to buy or sell power based on local needs. However, this re-allocation cannot come at the expense of life support function. To this end, participation in the auction is restricted to those processes meeting certain tolerance constraints. These tolerances represent acceptable limits within which system processes can be operated. We present a simulation model and discuss some of our results.

  6. Materials science tools for regenerative medicine

    NASA Astrophysics Data System (ADS)

    Richardson, Wade Nicholas

    Regenerative therapies originating from recent technological advances in biology could revolutionize medicine in the coming years. In particular, the advent of human pluripotent stem cells (hPSCs), with their ability to become any cell in the adult body, has opened the door to an entirely new way of treating disease. However, currently these medical breakthroughs remain only a promise. To make them a reality, new tools must be developed to surmount the new technical hurdles that have arisen from dramatic departure from convention that this field represents. The collected work presented in this dissertation covers several projects that seek to apply the skills and knowledge of materials science to this tool synthesizing effort. The work is divided into three chapters. The first deals with our work to apply Raman spectroscopy, a tool widely used for materials characterization, to degeneration in cartilage. We have shown that Raman can effectively distinguish the matrix material of healthy and diseased tissue. The second area of work covered is the development of a new confocal image analysis for studying hPSC colonies that are chemical confined to uniform growth regions. This tool has important application in understanding the heterogeneity that may slow the development of hPSC -based treatment, as well as the use of such confinement in the eventually large-scale manufacture of hPSCs for therapeutic use. Third, the use of structural templating in tissue engineering scaffolds is detailed. We have utilized templating to tailor scaffold structures for engineering of constructs mimicking two tissues: cartilage and lung. The work described here represents several important early steps towards large goals in regenerative medicine. These tools show a great deal of potential for accelerating progress in this field that seems on the cusp of helping a great many people with otherwise incurable disease.

  7. The TMI Regenerative Solid Oxide Fuel Cell

    NASA Technical Reports Server (NTRS)

    Cable, Thomas L.; Ruhl, Robert C.; Petrik, Michael

    1996-01-01

    Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. Systems generally consist of photovoltaic solar arrays which operate (during sunlight cycles) to provide system power and regenerate fuel (hydrogen) via water electrolysis and (during dark cycles) fuel cells convert hydrogen into electricity. Common configurations use two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Reliability, power to weight and power to volume ratios could be greatly improved if both power production (fuel cells) and power storage (electrolysis) functions can be integrated into a single unit. The solid oxide fuel cell (SOFC) based design integrates fuel cell and electrolyzer functions and potentially simplifies system requirements. The integrated fuel cell/electrolyzer design also utilizes innovative gas storage concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H20 electrode (SOFC anode/electrolyzer cathode) materials for regenerative fuel cells. Tests have shown improved cell performance in both fuel and electrolysis modes in reversible fuel cell tests. Regenerative fuel cell efficiencies, ratio of power out (fuel cell mode) to power in (electrolyzer mode), improved from 50 percent using conventional electrode materials to over 80 percent. The new materials will allow a single SOFC system to operate as both the electolyzer and fuel cell. Preliminary system designs have also been developed to show the technical feasibility of using the design for space applications requiring high energy storage efficiencies and high specific energy. Small space systems also have potential for dual-use, terrestrial applications.

  8. Performance Analysis of Markov Regenerative Reward Mikl'os Telek, Andr'as Pfening

    E-print Network

    Telek, Miklós

    Performance Analysis of Markov Regenerative Reward Models ? Mikl'os Telek, Andr'as Pfening for the analysis of Markov Regenerative Processes (MRGP). The widely used description of MRGPs, i.e. by the local regenerative property for the analysis of Markov Regenerative Reward Mod­ els (MRRM). The distribution

  9. Hepatic focal nodular hyperplasia: CT and sonographic spectrum

    Microsoft Academic Search

    A. Shirkhoda; M. C. Farah; E. Bernacki; B. Madrazo; J. Roberts

    1994-01-01

    Fifteen patients with pathologically proven focal nodular hyperplasia (FNH) of the liver had abdominal computed tomography (CT) (15) and ultrasound (11). In seven patients, the lesions were incidentally found during gallbladder or renal examination, whereas the other eight had a primary neoplasm and the liver was studied for possible metastasis. In 11 unenhanced CT scans, the ratio of isodense to

  10. Focal nodular hyperplasia of the liver: Radiologic findings

    Microsoft Academic Search

    Kohkan Shamsi; Arthur De Schepper; Hendrik Degryse; Filip Deckers

    1993-01-01

    A retrospective analysis of the results of ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) of 24 cases (28 lesions) of proven focal nodular hyperplasia (FNH) is presented. While US exhibited nonspecific features, CT frequently showed characteristic features: hypodensity on precontrast scans (69%), transient immediate enhancement after bolus injection (96%), and homogeneity (85%). A scar was noted in

  11. Diagnosis and management of hepatic focal nodular hyperplasia

    Microsoft Academic Search

    A. Venturi; F. Piscaglia; G. Vidili; S. Flori; R. Righini; R. Golfieri; L. Bolondi

    2007-01-01

    Focal nodular hyperplasia (FNH) is the second most common benign tumor of the liver, after hemangioma. It is generally found incidentally and is most common in reproductive-aged women, but it also affects males and can be diagnosed at any age. Patients are rarely symptomatic, but FNH sometimes causes epigastric or right upper quadrant pain. The main clinical task is to

  12. Microwave applicators for thermotherapy of benign prostatic hyperplasia: a primer.

    PubMed

    Bolmsjö, M B; Vrba, T

    2000-12-01

    Microwave thermotherapy for treatment of benign prostatic hyperplasia (BPH) is becoming increasingly more common. This article provides an introduction to the functional principles of microwave antennas for delivery of energy to the prostatic gland. Different antenna designs (monopole, dipole, and helical coil types) and impedance matching are discussed. PMID:11108559

  13. INDUCTION OF PROSTATE APOPTOSIS BY DOXAZOSIN IN BENIGN PROSTATIC HYPERPLASIA

    Microsoft Academic Search

    NATASHA KYPRIANOU; JUAN P. LITVAK; ANDREW BORKOWSKI; RICHARD ALEXANDER; STEPHEN C. JACOBS

    1998-01-01

    PurposeThe molecular mechanisms underlying the therapeutic effect of the alpha 1 blocker, doxazosin, on benign prostatic hyperplasia (BPH) are poorly understood. We evaluated the effect of doxazosin on cell proliferation and apoptosis in the prostatic glandular epithelium and stroma of patients with BPH.

  14. Managing benign prostatic hyperplasia and prostate cancer – the challenges today

    Microsoft Academic Search

    Michael Marberger

    2010-01-01

    Many men who reach average life expectancy will experience benign prostatic hyperplasia (BPH) or prostate cancer and together these conditions account for a considerable amount of ill-health and distress for men and their partners. Although there is considerable overlap across BPH and prostate cancer in symptom and risk profiles, management approaches are very different for each condition and appropriate diagnostic

  15. Apoptotic versus proliferative activities in human benign prostatic hyperplasia

    Microsoft Academic Search

    Natasha Kyprianou; Huacheng Tu; Stephen C Jacobs

    1996-01-01

    Cell growth in the normal prostate is regulated by a delicate balance between cell death and cell proliferation (ie, apoptotic v proliferative activity). Disruption of the molecular mechanisms that regulate these two processes may underline the abnormal growth of the gland leading to benign prostatic hyperplasia (BPH). In this study, the incidence of programmed cell death (apoptosis) and cell proliferation

  16. Pulmonary Nodular Lymphoid Hyperplasia Associated with Sjögren's Syndrome

    Microsoft Academic Search

    Moo-Kon Song; Young-Mi Seol; Young-Eun Park; Yun-Seong Kim; Min-Ki Lee; Chang-Hun Lee; Yeon-Ju Jeong

    2007-01-01

    Pulmonary nodular lymphoid hyperplasia (NLH) is a term first suggested by Kradin and Mark to describe one or more pulmonary nodules or localized lung infiltrates consisting of reactive lymphoid proliferation. To date, there have been only a few cases of pulmonary NLH reported associated with autoimmune disorders. There is no case of NLH associated with Sjögren's syndrome from Korea in

  17. Mistaken gender identity in non-classical congenital adrenal hyperplasia

    PubMed Central

    Kukreti, Prerna; Kandpal, Manish; Jiloha, R. C.

    2014-01-01

    Gender identity is the sense of belonging that one feels for a particular sex psychologically and socially, independent of one's biological sex. There is much less systematic data on gender identity in females with congenital adrenal hyperplasia (CAH). We report a case of non-classical CAH presenting as a case of gender identity disorder. PMID:24891708

  18. Early Hormonal Influences on Cognitive Functioning in Congenital Adrenal Hyperplasia.

    ERIC Educational Resources Information Center

    Resnick, Susan M.; And Others

    1986-01-01

    Reports the results of cognitive test performance and early childhood activities in individuals with congenital adrenal hyperplasia, an autosomal recessive disorder associated with elevated prenatal adrenal androgen levels, demonstrating the effects of early exposure to excess androgenizing hormones on sexually dimorphic cognitive functioning.…

  19. Hepatic focal nodular hyperplasia: angiography, CT, sonography, and scintigraphy

    SciTech Connect

    Rogers, J.V. (Univ. of Washington, Seattle); Mack, L.A.; Freeny, P.C.; Johnson, M.L.; Sones, P.J.

    1981-11-01

    Eleven patients with focal nodular hyperplasia of the liver underwent a combination of radiologic procedures, including sonography, computed tomography (CT), hepatic scintigraphy, and angiography. This paper describes the radiologic findings in this group of patients and reviews the current literature. In the present series, sonography was the most sensitive (100%) method for detection of focal nodular hyperplasia, while CT was able to detect only seven (78%) of nine cases. Arteriographic findings were felt to be characteristic in nine (82%) of 11 cases. Hepatic scintigraphy demonstrated normal colloid uptake in six (55%) of 11 lesions. In this series, an accurate radiologic diagnosis of focal nodular hyperplasia was made in 73% of cases. Hepatic scintigraphy is the pivotal examination. Normal colloid uptake by a focal hepatic mass is virtually diagnostic. However, in the patients in whom the colloid scan shows decreased or absent uptake, angiography may show findings diagnostic of focal nodular hyperplasia in up to 75% of cases, thus avoiding the need for liver biopsy or surgery.

  20. Imaging Modalities for Focal Nodular Hyperplasia and Hepatocellular Adenoma

    Microsoft Academic Search

    Jacomina W. van den Esschert; Thomas M. van Gulik; Saffire S. K. S. Phoa

    2010-01-01

    Background\\/Aims: There are several imaging modalities available for the detection of focal liver lesions. Differentiation between focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) is important because of the consequences for management. However, differentiation based on imaging alone still shows limitations. Methods: We reviewed the literature for typical features of FNH and HCA on radiologic and nuclear imaging with emphasis

  1. Regenerative fuel cell combines high efficiency with low cost

    NASA Technical Reports Server (NTRS)

    Doyle, H.; Frank, H.; Stephens, C. W.

    1965-01-01

    Hydrogen/oxygen regenerative fuel cell stores electrical energy efficiently and inexpensively. The fuel cell has a high energy-to-weight ratio, and is adapted for a large number of cycles with deep discharge.

  2. Performance analysis and comparision of ultracapacitor based regenerative braking system

    Microsoft Academic Search

    Tongzhen Wei; Sibo Wang; Xuhua Gao

    2009-01-01

    In this paper three types of energy storage system for regenerative braking are presented. The advantages and disadvantages are discussed after the simulation and experimental results are presented. Problems are discussed and the design guidelines are suggested.

  3. An examination of regenerative organic Rankine cycles using dry fluids

    Microsoft Academic Search

    Pedro J. Mago; Louay M. Chamra; Kalyan Srinivasan; Chandramohan Somayaji

    2008-01-01

    This paper presents an analysis of regenerative organic Rankine cycles “ORC” using dry organic fluids, to convert waste energy to power from low-grade heat sources. The dry organic working fluids selected for this investigation are R113, R245ca, R123, and isobutane, with boiling points ranging from ?12°C to 48°C. Regenerative ORC is analyzed and compared with the basic ORC in order

  4. Physiological regeneration of skin appendages and implications for regenerative medicine

    PubMed Central

    Chuong, Cheng-Ming; Randall, Valerie A; Widelitz, Randall B.; Wu, Ping; Jiang, Ting-Xin

    2013-01-01

    The concept of regenerative medicine is relatively new, but animals are well known to remake their hair and feathers regularly by normal regenerative physiological processes. Here we focus on 1) how extra-follicular environments can regulate hair and feather stem cell activities and 2) how different configurations of stem cells can shape organ forms in different body regions to fulfil changing physiological needs. PMID:22505663

  5. Manufacturing road map for tissue engineering and regenerative medicine technologies.

    PubMed

    Hunsberger, Joshua; Harrysson, Ola; Shirwaiker, Rohan; Starly, Binil; Wysk, Richard; Cohen, Paul; Allickson, Julie; Yoo, James; Atala, Anthony

    2015-02-01

    SummaryThe Regenerative Medicine Foundation Annual Conference held on May 6 and 7, 2014, had a vision of assisting with translating tissue engineering and regenerative medicine (TERM)-based technologies closer to the clinic. This vision was achieved by assembling leaders in the field to cover critical areas. Some of these critical areas included regulatory pathways for regenerative medicine therapies, strategic partnerships, coordination of resources, developing standards for the field, government support, priorities for industry, biobanking, and new technologies. The final day of this conference featured focused sessions on manufacturing, during which expert speakers were invited from industry, government, and academia. The speakers identified and accessed roadblocks plaguing the field where improvements in advanced manufacturing offered many solutions. The manufacturing sessions included (a) product development toward commercialization in regenerative medicine, (b) process challenges to scale up manufacturing in regenerative medicine, and (c) infrastructure needs for manufacturing in regenerative medicine. Subsequent to this, industry was invited to participate in a survey to further elucidate the challenges to translation and scale-up. This perspective article will cover the lessons learned from these manufacturing sessions and early results from the survey. We also outline a road map for developing the manufacturing infrastructure, resources, standards, capabilities, education, training, and workforce development to realize the promise of TERM. PMID:25575525

  6. New Regenerative Cycle for Vapor Compression Refrigeration

    SciTech Connect

    Mark J. Bergander

    2005-08-29

    The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and second step of compression. In the proposed system, the compressor compresses the vapor only to 50-60% of the final pressure, while the additional compression is provided by a jet device using internal potential energy of the working fluid flow. Therefore, the amount of mechanical energy required by a compressor is significantly reduced, resulting in the increase of efficiency (either COP or EER). The novelty of the cycle is in the equipment and in the way the multi-staging is accomplished. The anticipated result will be a new refrigeration system that requires less energy to accomplish a cooling task. The application of this technology will be for more efficient designs of: (1) Industrial chillers, (2) Refrigeration plants, (3) Heat pumps, (4) Gas Liquefaction plants, (5) Cryogenic systems.

  7. REGENERATIVE MEDICINE AS APPLIED TO GENERAL SURGERY

    PubMed Central

    Orlando, Giuseppe; Wood, Kathryn J; De Coppi, Paolo; Baptista, Pedro M; Binder, Kyle W; Bitar, Khalil N; Breuer, Christopher; Burnett, Luke; Christ, George; Farney, Alan; Figliuzzi, Marina; Holmes, James H; Koch, Kenneth; Macchiarini, Paolo; Sani, Sayed-Hadi Mirmalek; Opara, Emmanuel; Remuzzi, Andrea; Rogers, Jeffrey; Saul, Justin M; Seliktar, Dror; Shapira-Schweitzer, Keren; Smith, Tom; Solomon, Daniel; Van Dyke, Mark; Yoo, James J; Zhang, Yuanyuan; Atala, Anthony; Stratta, Robert J; Soker, Shay

    2012-01-01

    The present review illustrates the state of the art of regenerative medicine (RM) as applied to surgical diseases and demonstrates that this field has the potential to address some of the unmet needs in surgery. RM is a multidisciplinary field whose purpose is to regenerate in vivo or ex vivo human cells, tissues or organs in order to restore or establish normal function through exploitation of the potential to regenerate, which is intrinsic to human cells, tissues and organs. RM uses cells and/or specially designed biomaterials to reach its goals and RM-based therapies are already in use in several clinical trials in most fields of surgery. The main challenges for investigators are threefold: Creation of an appropriate microenvironment ex vivo that is able to sustain cell physiology and function in order to generate the desired cells or body parts; identification and appropriate manipulation of cells that have the potential to generate parenchymal, stromal and vascular components on demand, both in vivo and ex vivo; and production of smart materials that are able to drive cell fate. PMID:22330032

  8. Regenerative life support system research and concepts

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Life support systems that involve recycling of atmospheres, water, food and waste are so complex that models incorporating all the interactions and relationships are vital to design, development, simulations, and ultimately to control of space qualified systems. During early modeling studies, FORTRAN and BASIC programs were used to obtain numerical comparisons of the performance of different regenerative concepts. Recently, models were made by combining existing capabilities with expert systems to establish an Intelligent Design Support Environment for simpliflying user interfaces and to address the need for the engineering aspects. Progress was also made toward modeling and evaluating the operational aspects of closed loop life support systems using Time-step and Dynamic simulations over a period of time. Example models are presented which show the status and potential of developed modeling techniques. For instance, closed loop systems involving algae systeMs for atmospheric purification and food supply augmentation, plus models employing high plants and solid waste electrolysis are described and results of initial evaluations are presented.

  9. High power, high beam quality regenerative amplifier

    DOEpatents

    Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Livermore, CA)

    1993-01-01

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  10. High power, high beam quality regenerative amplifier

    DOEpatents

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  11. Unitized Regenerative Fuel Cell System Development

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.

    2003-01-01

    Unitized Regenerative Fuel Cells (URFC) have recently been developed by several fuel cell manufacturers. These manufacturers have concentrated their efforts on the development of the cell stack technology itself, and have not up to this point devoted much effort to the design and development of the balance of plant. A fuel cell technology program at the Glenn Research Center (GRC) that has as its goal the definition and feasibility testing of the URFC system balance of plant. Besides testing the feasibility, the program also intends to minimize the system weight, volume, and parasitic power as its goal. The design concept currently being developed uses no pumps to circulate coolant or reactants, and minimizes the ancillary components to only the oxygen and hydrogen gas storage tanks, a water storage tank, a loop heat pipe to control the temperature and two pressure control devices to control the cell stack pressures during operation. The information contained in this paper describes the design and operational concepts employed in this concept. The paper also describes the NASA Glenn research program to develop this concept and test its feasibility.

  12. Advent and maturation of regenerative medicine.

    PubMed

    Mhashilkar, Abner M; Atala, Anthony

    2012-11-01

    The field of regenerative medicine (RM), encompassing stem cell (SC) technologies, therapeutics, tissue engineering (TE), biomaterials, scaffolds and other enabling technologies provides a wide gamut of tools and tracks to combat, manage and hopefully cure serious human and animal injuries, dysfunctions and diseases. This review illustrates the trends that are becoming the major platforms in this field. The last 10 years in itself has seen major definitive observations, including multi-track directives of adult stem cell translational technologies, tissue and organ engineering protocols, iPS cell applications and understanding of the role of cancer stem cells to develop effective anti-cancer regimens. With the rapid advances of RM translational research, further advances are expected to be implemented for personalized repair and curative outcomes. RM future is bright although laden with challenges of global fragmentation which needs coherent consolidation, stringent cost and time effective regulation and long-term funding mechanisms, so clinical and diagnostic solutions are realized and recognized to combat unmet medical needs. PMID:23176292

  13. Minimally invasive surgery for coronoid hyperplasia: endoscopically assisted intraoral coronoidectomy.

    PubMed

    Robiony, Massimo; Casadei, Matteo; Costa, Fabio

    2012-11-01

    The term hyperplasia of the coronoid process of the mandible defines an abnormal elongation of the coronoid process consisting of histologically normal bone. The main clinical finding of hyperplasia of the coronoid process is a progressive painless difficulty in opening the mouth owing to the contact with the temporal surface of the zygomatic bone or medial surface of the zygomatic arch. Computed tomography with three-dimensional reconstruction is essential and is the gold standard for an accurate diagnosis. The etiology remains unknown, although several theories have been suggested. The main aim of treatment was to restore mouth opening, and this article introduces and illustrates the advantages of endoscopic assistance for coronoidectomy through the classic "intraoral" approach and emphasize this minimally invasive approach. PMID:23147302

  14. Pictures of focal nodular hyperplasia and hepatocellular adenomas.

    PubMed

    Sempoux, Christine; Balabaud, Charles; Bioulac-Sage, Paulette

    2014-08-27

    This practical atlas aims to help liver and non liver pathologists to recognize benign hepatocellular nodules on resected specimen. Macroscopic and microscopic views together with immunohistochemical stains illustrate typical and atypical aspects of focal nodular hyperplasia and of hepatocellular adenoma, including hepatocellular adenomas subtypes with references to clinical and imaging data. Each step is important to make a correct diagnosis. The specimen including the nodule and the non-tumoral liver should be sliced, photographed and all different looking areas adequately sampled for paraffin inclusion. Routine histology includes HE, trichrome and cytokeratin 7. Immunohistochemistry includes glutamine synthase and according to the above results additional markers such as liver fatty acid binding protein, C reactive protein and beta catenin may be realized to differentiate focal nodular hyperplasia from hepatocellular adenoma subtypes. Clues for differential diagnosis and pitfalls are explained and illustrated. PMID:25232451

  15. Focal epithelial hyperplasia (Heck's disease) in two Chinese females.

    PubMed

    Liu, N; Li, Y; Zhou, Y; Zeng, X

    2012-08-01

    Focal epithelial hyperplasia, or Heck's disease, is a relatively rare virus-induced benign disease. To the best of the authors' knowledge it has not been reported in an ethnic Chinese population. The authors report two cases of focal epithelial hyperplasia (FEH) in Chinese patients, which were clinically and histologically in accord with FEH. In particular, the lesions in one case were located on the gingival mucosa, which is rarely affected by FEH. DNA extracted from paraffin-embedded specimens from the two patients was tested for the presence of human papilloma virus followed by speci?c polymerase chain reaction testing for 16, 18, 13, and 32 subtypes in order to con?rm the clinical diagnosis. PMID:22154527

  16. Clinical outcomes of childhood x-irradiation for lymphoid hyperplasia

    SciTech Connect

    Pottern, L.M.

    1987-01-01

    A prospective study was conducted to explore the relationship between childhood x-irradiation for lymphoid hyperplasia and the subsequent development of thyroid gland and other head and neck disorders. All individuals under 18 years of age who were x-irradiated for lymphoid hyperplasia during the years 1938-69 at Children's Hospital Medical Center, Boston comprised the exposed population. The comparison group consisted of non-exposed, surgically treated individuals. The study included a health questionnaire and a clinical examination component. A history of thyroid cancer was reported by 11 exposed subjects and no non-exposed subjects. Significantly elevated standardized incidence ratios of thyroid cancer were seen for both exposed males and females, 19.9 and 12.1, respectively. The average thyroid radiation dose was 25.8 rads and the mean latency period was 17.3 years.

  17. Angiolymphoid hyperplasia with eosinophilia successfully treated with oral steroids.

    PubMed

    Fasanmade, Adekunmi; Anjum, Kashif; Hughes, Ceri; Dunnill, Giles; Thomas, Steve

    2010-01-01

    Angiolymphoid hyperplasia with eosinophilia is a rare benign vascular lesion most commonly affecting the head and neck region. This article reports a case of a 26-year-old white woman with rapidly enlarging nodules of the upper lip and cheek treated successfully with oral corticosteroids and cetirizine. Morbidity and cosmetic deformity associated with radical surgery to the face and possible consequences of radiation treatment were avoided. There were no long-term complications. PMID:19907735

  18. Sexual function in patients with benign prostatic hyperplasia

    Microsoft Academic Search

    Paul K. Hegarty; Nicholas J. Hegarty; John M. Fitzpatrick

    2001-01-01

    Sexual health has significant impact on quality of life among men with benign prostatic hyperplasia (BPH). The degree of sexual\\u000a dysfunction matches the severity of lower urinary tract symptoms (LUTS). Treatment of BPH affects not only LUTS, but sexual\\u000a function as well. Medical, surgical, and minimally invasive therapies differ in their effect on erectile function, ejaculation,\\u000a and sexual satisfaction. Choice

  19. The role of combination medical therapy in benign prostatic hyperplasia

    Microsoft Academic Search

    K A Greco; K T McVary

    2008-01-01

    To review key trials of monotherapy and combination therapy of ?1-adrenergic receptor antagonists (?1-ARAs), 5?-reductase inhibitors (5?RIs) and anti-muscarinic agents in the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). To assess the safety and efficacy of combination therapies for LUTS associated with BPH, a search of the MEDLINE and Cochrane databases (1976–2008) was conducted

  20. Benign prostate hyperplasia: evaluation of treatment response with DCE MRI

    Microsoft Academic Search

    J. T. Heverhagen; H. von Tengg-Kobligk; K. T. Baudendistel; G. Jia; H. Polzer; H. Henry; A. L. Levine; T. J. Rosol; M. V. Knopp

    2004-01-01

    Benign prostate hyperplasia (BPH) is a major disease and its non-surgical therapy a major area of interest. The purpose of this study was to establish perfusion parameters in beagles with BPH using dynamic contrast-enhanced (DCE) MRI and to investigate changes due to the effects of finasteride treatment. Twelve male beagles (mean age 4.4±0.9,years) were divided into a control and treatment

  1. New Advances in Benign Prostatic Hyperplasia: Laser Therapy

    Microsoft Academic Search

    Jessica Mandeville; Ehud Gnessin; James E. Lingeman

    2011-01-01

    Throughout the past decade, numerous techniques for the treatment of benign prostatic hyperplasia have emerged. Laser therapy,\\u000a in particular, has gained widespread popularity among urologists. Since its inception in 1996, holmium laser enucleation of\\u000a the prostate (HoLEP) has been evaluated rigorously in the treatment of glands of all sizes. HoLEP has produced superior relief\\u000a of bladder outlet obstruction as compared

  2. Overview of interventional treatment options for benign prostatic hyperplasia.

    PubMed

    Elhilali, Mostafa M

    2012-10-01

    Transurethral resection of the prostate (TURP) remains the gold standard surgical intervention for men with benign prostatic hyperplasia (BPH). However, there are other, newer technologies that have also demonstrated safety and efficacy at least equivalent to that of TURP (e.g., Holmium laser, photoselective vaporization of the prostate). These minimally invasive techniques may be particularly useful for selected patient populations (e.g., those on anticoagulant therapy). PMID:23092781

  3. Regenerative potential of allopregnanolone Jun Ming Wang, Lifei Liu, Ronald W. Irwin, Shuhua Chen, Roberta Diaz Brinton

    E-print Network

    Brinton, Roberta Diaz

    Review Regenerative potential of allopregnanolone Jun Ming Wang, Lifei Liu, Ronald W. Irwin, Shuhua to mild to severe. Initial analyses suggest that AP may maintain the regenerative ability of the brain. Challenges of regenerative therapeutics for Alzheimer's disease

  4. [Castelman's angiofollicular hyperplasia of multifocal form Apropos of 2 cases].

    PubMed

    Horschowski, N; Harle, J R; Durand, J M; Sainty, D; Fossat, C; David, M; Sauch, F; Weiller, P J; Mongin, M

    1986-01-01

    Castelman described as angiofollicular hyperplasia (AFH) a benign lymphovascular hyperplasia forming a single tumour, classically situated in the mediastinum. A multifocal lymph node form of AFH was individualised by Leibetseder and Turner about 10 years ago (MAFH). This is a rare syndrome, the clinical and biological characteristics of which are almost identical to angioimmunoblastic lymphadenopathy (AIL). The only difference is in the histology of the ganglia which shows changes of AFH. We report two cases of MAFH. In one patient with histological confirmation of splenic involvement the evolution was subacute. In the second case, the histological features of the lesions were observed to change during successive biopsies: appearances of AFH changed to typical AIL. This observation suggests that MAFH may be a disorder of the immune system. Usually considered as benign lymphatic hyperplasia with a chronic evolution, the long-term development of lymphoma poses the problem of the evolutionary potential of this condition, which may be likened to AIL in which lymphomatous transformation is also recognised. PMID:3813299

  5. A Novel Unitized Regenerative Proton Exchange Membrane Fuel Cell

    NASA Technical Reports Server (NTRS)

    Murphy, O. J.; Cisar, A. J.; Gonzalez-Martin, A.; Salinas, C. E.; Simpson, S. F.

    1996-01-01

    A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. Drawbacks associated with existing regenerative fuel cells have been addressed. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane. Lateral diffusion of water along the polymer chains of the PEM provides the water needed at electrode/PEM interfaces. Fabrication of the novel single cell unitized regenerative fuel cell and results obtained on testing it are presented.

  6. Rethinking Regenerative Medicine: A Macrophage-Centered Approach

    PubMed Central

    Brown, Bryan N.; Sicari, Brian M.; Badylak, Stephen F.

    2014-01-01

    Regenerative medicine, a multi-disciplinary approach that seeks to restore form and function to damaged or diseased tissues and organs, has evolved significantly during the past decade. By adapting and integrating fundamental knowledge from cell biology, polymer science, and engineering, coupled with an increasing understanding of the mechanisms which underlie the pathogenesis of specific diseases, regenerative medicine has the potential for innovative and transformative therapies for heretofore unmet medical needs. However, the translation of novel technologies from the benchtop to animal models and clinical settings is non-trivial and requires an understanding of the mechanisms by which the host will respond to these novel therapeutic approaches. The role of the innate immune system, especially the role of macrophages, in the host response to regenerative medicine based strategies has recently received considerable attention. Macrophage phenotype and function have been suggested as critical and determinant factors in downstream outcomes. The constructive and regulatory, and in fact essential, role of macrophages in positive outcomes represents a significant departure from the classical paradigms of host–biomaterial interactions, which typically consider activation of the host immune system as a detrimental event. It appears desirable that emerging regenerative medicine approaches should not only accommodate but also promote the involvement of the immune system to facilitate positive outcomes. Herein, we describe the current understanding of macrophage phenotype as it pertains to regenerative medicine and suggest that improvement of our understanding of context-dependent macrophage polarization will lead to concurrent improvement in outcomes. PMID:25408693

  7. A novel unitized regenerative proton exchange membrane fuel cell

    NASA Technical Reports Server (NTRS)

    Murphy, O. J.; Cisar, A. J.; Gonzalez-Martin, A.; Salinas, C. E.; Simpson, S. F.

    1995-01-01

    A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. Drawbacks associated with existing regenerative fuel cells have been addressed in work performed at Lynntech. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane. Lateral diffusion of water along the polymer chains of the PEM provides the water needed at electrode/PEM interfaces. Fabrication of the novel unitized regenerative fuel cell and results obtained on testing it will be presented.

  8. Erich Regener and the ionisation maximum of the atmosphere

    NASA Astrophysics Data System (ADS)

    Carlson, P.; Watson, A. A.

    2014-12-01

    In the 1930s the German physicist Erich Regener (1881-1955) did important work on the measurement of the rate of production of ionisation deep under water and in the atmosphere. Along with one of his students, Georg Pfotzer, he discovered the altitude at which the production of ionisation in the atmosphere reaches a maximum, often, but misleadingly, called the Pfotzer maximum. Regener was one of the first to estimate the energy density of cosmic rays, an estimate that was used by Baade and Zwicky to bolster their postulate that supernovae might be their source. Yet Regener's name is less recognised by present-day cosmic ray physicists than it should be, largely because in 1937 he was forced to take early retirement by the National Socialists as his wife had Jewish ancestors. In this paper we briefly review his work on cosmic rays and recommend an alternative naming of the ionisation maximum. The influence that Regener had on the field through his son, his son-in-law, his grandsons and his students, and through his links with Rutherford's group in Cambridge, is discussed in an appendix. Regener was nominated for the Nobel Prize in Physics by Schrödinger in 1938. He died in 1955 at the age of 73.

  9. Validation of Contrast-Enhanced MRI to Monitor Regenerative Efficacy after Cell Therapy in a Porcine Model of Convalescent Myocardial Infarction

    PubMed Central

    Malliaras, Konstantinos; Smith, Rachel R.; Kanazawa, Hideaki; Yee, Kristine; Seinfeld, Jeffrey; Tseliou, Eleni; Dawkins, James F.; Kreke, Michelle; Cheng, Ke; Luthringer, Daniel; Ho, Chak-Sum; Blusztajn, Agnieszka; Valle, Ileana; Chowdhury, Supurna; Makkar, Raj R.; Dharmakumar, Rohan; Li, Debiao; Marbán, Linda; Marbán, Eduardo

    2014-01-01

    Background Magnetic Resonance Imaging (MRI) in the CADUCEUS trial revealed that cardiosphere-derived cells (CDCs) decrease scar size and increase viable myocardium post-myocardial infarction (MI), but MRI has not been validated as an index of regeneration after cell therapy. We tested the validity of contrast-enhanced MRI in quantifying scarred and viable myocardium after cell therapy in a porcine model of convalescent MI. Methods and Results Yucatan minipigs underwent induction of MI and 2-3 weeks later were randomized to receive intracoronary infusion of 12.5×106 mismatched allogeneic CDCs or vehicle. Allogeneic CDCs induced mild local mononuclear infiltration but no systemic immunogenicity. MRI revealed that allogeneic CDCs attenuated remodeling, improved global and regional function, decreased scar size and increased viable myocardium compared to placebo 2 months post-treatment. Extensive histological analysis validated quantitatively the MRI measurements of scar size, scar mass and viable mass. CDCs neither altered gadolinium contrast myocardial kinetics, nor induced changes in vascular density or architecture in viable and scarred myocardium. Histology demonstrated that CDCs lead to cardiomyocyte hyperplasia in the border zone, consistent with the observed stimulation of endogenous regenerative mechanisms (cardiomyocyte cycling, upregulation of endogenous progenitors, angiogenesis). Conclusions Contrast-enhanced MRI accurately measures scarred and viable myocardium after cell therapy in a porcine model of convalescent MI. MRI represents a useful tool for assessing dynamic changes in the infarct and monitoring regenerative efficacy. PMID:24061088

  10. Hepatic hyperplasia and cancer in rats: Metabolic alterations associated with cell growth

    Microsoft Academic Search

    KN Rao; RH Kelly; N Chandar; EP Brady; B Rao; H Shinozuka; PK Eagon

    1997-01-01

    BACKGROUND & AIMS: We showed previously that the peroxisome proliferators di(2-ethylhexyl)phthalate (DEHP), clofibrate, and 4- chloro-6-(2,3 xylidino)-2-pyrimidinylthio (N-beta-hydroxyl)acetamide (BR931) alter hepatic sex steroid metabolism and receptor expression during induction of hepatic hyperplasia and hepatocellular carcinoma (HCC) in rats. The aim of this study was to identify metabolic changes associated with cell growth during hyperplasia and HCC. METHODS: Hepatic hyperplasia was

  11. Immunosuppression-free transplantation reconsidered from a regenerative medicine perspective.

    PubMed

    Orlando, Giuseppe

    2012-02-01

    Recent groundbreaking progress in regenerative medicine has shown its potential to meet the two major needs of solid organ transplantation, namely the achievement of an immunosuppression-free state (IFS) and the identification of a new, potentially inexhaustible source of organs. This review illustrates how regenerative medicine technology may contribute to the achievement of IFS. There are three possible strategies: organ bioengineering, immuno-isolation and thymus bioengineering. The goal of organ bioengineering is to manufacture organs ex vivo from autologous cells. Immuno-isolation technology implements strategies aiming to prevent recognition of nonself antigens by the host immune system. Thymus organoids have been bioengineered with scaffold-seeding methods to allow deletion of T-cell clones responsible for allograft rejection. Despite the several hurdles that must be overcome, regenerative medicine technologies offer alternative strategies aimed at establishing immediate, stable and durable IFS in solid organ graft recipients. PMID:22288456

  12. 25th anniversary article: supramolecular materials for regenerative medicine.

    PubMed

    Boekhoven, Job; Stupp, Samuel I

    2014-03-19

    In supramolecular materials, molecular building blocks are designed to interact with one another via non-covalent interactions in order to create function. This offers the opportunity to create structures similar to those found in living systems that combine order and dynamics through the reversibility of intermolecular bonds. For regenerative medicine there is a great need to develop materials that signal cells effectively, deliver or bind bioactive agents in vivo at controlled rates, have highly tunable mechanical properties, but at the same time, can biodegrade safely and rapidly after fulfilling their function. These requirements make supramolecular materials a great platform to develop regenerative therapies. This review illustrates the emerging science of these materials and their use in a number of applications for regenerative medicine. PMID:24496667

  13. 25th Anniversary Article: Supramolecular Materials for Regenerative Medicine

    PubMed Central

    Boekhoven, Job

    2014-01-01

    In supramolecular materials, molecular building blocks are designed to interact with one another via non-covalent interactions in order to create function. This offers the opportunity to create structures similar to those found in living systems that combine order and dynamics through the reversibility of intermolecular bonds. For regenerative medicine there is a great need to develop materials that signal cells effectively, deliver or bind bioactive agents in vivo at controlled rates, have highly tunable mechanical properties, but at the same time, can biodegrade safely and rapidly after fulfilling their function. These requirements make supramolecular materials a great platform to develop regenerative therapies. This review illustrates the emerging science of these materials and their use in a number of applications for regenerative medicine. PMID:24496667

  14. Lightweight pressure vessels and unitized regenerative fuel cells

    SciTech Connect

    Mitlitsky, F.; Myers, B.; Weisberg, A.H.

    1996-09-06

    Energy storage systems have been designed using lightweight pressure vessels with unitized regenerative fuel cells (URFCs). The vessels provide a means of storing reactant gases required for URFCs; they use lightweight bladder liners that act as inflatable mandrels for composite overwrap and provide a permeation barrier. URFC systems have been designed for zero emission vehicles (ZEVs); they are cost competitive with primary FC powered vehicles that operate on H/air with capacitors or batteries for power peaking and regenerative braking. URFCs are capable of regenerative braking via electrolysis and power peaking using low volume/low pressure accumulated oxygen for supercharging the power stack. URFC ZEVs can be safely and rapidly (<5 min.) refueled using home electrolysis units. Reversible operation of cell membrane catalyst is feasible without significant degradation. Such systems would have a rechargeable specific energy > 400 Wh/kg.

  15. Biomolecule Delivery to Engineer the Cellular Microenvironment for Regenerative Medicine

    PubMed Central

    Bishop, Corey J.; Kim, Jayoung; Green, Jordan J.

    2013-01-01

    To realize the potential of regenerative medicine, controlling the delivery of biomolecules in the cellular microenvironment is important as these factors control cell fate. Controlled delivery for tissue engineering and regenerative medicine often requires bioengineered materials and cells capable of spatiotemporal modulation of biomolecule release and presentation. This review discusses biomolecule delivery from the outside of the cell inwards through the delivery of soluble and insoluble biomolecules as well as from the inside of the cell outwards through gene transfer. Ex vivo and in vivo therapeutic strategies are discussed, as well as combination delivery of biomolecules, scaffolds, and cells. Various applications in regenerative medicine are highlighted including bone tissue engineering and wound healing. PMID:24170072

  16. Electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, Susan R. (Wixom, MI)

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  17. Electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  18. Proteins and Small Molecules for Cellular Regenerative Medicine

    PubMed Central

    Green, Eric M.

    2013-01-01

    Regenerative medicine seeks to understand tissue development and homeostasis and build on that knowledge to enhance regeneration of injured tissues. By replenishing lost functional tissues and cells, regenerative medicine could change the treatment paradigm for a broad range of degenerative and ischemic diseases. Multipotent cells hold promise as potential building blocks for regenerating lost tissues, but successful tissue regeneration will depend on comprehensive control of multipotent cells–differentiation into a target cell type, delivery to a desired tissue, and integration into a durable functional structure. At each step of this process, proteins and small molecules provide essential signals and, in some cases, may themselves act as effective therapies. Identifying these signals is thus a fundamental goal of regenerative medicine. In this review we discuss current progress using proteins and small molecules to regulate tissue regeneration, both in combination with cellular therapies and as monotherapy. PMID:23303911

  19. Regenerative Phase Shift and its Effect on Coherent Laser Arrays

    SciTech Connect

    Ray, William R [ORNL; Durville, Frederic [Corcoran Engineering, Inc.; Corcoran, Christopher J. [Corcoran Engineering, Inc.

    2011-01-01

    A coherent array of regenerative amplifiers in an external cavity with a rank 1 scattering matrix is described and analyzed. Using a resonant cavity analysis, it is shown how the addition of regenerative feedback to each element in the array creates a phase shift relative to the well-known 'cold-cavity phase shift'. This phase shift is quantified and found to significantly affect the phasing properties of coherent arrays, even in the absence of the nonlinear Kerr effect and the gain-dependent phase shift. In particular, this regenerative phase shift is shown to concentrate the distribution of phases at the output of the laser array into a narrower phase range compared to the random distribution expected using a nonregenerative amplifier in the presence of effectively random cold-cavity phase shifts.

  20. Postdoctoral Position inStem (http://instem.res.in), is a new institute for Stem Cell Biology and Regenerative

    E-print Network

    Udgaonkar, Jayant B.

    and Regenerative Medicine located at the National Centre for Biological Sciences (NCBS, www, and regenerative medicine. Current projects include the study of biochemical and biophysical alterations in mutant

  1. ECLSS regenerative systems comparative testing and subsystem selection

    NASA Technical Reports Server (NTRS)

    Carasquillo, Robyn L.; Carter, Donald L.; Holder, Donald W., Jr.; Mcgriff, Cindy F.; Ogle, Kathryn Y.

    1991-01-01

    In support of Space Station Freedom Phase C/D Environmental Control and Life Support Systems (ECLSS) regenerative systems development, comparative testing was performed on predevelopment hardware of competing technologies for each regenerative function. The purpose of the test program was to collect data on latest generation hardware in order to make final technology selections for each subassembly in the oxygen recovery and water reclamation strings. This paper discusses the testing performed, test results, and evaluation of these results relative to subsystem selections for CO2 reduction, O2 generation, potable water processing, hygiene water processing, and urine processing.

  2. A high-power compact regenerative amplifier FEL

    SciTech Connect

    Nguyen, D.C.; Sheffield, R.L.; Fortgang, C.M.; Kinross-Wright, J.M.; Ebrahim, N.A.; Goldstein, J.C.

    1997-08-01

    The Regenerative Amplifier FEL (RAFEL) is a new FEL approach aimed at achieving the highest optical power from a compact rf-linac FEL. The key idea is to feed back a small fraction (< 10%) of the optical power into a high-gain ({approximately}10{sup 5} in single pass) wiggler to enable the FEL to reach saturation in a few passes. This paper summarizes the design of a high-power compact regenerative amplifier FEL and describes the first experimental demonstration of the RAFEL concept.

  3. A study on regenerative braking for a parallel hybrid electric vehicle

    Microsoft Academic Search

    Sungwook Jang; Hoon Yeo; Chulsoo Kim; Hyunsoo Kim

    2001-01-01

    In this paper, a regenerative braking algorithm is presented and performance of a hybrid electric vehicle (HEV) is investigated.\\u000a The regenerative braking algorithm calculates the available regenerative braking torque by considering the motor characteristics,\\u000a the battery SOC and the CVT speed ratio. When the regenerative braking and the friction braking are applied simultaneously,\\u000a the friction braking torque corresponding to the

  4. SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

    NASA Technical Reports Server (NTRS)

    Mcelroy, J. F.

    1990-01-01

    Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

  5. An Knowledge Model for Self-regenerative Service Activations Adaptation across Standards

    E-print Network

    Taleb-Bendiab, A.

    An Knowledge Model for Self-regenerative Service Activations Adaptation across Standards Mengjie Yu such as the self-regenerative system[2] adopt the biological- inspired [2, 3]notions such as natural diversity on an ongoing research into self-regenerative programming model, this paper presents a knowledge

  6. Markov Regenerative SPN with Non-Overlapping Activity Cycles Andrea Bobbio Mikl os Telek

    E-print Network

    Telek, Miklós

    Markov Regenerative SPN with Non-Overlapping Activity Cycles Andrea Bobbio Mikl#19;os Telek Nets, semi-Markov Reward Models, Markov regenerative processes. 1 Introduction In the usual de#12 in [10]. Choi et al. [7] have recognized that the mark- ing process underlying a DSPN is a Markov Regen

  7. A FULL-DIVERSITY DISTRIBUTED SPACE-TIME CODING SYSTEM WITH REGENERATIVE RELAYS

    E-print Network

    Leus, Geert

    A FULL-DIVERSITY DISTRIBUTED SPACE-TIME CODING SYSTEM WITH REGENERATIVE RELAYS Paul A. Anghel1 design DSTC systems with one regenerative relay that improve on the classical Alamouti scheme when of regenerative relay systems by proposing and analyzing distributed space-time coding (DSTC) schemes with one

  8. Spatial structure of broad-area vertical-cavity regenerative T. Ackemann

    E-print Network

    Lange, Wulfhard

    Spatial structure of broad-area vertical-cavity regenerative amplifiers T. Ackemann , S. Barland, M-cavity regenerative amplifiers with injection of a homogeneous beam. The emerging patterns have a dominantly six-emitting lasers (VCSEL) which are operated as regenerative amplifiers, i.e. biased electrically below threshold

  9. Regenerative Simulation of Stochastic Petri Nets with Discrete and Continuous Timing

    E-print Network

    Ciardo, Gianfranco

    Regenerative Simulation of Stochastic Petri Nets with Discrete and Continuous Timing Rob Jones ASRC@cs.wm.edu Abstract We present a regenerative simulation method applica- ble to a special class of non, instead, a new regenerative simulation technique that offers efficient anal- ysis of PDPNs where numerical

  10. Name: dhr. prof. dr. W.J.A Dhert Regenerative Medicine

    E-print Network

    Utrecht, Universiteit

    Name: dhr. prof. dr. W.J.A Dhert Profile Teaching commitment Regenerative Medicine Faculty Medicine May 15;31(11 Suppl):S89-95; discussion S104. #12;Teaching Program leader of PhD Program `Regenerative Congress 2008 · Vice chair Dutch Forum Regenerative Medicine · Board member Dutch Program for Tissue

  11. Broadband Yb:CaF2 regenerative amplifier for millijoule range ultrashort pulse amplification

    E-print Network

    Paris-Sud XI, Université de

    Broadband Yb:CaF2 regenerative amplifier for millijoule range ultrashort pulse amplification, 14050 Caen, France ABSTRACT We report on a diode-pumped regenerative amplifier based on Yb:CaF2 material lasers. Keywords: Regenerative amplifier, Ytterbium doped material, Ultrafast laser 1. INTRODUCTION More

  12. system is maintained by stem cells with long-and short-term regenerative poten-

    E-print Network

    Mootha, Vamsi K.

    system is maintained by stem cells with long- and short-term regenerative poten- tial, which. Cowan1,2,* 1Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA 2Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA

  13. Design and Analysis of a Distributed Regenerative Frequency Divider Using a Distributed Mixer

    E-print Network

    Heydari, Payam

    Design and Analysis of a Distributed Regenerative Frequency Divider Using a Distributed Mixer Amin-2625 ABSTRACT In this paper we present the design and analysis of a distributed regenerative frequency divider in 1939, a regenerative frequency divider is essentially a non-linear feedback circuit consisting

  14. Optimal Control of Markov Regenerative Processes Andr'as Pfening, Mikl'os Telek

    E-print Network

    Telek, Miklós

    Optimal Control of Markov Regenerative Processes Andr'as Pfening, Mikl'os Telek Department In the paper the integration of available results on Semi­ Markov Decision Processes and on Markov Regenerative the un­ derlying structure state process is a Markov Regenerative Process, referred to as Markov

  15. Non-Regenerative Full Distributed Space-Time Codes in Cooperative Relaying Networks

    E-print Network

    Paris-Sud XI, Université de

    Non-Regenerative Full Distributed Space-Time Codes in Cooperative Relaying Networks Le Quang Vinh systems with one and two non- regenerative relays is given, while the performance of DSTC systems with regenerative relays is done in [4]. The DSTC protocol for wireless multi-hop networks is lately designed

  16. Local circadian clock gates cell cycle progression of transient amplifying cells during regenerative

    E-print Network

    Chuong, Cheng-Ming

    regenerative hair cycling Maksim V. Plikusa,b , Christopher Vollmersc , Damon de la Cruza , Amandine Chaixc, and approved April 18, 2013 (received for review September 24, 2012) Regenerative cycling of hair follicles. We wanted to examine the role of circadian rhythms in hair cycle, which is a complex regenerative

  17. Dual Mode Vehicle with In-Wheel Motor: Regenerative Braking Optimization

    E-print Network

    Paris-Sud XI, Université de

    Dual Mode Vehicle with In-Wheel Motor: Regenerative Braking Optimization G. Le Solliec1*, A. Chasse: Regenerative Braking Optimization -- To meet the growing need for mobility of people and goods while massively the benefit of such an architecture to optimize the regenerative braking while ensuring a safe dynamic

  18. Mode-Coupled Regenerative Machine Tool Vibrations Tams Kalmr-Nagy1

    E-print Network

    Mode-Coupled Regenerative Machine Tool Vibrations Tamás Kalmár-Nagy1 , Francis C. Moon2 1 United the regenerative e¤ect (time delay) can produce an instability criteria that admits low-level or zero chip. Numerous researchers investigated single degree-of- freedom regenerative tool models (Tobias [39], Hanna

  19. Diode-pumped Nd:glass kilohertz regenerative amplifier for subpicosecond microjoule level pulses

    E-print Network

    Keller, Ursula

    Diode-pumped Nd:glass kilohertz regenerative amplifier for subpicosecond microjoule level pulses:fluorophosphate regenerative amplifier was developed. Chirped seed pulses were amplified to 24 J at repetition rates to 1 k, regenerative amplifier, Nd:glass, chirped-pulse amplification. 1. Introduction With the maturation of high

  20. A Full-Diversity Distributed Space-Time Coding System with Regenerative Relays

    E-print Network

    Leus, Geert

    A Full-Diversity Distributed Space-Time Coding System with Regenerative Relays Paul A. Anghel1 a bit error rate based antenna selection approach, we design DSTC systems with one regenerative relay to the area of regenerative relay systems by proposing and analyzing distributed space-time coding (DSTC

  1. AN EFFICIENT TWO-STAGE ITERATIVE METHOD FOR THE STEADY-STATE ANALYSIS OF MARKOV REGENERATIVE

    E-print Network

    Illinois at Urbana-Champaign, University of

    AN EFFICIENT TWO-STAGE ITERATIVE METHOD FOR THE STEADY-STATE ANALYSIS OF MARKOV REGENERATIVE is a Markov regenerative process MRP when at most one non-exponential transition is enabled in each marking: Markov Regenerative Stochastic Petri Nets, Deterministic Stochastic Petri Nets, Stochastic Activity

  2. Regenerative Block-Bootstrap Condence Intervals for Tail and Extremal Indexes

    E-print Network

    Boyer, Edmond

    Regenerative Block-Bootstrap Condence Intervals for Tail and Extremal Indexes Patrice Bertail the extremal and tail indexes. Regenerative properties of the chain X (or of a Nummelin extension of the latter is also tackled. It is then proved that, based on these estimators, the (approximate) regenerative block

  3. Short pulse and high repetition rate diode-pumped Yb:CaF2 regenerative amplifier

    E-print Network

    Boyer, Edmond

    Short pulse and high repetition rate diode-pumped Yb:CaF2 regenerative amplifier S. Ricaud1,4 , F.ricaud@institutoptique.fr Abstract: We present a diode-pumped regenerative amplifier based on an Yb:CaF2 crystal optimized to produce obtained. Nevertheless, for energies above the mJ range, regenerative amplifiers are required

  4. The Extremal Behaviour over Regenerative Cycles for Markov Additive Processes with

    E-print Network

    Sørensen, Michael

    The Extremal Behaviour over Regenerative Cycles for Markov Additive Processes with Heavy Tails behaviour of the distri- bution of the maximum over a regenerative cycle in the case with subexponential of the reflected Markov controlled additive process over a regenerative cycle is also tail equivalent to H

  5. ccsd-00013321,version1-7Nov2005 Regenerative real trees

    E-print Network

    Boyer, Edmond

    ccsd-00013321,version1-7Nov2005 Regenerative real trees Mathilde Weill D.M.A., ´Ecole normale sup of all -finite measures on the space of rooted compact R-trees which satisfy a certain regenerative property. We show that any infinite measure which satisfies the regenerative property is the "law" of a L

  6. Regenerative braking for electric vehicle based on fuzzy logic control strategy

    Microsoft Academic Search

    Zijian Zhang; Guoqing Xu; Weimin Li; Liang Zheng

    2010-01-01

    In order to recycle more energy in the process of regenerative braking, we design a regenerative braking force calculation controller based on fuzzy logic. The sugeno's interface fuzzy logic controller has three-inputs including the driver's brake requirements, vehicle speed and batteries' SOC and one-output which is the regenerative braking force. To ensure charging safety, the influence of batteries' temperature is

  7. Analysis of compressed air regenerative braking and a thermally enhanced option

    Microsoft Academic Search

    F. Wicks; J. Maleszweski; C. Wright; J. Zarybnicky

    2002-01-01

    Obtaining a net benefit from regenerative braking is difficult. Various forms of regenerative braking systems have been proposed. They include electric batteries, capacitors, flywheels, and compressed air. Some have been implemented on a limited scale. The benefits of regenerative braking systems are easy to qualitatively describe, but can be challenging to quantify. The potential benefits depend upon obvious things such

  8. Regenerative braking algorithm for a parallel hybrid electric vehicle with continuously variable transmission

    Microsoft Academic Search

    Wang Feng; Zhong Hu; Mao Xiao-jian; Yang Lin; Zhuo Bin

    2007-01-01

    A novel regenerative braking algorithm based on continuously variable transmission is proposed to make effective and maximum use of the brake energy in order to improve fuel economy. In the braking torque distribution of the novel regenerative algorithm, the regenerative torque is determined by considering the vehicle velocity, the maximal generation torque and state of the electric motor, the maximal

  9. Design and implementation of a regenerative braking system for electric bicycles based on DSP

    Microsoft Academic Search

    Chih-Chiang Hua; Shih-Jyun Kao

    2011-01-01

    This paper proposes a regenerative braking system for electric bicycle based on DSP. The proposed method is used to adjust the switching sequence of the inverter, so that the braking energy will be returned to charge the battery. With the cooperation of regenerative braking energy recovery technologies and digital signal processor (TMS320LF2407) as the control unit, the regenerative braking energy

  10. A Regenerative High-Rise Tower in Shreveport, Louisiana 

    E-print Network

    Garrison, M.

    2010-01-01

    by example the pedagogy of regenerative design. The 16-story structure — built in the 1950s and named the Petroleum Tower, reflecting the commodity that then ruled the local economy — was vacant and asbestos-laden when given to the non-profit Community...

  11. Noise Analysis of Regenerative Comparators for Reconfigurable ADC Architectures

    Microsoft Academic Search

    Pierluigi Nuzzo; Fernando De Bernardinis; Pierangelo Terreni; Geert Van der Plas

    2008-01-01

    The need for highly integrable and programmable analog-to-digital converters (ADCs) is pushing towards the use of dynamic regenerative comparators to maximize speed, power efficiency and reconfigurability. Comparator thermal noise is, however, a limiting factor for the achievable resolution of several ADC architectures with scaled supply voltages. While mismatch in these comparators can be compensated for by calibration, noise can irreparably

  12. Power allocation for non-regenerative OFDM relaying channels

    Microsoft Academic Search

    Yu Guan-Ding; Zhang Zhao-Yang; Chen Yan; Chen Shi; Qiu Pei-liang

    2005-01-01

    Relayed transmission is an efficient way to combat wireless channel fading and to increase system throughput. By allocating the overall power to the transmitter and the relay optimally, the system performance can be further improved. This paper discusses the optimal power allocation in frequency-selective non-regenerative relaying channels, where OFDM is employed. Firstly, the optimal power allocation between a cooperative subcarrier

  13. Optimization of cascaded regenerative links based on phase sensitive amplifiers

    E-print Network

    Turitsyn, Sergei K.

    optimization of the transfer function and the signal alphabet. The model is general and can be applied to any regenerative system. © 2013 Optical Society of America OCIS codes: (060.2330) Fiber optics communications; (060.4370) Nonlinear optics, fibers; (190.4370) Nonlinear optics, fibers; (060.1660) Coherent communications; (000

  14. Regenerative Snubber For GTO-Commutated SCR Inverter

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E.; Edwards, Dean B.

    1992-01-01

    Proposed regenerative snubbing circuit substituted for dissipative snubbing circuit in inverter based on silicon controlled rectifiers (SCR's) commutated by gate-turn-off thyristor (GTO). Intended to reduce loss of power that occurs in dissipative snubber. Principal criteria in design: low cost, simplicity, and reliability.

  15. Status of the Regenerative ECLS Water Recovery System

    NASA Technical Reports Server (NTRS)

    Carter, Donald Layne

    2010-01-01

    The regenerative Water Recovery System (WRS) has completed its first full year of operation on the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the on-orbit status as of May 2010, and describes the technical challenges encountered and lessons learned over the past year.

  16. Regenerative fuel cells for use in Space Stations

    Microsoft Academic Search

    Uwe Benz; Werner Tillmetz

    1990-01-01

    The conversion and storage of energy with high efficiency and high energy density, respectively, will be an important factor in future space activities as well as for terrestrial applications. The basic concepts of a regenerative fuel cell system (RFCS) based on the immobile alkaline electrolyte technology, which has been identified as the most promising technology for space application, are presented.

  17. Lightweight pressure vessels and unitized regenerative fuel cells

    Microsoft Academic Search

    F. Mitlitsky; B. Myers; A. H. Weisberg

    1996-01-01

    Energy storage systems have been designed using lightweight pressure vessels with unitized regenerative fuel cells (URFCs). The vessels provide a means of storing reactant gases required for URFCs; they use lightweight bladder liners that act as inflatable mandrels for composite overwrap and provide a permeation barrier. URFC systems have been designed for zero emission vehicles (ZEVs); they are cost competitive

  18. High energy density regenerative fuel cell systems for terrestrial applications

    Microsoft Academic Search

    K. A. Burke

    1999-01-01

    Regenerative Fuel Cell System (RFCS) technology for energy storage has been a NASA power system concept for many years. Compared to battery-based energy storage systems, RFCS has received relatively little attention or resources for development because the energy density and electrical efficiency were not sufficiently attractive relative to advanced battery systems. Even today, RFCS remains at a very low technology

  19. Vehicular hydrogen storage using lightweight tanks (regenerative fuel cell systems)

    Microsoft Academic Search

    Fred Mitlitsky; B Myers; A H Weisberg

    1999-01-01

    Energy storage systems with extremely high specific energy (>400 Wh\\/kg) have been designed that use lightweight tankage to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs). Lawrence Livermore National Laboratory (LLNL) will leverage work for aerospace applications supported by other sponsors (including BMDO, NASA, and USAF) to develop URFC systems for transportation and utility applications. Lightweight tankage

  20. A novel bifunctional electrocatalyst for unitized regenerative fuel cell

    Microsoft Academic Search

    Yining Zhang; Huamin Zhang; Yuanwei Ma; Jinbin Cheng; Hexiang Zhong; Shidong Song; Haipeng Ma

    2010-01-01

    5wt.% of platinum (Pt) nanoparticles are highly dispersed on the surface of IrO2 by chemical reduction, and the catalyst is mixed with Pt black to be used as a novel bifunctional oxygen electrocatalyst for the unitized regenerative fuel cell (URFC). The novel cell has been evaluated in the hydrogen and oxygen fuel cell and water electrolysis modes, and compared to

  1. Long life Regenerative Fuel Cell technology development plan

    Microsoft Academic Search

    Franklin D. Littman; Robert L. Cataldo; James F. McElroy; Jay K. Stedman

    1992-01-01

    This paper summarizes a technology roadmap for completing advanced development of a Proton Exchange Membrane (PEM) Regenerative Fuel Cell (RFC) to meet long life (20,000 hrs at 50 percent duty cycle) mobile or portable power system applications on the surface of the moon and Mars. Development of two different sized RFC power system modules is included in this plan (3

  2. Alkaline regenerative fuel cell systems for energy storage

    Microsoft Academic Search

    F. H. Schubert; M. A. Reid; R. E. Martin

    1981-01-01

    This paper presents the results of a preliminary design study of a Regenerative Fuel Cell Energy Storage system for application to future low-earth orbit space missions. This high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. 11 refs.

  3. A power electronics conversion topology for regenerative fuel cell systems

    Microsoft Academic Search

    P. G. Marambeas; S. Papathanassiou; S. Mouroutsos; G. Ioannidis

    2008-01-01

    The aim of this paper is to present and analyze a novel power electronics conditioning topology for hybrid energy generation and storage systems for residential applications. The hybrid energy system combines regenerative fuel cells, photovoltaic generators and batteries. The proposed power conditioning topology, which can be implemented at low cost, can provide bi-directional power flow with high frequency ohmic isolation,

  4. Regenerative Fuel Cells For Space And Terrestrial Use

    Microsoft Academic Search

    Werner Tillmetz; Guenther Dietrich; Uwe Benz

    1990-01-01

    Electrolysis, fuel cell, and energy storage technologies are compared and evaluated. The use of a fuel cell and electrolyzer with an immobilized electrolyte is selected as the most promising technique. A comparison of the batteries demonstrates that a RFCS (regenerative fuel cell system) could be a serious competitor in future space activities, especially with increasing power level and energy to

  5. A NITROSYL CHLORIDE SOLAR REGENERATIVE FUEL CELL SYSTEM

    Microsoft Academic Search

    W. E. McKee; E. Findl; J. D. Margerum; W. B. Lee

    1961-01-01

    The experimenial work accomplished during the period of October 1960 to ; April 1961 in the development of the nitrosyl chloride solar regenerative fuel ; cell system is described. Regeneration is accomplished utilizing solar energy to ; dissociate nitrosyl chloride into nitric oxide and chlorine. Product separation ; is accomplished using solvent extraction techniques. The separated dissociation ; products are

  6. Feasibility study of a simple unitized regenerative fuel cell

    Microsoft Academic Search

    A. Verma; S. Basu

    2004-01-01

    Conventional fuel cells use hydrogen and oxygen as the fuel and oxidant, respectively. Hydrogen and oxygen can be produced through electrolysis of water in an electrochemical cell. A simple unitized regenerative fuel cell (URFC), by combining an electrolyzer and a fuel cell, is constructed to check the feasibility of such a device. In the first cycle, hydrogen and oxygen gases

  7. Membrane electrode assemblies for unitised regenerative polymer electrolyte fuel cells

    Microsoft Academic Search

    U. Wittstadt; E. Wagner; T. Jungmann

    2005-01-01

    Membrane electrode assemblies for regenerative polymer electrolyte fuel cells were made by hot pressing and sputtering. The different MEAs are examined in fuel cell and water electrolysis mode at different pressure and temperature conditions. Polarisation curves and ac impedance spectra are used to investigate the influence of the changes in coating technique. The hydrogen gas permeation through the membrane is

  8. Regenerative Medicines for Remyelination: From Aspiration to Reality.

    PubMed

    Franklin, Robin J M

    2015-06-01

    Stimulating an endogenous regenerative response is a powerful approach for potential treatment of chronic demyelinating diseases such as multiple sclerosis. Recently in Nature, Najm et al. (2015) identified two clinically relevant, FDA-approved compounds that promote oligodendrocyte progenitor cell differentiation and induce remyelination in demyelinating disease models. PMID:26046755

  9. Stem Cells, Regenerative Medicine, and Animal Models of Disease

    Microsoft Academic Search

    Dennis A. Steindler

    2007-01-01

    The field of stem cell biology and regenerative medicine is rapidly moving toward translation to clinical practice, and in doing so has become even more dependent on animal donors and hosts for generating cellular reagents and assay- ing their potential therapeutic efficacy in models of human disease. Advances in cell culture technologies have revealed a remarkable plasticity of stem cells

  10. Induced pluripotent stem cells: developmental biology to regenerative medicine

    Microsoft Academic Search

    Almudena Martinez-Fernandez; Andre Terzic; Timothy J. Nelson

    2010-01-01

    Nuclear reprogramming of somatic cells with ectopic stemness factors to bioengineer pluripotent autologous stem cells signals a new era in regenerative medicine. The study of developmental biology has provided a roadmap for cardiac differentiation from embryonic tissue formation to adult heart muscle rejuvenation. Understanding the molecular mechanisms of stem-cell-derived cardiogenesis enables the reproducible generation, isolation, and monitoring of progenitors that

  11. Feasibility Study of Regenerative Burners in Aluminum Holding Furnaces

    NASA Astrophysics Data System (ADS)

    Hassan, Mohamed I.; Al Kindi, Rashid

    2014-09-01

    Gas-fired aluminum holding reverberatory furnaces are currently considered to be the lowest efficiency fossil fuel system. A considerable volume of gas is consumed to hold the molten metal at temperature that is much lower than the flame temperature. This will lead to more effort and energy consumption to capture the excessive production of the CO2. The concern of this study is to investigate the feasibility of the regenerative-burners' furnaces to increase the furnace efficiency to reduce gas consumption per production and hence result in less CO2 production. Energy assessments for metal holding furnaces are considered at different operation conditions. Onsite measurements, supervisory control and data acquisition data, and thermodynamics analysis are performed to provide feasible information about the gas consumption and CO2 production as well as area of improvements. In this study, onsite measurements are used with thermodynamics modeling to assess a 130 MT rectangular furnace with two regenerative burners and one cold-air holding burner. The assessment showed that the regenerative burner furnaces are not profitable in saving energy, in addition to the negative impact on the furnace life. However, reducing the holding and door opening time would significantly increase the operation efficiency and hence gain the benefit of the regenerative technology.

  12. Regenerative vapor cycle with isobutane as working fluid

    Microsoft Academic Search

    J. C. S. Chou; R. K. Ahluwalia; E. Y. K. Woo

    1974-01-01

    One of the methods of generating geothermal power is to use a suitable working fluid which extracts heat from geothermal fluids and generates power in a closed cycle. This paper presents a discussion of an improvement of the basic closed cycle with isobutane as a working fluid. A regenerative heat exchanger is added for heating the cold condensate of isobutane

  13. Modeling and Simulation about an Electric Car's Regenerative Braking System

    Microsoft Academic Search

    Zuowu Ding; Dongbiao Zhao; Jianmin Zuo

    2007-01-01

    A kind of regenerative braking system of an electric car is studied in the paper. The car's speed, acceleration, the hydraulic accumulator's pressure and volume are simulated with Matlab while the electric car is braking or accelerating from stop. The hydraulic accumulator can absorb all of the braking energy when braking and the energy stored in the hydraulic accumulator can

  14. Validating the heavy traffic performance of regenerative simulation

    Microsoft Academic Search

    Søren Asmussen

    1989-01-01

    Following a theoretical study by Asmussen [2] indicating severe problems associated with a number of standard queueing simulation schemes in heavy traffic situations, we look into one of the possible settings of regenerative simulation from a more empirical point of view. Sequences of queues with are simulated subject to various growth rates of the sample size t:, the empirical distribution

  15. Combustor for regenerative open cycle gas turbine system

    Microsoft Academic Search

    1984-01-01

    A counter flow combustor for regenerative open cycle turbine systems has an outer casing defining a head cavity at one end, an inner casing mounting in said outer casing, said inner casing defining a combustion chamber. An annular insulated partition and support means is connected at its upper end to the inner wall of the outer casing and at its

  16. The Forced-Commutated Inverter as a Regenerative Rectifier

    Microsoft Academic Search

    James W. A. Wilson

    1978-01-01

    The application of a three-phase 120°-gated forced commutated thyristor inverter as a regenerative rectification circuit is discussed. The circuit has the ability to accept or deliver dc current without change of nominal dc voltage magnitude or polarity and also has the capability to instantaneously change from ``motoring'' to ``generating'' and vice versa. An analysis of the circuit is undertaken to

  17. Regenerative capacity of the corneal endothelium in rabbit and cat

    Microsoft Academic Search

    Diane L. Van Horn; Deborah D. Sendele; Sam Seideman; Paul J. Buco

    Transcorneal freezing was used to destroy the central 10, 50, or 90 percent of the endothelium in rabbit and cat cornea. The regenerative process was studied in each species by pachometry, electron microscopy, and autoradiographic analysis of the incorporation of tritiated thymidine into nuclear DNA. In rabbit, extensive cellular division occurred at the margin of the wound; in most cases

  18. Bromodeoxyuridine Specifically Labels the Regenerative Stem Cells of Planarians

    Microsoft Academic Search

    Phillip A. Newmark; Alejandro Sánchez Alvarado

    2000-01-01

    The singular regenerative abilities of planarians require a population of stem cells known as neoblasts. In response to wounding, or during the course of cell turnover, neoblasts are signaled to divide and\\/or differentiate, thereby replacing lost cell types. The study of these pluripotent stem cells and their role in planarian regeneration has been severely hampered by the reported inability of

  19. Frequency-Domain Analysis of Super-Regenerative Amplifiers

    E-print Network

    Dawson, Joel L.

    Since its invention in 1922, the super-regenerative amplifier (SRA) has been used in a variety of short-range, low-power, and/or low-cost wireless systems due to its simple implementation and excellent performance for a ...

  20. Pro-regenerative properties of cytokine-activated astrocytes

    Microsoft Academic Search

    Christina M. Liberto; P. J. Albrecht; L. M. Herx; V. W. Yong; S. W. Levison

    2004-01-01

    The prevailing view of the astrocytic response to injury is that reactive astrocytes impede the regenerative process by form- ing scar tissue. As the levels of many cytokines dramatically increase following CNS insult and as this increase in cytokine expression precedes the production of the glial scar, a long- standing view has been that cytokines diminish neuronal survival and regeneration

  1. Regenerative Simulation of Response Times in Networks of Queues

    Microsoft Academic Search

    Donald L. Iglehart; Gerald S. Shedler

    1978-01-01

    A technique ~s presented for the estmaatton by simulation of response time characteristics of queuemg network models of multlprogrammed computer systems The techmque is based on the regenerative method for the simulation of stochastic systems and the ~dea of trackmg a marked job m the network Illustrative numencal results m part obtained from a simulation of a queuemg model of

  2. Energy savings through regenerative braking using retrofit converters

    Microsoft Academic Search

    Frank Flinders; Rajan Mathew; Wardina Oghanna

    1995-01-01

    This paper explores the benefits and feasibility of retrofitting existing phase controlled DC motor drives in the Queensland Rail coal transport system with PWM rectifier technology. The major benefits of this would be, the replacement of the dynamic brake with a regenerative system and unity power factor operation with a high quality input current waveshape. Test results indicate that very

  3. A New Three-Phase Rectifier for Regenerative Braking Application

    Microsoft Academic Search

    Lihua Li; Keyue Smedley; Taotao Jin

    2007-01-01

    This paper proposes a new regenerative rectifier for motor loads. The controller is implemented with simple analog components. Yet, it has the power of controlling a three-phase Voltage Source Inverter to operate either as a Power Factor Correction rectifier or as a Grid Connected Inverter according to motor's operational status. In both cases, the currents are sinusoidal. A 5 KW

  4. Natal Tooth Associated with Fibrous Hyperplasia – A Rare Case Report

    PubMed Central

    Munjal, Deepti; Dhingra, Renuka; Malik, Narender Singh; Sidhu, Gagandeep Kaur

    2015-01-01

    Eruption of tooth at about 6 months of age is a significant stage in child’s life and is an emotional event for parents. However, a tooth present in the oral cavity of newborn can lead to a lot of delusions. Natal and neonatal teeth are of utmost importance not only for a dentist but also for a paediatrician due to parent’s anxiety, folklore superstitions and numerous associated complications with it. This paper reports a rare case, wherein a natal tooth has led to the development of a reactive fibrous hyperplasia in an 8-week-old infant. PMID:26023656

  5. Diffuse pulmonary neuroendocrine cell hyperplasia involving the chest wall.

    PubMed

    Al-Ayoubi, Adnan M; Ralston, Jonathan S; Richardson, S Russ; Denlinger, Chadrick E

    2014-01-01

    Diffuse pulmonary neuroendocrine cell hyperplasia (DIPNECH) is characterized by a diffuse hypertrophy of neuroendocrine cells along the distal bronchioles. This condition is characterized by obstructive lung physiology and the development of small carcinoid tumors. We present a case of DIPNECH in a patient undergoing surgery for a primary lung adenocarcinoma. Interestingly, the chest wall also demonstrated involvement of DIPNECH indicated by the presence of small carcinoid tumors. The absence of any lung carcinoid tumor greater than 5 mm and the absence of lymph node metastases render the chest wall involvement unlikely to represent metastatic disease. PMID:24384190

  6. Natal tooth associated with fibrous hyperplasia - a rare case report.

    PubMed

    Sethi, Harsimran Singh; Munjal, Deepti; Dhingra, Renuka; Malik, Narender Singh; Sidhu, Gagandeep Kaur

    2015-04-01

    Eruption of tooth at about 6 months of age is a significant stage in child's life and is an emotional event for parents. However, a tooth present in the oral cavity of newborn can lead to a lot of delusions. Natal and neonatal teeth are of utmost importance not only for a dentist but also for a paediatrician due to parent's anxiety, folklore superstitions and numerous associated complications with it. This paper reports a rare case, wherein a natal tooth has led to the development of a reactive fibrous hyperplasia in an 8-week-old infant. PMID:26023656

  7. A huge benign prostatic hyperplasia presenting with renal failure

    PubMed Central

    Basatac, Cem; Cicek, Mehmet Cagatay

    2015-01-01

    Although transurethral resection of the prostate is still standard of care in many patients suffering from benign prostatic hyperplasia, traditional open prostatectomy (OP) seems as a widely applied method in larger glands. In spite of the fact that holmium laser enucleation can be performed in large glands, upper limits of prostate size in this method are not clearly identified in the current literature. In this case, we aim to report feasibility and efficacy of OP in huge prostate size measured as 680 ml by transrectal ultrasound and review the current literature. PMID:26034239

  8. Pituitary Lactotroph Hyperplasia and Chronic Hyperprolactinemia in Dopamine D2 Receptor-Deficient Mice

    Microsoft Academic Search

    Michele A Kelly; Marcelo Rubinstein; Sylvia L Asa; Ge Zhang; Carmen Saez; James R Bunzow; Richard G Allen; Robert Hnasko; Nira Ben-Jonathan; David K Grandy; Malcolm J Low

    1997-01-01

    Dopamine secreted from hypophysial hypothalamic neurons is a principal inhibitory regulator of pituitary hormone secretion. Mice with a disrupted D2 dopamine receptor gene had chronic hyperprolactinemia and developed anterior lobe lactotroph hyperplasia without evidence of adenomatous transformation. Unexpectedly, the mutant mice had no hyperplasia of the intermediate lobe melanotrophs. Aged female D2 receptor ?\\/? mice developed uterine adenomyosis in response

  9. Angiolymphoid hyperplasia with eosinophilia: a previously unreported complication of ear piercing.

    PubMed

    Okman, Jonathan S; Bhatti, Tricia R; Jackson, Oksana A; Rubin, Adam I

    2014-01-01

    Angiolymphoid hyperplasia with eosinophilia is a rare, benign vascular lesion characterized by discrete, painful papules. Although the exact etiology is unknown, trauma precedes many cases. We present a case of angiolymphoid hyperplasia with eosinophilia in the earlobes of a 15-year-old girl after ear piercing. PMID:25424213

  10. Total urogenital sinus mobilization in the repair of cloacal anomalies and congenital adrenal hyperplasia

    Microsoft Academic Search

    Alaa F. Hamza; Hesham A. Soliman; Sameh A. Abdel Hay; Ashraf A. Kabesh; Mossad M. Elbehery

    2001-01-01

    Purpose: Urogenital sinus mobilization has facilitated markedly the vaginal reconstruction in cases of cloacal anomalies. Application of the same technique in cases of congenital adrenal hyperplasia has resulted in cosmetic and functional improvement. Methods: Total urogenital sinus mobilization was used as a part of the repair in 9 patients: 6 with congenital adrenal hyperplasia (4 high and 2 mid vaginal

  11. Histologic Influence of Doxazosin and Finasteride in Benign Prostatic Hyperplasia Accompanying Chronic Inflammation

    Microsoft Academic Search

    Dong Soo Park; Jeong Yun Shim

    2008-01-01

    Aim: To evaluate the influence of doxazosin and finasteride on histologic findings in benign prostatic hyperplasia accompanied by prostatitis, and to examine the factors related with prostate carcinogenesis. Materials and Methods: Prostate tissue from 17 cases of prostatic hyperplasia were divided into three groups; group 1: no medication history, group 2: both doxazosin and finasteride for at least 6 months

  12. A New 3-D Automated Computational Method to Evaluate In-Stent Neointimal Hyperplasia in

    E-print Network

    Yanikoglu, Berrin

    of the coronary artery. Our experiments over OCT cross-sections taken from 7 patients presenting varying degreesA New 3-D Automated Computational Method to Evaluate In-Stent Neointimal Hyperplasia in In (PCI) and quantification of in-stent neointimal hyperplasia (NIH) are important. In this paper, we

  13. Targeted transurethral microwave thermotherapy versus alpha-blockade in benign prostatic hyperplasia: outcomes at 18 months

    Microsoft Academic Search

    Bob Djavan; Christian Seitz; Claus G Roehrborn; Mesut Remzi; Mitra Fakhari; Matthias Waldert; Ali Basharkhah; Bernhard Planz; Mike Harik; Michael Marberger

    2001-01-01

    Objectives. To compare directly the efficacy, safety, and durability of targeted transurethral microwave thermotherapy with that of alpha-blocker treatment for lower urinary tract symptoms of benign prostatic hyperplasia.Methods. In a randomized, controlled clinical trial, 52 patients with lower urinary tract symptoms due to benign prostatic hyperplasia received terazosin treatment and 51 underwent microwave treatment under topical anesthesia. The patient evaluation

  14. Imaging findings in pancreatic neoplasia and nodular hyperplasia in 19 cats

    Microsoft Academic Search

    Silke Hecht; DOMINIQUE G. PENNINCK; J H Keatin

    2007-01-01

    Pancreatic neoplasia in cats is rare and associated with a poor prognosis, but pancreatic nodular hyperplasia is a common incidental finding. The purpose of this study was to describe radiographic and ultrasonographic findings in cats with pancreatic neoplasia or nodular hyperplasia. Fourteen cats (age 3-18 years) were diagnosed with malignant pancreatic tumors: carcinoma\\/adenocarcinoma (n = 11), lymphoma (n = 1),

  15. *http://nist.gov/mml/polymers/biomaterials/functional_imaging_regenerative_medicine_workshop. ANNOUNCING Functional Imaging for Regenerative Medicine

    E-print Network

    Adams, Mark

    and image analysis to advance the field. Meanwhile, many areas of imaging science and technology have-edge imaging in (TERM), the Multi-Agency Tissue Engineering Science (MATES) Working Group is sponsoring, and attendees are encouraged to present posters related to their work in imaging or regenerative medicine

  16. The -Catenin Pathway is Activated in Focal Nodular Hyperplasia but not in Cirrhotic FNH-like Nodules

    E-print Network

    : Focal nodular hyperplasias (FNHs) are benign liver lesions considered to be a hyperplastic responseForReview Only The -Catenin Pathway is Activated in Focal Nodular Hyperplasia but not in Cirrhotic, Tania; University of Leuven Bioulac-Sage, Paulette; Inserm U889 Key Words: Focal nodular hyperplasia

  17. Tranilast suppresses the vascular intimal hyperplasia after balloon injury in rabbits fed on a high-cholesterol diet

    Microsoft Academic Search

    Juichi Fukuyama; Kiyoshi Ichikawa; Shuichiro Hamano; Nobuo Shibata

    1996-01-01

    Intimal hyperplasia is a serious problem after percutaneous transluminal coronary angioplasty. In this study, we assessed the effect of tranilast on vascular intimal hyperplasia after balloon injury in rabbits fed on a high-cholesterol diet. In this animal model, intimal hyperplasia more severe than that in rabbits fed on a normal diet was observed. In addition, medial thickening and lipid deposits

  18. Lymphoid hyperplasia and lymphoma in KSHV K1 transgenic mice.

    PubMed

    Berkova, Zuzana; Wang, Shu; Sehgal, Lalit; Patel, Keyur Pravinchandra; Prakash, Om; Samaniego, Felipe

    2015-05-01

    Growing evidence supports the involvement of human herpervirus 8, Kaposi's sarcoma associated herpesvirus (KSHV), in the pathology of primary effusion lymphoma, multicentric Castleman's disease, and Kaposi's sarcoma, but the exact mechanism of KSHV contribution to the oncogenic process remains elusive. We studied transgenic mice expressing the ORF K1 of KSHV, whose position in the KSHV genome corresponds to known lymphoproliferative genes of other herpesviruses. K1 protein was previously shown to contain a constitutively active ITAM domain, involved in activation of Akt and pro-survival signaling, and to inhibit Fas-mediated apoptosis by interfering with binding of FasL. All this pointed to a possible role of K1 in the pathogenesis of KSHV-associated cancers. K1 transgenic mice (80-90%) developed lymphoid hyperplasia and splenomegaly at 8 and 10 months of age, 25% had confirmed diagnosis of lymphoma, and 50% developed abdominal and/or hepatic tumors by 18 months of age. Histological examination showed loss of splenic architecture and increased cellularity. Lymph nodes showed disrupted architecture with effaced follicles and other pathological changes, including signs of angiofollicular lymphoid hyperplasia. One of the livers showed signs of angiosarcoma. In summary, our histology results revealed pathological changes in K1 transgenic mice similar to lymphoma, Castleman's disease, and angiosarcoma, suggesting that K1 may contribute to the development of KSHV-associated cancers. PMID:25301266

  19. Adrenal Nodular Hyperplasia in Hereditary Leiomyomatosis and Renal Cell Cancer

    PubMed Central

    Shuch, Brian; Ricketts, Christopher J.; Vocke, Cathy D.; Valera, Vladimir A.; Chen, Clara C.; Gautam, Rabi; Gupta, Gopal N.; Macias, Gabriela S. Gomez; Merino, Maria J.; Bratslavsky, Gennady; Linehan, W Marston

    2015-01-01

    Purpose Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is characterized by cutaneous leiomyomas, uterine fibroids, and aggressive papillary renal cell carcinoma (RCC). A number of our HLRCC patients were found to have atypical adrenal nodules and which were further evaluated to determine if these adrenal nodules were associated with HLRCC. Methods HLRCC patients underwent a comprehensive clinical and genetic evaluation. Clinical presentation, anatomic and functional imaging, endocrine evaluation, pathologic examination and the results from germline mutation testing were reviewed. Results Twenty of 255 HLRCC patients (7.8%) were found to have primary adrenal lesions. Among these, three were found to have bilateral adrenal lesions and four were found to have multiple nodules. Two patients had ACTH-independent hypercortisolism. A total of 27 adrenal lesions were evaluated. The imaging characteristics of five (18.5%) of these lesions were not consistent with adenoma by non-contrast CT criteria. PET imaging was positive in 7 of 10 cases (70%). Twelve nodules were surgically resected from ten adrenal glands. Pathologic examination revealed macronodular adrenal hyperplasia in all specimens. Conclusions Unilateral and bilateral adrenal nodular hyperplasia was detected in a subset of patients affected with HLRCC. A functional endocrine evaluation is recommended when an adrenal lesion is discovered. Imaging frequently demonstrates lesions that are not typical of adenomas and PET imaging may be positive. To date, no patient has been found to have adrenal malignancy and active surveillance of HLRCC adrenal nodules appears justified. PMID:22982371

  20. Congenital adrenal hyperplasia: experience at intersex clinic, AIIMS.

    PubMed

    Menon, P S; Virmani, A; Sethi, A K; Verma, I C; Rohatgi, M; Gupta, D K; Gupta, A K

    1992-01-01

    During 1981-88, 63 cases of female pseudohermaphroditism (FPH) were seen at the Intersex clinic at AIIMS, of whom 34 (54%) were diagnosed as due to congenital adrenal hyperplasia (CAH). Though ambiguity was present at birth in most cases, only one child was brought immediately after birth, while 14 presented after one year. Family history of affected siblings and fetal wastage was present in 10. Salt wasting symptoms were present in 13 (38.2%), evidence of early virilization in 10 (29.4%) and generalised hyperpigmentation in 7 (20.6%). Clitoromegaly was present in 30 children with labial fusion in 10 and scrotalisation of labia in 6. The urogenital opening was single in 25 (73.5%). Buccal smear was positive for sex chromatin in 19. Chromosomal pattern showed 46 XX in 33. Dyselectrolytemia was present in 16 children. Bone age was advanced in all. Adrenal hyperplasia could be documented in 3 on CT scan. All the girls were put on hydrocortisone or prednisolone, and fluodrocortisone was given only to children with salt wasting CAH. Children with CAH are being brought to medical attention much too late and investigative and therapeutic facilities are grossly inadequate. There is a need to educate primary care physicians for early case detection and provide minimum diagnostic and therapeutic facilities in regional centres. PMID:1452272

  1. Benign prostatic hyperplasia and urinary symptoms: Evaluation and treatment.

    PubMed

    Mobley, David; Feibus, Allison; Baum, Neil

    2015-04-01

    Benign prostatic hyperplasia (BPH) is one of the most common conditions affecting middle-aged men. This condition can be microscopic, macroscopic, symptomatic, or asymptomatic. Up to 15% to 25% of men aged 50-65 years have lower urinary tract symptoms (LUTS) consisting of nocturia, urgency, frequency, a sensation of not completely emptying the bladder, stop-start urination, straining to urinate, a need to urinate soon after voiding, and weak urinary stream. These symptoms usually are associated with benign enlargement of the prostate gland that is of sufficient severity to interfere with a man's quality of life. Although LUTS is often associated with BPH, LUTS can also be due to various unrelated syndromes such as heart failure, urinary tract infections, and diabetes. Most men will have benign hyperplasia of the prostate gland and this benign growth compresses the urethra resulting in LUTS. This article will discuss the evaluation, pharmacological management, minimally invasive treatment, and surgical therapy of this common condition affecting millions of American men. PMID:25823641

  2. Benign Prostatic Hyperplasia: Implications for Pharmacologic Treatment and Perioperative Care.

    PubMed

    Leedahl, David D; Vo, Phil H; Maxson, Pamela M; Lovely, Jenna K

    2012-07-13

    This review provides an update on the treatment of benign prostatic hyperplasia and the pharmacologic considerations for perioperative care. By age 85 years, approximately 90% of men have prostate histologic characteristics consistent with benign prostatic hyperplasia. Pharmacologic treatment with an alpha(1) receptor antagonist may reduce symptoms and, when given in combination with a 5-alpha-reductase inhibitor, may decrease the risk of urinary retention and the need for surgical intervention. Transurethral resection of the prostate has been the historical standard when surgical intervention is indicated. However, recent evidence suggests that Holmium laser enucleation of the prostate may have similar efficacy with less risk of complications and with decreased catheterization time. Prostatic urological operations may have perioperative complications, including urethral bleeding, acute urinary retention, urinary tract infection, urge incontinence, and venous thromboembolism. Pharmacist recommendations for the appropriate use of laxatives, antibiotics, anticoagulation, and urinary antispasmodics are key components of perioperative management. Surgical interventions improve symptoms but may have complications, providing the pharmacist an opportunity to improve perioperative care. PMID:22797835

  3. TOPICAL REVIEW: Powering MEMS portable devices---a review of non-regenerative and regenerative power supply systems with special emphasis on piezoelectric energy harvesting systems

    Microsoft Academic Search

    K. A. Cook-Chennault; N. Thambi; A. M. Sastry

    2008-01-01

    Power consumption is forecast by the International Technology Roadmap of Semiconductors (ITRS) to pose long-term technical challenges for the semiconductor industry. The purpose of this paper is threefold: (1) to provide an overview of strategies for powering MEMS via non-regenerative and regenerative power supplies; (2) to review the fundamentals of piezoelectric energy harvesting, along with recent advancements, and (3) to

  4. Molecular Cytogenetic Comparison of Apocrine Hyperplasia and Apocrine Carcinoma of the Breast

    PubMed Central

    Jones, Chris; Damiani, Stefania; Wells, Dagan; Chaggar, Ranbir; Lakhani, Sunil R.; Eusebi, Vincenzo

    2001-01-01

    The relationship of apocrine metaplasia to invasive breast cancer is controversial. Different authors have reported that apocrine differentiation in proliferative lesions may be a risk factor, a precursor lesion, or have no association with malignancy. The aim of this study was to compare the genetic alterations in benign apocrine hyperplasia with apocrine ductal carcinoma in situ (DCIS) and invasive apocrine carcinomas of the breast using comparative genomic hybridization. The mean number of alterations in apocrine hyperplasia was 4.1 (n = 10) compared to 10.2 in apocrine DCIS (n = 10) and 14.8 (n = 4) in invasive carcinoma. The most common alterations in apocrine hyperplasia were gains of 2q, 13q, and 1p and losses of 1p, 17q, 22q, 2p, 10q, and 16q. Apocrine DCIS and invasive carcinomas showed gains of 1q, 2q, 1p, and losses of 1p, 22q, 17q, 12q, and 16q as their most common DNA copy number changes. Apocrine hyperplasia is considered to be a benign lesion and its relationship to invasive carcinoma remains unclear. Our data suggest that some apocrine hyperplasias may be clonal proliferations. The mean number of alterations are lower in apocrine hyperplasia, however the changes show considerable overlap with those identified in in situ and invasive apocrine carcinoma. These alterations are also commonly seen in nonapocrine breast cancer. The data are consistent with apocrine hyperplasia as a putative nonobligate precursor of apocrine carcinoma. PMID:11141494

  5. Reprogramming and transdifferentiation shift the landscape of regenerative medicine.

    PubMed

    Guo, Jingjing; Wang, Hu; Hu, Xingchang

    2013-10-01

    Regenerative medicine is a new interdisciplinary field in biomedical science, which aims at the repair or replacement of the defective tissue or organ by congenital defects, age, injury, or disease. Various cell-related techniques such as stem cell-based biotherapy are a hot topic in the current press, and stem cell research can help us to expand our understanding of development as well as the pathogenesis of disease. In addition, new technology such as reprogramming or dedifferentiation and transdifferentiation open a new area for regenerative medicine. Here we review new approaches of these technologies used for cell-based therapy and discuss future directions and challenges in the field of regeneration. PMID:23930590

  6. Antarctic analogs as a testbed for regenerative life support technologies

    NASA Technical Reports Server (NTRS)

    Roberts, D. R.; Andersen, D. T.; Mckay, C. P.; Wharton, R. A., Jr.; Rummel, J. D.

    1991-01-01

    The feasibility of using Antarctica as a platform for creating earth-based simulations of regenerative life support systems (LSSs) for future space missions is discussed. The requirements for a bioregenerative LSS and the types of technologies that may be used in such a system are examined. Special attention is given to the objectives and the organization of the NASA's CELSS program for the development of regenerative LSSs to support long-duration human missions in space, largely independent of resupply, in a safe and reliable manner. There are two types of locations on the continent of Antarctica suitable for the placement of simulation facilities: the polar plateau and the ice-free dry valleys. The unique attributes that lend each type of location to very different functions as simulation facilities are discussed.

  7. Regenerative Environmental Control and Life Support System Diagram

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This diagram shows the flow of recyclable resources in the International Space Station (ISS). The Environmental Control and Life Support System (ECLSS) Group of the Flight Projects Directorate at the Marshall Space Flight Center is responsible for the regenerative ECLSS hardware, as well as providing technical support for the rest of the system. The regenerative ECLSS, whose main components are the Water Recovery System (WRS), and the Oxygen Generation System (OGS), reclaims and recycles water and oxygen. The ECLSS maintains a pressurized habitation environment, provides water recovery and storage, maintains and provides fire detection / suppression, and provides breathable air and a comfortable atmosphere in which to live and work within the ISS. The ECLSS hardware will be located in the Node 3 module of the ISS.

  8. Investigation of electroforming techniques. [fabrication of regeneratively cooled thrust chambers

    NASA Technical Reports Server (NTRS)

    Malone, G. A.

    1975-01-01

    Copper and nickel electroforming was examined for the purpose of establishing the necessary processes and procedures for repeatable, successful fabrication of the outer structures of regeneratively cooled thrust chambers. The selection of electrolytes for copper and nickel deposition is described. The development studies performed to refine and complete the processes necessary for successful chamber shell fabrication and the testing employed to verify the applicability of the processes and procedures to small scale hardware are described. Specifications were developed to afford a guideline for the electroforming of high quality outer shells on regeneratively cooled thrust chamber liners. Test results indicated repeatable mechanical properties could be produced in copper deposits from the copper sulfate electrolyte with periodic current reversal and in nickel deposits from the sulfamate solution. Use of inert, removable channel fillers and the conductivizing of such is described. Techniques (verified by test) which produce high integrity bonds to copper and copper alloy liners are discussed.

  9. Nanotechnologies and regenerative medical approaches for space and terrestrial medicine.

    PubMed

    Grattoni, Alessandro; Tasciotti, Ennio; Fine, Daniel; Fernandez-Moure, Joseph S; Sakamoto, Jason; Hu, Ye; Weiner, Bradley; Ferrari, Mauro; Parazynski, Scott

    2012-11-01

    One purpose of the International Space Station (ISS) is to explore powerful new areas of biomedical science in microgravity. Recent advances in nanotechnology applied to medicine--what we now refer to as nano-medicine--and regenerative medicine have enormous untapped potential for future space and terrestrial medical applications. Novel means for drug delivery and nanoscale screening tools will one day benefit astronauts venturing to Mars and places beyond, while the space laboratory will foster advances in nanotechnologies for diagnostic and therapeutic tools to help our patients here on Earth. Herein we review a series of nanotechnologies and selected regenerative medical approaches and highlight key areas of ongoing and future investigation that will benefit both space and terrestrial medicine. These studies target significant areas of human disease such as osteoporosis, diabetes, radiation injury, and many others. PMID:23156089

  10. Regenerative medicine for the kidney: stem cell prospects & challenges

    PubMed Central

    2013-01-01

    The kidney has key roles in maintaining human health. There is an escalating medical crisis in nephrology as growing numbers of patients suffer from kidney diseases that culminate in organ failure. While dialysis and transplantation provide life-saving treatments, these therapies are rife with limitations and place significant burdens on patients and healthcare systems. It has become imperative to find alternative ways to treat existing kidney conditions and preemptive means to stave off renal dysfunction. The creation of innovative medical approaches that utilize stem cells has received growing research attention. In this review, we discuss the regenerative and maladaptive cellular responses that occur during acute and chronic kidney disease, the emerging evidence about renal stem cells, and some of the issues that lie ahead in bridging the gap between basic stem cell biology and regenerative medicine for the kidney. PMID:23688352

  11. The theory of an active magnetic regenerative refrigerator

    NASA Technical Reports Server (NTRS)

    Barclay, J. A.

    1983-01-01

    The adiabatic temperature change with field which is limited to about 2 K/Tesla for ferromagnets near their Curie temperatures by the change of magnetization with temperature and the lattice heat capacity is discussed. Practical magnetic refrigerators operate on a regenerative cycle such as the Brayton cycle. This cycle can be executed through the use of an active magnetic regenerator, i.e., a regenerator composed of magnetic material that is cycled in an out of a magnetic field with appropriate fluid flows. The theory of these devices is predicted by solving the partial differential equations that describe fluid and the magnetic solid. The active magnetic regenerator is described along with the method of calculation. Temperature profiles for a normal regenerator and a magnetic regenerative refrigerator are shown.

  12. Trends in the stem cell and regenerative medicine industry.

    PubMed

    Ilic, Dusko

    2012-09-01

    The World Stem Cell Regenerative Medicine Congress series, now in its 7th year, is organized annually in the USA, Europe and Asia by Terrapinn, a business media company with its head office in London, and has grown over the last several years into the largest and probably the most important strategic stem cell conference where regulators, investors, big pharma, and small and medium enterprises gather to share and create synergy in developing and commercializing stem cell applications. The conference, held in London on 21-23 May 2012, only confirmed that this series is the meeting to attend if you want to get a clear understanding of trends in the stem cell and regenerative medicine industry. PMID:22954435

  13. Hypothetical considerations in the regenerative treatment of molar furcation defects.

    PubMed

    Hutchens, L H

    1996-01-01

    Treatment of the molar furcation defect is a challenge to the dental professional. Responses of molar furcation sites to both closed and open surgical debridement have not been shown to result in significant clinical improvement or bone fill. Regenerative techniques using grafting materials, guided tissue regeneration with resorbable and nonresorbable membranes, coronally positioned flaps, and combination techniques are more frequently used to treat class II molar furcations. The clinical responses to these surgical approaches have shown varied results. This article reviews some of the studies on regeneration in furcation defects as well as some of the uniqueness and complexities of the furcation problem. The bone morphology differences in molar bifurcation and trifurcation defects are discussed, and a bone morphologic classification is presented in an effort to standardize future regenerative studies in class II furcations. PMID:8624561

  14. Regenerative periodontal therapy in mucogingival surgery for root coverage.

    PubMed

    Abitbol, T; Santi, E; Urbani, G

    1997-02-01

    This article illustrates the potential benefits of regenerative periodontal therapy in mucogingival surgery and esthetic dental treatment. Cases are described in which the treatment of soft-tissue recessions and root exposures are treated with surgical procedures where both clinical soft-tissue augmentation and the regeneration of periodontal attachment are obtained. Cases are also presented to illustrate the clinical application of guided tissue regeneration. Resorbable and nonresorbable barriers are placed over the root surface and bone and covered by the overlying flap, which allows the selective repopulation of the lesion by progenitor cells and the inhibition of a long junctional epithelium. Emphasis is placed on regenerative procedures in soft-tissue augmentation, particularly with respect to rationales, techniques, and indications. PMID:9452536

  15. Regenerative thermal oxidation and alternative technologies for VOC control

    SciTech Connect

    Biedell, E.L. [REECQ, Somerville, NJ (United States)

    1995-12-31

    Thermal oxidation technologies have been used successfully to control VOC`s for many years but the recent 1990 Clean Air Act Amendments have spurred improvements in the established processes and development of economic alternatives. The combination of the regulatory maze and confusion in the selection of the best technology for a particular application has created a potential nightmare for those companies facing a need to reduce their VOC EMISSIONS. The relative advantages and disadvantages of regenerative, recuperative and catalytic oxidizers will be reviewed, with an emphasis on the economic justification for regenerative thermal oxidation (RTO). Control efficiencies of more than 99% have been demonstrated for RTO`s on a multitude of industrial process exhaust streams. Lowest evaluated cost over a fifteen to twenty year effective equipment life is a key selection criteria. This paper describes the underlying principles of thermal oxidation, and discusses the applicability of these and other emerging technologies for VOC control.

  16. Seikan tunnel electric train propulsion -- Regenerative energy management

    SciTech Connect

    Isshiki, Seita [Ashikaga Inst. of Tech., Tokyo (Japan); Wyczalek, F.A. [FW Lilly Inc., Bloomfield, Hills, MI (United States)

    1997-12-31

    The mission was to model the electric propulsion and regenerative energy requirements for the Kaikyo passenger train and the Kamotsusen freight train system currently operating between Tappikaitei and Yoshiokakaitei through the Seikan tunnel under the Pacific Ocean. The Seikan tunnel is over 54 km in length and connects Aomori on the main Japanese island of Honshu to the North island of Hokkaido. Further, over 24 km of the Seikan tunnel is 100 meters below the sea bed of the Tsugaru Strait which joins the Pacific with the Sea of Japan. While, the sea bed is 140 meters below the mean Pacific sea level, at the deepest point. Safety and energy conservation issues led to reliable regenerative energy recovery and braking systems.

  17. Tissue engineering and regenerative medicine: concepts for clinical application.

    PubMed

    Atala, Anthony

    2004-01-01

    Patients suffering from diseased and injured organs may be treated with transplanted organs. However, there is a severe shortage of donor organs that is worsening yearly given the aging population. Scientists in the field of regenerative medicine and tissue engineering apply the principles of cell transplantation, material science, and bioengineering to construct biological substitutes that will restore and maintain normal function in diseased and injured tissues. Therapeutic cloning, where the nucleus from a donor cell is transferred into an enucleated oocyte in order to extract pluripotent embryonic stem cells, offers a potentially limitless source of cells for tissue engineering applications. The stem cell field is also advancing rapidly, opening new options for therapy. This paper reviews recent advances that have occurred in regenerative medicine and describes applications of these new technologies that may offer novel therapies for patients with end-stage organ failure. PMID:15256042

  18. Average outage duration of multihop communication systems with regenerative relays

    Microsoft Academic Search

    Lin Yang; Mazen O. Hasna; Mohamed-slim Alouini

    2005-01-01

    Closed-form expressions for the average outage duration (AOD) of multihop regenerative communication systems over generalized fading channels are presented. Both noise-limited and interference-limited systems are studied. To show the usefulness of the presented expressions, some specific fading scenarios are considered. In addition, some numerical examples of interest comparing direct versus relayed transmission and studying the effect of increasing the number

  19. Status of the Regenerative ECLSS Water Recovery System

    NASA Technical Reports Server (NTRS)

    Carter, Donald Layne

    2009-01-01

    NASA has completed the delivery of the regenerative Water Recovery System (WRS) for the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the final effort to deliver the hardware to the Kennedy Space Center for launch on STS-126, the on-orbit status as of April 2009, and describes some of the technical challenges encountered and lessons learned over the past year.

  20. The Ovonic Regenerative Fuel Cell, A Fundamentally New Approach

    NSDL National Science Digital Library

    Corrigan, D.A.

    This report introduces the Ovonic Regenerative fuel cell, which is a technology that "utilizes Ovonic metal hydride materials in place of traditional noble metal catalysts in the hydrogen fuel electrode." The paper goes into detail about how these fuel cells work and includes graphical representations of the processes involved. This paper was presented at the Hydrogen and Fuel Cells 2004 Conference and Trade Show in Toronto, Canada. This document may be downloaded in PDF file format.

  1. Long-duration space mission regenerative life support

    Microsoft Academic Search

    A. I. Grogoriev; J. E. Sinjak; L. I. Gavrilov; V. M. Novikov; N. S. Farafonov; J. I. Grigoriev; E. N. Zaitsev; S. J. Romanov

    2000-01-01

    The paper deals with the construction of physical\\/chemical life support systems of orbiting space station Mir and the Russian segment of the international space station (ISS). Based on experience gained in development and long-term operation of systems for water recovery and air revitalization balance and energy\\/mass characteristics of promising life support systems (LSS) are analyzed.Physical\\/chemical life support systems with regenerative

  2. Regenerative fuel cell architectures for lunar surface power

    Microsoft Academic Search

    D. W. Harris; S. P. Gill; T. M. Nguyen; J. J. Vrolyk

    1991-01-01

    Various Regenerative Fuel Cell (RFC) configurations for the stationary lunar missions were examined using a RFC computer model. For the stationary applications, a GaAs\\/Ge photovoltaic (PV) array with a 3000 psi gas storage proton exchange membrane (PEM) RFC providing 25 kWe during the day and 12.5 kWe at night was designed. PV\\/RFC systems utilizing supercritical H2\\/O2 storage and cryogenic H2\\/O2

  3. NASA Lewis evaluation of Regenerative Fuel Cell (RFC) systems

    Microsoft Academic Search

    N. H. Hagedorn; O. D. Gonzalez-Sanabria; L. L. Kohout

    1986-01-01

    Evaluation of two regenerative fuel cell (RFC) systems was begun in-house, and under contracts and grants. The passive hydrogen-oxygen RFC offers the possibility of a high-energy density, long-life storage system for geosynchronous Earth orbit missions. The hydrogen-bromine RFC offers the combination of high efficiency and moderate energy density that could ideally suit low Earth orbit missions if successfully developed. Either

  4. Regenerative fuel cell study for satellites in GEO orbit

    Microsoft Academic Search

    Alexander Levy; Leslie L. Vandine; James K. Stedman

    1987-01-01

    Summarized are the results of a 12-month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application. Emphasis was placed on concepts with the potential for high energy density (W-hr\\/lb) and passive means for water and heat management to maximize system reliability. Both polymer membrane and alkaline electrolyte fuel cells were considered, with emphasis on the

  5. Design of a regenerative fuel cell system for Space Station

    NASA Technical Reports Server (NTRS)

    Hoberecht, M. A.; Rieker, L. L.

    1985-01-01

    The NASA Space Station will employ alkaline regenerative fuel cells (RFCs) as its sole electrochemical energy storage system, in virtue of demonstrated technology readiness and a high degree of system-level design flexibility. NASA Johnson and NASA Lewis are currently engaged in the development of a 10-kW alkaline engineering model system, for 1987 delivery, which will encompass a fully autonomous 120-V system with 55 percent overall electrical efficiency and a 20,000-hr service life.

  6. Theory, modelling and performance measurement of unitised regenerative fuel cells

    Microsoft Academic Search

    A. Doddathimmaiah; J. Andrews

    2009-01-01

    Unitised Regenerative Fuel Cells (URFCs) based on Proton Exchange Membrane (PEM) technology provide a promising opportunity for reducing the cost of the hydrogen subsystem used in renewable-energy hydrogen systems for remote area power supply. A general theoretical relationship between cell potential and current density of a single-cell URFC operating in both fuel-cell and electrolyser modes is derived using the Butler–Volmer

  7. Transient electrolyser response in a renewable-regenerative energy system

    Microsoft Academic Search

    A. Bergen; L. Pitt; A. Rowe; P. Wild; N. Djilali

    2009-01-01

    In a renewable-regenerative electrolyser\\/fuel-cell system, the electrolyser performs the critical function of converting excess renewable input energy into hydrogen. Electrolyser operation on time scales and duty cycles that are relevant to common renewable resources (e.g., wind and solar) were probed using an experimental residential-scale system. Experimental results indicate that the electrolyser's transient characteristics have a significant impact on the efficiency

  8. A vapor injector-based novel regenerative organic Rankine cycle

    Microsoft Academic Search

    Rong-Ji Xu; Ya-Ling He

    2011-01-01

    A regenerative organic Rankine cycle (RORC) that uses a vapor injector as the regenerator is proposed. The physical process is theoretically described and the numerical analysis of the injector performance based on a one-dimensional model is also presented. The thermal performance of both the novel cycle and the basic ORC is calculated and compared by using R123 as the working fluid.

  9. Failure rates of regenerative systems with heavy tails

    Microsoft Academic Search

    S. Asmussen; V. Kalashnikov

    1999-01-01

    Let ?t be a regenerative process and assume that, at each state x, the process can fail with intensity ?(x). If the inter-regeneration\\u000a times have a finite exponential moment orinf\\u000a x?(x)>0, then ?(?t) tends to some limiting positive intensity as t?? (under mild additional restrictions). This fact is widely used in engineering\\u000a because the limiting intensity can be employed in

  10. A functional central limit theorem for regenerative chains

    E-print Network

    Maillard, G

    2008-01-01

    Using the regenerative scheme of Comets, Fern\\'andez and Ferrari (2002), we establish a functional central limit theorem (FCLT) for discrete time stochastic processes (chains) with summable memory decay. Furthermore, under stronger assumptions on the memory decay, we identify the limiting variance in terms of the process only. As applications, we define classes of binary autoregressive processes and power-law Ising chains for which the FCLT is fulfilled.

  11. Power conditions and control of a regenerative brake

    Microsoft Academic Search

    Vladimir Blasko

    1998-01-01

    Braking capability is typically accomplished by adding a dynamic\\/resistive brake (DB) module to a standard drive. Regenerating energy is dissipated in the braking resistor creating heat and decreasing the overall efficiency of the drive. To overcome the shortcomings of the DB solution, a regenerative brake (RB) was developed. The RB is a stand-alone, add-on unit to the drive. It operates

  12. Human dental pulp stem cells: Applications in future regenerative medicine

    PubMed Central

    Potdar, Pravin D; Jethmalani, Yogita D

    2015-01-01

    Stem cells are pluripotent cells, having a property of differentiating into various types of cells of human body. Several studies have developed mesenchymal stem cells (MSCs) from various human tissues, peripheral blood and body fluids. These cells are then characterized by cellular and molecular markers to understand their specific phenotypes. Dental pulp stem cells (DPSCs) are having a MSCs phenotype and they are differentiated into neuron, cardiomyocytes, chondrocytes, osteoblasts, liver cells and ? cells of islet of pancreas. Thus, DPSCs have shown great potentiality to use in regenerative medicine for treatment of various human diseases including dental related problems. These cells can also be developed into induced pluripotent stem cells by incorporation of pluripotency markers and use for regenerative therapies of various diseases. The DPSCs are derived from various dental tissues such as human exfoliated deciduous teeth, apical papilla, periodontal ligament and dental follicle tissue. This review will overview the information about isolation, cellular and molecular characterization and differentiation of DPSCs into various types of human cells and thus these cells have important applications in regenerative therapies for various diseases. This review will be most useful for postgraduate dental students as well as scientists working in the field of oral pathology and oral medicine. PMID:26131314

  13. Regulators of pluripotency and their implications in regenerative medicine

    PubMed Central

    El-Badawy, Ahmed; El-Badri, Nagwa

    2015-01-01

    The ultimate goal of regenerative medicine is to replace damaged tissues with new functioning ones. This can potentially be accomplished by stem cell transplantation. While stem cell transplantation for blood diseases has been increasingly successful, widespread application of stem cell therapy in the clinic has shown limited results. Despite successful efforts to refine existing methodologies and to develop better ones for reprogramming, clinical application of stem cell therapy suffers from issues related to the safety of the transplanted cells, as well as the low efficiency of reprogramming technology. Better understanding of the underlying mechanism(s) involved in pluripotency should accelerate the clinical application of stem cell transplantation for regenerative purposes. This review outlines the main decision-making factors involved in pluripotency, focusing on the role of microRNAs, epigenetic modification, signaling pathways, and toll-like receptors. Of special interest is the role of toll-like receptors in pluripotency, where emerging data indicate that the innate immune system plays a vital role in reprogramming. Based on these data, we propose that nongenetic mechanisms for reprogramming provide a novel and perhaps an essential strategy to accelerate application of regenerative medicine in the clinic. PMID:25960670

  14. Human dental pulp stem cells: Applications in future regenerative medicine.

    PubMed

    Potdar, Pravin D; Jethmalani, Yogita D

    2015-06-26

    Stem cells are pluripotent cells, having a property of differentiating into various types of cells of human body. Several studies have developed mesenchymal stem cells (MSCs) from various human tissues, peripheral blood and body fluids. These cells are then characterized by cellular and molecular markers to understand their specific phenotypes. Dental pulp stem cells (DPSCs) are having a MSCs phenotype and they are differentiated into neuron, cardiomyocytes, chondrocytes, osteoblasts, liver cells and ? cells of islet of pancreas. Thus, DPSCs have shown great potentiality to use in regenerative medicine for treatment of various human diseases including dental related problems. These cells can also be developed into induced pluripotent stem cells by incorporation of pluripotency markers and use for regenerative therapies of various diseases. The DPSCs are derived from various dental tissues such as human exfoliated deciduous teeth, apical papilla, periodontal ligament and dental follicle tissue. This review will overview the information about isolation, cellular and molecular characterization and differentiation of DPSCs into various types of human cells and thus these cells have important applications in regenerative therapies for various diseases. This review will be most useful for postgraduate dental students as well as scientists working in the field of oral pathology and oral medicine. PMID:26131314

  15. Thermal regenerative design of a fuel cell cogeneration system

    NASA Astrophysics Data System (ADS)

    Hwang, Jenn-Jiang

    2012-12-01

    The objective of the present work is to design and fabricate a thermal management system (TMS) that commands a proton exchange membrane fuel cell (PEMFC) based cogeneration system to generate the electricity and hot water efficiently. Parametric studies include the external load (PL) and the regenerative temperature (TR). A thermostat valve is employed to optimize the stack operation temperature, while a thermal regenerative unit (TRU) containing a planar heat exchanger is used to recover the heat dissipated by the stack. First, the dynamics of thermal and electrical characteristics such as voltage, current, power, coolant temperature, coolant flow rate, and hydrogen flow rate are measured to check the reliability of the TMS. Then, the effectiveness of the planar heat exchanger is determined to verify the cooling ability of the TRU. Moreover, the transient system efficiencies, including electrical efficiency, thermal efficiency, and overall efficiency are determined. Furthermore, the effect of the regenerative temperature on the time-averaged system efficiencies is examined under different external loads. Finally, an empirical correlation for time-averaged overall efficiency is proposed for helping in design of the PEMFC cogeneration system.

  16. Potential regenerative treatment strategies for intervertebral disc degeneration in dogs

    PubMed Central

    2014-01-01

    Pain due to spontaneous intervertebral disc (IVD) disease is common in dogs. In chondrodystrophic (CD) dogs, IVD disease typically develops in the cervical or thoracolumbar spine at about 3–7 years of age, whereas in non-chondrodystrophic (NCD) dogs, it usually develops in the caudal cervical or lumbosacral spine at about 6–8 years of age. IVD degeneration is characterized by changes in the biochemical composition and mechanical integrity of the IVD. In the degenerated IVD, the content of glycosaminoglycan (GAG, a proteoglycan side chain) decreases and that of denatured collagen increases. Dehydration leads to tearing of the annulus fibrosus (AF) and/or disc herniation, which is clinically characterized by pain and/or neurological signs. Current treatments (physiotherapy, anti-inflammatory/analgesic medication, surgery) for IVD disease may resolve neurological deficits and reduce pain (although in many cases insufficient), but do not lead to repair of the degenerated disc. For this reason, there is interest in new regenerative therapies that can repair the degenerated disc matrix, resulting in restoration of the biomechanical function of the IVD. CD dogs are considered a suitable animal model for human IVD degeneration because of their spontaneous IVD degeneration, and therefore studies investigating cell-, growth factor-, and/or gene therapy-based regenerative therapies with this model provide information relevant to both human and canine patients. The aim of this article is to review potential regenerative treatment strategies for canine IVD degeneration, with specific emphasis on cell-based strategies. PMID:24387033

  17. Diagnosis and management of hepatic focal nodular hyperplasia.

    PubMed

    Venturi, A; Piscaglia, F; Vidili, G; Flori, S; Righini, R; Golfieri, R; Bolondi, L

    2007-09-01

    Focal nodular hyperplasia (FNH) is the second most common benign tumor of the liver, after hemangioma. It is generally found incidentally and is most common in reproductive-aged women, but it also affects males and can be diagnosed at any age. Patients are rarely symptomatic, but FNH sometimes causes epigastric or right upper quadrant pain. The main clinical task is to differentiate it from other hypervascular hepatic lesions such as hepatic adenoma, hepatocellular carcinoma, or hypervascular metastases, but invasive diagnostic procedures can generally be avoided with the appropriate use of imaging techniques. Magnetic resonance (MR) imaging is more sensitive and specific than conventional ultrasonography (US) or computed tomography (CT), but Doppler US and contrast-enhanced US (CEUS) can greatly improve the accuracy in the diagnosis of FNH. Once a correct diagnosis has been made, in most cases there is no indication for surgery, and treatment includes conservative clinical follow-up in asymptomatic patients. PMID:23396642

  18. Mandible condylar hyperplasia: a review of diagnosis and treatment protocol

    PubMed Central

    Olate, Sergio; Netto, Henrique Duque; Rodriguez-Chessa, Jaime; Alister, Juan Pablo; de Albergaria-Barbosa, Jose; de Moraes, Márcio

    2013-01-01

    Condylar hyperplasia (CH) is a bone disease characterized by the increased development of one mandibular condyle. It regularly presents as an active growth with facial asymmetry generally without pain. Statistically it affects more women in adolescence, although it does not discriminate by age or gender. Its best-known consequence is asymmetric facial deformity (AFD), which combined with alteration of the dental occlusion with unilateral crossbite or open bite. It is not known when CH begins and how long it lasts; diagnostic examinations are described and are efficient in some research about diagnosis. Protocol treatment is not well studie and depends on the criteria described in this paper. The aim of this research is to provide up-to-date information about the diagnosis of this disease and to analyze the treatment protocol, visualizing the CH and AFD presented. PMID:24179565

  19. Screening and diagnosis of congenital adrenal hyperplasia in Basilicata (Italy).

    PubMed

    Cordova, R A; Vignola, G

    1999-01-01

    Research of the frequency of 21-OH enzyme deficiency, autosomal recessive disease, caused by aberrations in the short arm of chromosome 6 was performed in order to prevent CAH (Congenital Adrenal Hyperplasia) manifested by: 1) possible cerebral damage 2) errors of sex attribution 3) behavioral hyperandrogenism 4) metabolic damage. Radioimmunoassay was used where there is competition between a radioactive and a non-radioactive antigens for a fixed number of antibody binding sites. In an 18 month period of screening 6,000 newborns we found one positive case of CAH which we confirmed by dosaging steroids such as, 4-androstenedione, testosterone, ACTH, PRA and electrolytic activity on the serum. We ascertained that an incidence of 1:6,000 in a 18 month period is high enough to deserve attention. PMID:11400742

  20. Diagnosis and management of classical congenital adrenal hyperplasia.

    PubMed

    Marumudi, Eunice; Khadgawat, Rajesh; Surana, Vineet; Shabir, Iram; Joseph, Angela; Ammini, Ariachery C

    2013-08-01

    Congenital adrenal hyperplasia (CAH) is among the most common genetic disorders. Deficiency of adrenal steroid 21-hydroxylase deficiency due to mutations in the CYP21A2 gene accounts for about 95% cases of CAH. This disorder manifests with androgen excess with or without salt wasting. It also is a potentially life threatening disorder; neonatal screening with 17-hydroxyprogesterone measurement can diagnose the condition in asymptomatic children. Carefully monitored therapy with glucocorticoid and mineralocorticoid supplementation will ensure optimal growth and development for children with CAH. Genital surgery may be required for girls with CAH. Continued care is required for individuals with CAH as adults to prevent long-term adverse consequences of the disease, including infertility, metabolic syndrome and osteoporosis. PMID:23624029

  1. Management of the Adult with Congenital Adrenal Hyperplasia

    PubMed Central

    Auchus, Richard J.

    2010-01-01

    Congenital adrenal hyperplasia (CAH), most commonly due to 21-hydroxylase deficiency (21OHD), has been studied by pediatric endocrinologists for decades. Advances in the care of these patients have enabled many of these children to reach adulthood. In contrast to the course and management of the disease in childhood, little is known about CAH in adults. In many patients, the proclivity to salt-wasting crises decreases. Linear growth ceases, and reproductive function becomes an issue. Most importantly, management must minimize the potential for long-term consequences of conventional therapies. Here we review the existing literature regarding comorbidities of adults with 21OHD, goals of treatment, and approaches to therapy, with an emphasis on need for improved management strategies. PMID:20613954

  2. Iris mammillations in two female siblings with congenital adrenal hyperplasia

    PubMed Central

    Peyman, Mohammadreza; Ong, Ming Jew; Iqbal, Tajunisah; Subrayan, Visvaraja

    2010-01-01

    Iris mammillations are dark brown, smooth, mound- or dome-shaped protuberances that are typically found on the anterior iris surface and are presumed to be congenital in origin. This congenital anomaly is usually unilateral and can be hereditary or sporadic. Lisch nodules in neurofibromatosis, tapioca melanoma of the iris, inflammatory iris granulomata and Cogan–Reese syndrome should be considered in the differential diagnosis. In this case report, the authors present a case of a bilateral iris mammillations in two siblings with congenital adrenal hyperplasia (CAH). To our knowledge, this is the first case where bilateral iris mammilations have been found to be associated with a systemic condition. Iris mammillations can be considered as one of the clinical signs in CAH in view of the pathogenesis discussed. Detailed ocular examination in CAH may reveal an increased incidence. PMID:22802477

  3. [Benign prostatic hyperplasia and erectile dysfunction: an update].

    PubMed

    Fan, Yu

    2013-06-01

    Epidemiological studies have confirmed that benign prostatic hyperplasia (BPH) and erectile dysfunction (ED) are correlated, independent of age or comorbidities as diabetes. Although researchers have not yet established a direct causal relationship between the two problems, several pathophysiological factors may serve to explain it, which include the alteration in nitric oxide bioavailability, increased autonomic activity, a1-adrenergic receptor hyperactivity, imbalance of RhoA/Rho-kinase, and metabolic syndrome X. Men seeking care for BPH should always be screened for sexual function and complaints of ED. PDE5 inhibitors show promise as a future treatment for lower urinary tract symptoms secondary to BPH. Further investigation is required for future therapies and possible preventative strategies. PMID:23862240

  4. Management considerations for the adult with congenital adrenal hyperplasia.

    PubMed

    Auchus, Richard J

    2015-06-15

    The congenital adrenal hyperplasias (CAH) are a group of genetic defects in cortisol biosynthesis, most commonly steroid 21-hydroxylase deficiency (21OHD). With the advent of cortisone therapy in the 1960s and newborn screening in the 1990s, most children with 21OHD now reach adulthood. The needs and concerns of adults with 21OHD overlap with those of children, but the focus and approach shift as these patients reach adulthood. Cohort studies suggest that adults with 21OHD experience significant health concerns such as infertility, obesity, short stature, neoplasia, and bone loss, as well as reduced quality of life. Nevertheless, the spectrum of health status and disease severity is broad, but only some of the reasons for these disparities are known. This review will summarize the current state of knowledge and suggested approaches to management adults with classic 21OHD, plus a few major considerations for adults with nonclassic 21OHD. PMID:25643980

  5. [Interpretation of results of clinical trials in benign prostatic hyperplasia].

    PubMed

    Millán Rodríguez, F; Rodríguez Vallejo, J M; Carballido Rodríguez, J

    2002-01-01

    The random clinical trial (RCT) is the most suitable study to evaluate the treatment effectiveness in the benign prostatic hyperplasia (BPH). Although most of the urologists will not collaborate in a RCT development, they will treat BPH patients, so it is very important to know if a CRT in BPH is well designed and their conclusions are correct. The aim of this article is to give the basic elements of analysis that urologists need in order to evaluate the quality and the level of evidence of a RCT in BPH. This article emphasizes the three main elements of a RCT: to check if the study has been correctly performed (internal validity), to evaluate if the treatment achieves an important clinical improvement (relevance of the results) and the applicability of the results in our patients (external validity). The article shows that to analyse these elements common sense and clinical judgment are needed rather than statistical knowledge. PMID:11899738

  6. The link between benign prostatic hyperplasia and prostate cancer.

    PubMed

    Ørsted, David D; Bojesen, Stig E

    2013-01-01

    Benign prostatic hyperplasia (BPH) and prostate cancer are among the most common diseases of the prostate gland and represent significant burdens for patients and health-care systems in many countries. The two diseases share traits such as hormone-dependent growth and response to antiandrogen therapy. Furthermore, risk factors such as prostate inflammation and metabolic disruption have key roles in the development of both diseases. Despite these commonalities, BPH and prostate cancer exhibit important differences in terms of histology and localization. Although large-scale epidemiological studies have shown that men with BPH have an increased risk of prostate cancer and prostate-cancer-related mortality, it remains unclear whether this association reflects a causal link, shared risk factors or pathophysiological mechanisms, or detection bias upon statistical analysis. Establishing BPH as a causal factor for prostate cancer development could improve the accuracy of prognostication and expedite intervention, potentially reducing the number of men who die from prostate cancer. PMID:23165396

  7. Idiopathic Myointimal Hyperplasia of the Mesenteric Veins Diagnosed Preoperatively.

    PubMed

    Wangensteen, Kirk J; Fogt, Franz; Kann, Brian R; Osterman, Mark T

    2015-07-01

    Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) of the colon is a very rare disease that in previously reported cases was often mistaken for inflammatory bowel disease because of similar clinical characteristics. In our review of the literature, we found a total of 15 cases described, generally featuring sigmoid and rectal colitis and symptoms of abdominal pain, diarrhea, and hematochezia refractory to treatment with immunosuppressants. In all previously reported cases, the diagnosis was achieved only after surgical resection of the affected area. Herein, we report a case of IMHMV that was diagnosed preoperatively based on clinical information and endoscopy with biopsies. This led to the withdrawal of immunosuppression before a carefully planned surgical resection, with confirmation of the diagnosis in the resected tissue. To our knowledge, our case of IMHMV is the first to be diagnosed preoperatively. PMID:25626629

  8. Long-term healing of photodynamic therapy: treatment of experimental intimal hyperplasia

    NASA Astrophysics Data System (ADS)

    LaMuraglia, Glenn M.; ChandraSekar, N. R.; Flotte, Thomas J.; Hasan, Tayyaba

    1994-07-01

    A study was performed to determine whether intimal hyperplasia can be chronically inhibited and the artery wall integrity maintained after cells are depleted from the artery with photodynamic therapy. Utilizing chloroaluminum sulfonated phthalocyanine or saline for control, limited balloon injury of the common carotid artery was performed before irradiation with 675 mm laser light. Results demonstrated carotid inhibition of intimal hyperplasia in PDT treated arteries without aneurysm formation or artery dilatation. By 4 weeks there was reendothelialization of the intima of the PDT arteries and repopulation of the adventitia with myofibroblasts. This data was encouraging in that PDT can chronically inhibit intimal hyperplasia without precipitating a weakness in the arterial wall.

  9. Nerve hyperplasia: a unique feature of ketamine cystitis

    PubMed Central

    2013-01-01

    Background There is an emerging association between ketamine abuse and the development of urological symptoms including dysuria, frequency and urgency, which have a neurological component. In addition, extreme cases are associated with severe unresolving bladder pain in conjunction with a thickened, contracted bladder and an ulcerated/absent urothelium. Here we report on unusual neuropathological features seen by immunohistology in ketamine cystitis. Results In all cases, the lamina propria was replete with fine neurofilament protein (NFP+) nerve fibres and in most patients (20/21), there was prominent peripheral nerve fascicle hyperplasia that showed particular resemblance to Morton’s neuroma. The nerve fascicles, which were positive for NFP, S100 and the p75 low-affinity nerve growth factor receptor (NGFR), were generally associated with a well-developed and in places, prominent, epithelial membrane antigen+/NGFR+ perineurium. This peripheral nerve fascicle hyperplasia is likely to account for the extreme pain experienced by ketamine cystitis patients. Urothelial damage was a notable feature of all ketamine cystitis specimens and where urothelium remained, increased NGFR expression was observed, with expansion from a basal-restricted normal pattern of expression into the suprabasal urothelium. Conclusions The histological findings were distinguishing features of ketamine cystitis and were not present in other painful bladder conditions. Ketamine cystitis afflicts predominantly young patients, with unknown long-term consequences, and requires a strategy to control severe bladder pain in order to remove a dependency on the causative agent. Our study indicates that the development of pain in ketamine cystitis is mediated through a specific neurogenic mechanism that may also implicate the urothelium. PMID:24252413

  10. An intrinsic microRNA timer regulates progressive decline in shoot regenerative capacity in plants.

    PubMed

    Zhang, Tian-Qi; Lian, Heng; Tang, Hongbo; Dolezal, Karel; Zhou, Chuan-Miao; Yu, Sha; Chen, Juan-Hua; Chen, Qi; Liu, Hongtao; Ljung, Karin; Wang, Jia-Wei

    2015-02-01

    Plant cells are totipotent and competent to regenerate from differentiated organs. It has been shown that two phytohormones, auxin and cytokinin, play critical roles within this process. As in animals, the regenerative capacity declines with age in plants, but the molecular basis for this phenomenon remains elusive. Here, we demonstrate that an age-regulated microRNA, miR156, regulates shoot regenerative capacity. As a plant ages, the gradual increase in miR156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors leads to the progressive decline in shoot regenerative capacity. In old plants, SPL reduces shoot regenerative capacity by attenuating the cytokinin response through binding with the B-type ARABIDOPSIS RESPONSE REGULATORs, which encode the transcriptional activators in the cytokinin signaling pathway. Consistently, the increased amount of exogenous cytokinin complements the reduced shoot regenerative capacity in old plants. Therefore, the recruitment of age cues in response to cytokinin contributes to shoot regenerative competence. PMID:25649435

  11. Reactive lymphoid hyperplasia of the liver mimicking hepatocellular carcinoma: incidental finding of two cases

    PubMed Central

    Lv, Ang; Liu, Wendy; Qian, Hong-Gang; Leng, Jia-Hua; Hao, Chun-Yi

    2015-01-01

    Reactive lymphoid hyperplasia is a rare disease that forms a mass-like lesion and is characterized by the proliferation of non-neoplastic, polyclonal lymphocytes forming follicles. We recently encountered 2 cases of reactive lymphoid hyperplasia of liver, both of which were asymptomatic and mimicked hepatocellular carcinoma by various imaging modalities. Based on the clinical impression of hepatocellular carcinoma, surgical resections were performed. Microscopic findings revealed that both lesions consisted of an aggregation of lymphocytes consisting of predominantly B-cells, with multiple lymphoid follicles positive for CD10 and negative for bcl-2, consistent with the diagnosis of reactive lymphoid hyperplasia. Polyclonality of both lesions was further confirmed by B cell receptor gene rearrangement study. The incidence of reactive lymphoid hyperplasia in the liver is exceedingly rare, and it is difficult to differentiate such lesions from hepatic malignancies based upon clinical grounds. The clinicopathological findings and literature review of this report may be helpful to improve the clinical decision-making.

  12. Long-term 6-year experience with finasteride in patients with benign prostatic hyperplasia

    Microsoft Academic Search

    Franklin C Lowe; John D McConnell; Perry B Hudson; Nicholas A Romas; Rex Boake; Michael Lieber; Mostafa Elhilali; Jack Geller; Juliane Imperto-McGinely; Gerald L Andriole; Reginald C Bruskewitz; Patrick C Walsh; Georg Bartsch; John N Nacey; Sukrut Shah; Frances Pappas; Amy Ko; Thomas Cook; Elizabeth Stoner; Joanne Waldstreicher

    2003-01-01

    ObjectivesTo summarize the 6-year clinical trial data with finasteride. Benign prostatic hyperplasia is a chronic and progressive disease and therefore assessment of long-term safety and efficacy is important.

  13. Dutasteride: a potent dual inhibitor of 5-alpha-reductase for benign prostatic hyperplasia.

    PubMed

    Rabasseda, Xavier

    2004-08-01

    Dutasteride is a 5alpha-reductase inhibitor that inhibits both types 1 and 2 isozymes of 5alpha-reductase, the enzyme responsible for converting testosterone to dihydrotestosterone in the prostate and other tissues. Dihydrotestosterone is the primary cause of prostate growth and has been proven to play a key role in the development and progression of benign prostatic hyperplasia. Dutasteride has been investigated in three multicenter studies involving 4325 men aged 50 years and above with benign prostatic hyperplasia. Data from these two-year, placebo-controlled studies demonstrated that dutasteride 0.5 mg once daily reduced the risk of both acute urinary retention and the need for benign prostatic hyperplasia-related surgical intervention, improved benign prostatic hyperplasia-related symptoms, decreased prostate volume and increased maximum urinary flow rates with a low incidence of generally mild to moderate adverse events. PMID:15510237

  14. Multfocal micronodular pneumocyte hyperplasia in a Chinese man masquerading as miliary tuberculosis

    PubMed Central

    Sun, Qi; Cai, Hou-Rong; Mark, Eugene J; Miao, Li-Yun; Wu, Hong-Yan; Zhou, Qiang; Chen, Jun; Zhang, Wei; Meng, Fan-Qing

    2015-01-01

    Multifocal Micronodular Pneumocyte Hyperplasia (MMPH) is a rare and histologically, distinctive pulmonary manifestation of tuberous sclerosis complex (TSC) characterized by numerous and extensive proliferative lesions of type II pneumocytes similar to atypical adenomatous hyperplasia (AAH) or non-mucinous adenocarcinoma in situ (AIS). We reported MMPH in a 38-year-old Chinese man with TSC masquerading for 16 months as miliary tuberculosis and discussed the differential diagnosis. PMID:25973120

  15. Experience of Long-Term Afala Treatment in Benign Prostatic Hyperplasia

    Microsoft Academic Search

    A. V. Gudkov

    2009-01-01

    The use of ultralow doses of antibodies to prostate-specific antigen (afala) for long-term treatment of benign prostatic hyperplasia\\u000a in patients with moderate symptoms rapidly and effectively reduces irritative and obstructive symptoms, significantly decreases\\u000a residual urine volume, and increases the rate of urination. Afala therapy is indicated for patients with stage I-II benign\\u000a prostatic hyperplasia of moderately pronounced symptoms.

  16. Focal nodular hyperplasia of the liver: a rational approach to treatment.

    PubMed Central

    Mowat, A P; Gutjahr, P; Portmann, B; Dawson, J L; Williams, R

    1976-01-01

    Focal nodular hyperplasia of the liver in a 3 year old child has been successfully treated by ligation of the hepatic artery branches supplying the lesion. The prominence of the abnormal vasculature in the lesion and its possible aetiological involvement is stressed. Because of the risks of partial hepatectomy, hepatic artery ligation is suggested as the treatment of choice for focal nodular hyperplasia. Images Fig. 1 Fig. 2 PMID:964681

  17. Integration of regenerative shock absorber into vehicle electric system

    NASA Astrophysics Data System (ADS)

    Zhang, Chongxiao; Li, Peng; Xing, Shaoxu; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

    2014-03-01

    Regenerative/Energy harvesting shock absorbers have a great potential to increase fuel efficiency and provide suspension damping simultaneously. In recent years there's intensive work on this topic, but most researches focus on electricity extraction from vibration and harvesting efficiency improvement. The integration of electricity generated from regenerative shock absorbers into vehicle electric system, which is very important to realize the fuel efficiency benefit, has not been investigated. This paper is to study and demonstrate the integration of regenerative shock absorber with vehicle alternator, battery and in-vehicle electrical load together. In the presented system, the shock absorber is excited by a shaker and it converts kinetic energy into electricity. The harvested electricity flows into a DC/DC converter which realizes two functions: controlling the shock absorber's damping and regulating the output voltage. The damping is tuned by controlling shock absorber's output current, which is also the input current of DC/DC converter. By adjusting the duty cycles of switches in the converter, its input impedance together with input current can be adjusted according to dynamic damping requirements. An automotive lead-acid battery is charged by the DC/DC converter's output. To simulate the working condition of combustion engine, an AC motor is used to drive a truck alternator, which also charges the battery. Power resistors are used as battery's electrical load to simulate in-vehicle electrical devices. Experimental results show that the proposed integration strategy can effectively utilize the harvested electricity and power consumption of the AC motor is decreased accordingly. This proves the combustion engine's load reduction and fuel efficiency improvement.

  18. Regenerative thermal oxidation for non-conventional applications

    SciTech Connect

    Gosselin, G.; Gravel, J.J.O.

    1999-07-01

    Regenerative Thermal Oxidation has been applied by Biothermica to treat non-conventional emissions. These emissions include pollutants as VOC, COC, TRS, PAH, PCB, HCl and odors. In the kraft pulping industry, environmental requirements for reduced emissions of total reduced sulfur (TRS) and volatile organic compounds (VOC) from pulping operations are leading to incinerators of high destruction efficiency and thermal performance. The first installation in Canada of a Regenerative Thermal Oxidation (RTO) was placed in service early in 1997 at a kraft pulp mill in the province of Quebec. Tests have shown a TRS reduction of 99.6% with a thermal efficiency of 88.5% in the RTO. It can be considered the best method to comply with the new norms for TRS atmospheric emissions in the pulp and paper industry. In the primary aluminum process, a marked improvement in anode properties can be gained by preparing the paste at high temperature, followed by cooling with a water addition in an intensive mixer. However, the addition of cooling water results in a large increase in the emissions of VOC and PAH which can prejudice the process. A number of emission control processes were evaluated. An improved Regenerative Thermal Oxidation (RTO) unit was installed in a modern aluminum plant in Canada. The emissions of VOCs and PAHs from an EIRICH intensive mixer-cooler were reduced by more than 99.9% while all troublesome deposits in the fumes collection system were eliminated. This enabled the plant to remain well within the emission levels allowed by the environmental authority while enjoying considerable benefits from improved anode qualities. In the asphalt roofing industry, RTO was applied to treat the VOC and COC emissions and several units have been in operation since 1990. In the United States two units were installed in asphalt shingle plants and new features in the process show a VOC and COC reduction of 99%.

  19. Influence of curvature in regenerative cooling system of rocket engine

    NASA Astrophysics Data System (ADS)

    Torres, Y.; Stefanini, L.; Suslov, D.

    2009-09-01

    Thermomechanical loads in rocket engines can be drastically reduced by a reliable cooling system. The regenerative cooling system uses propellants as coolant which flows through milled cooling channels in the chamber walls. Due to centrifugal forces, dynamic secondary motions appear in cooling-channel curvatures, which strongly modify heat transfer. Three-dimensional (3D) numerical calculations have been performed in order to compare this heat flux modification with empirical correlations. Different turbulence models and wall treatments have been tested to develop a complete numerical data base about asymmetrical (concave side) heat transfer in curved cooling channels of rocket engine.

  20. Tissue Engineering and Regenerative Medicine Strategies in Meniscus Lesions

    Microsoft Academic Search

    Helder Pereira; Ana M. Frias; Joaquim Miguel Oliveira; Joao Espregueira-Mendes; Rui Luis Reis

    2011-01-01

    Purpose: The aim of this systematic review was to address tissue\\u000d\\u000a engineering and regenerative medicine (TERM) strategies applied to the\\u000d\\u000a meniscus, specifically (1) clinical applications, indications, results,\\u000d\\u000a and pitfalls and (2) the main trends in research assessed by evaluation\\u000d\\u000a of preclinical (in vivo) studies. Methods: Three independent reviewers\\u000d\\u000a performed a search on PubMed, from 2006 to March 31, 2011, using

  1. An alexandrite regenerative amplifier for water vapor and temperature measurements

    NASA Technical Reports Server (NTRS)

    Thro, P.-Y.; Boesenberg, J.; Wulfmeyer, V.

    1992-01-01

    The Differential Absorption Lidar (DIAL) technique is a powerful method for determining meteorological parameters, but it requires high quality of the laser source: high energy, very narrow bandwidth, high wavelength stability, and spectral purity. Although many efforts have been made to improve the lasers in view of these aspects, a satisfactory solution has not been demonstrated up to now. We describe a regenerative amplifier, using a Ti:sapphire laser as master oscillator and an alexandrite laser as slave amplifier, which is expected to meet the requirements for water vapor concentration and temperature measurements.

  2. NASA Lewis evaluation of Regenerative Fuel Cell (RFC) systems

    NASA Astrophysics Data System (ADS)

    Hagedorn, N. H.; Gonzalez-Sanabria, O. D.; Kohout, L. L.

    1986-09-01

    Evaluation of two regenerative fuel cell (RFC) systems was begun in-house, and under contracts and grants. The passive hydrogen-oxygen RFC offers the possibility of a high-energy density, long-life storage system for geosynchronous Earth orbit missions. The hydrogen-bromine RFC offers the combination of high efficiency and moderate energy density that could ideally suit low Earth orbit missions if successfully developed. Either or both of these systems would be attractive additions to the storage options available to designers of future missions.

  3. Regenerative fuel cells for space and terrestrial use

    NASA Astrophysics Data System (ADS)

    Tillmetz, Werner; Dietrich, Guenther; Benz, Uwe

    Electrolysis, fuel cell, and energy storage technologies are compared and evaluated. The use of a fuel cell and electrolyzer with an immobilized electrolyte is selected as the most promising technique. A comparison of the batteries demonstrates that a RFCS (regenerative fuel cell system) could be a serious competitor in future space activities, especially with increasing power level and energy to be stored. Also, for many terrestrial applications, highly efficient energy storage systems will be of great interest in the near future. Aspects of the terrestrial use of a RFCS are discussed.

  4. Hybrid regenerative fuel cell systems for space applications

    NASA Technical Reports Server (NTRS)

    Saucier, David R.

    1988-01-01

    This paper describes a hybrid regenerative fuel cell (RFC) system for space application, which is made up of an alkaline fuel cell (Space Shuttle fuel cell) and an acid electrolysis unit (solid polymer electrolyte). In the RFC, gas produced from the acid electrolysis unit and water produced by the alkaline fuel cell are repeatedly reacted in the other unit. The results of RFC's tests indicate that the system is feasible in terms of fluid/unit compatibility. In addition, the fuel cell thermal-control system proved capable of controlling fuel cell temperatures throughout long open-circuit periods. Diagrams of the RFC and its subsystems are included.

  5. Status of the Regenerative ECLSS Water Recovery System

    NASA Technical Reports Server (NTRS)

    Bagdigian, Robert M.; Carter, D. Layne; Bedard, John

    2007-01-01

    NASA is developing a regenerative water recovery system (WRS) for deployment on the International Space Station (ISS), The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). The WPA has been developed by Hamilton Sundstrand Space Systems International (HSSSI), Inc., while the UPA has been developed by the Marshall Space Flight Center (MSFC). Test and verification activities have been completed for the system and planning for launch and on-orbit activation is underway. This paper summarizes the status as of April 2007 and describes some of the technical challenges encountered and lessons learned over the past year.

  6. TMJ function after partial condylectomy in active mandibular condylar hyperplasia

    PubMed Central

    Olate, Sergio; Martinez, Felipe; Uribe, Francisca; Pozzer, Leandro; Cavalieri-Pereira, Lucas; de Moraes, Marcio

    2014-01-01

    Condylar hyperplasia is a frequent pathology that causes severe facial asymmetries. The partial condylectomy generally halts the disease. The aim of this research was to examine post-condylectomy TMJ function; 14 patients were included in this study, 6 male and 8 female. The average age was 21 years old. In all, the partial condylectomy was performed with preauricular or endaural access and the osteotomy were performed with drills, saw or an ultrasonic system. The patients were assessed with 3 or more time after surgery and were considering maximum mouth opening, right and left lateralities, presence of pain, noises, alterations in the facial nerve (VII) and esthetic alteration from the scar. The analysis was performed with the visual analog scale (VAS) and with a 7 cm metallic rule. Data analysis was descriptive plus chi-square test considering p value < 0.05 for statistical differences. With an average of 11 month after surgery, the results showed that the open mouth (over 35 mm) and lateralities (average 9 mm for the both right and left side) were normal and without statistical differences between the right or left side. Noise was observed in 3 patients and pain was observed in two patients with level 2 and 1 (VAS score). Scar was not related to problem with patient and the temporal branch of facial nerve was observed with limitations but without problem for patients. It can be concluded that the condylectomy is a safe and effective procedure with low morbidity for patients. PMID:24753777

  7. Impact of molecular genetics on congenital adrenal hyperplasia management.

    PubMed

    Balsamo, A; Baldazzi, L; Menabò, S; Cicognani, A

    2010-09-01

    Congenital adrenal hyperplasia (CAH) is a family of autosomal recessive disorders caused by mutations in genes encoding the enzymes involved in one of the 5 steps of adrenal steroid synthesis or the electron donor P450 oxidoreductase (POR) enzyme. Steroid 21-hydroxylase deficiency (21-OHD), the principal focus of this review, accounts for about 90-95% of all CAH cases, and its biochemical and clinical severity depends on the underlying CYP21A2 gene disruption. Molecular genetic advancements have been achieved in recent years, and the aim of this review is to attempt to highlight its contribution to the comprehension and management of the disease. When possible, we will try to achieve this goal also by providing some results from our personal experience regarding: some aspects of CYP21A2 gene analysis, with basic genotype/phenotype relationships; its crucial role in both genetic counselling and in prenatal diagnosis and treatment in families at risk for 21-OHD; its help in the comprehension of the severity of the disease in patients diagnosed by neonatal screening and possibly treated before an evident salt-loss crisis or before performing adequate blood sampling; its usefulness in the definition of post ACTH 17-hydroxyprogesterone values, discriminating between non-classic, heterozygote and normal subjects; and finally the contribution of genes other than CYP21A2 whose function or dysfunction could influence 21-hydroxylase activity and modify the presentation or management of the disease. PMID:20639616

  8. Congenital adrenal hyperplasia (21-hydroxylase deficiency) without demonstrable genetic mutations.

    PubMed

    Nimkarn, S; Cerame, B I; Wei, J Q; Dumic, M; Zunec, R; Brkljacic, L; Skrabi?, V; New, M I; Wilson, R C

    1999-01-01

    Congenital adrenal hyperplasia (CAH) owing to 21-hydroxylase deficiency (21-OHD) is the most common inherited defect of adrenal steroid biosynthesis. At least 36 mutations in the CYP21 gene, which is mapped to chromosome 6p21.3, have been described. We performed genetic analysis of the CYP21 gene in a patient with classic 21-OHD CAH and her family. The entire exonic coding regions and intronic regions, as well as the -1 kb 5' upstream promoter region, were thoroughly sequenced and analyzed. Despite extensive sequencing, no mutation was found in this 3.7 kb area. The 11beta-hydroxylase defect, closely mimicking the clinical and biochemical phenotype of classic 21-OHD, was excluded by directly sequencing 2.6 kb covering the entire coding of the CYP11B1 gene. Herein we describe a phenotypically and hormonally affected patient with classic simple virilizing 21-OHD CAH who lacks a mutation in the entire CYP21 gene and coding region of the CYP11B1 gene. PMID:9920112

  9. Congenital adrenal hyperplasia and P450 oxidoreductase deficiency.

    PubMed

    Krone, Nils; Dhir, Vivek; Ivison, Hannah E; Arlt, Wiebke

    2007-02-01

    Congenital adrenal hyperplasia (CAH) comprises a group of autosomal recessive disorders, which are usually due to inactivating mutations in single enzymes involved in adrenal steroid biosynthesis. The characteristics of the biochemical and clinical phenotype depend on the specific enzymatic defect. In 21-hydroxylase and 11beta-hydroxylase deficiency only adrenal steroidogenesis is affected, whereas a defect in 3beta-hydroxysteroid dehydrogenase or 17alpha-hydroxylase also involves gonadal steroid biosynthesis. Recently, mutations in the electron donor enzyme P450 oxidoreductase were identified as the cause of CAH with apparent combined 17alpha-hydroxylase and 21-hydroxylase deficiency, thereby illustrating the impact of redox regulation enzymes on steroidogenesis. P450 oxidoreductase deficiency (ORD) has a complex phenotype including two unique features not observed in any other CAH variant, skeletal malformations and severe genital ambiguity in both sexes. Despite invariably low circulating androgens, females with ORD may present with virilized genitalia and mothers may suffer from virilization during pregnancy. This apparently contradictory finding may be explained by the existence of an alternative pathway in human androgen biosynthesis, with important implications for physiology and pathophysiology. This review discusses the biochemical and clinical presentation and the genetic and functional basis of the currently known CAH variants, with a specific focus on ORD. PMID:17223983

  10. Unravelling the molecular basis of micronodular adrenal hyperplasia

    PubMed Central

    Horvath, Anelia; Stratakis, Constantine

    2009-01-01

    Purpose of review This review discusses the molecular basis of micronodular adrenal hyperplasia (MAH). It focuses on the role of genetic defects in cAMP signaling related molecules, namely PRKAR1A, GNAS, PDE11A and PDE8B in the predisposition for tumor formation. It also discusses the involvement of cAMP signaling and related pathways, and their impact on the adrenocortical phenotype formation. Recent findings Molecular defects in the phosphodiesterases (PDE) family are the most recently discovered genetic defects predisposing to various adrenocortical tumor formation. In contrast to GNAS and PRKAR1A, defects in PDE genes are associated more frequently with incomplete penetrance. Summary Recent findings indicate the importance of cAMP signaling for normal adrenocortical functioning and the sensitivity of the adrenal gland to subtle alterations in cAMP levels. Identifying low-penetrance mutations in more than one PDEs in patients with MAH is suggestive for a complementary role of the different PDEs in the adrenal gland, and possible involvement of other members of this gene family in adrenocortical signaling PMID:18438169

  11. Congenital Adrenal Hyperplasia: Classification of Studies Employing Psychological Endpoints

    PubMed Central

    Stout, Stephanie A.; Litvak, Margarita; Robbins, Natashia M.; Sandberg, David E.

    2010-01-01

    Psychological outcomes in persons with congenital adrenal hyperplasia (CAH) have received substantial attention. The objectives of this paper were to (1) catalog psychological endpoints assessed in CAH outcome studies and (2) classify the conceptual/theoretical model shaping the research design and interpretation of CAH-related psychological effects. A total of 98 original research studies, published between 1955 and 2009, were categorized based on psychological endpoints examined as well as the research design and conceptual model guiding analysis and interpretation of data. The majority of studies (68%) investigated endpoints related to psychosexual differentiation. The preponderance of studies (76%) examined a direct relationship (i.e., inferring causality) between prenatal androgen exposure and psychological outcomes. Findings are discussed in relation to the observed imbalance between theoretical interest in the role of prenatal androgens in shaping psychosexual differentiation and a broader conceptual model that examines the role of other potential factors in mediating or moderating the influence of CAH pathophysiology on psychological outcomes in both affected females and males. The latter approach offers to identify factors amenable to clinical intervention that enhance both health and quality of life outcomes in CAH as well as other disorders of sex development. PMID:20976294

  12. Benign prostatic hyperplasia: An overview of existing treatment

    PubMed Central

    Dhingra, Neelima; Bhagwat, Deepak

    2011-01-01

    Benign prostatic hyperplasia (BPH) is the most common condition in aging men, associated with lower urinary tract symptoms (LUTS). A better understanding of the prostate physiology, function, and pathogenesis has led to the development of promising agents, useful in the management of LUTS in men. The specific approach used to treat BPH depends upon number of factors like age, prostrate size, weight, prostate-specific antigen level, and severity of the symptoms. 5?-reductase inhibitors decrease the production of dihydrotestosterone within the prostate, which results in decreased prostate volume, increased peak urinary flow rate, improvement of symptoms, decreased risk of acute urinary retention, and need for surgical intervention. ?1-adrenergic receptor (?1-AR) antagonists decrease LUTS and increase urinary flow rates in men with symptomatic BPH, but do not reduce the long-term risk of urinary retention or need for surgical intervention. Clinical efficacy of either 5?-reductase inhibitor or ?1-AR antagonist has been further improved by using combination therapy; however, long-term outcomes are still awaited. Many more potential new therapies are under development that may improve the treatment of BPH. This article gives a brief account of rationale and efficacy of different treatment options presently available in the management of BPH. PMID:21455413

  13. Hypokalaemia in a hyperthyroid domestic shorthair cat with adrenal hyperplasia.

    PubMed

    Fryers, Adele; Elwood, Clive

    2014-10-01

    A 13-year-old female domestic shorthair cat presented with polyphagia and weight loss. Marked systolic hypertension was found on examination. Elevated total thyroxine levels confirmed hyperthyroidism, and hypokalaemia was also documented. A euthyroid state and normotension were achieved following 4 weeks of treatment with carbimazole and amlodipine. Despite potassium supplementation, the hypokalaemia worsened. Abdominal ultrasonography revealed left adrenomegaly. Plasma aldosterone concentrations were initially in the lower half of the reference interval and, when repeated 2 months later, were undetectable. Urea and creatinine remained in the lower half of the reference interval throughout treatment, and urine specific gravity suggested good urine concentrating ability. The fractional excretion of potassium confirmed a renal source of potassium loss. Blood gas analysis was unremarkable. It was theorised that an aldosterone precursor was causing signs of mineralocorticoid excess and undetectable plasma aldosterone levels. Treatment with an aldosterone receptor antagonist successfully increased the serum potassium concentration. Owing to difficulties administering medication and associated effects on life quality the cat was euthanased. Adrenal hyperplasia was apparent on post-mortem histopathology. PMID:24621855

  14. Photoselective vaporization of the prostate for treating benign prostatic hyperplasia.

    PubMed

    Chughtai, Bilal; Te, Alexis

    2011-09-01

    Benign prostatic hyperplasia (BPH) commonly occurs in older men. Traditionally, the gold standard for treatment of BPH has been the electrocautery-based transurethral resection of the prostate (TURP). However, TURP is associated with several complications and side effects. Therefore, there is an interest in a number of emerging minimally invasive therapies as alterative treatment options. Advancements in laser technology have led to the introduction of photoselective vaporization of the prostate (PVP) using the GreenLight™ laser (American Medical Systems, MN, USA). PVP uses a 532-nm laser to remove obstructive prostatic tissue. The laser energy is selectively absorbed by hemoglobin in the prostate tissue and results in tissue destruction. The GreenLight PVP laser system has gone through several evolutions from the original 60-W laser to the most recent 180-W GreenLight XPS™ system with MoXy™ Fiber. With the increasing use of GreenLight to treat BPH, there is a need to review the evidence regarding its use. We review the clinical implications of using GreenLight laser therapy for the treatment of BPH. PMID:22026624

  15. Acupuncture for benign prostatic hyperplasia: a systematic review protocol

    PubMed Central

    Zhang, Wei; Yu, Jinna; Liu, Zhishun; Peng, Weina

    2015-01-01

    Introduction Benign prostatic hyperplasia (BPH) is a non-malignant enlargement of the prostate commonly encountered in older men. BPH has been treated with acupuncture inside and outside China, but its effects are uncertain. This review aims to assess the efficacy and safety of acupuncture therapy for BPH. Methods and analysis Seven databases will be searched from their inception: the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Chinese Biomedical Database, the China National Knowledge Infrastructure, the VIP Database and Wanfang Database. Randomised controlled clinical trials using acupuncture to treat BPH will be included. Outcome measures included urological symptom scores, urodynamic measures and quality-of-life scales. Adverse events will be assessed and reported for safety evaluation. Study selection and data extraction will be performed by two independent reviewers. Quality assessment (assessment of risk of bias) and data synthesis will be implemented using Review Manager (RevMan) software (V.5.2.3). Ethics and dissemination Ethical approval is not necessary because this systematic review will not include specific patient data. Updates will be conducted if there is enough new evidence that may cause any change in review conclusions. Trial registration number PROSPERO CRD42014013645. PMID:25838507

  16. What do we know about phytotherapy of benign prostatic hyperplasia?

    PubMed

    Allkanjari, Olta; Vitalone, Annabella

    2015-04-01

    Benign prostatic hyperplasia (BPH) is one of the most common urological diseases in aging men. Because of its long latency, BPH is a good target for prevention. The aim of the study has been to review the various options of treatment, currently available, in the field of phytotherapy. Watchful waiting, pharmacological therapy, and surgery are also helpful, depending on the severity of the disease. Although drug therapy (alpha1-blockers, 5alpha-reductase inhibitors) and surgery (prostatectomy, transurethral resection, etc.) seem to be most effective for patients with moderate-severe BPH, herbal medicines (i.e., Serenoa repens, Pygeum africanum, Urtica dioica) are also commonly used in patients with mild-moderate symptoms. On the basis of preclinical studies several mechanisms of action have been postulated, including 5alpha-reductase inhibition, alpha-adrenergic antagonism, dihydrotestosterone and estrogen receptor inhibition. Randomized clinical trials indicate significant efficacy in improving urinary symptoms and mild adverse effects for some phytotherapeutic agents, while further clinical evidence is needed for others (e.g., Epilobium spp., Secale cereale, Roystonea regia). Healthcare professionals should be constantly informed about BPH phytotherapy, taking into account the risk/benefit profile of the use of medicinal plants in the management of BPH. PMID:25703069

  17. Management of benign prostatic hyperplasia: role of phosphodiesterase-5 inhibitors.

    PubMed

    Gacci, M; Carini, M; Salvi, M; Sebastianelli, A; Vignozzi, L; Corona, G; Maggi, M; McVary, K T; Kaplan, S A; Oelke, M; Serni, S

    2014-06-01

    Several studies have highlighted a strong association between benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) and erectile dysfunction (ED), particularly in elderly men. Many epidemiological trials, such as in vitro and in vivo studies, have reported the emerging role of metabolic syndrome, including abdominal obesity, impaired glucose metabolism, hypertriglyceridemia, low high-density lipoprotein cholesterol, and hypertension, in the development and progression of urinary and sexual symptoms. Moreover, many authors have focused their studies on the identification of all the shared pathogenetic mechanisms of LUTS/BPH and ED, including alteration of cyclic guanosine monophosphate and RhoA-ROCK pathways or vascular and neurogenic dysfunction. All these are potential targets for proposed phosphodiesterase type 5 inhibitors (PDE5-Is). Therefore, several trials have recently been designed to evaluate the role of PDE5-Is alone or in combination with conventional treatment for BPH, such as ?-adrenergic blockers, in men affected by LUTS/BPH, with or without ED. Different PDE5-Is are in clinical use worldwide and currently six of them are licensed for the oral treatment of ED. All these compounds differ in pharmacokinetic factors, with influence on drug action, and subsequently in the overall safety and efficacy profile. PMID:24811735

  18. Clinical and molecular review of atypical congenital adrenal hyperplasia.

    PubMed

    Sahakitrungruang, Taninee

    2015-03-01

    Congenital adrenal hyperplasia (CAH) is one of the most common inherited metabolic disorders. It comprises a group of autosomal recessive disorders caused by the mutations in the genes encoding for steroidogenic enzymes that involved cortisol synthesis. More than 90% of cases are caused by a defect in the enzyme 21-hydroxylase. Four other enzyme deficiencies (cholesterol side-chain cleavage, 17?-hydroxylase [P450c17], 11?-hydroxylase [P450c11?], 3?-hydroxysteroid dehydrogenase) in the steroid biosynthesis pathway, along with one cholesterol transport protein defect (steroidogenic acute regulatory protein), and one electrontransfer protein (P450 oxidoreductase) account for the remaining cases. The clinical symptoms of the different forms of CAH result from the particular hormones that are deficient and those that are produced in excess. A characteristic feature of CAH is genital ambiguity or disordered sex development, and most variants are associated with glucocorticoid deficiency. However, in the rare forms of CAH other than 21-hydroxylase deficiency so-called "atypical CAH", the clinical and hormonal phenotypes can be more complicated, and are not well recognized. This review will focus on the atypical forms of CAH, including the genetic analyses, and phenotypic correlates. PMID:25883920

  19. Therapy monitoring in congenital adrenal hyperplasia by dried blood samples.

    PubMed

    Wieacker, Isabelle; Peter, Michael; Borucki, Katrin; Empting, Susann; Roehl, Friedrich-Wilhelm; Mohnike, Klaus

    2015-07-01

    Careful monitoring of the therapy is crucial for patients with congenital adrenal hyperplasia (CAH) in order to prevent the effects of increased androgen production as well as life-threatening salt-wasting crisis. The key metabolite, 17?-hydroxyprogesterone (17-OHP) can be detected in serum, saliva or dried blood. In clinical practice there are challenges due to discomfort of venous blood sampling and complicated retrieval of saliva during infancy. Furthermore, the immunoassay method is limited in its specificity due to cross-reactions. In this observational study we prospectively examined over a period of 5 years, 20 patients with CAH due to 21-hydroxylase deficiency using standard immunoassays for serum samples (radioimmunoassay and enzyme immunoassay) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) in dried blood spots. Bland-Altman plots show goodness of agreement between both the methods for the desirable therapeutic concentration range of 17-OHP. LC-MS/MS is characterized by a high accuracy in the therapeutic concentration range of 17-OHP <100 nmol/L (r=0.91). Dried blood samples are convenient and reliable specimen for 17-OHP measured by LC-MS/MS. This method could be used for home monitoring of hydrocortisone replacement therapy both in salt-waster and simple virilizer CAH. PMID:25781526

  20. Androgen Receptor Roles in the Development of Benign Prostate Hyperplasia

    PubMed Central

    Izumi, Kouji; Mizokami, Atsushi; Lin, Wen-Jye; Lai, Kuo-Pao; Chang, Chawnshang

    2014-01-01

    Benign prostate hyperplasia (BPH) is a major cause of lower urinary tract symptoms, with an increased volume of transitional zone and associated with increased stromal cells. It is known that androgen/androgen receptor (AR) signaling plays a key role in development of BPH, and that blockade of this signaling decreases BPH volume and can relieve lower urinary tract symptoms, but the mechanisms of androgen/AR signaling in BPH development remain unclear, and the effectiveness of current drugs for treating BPH is still limited. The detailed mechanisms of androgen/AR signaling need to be clarified, and new therapies are needed for better treatment of BPH patients. This review focuses on roles of AR in epithelial and stromal cells in BPH development. In epithelial cells, AR may contribute to BPH development via epithelial cell–stromal cell interaction with alterations of epithelial–mesenchymal transition, leading to proliferation of stromal cells. Data from several mouse models with selective knockout of AR in stromal smooth-muscle cells and/or fibroblasts indicate that the AR in stromal cells can also promote BPH development. In prostatic inflammation, AR roles in infiltrating macrophages and epithelial and stromal cells have been linked to BPH development, which has led to discovery of new therapeutic targets. For example, targeting AR with the novel AR degradation enhancer, ASC-J9 offers a potential therapeutic approach against BPH development. PMID:23570837

  1. Clonal analysis of focal nodular hyperplasia of the liver.

    PubMed Central

    Gaffey, M. J.; Iezzoni, J. C.; Weiss, L. M.

    1996-01-01

    Recent evidence suggests that focal nodular hyperplasia of the liver (FNH) may represent a hyperplastic response to a vascular malformation, but the precise etiology remains unclear. We performed a clonal analysis of ten FNHs from nine patients by patterns of X chromosome inactivation. DNA isolated from paraffin-embedded specimens was subjected to polymerase chain reaction amplification for a highly polymorphic region of the human androgen receptor gene (HUMARA). Predigestion of tumor DNA with the methylation-sensitive, restriction enzyme HpaII allowed for selective amplification of the methylated (inactivated) allele. Of the nine patients analyzed, seven were heterozygous for the HUMARA polymorphism and informative for analysis. One informative patient had two lesions, for a total of eight FNHS. Amplification of lesional DNA after HpaII digestion demonstrated clonality in six of the eight informative cases. Paired tissue samples from different lesional areas were available in four of the six FNHs with evidence of clonality. In three of the four cases, DNA extracted from the two tissue samples showed both evidence of clonality and an identical pattern of X chromosome inactivation. In the remaining case, one sample showed evidence of clonality whereas the other was nonclonal. Three hepatic adenomas from two informative patients were also analyzed for comparative purposes, all of which showed evidence of clonality after HpaII digestion. The current study illustrates that most cases of FNH show a uniform pattern of X chromosome inactivation consistent with clonality. Images Figure 1 Figure 2 Figure 3 PMID:8644851

  2. Clinical and molecular review of atypical congenital adrenal hyperplasia

    PubMed Central

    2015-01-01

    Congenital adrenal hyperplasia (CAH) is one of the most common inherited metabolic disorders. It comprises a group of autosomal recessive disorders caused by the mutations in the genes encoding for steroidogenic enzymes that involved cortisol synthesis. More than 90% of cases are caused by a defect in the enzyme 21-hydroxylase. Four other enzyme deficiencies (cholesterol side-chain cleavage, 17?-hydroxylase [P450c17], 11?-hydroxylase [P450c11?], 3?-hydroxysteroid dehydrogenase) in the steroid biosynthesis pathway, along with one cholesterol transport protein defect (steroidogenic acute regulatory protein), and one electrontransfer protein (P450 oxidoreductase) account for the remaining cases. The clinical symptoms of the different forms of CAH result from the particular hormones that are deficient and those that are produced in excess. A characteristic feature of CAH is genital ambiguity or disordered sex development, and most variants are associated with glucocorticoid deficiency. However, in the rare forms of CAH other than 21-hydroxylase deficiency so-called "atypical CAH", the clinical and hormonal phenotypes can be more complicated, and are not well recognized. This review will focus on the atypical forms of CAH, including the genetic analyses, and phenotypic correlates. PMID:25883920

  3. Multifocal adenomatous oncocytic hyperplasia of the parotid gland.

    PubMed

    Kinoshita, Yuichi; Harada, Hiroshi; Kobayashi, Tadao K; Yoshizawa, Katsuhiko; Yuri, Takashi; Takasu, Kosho; Tsubura, Airo; Shikata, Nobuaki

    2014-09-01

    Multifocal adenomatous oncocytic hyperplasia (MAOH) is a non-neoplastic lesion that is classified as oncocytosis. MAOH is a rare entity of the parotid gland and accounts for approximately 0.1% of salivary gland lesions. Here, we report a case of MAOH of the parotid gland. The patient was a 71-year-old woman who presented with discomfort at the left side of her neck. Fine-needle aspiration cytology of the parotid gland revealed a loose sheet-like cluster of round to polygonal cells with granular cytoplasm against a hemorrhagic background. The cells had round to oval, centrally located nuclei with granular chromatin and without distinct nucleoli. Histologically, the lesion was formed of many variable-sized nodules, comprising oncocyte-like cells with small round nuclei and eosinophilic granular cytoplasm that was positive for mitochondrial antibodies. The diagnosis of MAOH is difficult to make by cytology alone, because the findings overlap with those of other oncocytic lesions. In particular, the cytological findings of MAOH have not been sufficiently reported to date. A correlation of cytology and histology was expected. PMID:25580104

  4. The Senescence-Associated Secretory Phenotype Promotes Benign Prostatic Hyperplasia

    PubMed Central

    Vital, Paz; Castro, Patricia; Tsang, Susan; Ittmann, Michael

    2015-01-01

    Benign prostatic hyperplasia (BPH) is characterized by increased tissue mass in the transition zone of the prostate, which leads to obstruction of urine outflow and considerable morbidity in a majority of older men. Senescent cells accumulate in human tissues, including the prostate, with increasing age. Expression of proinflammatory cytokines is increased in these senescent cells, a manifestation of the senescence-associated secretory phenotype. Multiplex analysis revealed that multiple cytokines are increased in BPH, including GM-CSF, IL-1?, and IL-4, and that these are also increased in senescent prostatic epithelial cells in vitro. Tissue levels of these cytokines were correlated with a marker of senescence (cathepsin D), which was also strongly correlated with prostate weight. IHC analysis revealed the multifocal epithelial expression of cathepsin D and coexpression with IL-1? in BPH tissues. In tissue recombination studies in nude mice with immortalized prostatic epithelial cells expressing IL-1? and prostatic stromal cells, both epithelial and stromal cells exhibited increased growth. Expression of IL-1? in prostatic epithelial cells in a transgenic mouse model resulted in increased prostate size and bladder obstruction. In summary, both correlative and functional evidence support the hypothesis that the senescence-associated secretory phenotype can promote the development of BPH, which is the single most common age-related pathology in older men. PMID:24434012

  5. Pelvic ultrasound evaluation for benign prostatic hyperplasia: prediction of obstruction.

    PubMed

    Rukstalis, Daniel B

    2014-05-01

    Global improvements in water quality, management of infectious diseases, and other medical therapeutics have resulted in a growing population of healthy aging men. One obligate anatomic consequence of aging for these men is the development of benign prostatic hyperplasia (BPH) with secondary bladder outlet obstruction. Although the voiding symptoms associated with the change in bladder health over time predominantly impact the quality of a man's daily experience, there are also significant medical consequences of BPH that require intervention. It is a challenge to distinguish men who are at risk for these medical consequences from the much larger population of older men with voiding symptoms (lower urinary tract symptoms, LUTS). A variety of national guidelines have been developed to establish a diagnostic paradigm for meeting this challenge, but all suffer from inadequate sensitivity for the early identification of men at risk for permanent bladder injury. It is likely that the application of a thorough pelvic ultrasound designed to identify the pertinent anatomic aspects of both the bladder and prostate will improve the sensitivity of these diagnostic paradigms, with subsequent improvement in the outcomes for men with BPH/LUTS. PMID:24658830

  6. Outline of JUA clinical guidelines for benign prostatic hyperplasia.

    PubMed

    Homma, Yukio; Gotoh, Momokazu; Yokoyama, Osamu; Masumori, Naoya; Kawauchi, Akihiro; Yamanishi, Tomonori; Ishizuka, Osamu; Seki, Narihito; Kamoto, Toshiyuki; Nagai, Atsushi; Ozono, Seiichiro

    2011-11-01

    The Japanese Urological Association has developed Clinical Guidelines for Benign Prostatic Hyperplasia (BPH) for men with suspected BPH, which have been abridged and translated into English. This article is a shortened version of the English translation. The Guidelines were formulated on the basis of evidence retrieved from the PubMed database between 1995 and 2009, as well as other relevant sources. The target patients of these Guidelines are men with suspected BPH, and the target users are urologists. A mandatory assessment should include a medical history, a physical examination, the completion of symptom and quality of life questionnaires, urinalysis, prostate ultrasonography, measurement of serum prostate specific antigen and postvoid residual urine, and an uroflowmetry. Optional tests include a bladder diary, the measurement of serum creatinine, and upper urinary tract ultrasonography. Care should be taken to not overlook coexisting diseases such as an infection or malignancy that may obscure the diagnosis. Treatment should consist of conservative therapy or the use of medications such as ?(1) -adrenoceptor antagonists, or both. The use of 5?-reductase inhibitors or anticholinergic agents should be considered in patients with an enlarged prostate (>30 mL) or overactive bladder symptoms (overactive bladder symptom score ? 6), respectively. Surgical intervention is indicated when non-surgical treatments fail to provide sufficient symptomatic relief and bladder outlet obstruction is highly suspected. PMID:22050351

  7. Micro and bulk analysis of prostate tissues classified as hyperplasia

    NASA Astrophysics Data System (ADS)

    Kwiatek, W. M.; Bana?, A.; Bana?, K.; Cinque, G.; Dyduch, G.; Falkenberg, G.; Kisiel, A.; Marcelli, A.; Podgórczyk, M.

    2007-07-01

    BPH (Benign Prostatic Hyperplasia) is the most common benign neoplasm (non cancerous enlargement of the prostate gland), whose prevalence increases with age. The gland, when increased in size, exerts pressure on the urethra, causing obstruction to urine flow. The latter may result in severe urinary tract and kidney conditions. In this work prostate samples from patients diagnosed with BPH were analyzed using synchrotron radiation. Micro-analysis of the hyperplastic samples was carried out on the L-beam line at HASYLAB, DESY (Germany), while bulk analysis on selected samples was performed at the DRX2 beamline at LNF, Frascati (Italy). Microanalysis with a mono-energetic beam 15 ?m in diameter confirmed that concentrations of certain elements, such as S, Mn, Cu, Fe and Zn, are good indicators of pathological disorders in prostate tissue that may be considered effective tracers of developing compliant. The concentrations of Mn, Cu, Fe and Zn are higher in hyperplastic tissues, as compared to normal ones, while for sulphur the opposite is observed. Additionally, Fe and S K-edge XANES (X-ray Absorption Near Edge Structure) spectroscopy experiments were carried out in order to determine the chemical speciation of these elements in our samples.

  8. Suppression of benign prostate hyperplasia by Kaempferia parviflora rhizome

    PubMed Central

    Murata, Kazuya; Hayashi, Hirotaka; Matsumura, Shinichi; Matsuda, Hideaki

    2013-01-01

    Background: Kaempferia parviflora rhizome is used as a folk medicine in Thailand for the treatment of various symptoms. In the present study, the inhibitory activities of extract from K. parviflora rhizome against 5?-reductase (5?R) were subjected. Furthermore, the effects of the extract from K. parviflorar hizome in benign prostate hyperplasia (BPH) were studied using the model mice. Materials and Methods: Preparations of extracts from the rhizomes of K. parviflora, Curcuma zedoaria and Zingiber officinale, and methoxyflavones isolated from K. parviflora was used for 5?R inhibition assay. The effects of K. parviflora extract on growth suppression for the prostates and seminal vesicles were performed based on the Hershberger's method. The K. parviflora extract was administered to castrated mice for 14 days. Results: K. parviflora extract showed more potent inhibitory activity on 5?R than C. zedoaria and Z. officinale extracts. The active principles were identified as 3,5,7,3’,4’-pentamethoxyflavone and 5,7,3’,4’-tetramethoxyflavone by activity guided fractionation. Furthermore, K. parviflora extract suppressed the weights of prostates and seminal vesicles in BPH model rats by daily administration for 14 days. Conclusion: These results indicate that K. parviflora extract can be a promising agent for the treatment of BPH. PMID:24174827

  9. Hepatic focal nodular hyperplasia with congenital portosystemic shunt.

    PubMed

    Cho, Yuki; Shimono, Taro; Morikawa, Hiroyasu; Shintaku, Haruo; Tokuhara, Daisuke

    2014-12-01

    Hepatic focal nodular hyperplasia (FNH) is a rare benign tumor in children. Vascular anomalies have been identified as pathological features of FNH, but the etiology remains unclear. We describe a rare case including the time course of formation of hepatic FNH in response to congenital portosystemic shunt (PSS). A 4-month-old girl was identified on newborn mass screening to have hypergalactosemia, but no inherited deficiencies in galactose-metabolizing enzymes were found. Ultrasonography and per-rectal portal scintigraphy showed intrahepatic PSS of the right lobe as a cause of the hypergalactosemia. At age 12 months, the patient had elevated hepatic enzymes and small hypoechoic hepatic lesions around the shunt. On abdominal contrast-enhanced ultrasonography spoke-wheel sign and central stellate scar were seen, which are typical features of hepatic FNH without biopsy. Congenital intrahepatic PSS should be evaluated on abdominal contrast-enhanced ultrasonography and observed over time because of its potential to develop into hepatic FNH. PMID:25521987

  10. Estimation of the untapped regenerative braking energy in urban electric transportation network

    Microsoft Academic Search

    Leonards Latkovskis; L. Grigans

    2008-01-01

    The paper presents an estimation of the reserves of untapped regenerative braking energy in the power supply network of urban electric transport. The estimation is made by a method based on probabilistic principles, transport timetable and measured power diagrams. The amount of unused regenerative energy is calculated for two substations in the electric transport network in Riga, with power measurement

  11. Analysis of low temperature solar thermal electric generation using regenerative Organic Rankine Cycle

    Microsoft Academic Search

    Gang Pei; Jing Li; Jie Ji

    2010-01-01

    The innovative configuration of low temperature solar thermal electric generation with regenerative Organic Rankine Cycle (ORC) is designed, mainly consisting of small concentration ratio compound parabolic concentrators (CPC) and the regenerative ORC. Advantages of the innovative configuration such as effectively reducing heat transfer irreversibility and permitting the use of thermal storage with phase change materials (PCMs) are outlined. The numerical

  12. The Salvador\\/Warts\\/Hippo pathway controls regenerative tissue growth in Drosophila melanogaster

    Microsoft Academic Search

    Felix A. Grusche; Joffrey L. Degoutin; Helena E. Richardson; Kieran F. Harvey

    2011-01-01

    During tissue regeneration, cell proliferation replaces missing structures to restore organ function. Regenerative potential differs greatly between organs and organisms; for example some amphibians can regrow entire limbs whereas mammals cannot. The process of regeneration relies on several signaling pathways that control developmental tissue growth, and implies the existence of organ size-control checkpoints that regulate both developmental, and regenerative, growth.

  13. A short-cut optimization of the swept volume ratio for regenerative cycles [of heat engines

    Microsoft Academic Search

    B. Thomas; H. D. Kuhl; S. Schulz

    1989-01-01

    A short-cut method for the optimization of the swept volume ratio based on isothermal analysis is presented. A generalized Beale number is derived as an optimization criterion for various regenerative cycles. Results are presented for three cycles: the Stirling cycle, the Vuilleumier cycle, and a third regenerative cycle that is introduced here. The results are verified by a generalized adiabatic

  14. Regenerative fuel cells for energy storage: efficiency and weight trade-offs

    Microsoft Academic Search

    F. Barbir; T. Molter; L. Dalton

    2005-01-01

    In optimizing regenerative fuel cell systems for a given application, the operating efficiency of both the fuel cell and electrolyzer may be traded against the stack mass. Both efficiency and mass are important characteristics for energy storage, particularly for aerospace applications. This paper reports the results of a trade-off study conducted to optimize the design of regenerative fuel cell systems

  15. Regenerative fuel cell energy storage system for a low Earth orbit space station

    Microsoft Academic Search

    R. E. Martin; J. Garow; K. B. Michaels

    1984-01-01

    Results of a study to define the characteristics of a regenerative fuel cell energy storage system for a large space station operating in low earth orbit (LEO) are presented. The regenerative fuel cell system employs an alkaline electrolyte fuel cell with the option of employing either an alkaline or a solid polymer electrolyte electrolyzer.

  16. Application of regenerative fuel cells for space energy storage - A comparison to battery systems

    Microsoft Academic Search

    K. Bolwin

    1992-01-01

    A major advantage of regenerative fuel cells compared with battery systems arises from the decoupling of their rated power and their capacity, which determines the storage system. The mass of battery systems is related to the energy stored, whereas the masses of regenerative fuel cells systems are mainly determined by their rated power. On the other hand, average power and

  17. Engineering model system study for a regenerative fuel cell: Study report

    Microsoft Academic Search

    B. J. Chang; F. H. Schubert; A. J. Kovach; R. A. Wynveen

    1984-01-01

    Key design issues of the regenerative fuel cell system concept were studied and a design definition of an alkaline electrolyte based engineering model system or low Earth orbit missions was completed. Definition of key design issues for a regenerative fuel cell system include gaseous reactant storage, shared heat exchangers and high pressure pumps. A power flow diagram for the 75

  18. Regenerative fuel cell energy storage system for a low Earth orbit space station

    SciTech Connect

    Martin, R.E.; Garow, J.; Michaels, K.B.

    1984-08-01

    Results of a study to define the characteristics of a regenerative fuel cell energy storage system for a large space station operating in low earth orbit (LEO) are presented. The regenerative fuel cell system employs an alkaline electrolyte fuel cell with the option of employing either an alkaline or a solid polymer electrolyte electrolyzer.

  19. A new thermoeconomic approach and parametric study of an irreversible regenerative Brayton refrigeration cycle

    Microsoft Academic Search

    S. K. Tyagi; G. M. Chen; Q. Wang; S. C. Kaushik

    2006-01-01

    The detailed parametric study of an irreversible regenerative Brayton refrigerator cycle using the new thermoeconomic approach is presented in this paper. The external irreversibility is due to finite temperature difference between the cycle and the external reservoirs while the internal irreversibilities are due to the nonisentropic compression and expansion processes and the regenerative loss. The thermoeconomic objective function defined as

  20. Resampled Regenerative Estimators JAMES M. CALVIN, New Jersey Institute of Technology

    E-print Network

    Nakayama, Marvin K.

    multiple regenerative sequences. The esti- mators are obtained by resampling trajectories without with the semi-regenerative estimator. We show that when estimating the second moment of a cycle reward, the semi]: Probabilistic algorithms (including Monte Carlo) General Terms: Performance, Theory Additional Key Words

  1. PERFORMANCE AND ANALYSIS OF CHOPPER FED D.C. SEPARATELY EXCITED MOTOR UNDER REGENERATIVE BRAKING

    Microsoft Academic Search

    H. SATPATHI; G. K. DUBEY; L. P. SINGH

    1980-01-01

    A method is presented here to analyse the performance of a separately excited d.c. motor under regenerative braking mode and provides a technique to select the necessary inductance to reduce the ripple in the armature current as well as to eliminate the discontinuous conduction of the armature current and to optimize the regenerative power. The effect of armature reaction and

  2. A neural network based SRM drive control strategy for regenerative braking in EV and HEV

    Microsoft Academic Search

    Hongwei Gao; Yimin Gao; Mehrdad Ehsani

    2001-01-01

    The characteristics of the regenerative braking in EV and HEV are analyzed in this paper. A neural network based SRM drive control strategy is developed for satisfying the requirements of regenerative braking in EV and HEV when SRM is chosen as the power source of EV and HEV. The energy recovery efficiency of the proposed control strategy is also evaluated

  3. Study on the performance and control of SR machine for vehicle regenerative braking

    Microsoft Academic Search

    Xiaoling Yuan; Yimin Gao; M. Ehsani

    2008-01-01

    A regenerative braking system with simple structure, high efficiency, good performance and easy control is crucial for electric vehicle (EV), hybrid electric vehicle (HEV) and fuel cell vehicle (FCV). SR machine is one of the promising candidates. In this paper, the current and torque performance of a SR machine for application to vehicle regenerative braking has been studied. The relationship

  4. Power Management Strategy with Regenerative Braking For Fuel Cell Hybrid Electric Vehicle

    Microsoft Academic Search

    Yu Shuang; Zhang Junzhi; Wang Lifang

    2009-01-01

    A novel power management strategy based on regenerative braking is proposed to make optimal power distribution between fuel cell system and batteries in order to improve the utility of braking energy and decrease the power loss for fuel cell electric vehicle. With the integrated regenerative braking strategy, the novel control algorithm takes the charging power loss from regenerated energy into

  5. Regenerative-braking sliding mode control of electric vehicle based on neural network identification

    Microsoft Academic Search

    Jianbo Cao; Binggang Cao; Peng Xu; Zhifeng Bai

    2008-01-01

    Aiming at the main problems of electric vehicle (EV): short driving range, short life of batteries, and variation of model parameters, based on constructing the main circuit diagram of the EVpsilas control system, the mathematical model of regenerative-braking process was established, and a novel regenerative-braking controller was designed, which combined neural network (NN) with traditional sliding mode controller (SMC). The

  6. Data-driven fault diagnosis in a hybrid electric vehicle regenerative braking system

    Microsoft Academic Search

    Chaitanya Sankavaram; Bharath Pattipati; Krishna Pattipati; Yilu Zhang; Mark Howell; Mutasim Salman

    2012-01-01

    Regenerative braking is one of the most promising and environmentally friendly technologies used in electric and hybrid electric vehicles to improve energy efficiency and vehicle stability. In this paper, we discuss a systematic data-driven process for detecting and diagnosing faults in the regenerative braking system of hybrid electric vehicles. The process involves data reduction techniques, exemplified by multi-way partial least

  7. 604 OPTICS LETTERS / Vol. 17, No. 8 I April 15, 1992 Cr:LiSrAlF6 regenerative amplifier

    E-print Network

    Ditmire, Todd

    604 OPTICS LETTERS / Vol. 17, No. 8 I April 15, 1992 Cr:LiSrAlF6 regenerative amplifier M. D. Perry-lamp-pumped regenerative amplifier that utilizes the new laser material Cr:LiSrAlF6 is described. The device can be usedSAF regenerative amplifier for tunable and/or ultrashort-pulse amplification. A regenerative am- plifier

  8. High Energy Density Regenerative Fuel Cell Systems for Terrestrial Applications

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.

    1999-01-01

    Regenerative Fuel Cell System (RFCS) technology for energy storage has been a NASA power system concept for many years. Compared to battery-based energy storage systems, RFCS has received relatively little attention or resources for development because the energy density and electrical efficiency were not sufficiently attractive relative to advanced battery systems. Even today, RFCS remains at a very low technology readiness level (TRL of about 2 indicating feasibility has been demonstrated). Commercial development of the Proton Exchange Membrane (PEM) fuel cells for automobiles and other terrestrial applications and improvements in lightweight pressure vessel design to reduce weight and improve performance make possible a high energy density RFCS energy storage system. The results from this study of a lightweight RFCS energy storage system for a remotely piloted, solar-powered, high altitude aircraft indicate an energy density up to 790 w-h/kg with electrical efficiency of 53.4% is attainable. Such an energy storage system would allow a solar-powered aircraft to carry hundreds of kilograms of payload and remain in flight indefinitely for use in atmospheric research, earth observation, resource mapping. and telecommunications. Future developments in the areas of hydrogen and oxygen storage, pressure vessel design, higher temperature and higher- pressure fuel cell operation, unitized regenerative fuel cells, and commercial development of fuel cell technology will improve both the energy density and electrical efficiency of the RFCS.

  9. Tissue engineering and regenerative medicine –where do we stand?

    PubMed Central

    Horch, Raymund E; Kneser, Ulrich; Polykandriotis, Elias; Schmidt, Volker J; Sun, Jiaming; Arkudas, Andreas

    2012-01-01

    Abstract Tissue Engineering (TE) in the context of Regenerative Medicine (RM) has been hailed for many years as one of the most important topics in medicine in the twenty-first century. While the first clinically relevant TE efforts were mainly concerned with the generation of bioengineered skin substitutes, subsequently TE applications have been continuously extended to a wide variety of tissues and organs. The advent of either embryonic or mesenchymal adult stem-cell technology has fostered many of the efforts to combine this promising tool with TE approaches and has merged the field into the term Regenerative Medicine. As a typical example in translational medicine, the discovery of a new type of cells called Telocytes that have been described in many organs and have been detected by electron microscopy opens another gate to RM. Besides cell-therapy strategies, the application of gene therapy combined with TE has been investigated to generate tissues and organs. The vascularization of constructs plays a crucial role besides the matrix and cell substitutes. Therefore, novel in vivo models of vascularization have evolved allowing axial vascularization with subsequent transplantation of constructs. This article is intended to give an overview over some of the most recent developments and possible applications in RM through the perspective of TE achievements and cellular research. The synthesis of TE with innovative methods of molecular biology and stem-cell technology appears to be very promising. PMID:22436120

  10. Johnson Space Center's regenerative life support systems test bed

    NASA Technical Reports Server (NTRS)

    Henninger, Donald L.; Tri, Terry O.; Barta, Daniel J.; Stahl, Randal S.

    1991-01-01

    The Regenerative Life Support System (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for the evaluation of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. When completed, the facility will be comprised of two large scale plant growth chambers, each with approximately 10 m(exp 2) growing area. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), will be capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in Lunar or Martian habitats; the other chamber, the Ambient Pressure Growth Chamber (APGC) will operate at ambient atmospheric pressure. The root zone in each chamber will be configurable for hydroponic or solid state media systems. Research will focus on: (1) in situ resource utilization for CELSS systems, in which simulated lunar soils will be used in selected crop growth studies; (2) integration of biological and physicochemical air and water revitalization systems; (3) effect of atmospheric pressure on system performance; and (4) monitoring and control strategies.

  11. Tissue engineering and regenerative medicine -where do we stand?

    PubMed

    Horch, Raymund E; Kneser, Ulrich; Polykandriotis, Elias; Schmidt, Volker J; Sun, Jiaming; Arkudas, Andreas

    2012-06-01

    Tissue Engineering (TE) in the context of Regenerative Medicine (RM) has been hailed for many years as one of the most important topics in medicine in the twenty-first century. While the first clinically relevant TE efforts were mainly concerned with the generation of bioengineered skin substitutes, subsequently TE applications have been continuously extended to a wide variety of tissues and organs. The advent of either embryonic or mesenchymal adult stem-cell technology has fostered many of the efforts to combine this promising tool with TE approaches and has merged the field into the term Regenerative Medicine. As a typical example in translational medicine, the discovery of a new type of cells called Telocytes that have been described in many organs and have been detected by electron microscopy opens another gate to RM. Besides cell-therapy strategies, the application of gene therapy combined with TE has been investigated to generate tissues and organs. The vascularization of constructs plays a crucial role besides the matrix and cell substitutes. Therefore, novel in vivo models of vascularization have evolved allowing axial vascularization with subsequent transplantation of constructs. This article is intended to give an overview over some of the most recent developments and possible applications in RM through the perspective of TE achievements and cellular research. The synthesis of TE with innovative methods of molecular biology and stem-cell technology appears to be very promising. PMID:22436120

  12. Renal stem cell reprogramming: Prospects in regenerative medicine

    PubMed Central

    Morales, Elvin E; Wingert, Rebecca A

    2014-01-01

    Stem cell therapy is a promising future enterprise for renal replacement in patients with acute and chronic kidney disease, conditions which affect millions worldwide and currently require patients to undergo lifelong medical treatments through dialysis and/or organ transplant. Reprogramming differentiated renal cells harvested from the patient back into a pluripotent state would decrease the risk of tissue rejection and provide a virtually unlimited supply of cells for regenerative medicine treatments, making it an exciting area of current research in nephrology. Among the major hurdles that need to be overcome before stem cell therapy for the kidney can be applied in a clinical setting are ensuring the fidelity and relative safety of the reprogrammed cells, as well as achieving feasible efficiency in the reprogramming processes that are utilized. Further, improved knowledge about the genetic control of renal lineage development is vital to identifying predictable and efficient reprogramming approaches, such as the expression of key modulators or the regulation of gene activity through small molecule mimetics. Here, we discuss several recent advances in induced pluripotent stem cell technologies. We also explore strategies that have been successful in renal progenitor generation, and explore what these methods might mean for the development of cell-based regenerative therapies for kidney disease. PMID:25258667

  13. Johnson Space Center's Regenerative Life Support Systems Test Bed

    NASA Technical Reports Server (NTRS)

    Barta, D. J.; Henninger, D. L.

    1996-01-01

    The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with approximately 11 m2 growing area. The root zone in each chamber is configurable for hydroponic or solid media plant culture systems. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure. The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures. Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design. Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems.

  14. Johnson Space Center's Regenerative Life Support Systems Test Bed.

    PubMed

    Barta, D J; Henninger, D L

    1996-01-01

    The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with approximately 11 m2 growing area. The root zone in each chamber is configurable for hydroponic or solid media plant culture systems. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure. The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures. Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design. Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems. PMID:11538966

  15. Feasibility study of a simple unitized regenerative fuel cell

    NASA Astrophysics Data System (ADS)

    Verma, A.; Basu, S.

    Conventional fuel cells use hydrogen and oxygen as the fuel and oxidant, respectively. Hydrogen and oxygen can be produced through electrolysis of water in an electrochemical cell. A simple unitized regenerative fuel cell (URFC), by combining an electrolyzer and a fuel cell, is constructed to check the feasibility of such a device. In the first cycle, hydrogen and oxygen gases are generated from water containing NaHCO 3 when a given dc voltage is applied across Ni-Co/stainless steel electrodes. A solar photovoltaic cell is also used to provide the power. The generated gases are trapped between their respective electrodes and nylon mesh. In the second cycle, the hydrogen and oxygen gases are used in the same electrochemical cell (fuel cell) to produce electricity under a specific load. The current density and voltage are measured by varying different parameters, e.g., time of electrolysis, magnitude of voltage applied, and electrolyte concentration. An open-circuit voltage (OCV) of 1.3 V is obtained from two regenerative fuel cells in series with a total active electrode area of 300 cm 2. A current density of about 0.5 mA cm -2 is generated using 0.5N NaHCO 3 when 4.5 V is applied for 25 min. A maximum power of 36.5 mW is obtained at 0.21 mA cm -2.

  16. Induced pluripotent stem cells: developmental biology to regenerative medicine.

    PubMed

    Nelson, Timothy J; Martinez-Fernandez, Almudena; Terzic, Andre

    2010-12-01

    Nuclear reprogramming of somatic cells with ectopic stemness factors to bioengineer pluripotent autologous stem cells signals a new era in regenerative medicine. The study of developmental biology has provided a roadmap for cardiac differentiation from embryonic tissue formation to adult heart muscle rejuvenation. Understanding the molecular mechanisms of stem-cell-derived cardiogenesis enables the reproducible generation, isolation, and monitoring of progenitors that have the capacity to recapitulate embryogenesis and differentiate into mature cardiac tissue. With the advent of induced pluripotent stem (iPS) cell technology, patient-specific stem cells provide a reference point to systematically decipher cardiogenic differentiation through discrete stages of development. Interrogation of iPS cells and their progeny from selected cohorts of patients is an innovative approach towards uncovering the molecular mechanisms of disease. Thus, the principles of cardiogenesis can now be applied to regenerative medicine in order to optimize personalized therapeutics, diagnostics, and discovery-based science for the development of novel clinical applications. PMID:20956984

  17. Engineering model system study for a regenerative fuel cell: Study report

    NASA Technical Reports Server (NTRS)

    Chang, B. J.; Schubert, F. H.; Kovach, A. J.; Wynveen, R. A.

    1984-01-01

    Key design issues of the regenerative fuel cell system concept were studied and a design definition of an alkaline electrolyte based engineering model system or low Earth orbit missions was completed. Definition of key design issues for a regenerative fuel cell system include gaseous reactant storage, shared heat exchangers and high pressure pumps. A power flow diagram for the 75 kW initial space station and the impact of different regenerative fuel cell modular sizes on the total 5 year to orbit weight and volume are determined. System characteristics, an isometric drawing, component sizes and mass and energy balances are determined for the 10 kW engineering model system. An open loop regenerative fuel cell concept is considered for integration of the energy storage system with the life support system of the space station. Technical problems and their solutions, pacing technologies and required developments and demonstrations for the regenerative fuel cell system are defined.

  18. Engineering model system study for a regenerative fuel cell: Study report

    NASA Astrophysics Data System (ADS)

    Chang, B. J.; Schubert, F. H.; Kovach, A. J.; Wynveen, R. A.

    1984-09-01

    Key design issues of the regenerative fuel cell system concept were studied and a design definition of an alkaline electrolyte based engineering model system or low Earth orbit missions was completed. Definition of key design issues for a regenerative fuel cell system include gaseous reactant storage, shared heat exchangers and high pressure pumps. A power flow diagram for the 75 kW initial space station and the impact of different regenerative fuel cell modular sizes on the total 5 year to orbit weight and volume are determined. System characteristics, an isometric drawing, component sizes and mass and energy balances are determined for the 10 kW engineering model system. An open loop regenerative fuel cell concept is considered for integration of the energy storage system with the life support system of the space station. Technical problems and their solutions, pacing technologies and required developments and demonstrations for the regenerative fuel cell system are defined.

  19. Improving the efficiency and availability analysis of a modified reheat regenerative Rankine cycle

    SciTech Connect

    Bassily, A.M.

    1999-07-01

    Reheating in a reheat regenerative steam power cycle increases efficiency by increasing the average temperature of heat reception, but also increases the irreversibility of feed water heaters by raising the temperature of the superheated steam used for the regenerative process. This paper introduces some modifications to the regular reheat regenerative steam power cycle that reduce the irreversibility of the regenerative process. An availability analysis of the modified cycle and the regular reheat regenerative cycle as well as a comparison study between both cycles is done. The results indicate that a gain in energy efficiency of up to 2.5% as the steam generator pressure varies is obtained when applying such modifications at the same conditions of pressure, temperature's number of reheating stages, and feed water heaters. The availability analysis showed that such increase in efficiency is due to the reduction of the irreversibility of the regeneration process of the modified cycle.

  20. Development of a co-operative control algorithm during regenerative braking for a fuel cell electric vehicle

    Microsoft Academic Search

    Jiweon Ko; Jungwook Kim; Gaeun Lee; Sunggon Byun; Dongyoon Hyun; Hyunsoo Kim

    2011-01-01

    In this study, a regenerative braking control algorithm was developed for the fuel cell electric vehicle (FCEV) equipped with the front electronic wedge brake (EWB). A regenerative braking control algorithm was proposed for the regenerative braking and friction braking for the front wheels, and for the friction braking for the rear wheels; and a powertrain model of an FCEV composed