Application of research findings and summary of research needs: Bud Britton Memorial Symposium on Metabolic Disorders of Feedlot Cattle.

Science.gov (United States)

Galyean, M L; Eng, K S

1998-01-01

Updated research findings with acidosis, feedlot bloat, liver abscesses, and sudden death syndromes were presented at the Bud Britton Memorial Symposium on Metabolic Disorders of Feedlot Cattle. Possible industry applications include the need to establish guidelines for use of clostridial vaccines in feedlot cattle, further assessment of the relationship between acidosis and polioencephalomalacia, examination of the effects of various ionophores on the incidence of metabolic disorders, and evaluation of the effects of feed bunk management and limit- and restricted-feeding programs on the incidence of metabolic disorders. A multidisciplinary approach among researchers, consulting nutritionists and veterinarians, and feedlot managers will be required for effective progress in research and in the application of research findings. Areas suggested for further research include 1) assessment of feed consumption patterns and social behavior of cattle in large-pen, feedlot settings; 2) evaluation of the relationship between feed intake management systems (feed bunk management programs, limit- and programmed-feeding) and the incidence of metabolic disorders, including delineation of the role of variability in feed intake in the etiology of such disorders; 3) efforts to improve antemortem and postmortem diagnosis, and to establish standardized regional or national epidemiological databases for various metabolic disorders; 4) ascertaining the accuracy of diagnosis of metabolic disorders and determining the relationship of previous health history of animals to the incidence of metabolic disorders; 5) further defining ruminal and intestinal microbiology as it relates to metabolic disorders and deeper evaluation of metabolic changes that occur with such disorders; 6) continued appraisal of the effects of grain processing and specific feed ingredients and nutrients on metabolic disorders, and development of new feed additives to control or prevent these disorders; and 7

The Management of Pemphigus Vulgaris in a Burn Intensive Care Unit: A Case Report and Treatment Review

Science.gov (United States)

2014-10-01

achieving com- plete remission. J Am Acad Dermatol 2011;64:490–4. 10. Martin LK, Werth VP, Villaneuva EV, Murrell DF. A system- atic review of randomized...Cavacini LA, Posner MR. Treatment of pemphigus vulgaris with rituximab and intra- venous immune globulin. N Engl J Med 2006;355:1772–9. 29. Joly P

Teores do óleo essencial de cidrão [Aloysia triphylla (L'Hérit Britton (Verbenaceae] em diferentes horários de colheita e processamentos pós-colheita Lemon verbena's [Aloysia triphylla (L'Hérit Britton (Verbenaceae] essential oil content in different harvest periods and post-harvesting process

Directory of Open Access Journals (Sweden)

Renata da Silva Brant

2009-01-01

Full Text Available Este estudo foi realizado com o objetivo de avaliar o teor do óleo essencial de cidrão [Aloysia triphylla (L´Hérit Britton] em diferentes horários de colheita e processamentos pós-colheita. O delineamento utilizado foi inteiramente casualizado. As colheitas foram realizadas em três horários distintos (8 h, 12 h e 16 h, com três repetições. Os processamentos pós-colheita foram cinco: T1- folhas frescas fragmentadas em 1cm; T2- folhas frescas processadas em liquidificador; T3- folhas frescas inteiras; T4- folhas secas inteiras; T5- folhas secas pulverizadas em moinho, com três repetições. O óleo essencial de cada tratamento foi extraído pela técnica de hidrodestilação, utilizando o aparelho modificado de Clevenger, por uma hora e trinta minutos. Os horários de colheita quando se detectou maior teor de óleo foram 8 h e 16 h. Os maiores teores de óleo essencial foram encontrados em folhas frescas fragmentadas em 1cm, folhas frescas processadas em liquidificador, folhas frescas inteiras e folhas secas inteiras.This study was carried out in order to evaluate the essential oil content of lemon verbena at different harvest times and post-harvest processings. The experimental design used was completely randomized. The harvested material was collected at three different hours (8:00, 12:00 and 16:00 pm, and it was taken three times. In post-harvest processings, three replications and five treatments were us do: 1 cm fresh leaf fragments, blended fresh leaves, whole fresh leaves, whole dry leaves and dry leaves ground in mill. The essential oil was determined in Clevenger's modified apparatus for 1 hour and 30 minutes. The periods of the day that detected high essential oil content were at 8:00 am and 16:00 pm. The high essential oil level was in 1 cm fresh leaf fragments, blender processed fresh leaves, whole fresh leaves and whole dry leaves.

The Rock Pratincole Glareola nuchalis in Tanzania: the first ...

African Journals Online (AJOL)

population (Delany et al. 2009). Britton (1980) mentions only Siguri Falls in the. Selous Game Reserve for Tanzania and while suggesting that it breeds there, no breeding records were admitted in Brown & Britton (1980). Over the last three decades, a number of new observations―including the first breeding record―of this ...

Genomes of foodborne and waterborne pathogens

National Research Council Canada - National Science Library

Fratamico, Pina M; Liu, Yanhong; Kathariou, Sophia

2011-01-01

... of Pathogenic Vibrio cholerae * 85 Salvador Almagro-Moreno, Ronan A. Murphy, and E. Fidelma Boyd 8. Genomics of the Enteropathogenic Yersiniae * 101 Alan McNally, Nicholas R. Thomson, and Brendan W. ...

Continuation of a Postdoctoral Research Associateship Program

Science.gov (United States)

1998-12-01

reperfusion) focal ischemia, but also the differential neuroprotective effects of dextromethorphan (DM) in these methodologies. Use of a Loats Image...Britton, P., Lu, X.-C.M., Lloyd, D., Gribben, S., Loats., and Tortella, F. (1995). Neuroprotective effect of dextromethorphan following transient...Newman, A.H. and Britton, P. (1997). Post-treatment with the novel dextromethorphan (DM) analog AHN649, dose-dependently reduces infarct size following

The Effectiveness of an Interactive Map Display in Tutoring Geography

Science.gov (United States)

1976-08-01

MCIT LG Hanscom Field Bedford, MA 01730 Director, Office of Manpower Utilization Headquarters, Marine Corps (Code MPU ) MCB (Building 2009...Lantz University of Denver Denver Research Institute Industrial Economics Division Denver, CO 80210 Mr. Brian McNally Educational Testing Service

Sixteen-item Anxiety Sensitivity Index: Confirmatory factor analytic evidence, internal consistency, and construct validity in a young adult sample from the Netherlands

NARCIS (Netherlands)

Vujanovic, Anka A.; Arrindell, Willem A.; Bernstein, Amit; Norton, Peter J.; Zvolensky, Michael J.

The present investigation examined the factor structure, internal consistency, and construct validity of the 16-item Anxiety Sensitivity Index (ASI; Reiss Peterson, Gursky, & McNally 1986) in a young adult sample (n = 420)from the Netherlands. Confirmatory factor analysis was used to comparatively

Patient as teacher.

Science.gov (United States)

Kwilosz, Donna M

2005-10-01

The author provides some reflections based on her experiences as a member of Becky's treatment team (see Werth, this issue). She briefly highlights some of the areas that were most important in her work with Becky and others with life-limiting illnesses, including information-seeking, social support, maintaining normalcy, depression and decision-making, nausea and vomiting, post-traumatic stress disorder, and the role of psychotherapy. She ends with her reactions to working with Becky and how Becky touched her personally and professionally.

Decision Processes in Military Moral Dilemmas: The Role of Moral Intensity and Moral Judgment

Science.gov (United States)

2008-12-01

Kohlberg , L. (1969). Stage and sequence: The cognitive-developmental approach to socialization. In D. Goslin (Ed.), Handbook of Socialization Theory and...Research (pp. 347- 380). Chicago, IL: Rand McNally. [30] Kohlberg , L. (1981). The Philosophy of Moral Development (Vol. 1). San Francisco: Harper

Propagação vegetativa de Aloysia triphylla (L'Hér. Britton em função da concentração de AIB e do comprimento das estacas

Directory of Open Access Journals (Sweden)

D Paulus

2014-03-01

Full Text Available A Aloysia triphylla (L'Hér. Britton é uma planta medicinal de porte arbustivo com folhas aromáticas que possuem óleo essencial rico em citral. A crescente demanda da indústria farmacêutica e cosmética pelo óleo essencial de A. triphylla promoveram grande interesse sobre o cultivo dessa espécie. A estaquia é um dos principais métodos de propagação devido à dificuldade em obter sementes, e também pela vantagem dos descendentes serem iguais à planta-matriz. O objetivo do trabalho foi avaliar o efeito de diferentes concentrações de AIB e do comprimento das estacas no enraizamento de estacas de A. triphylla. O experimento foi conduzido em ambiente protegido no período de Novembro de 2010 a Janeiro de 2011. O delineamento experimental foi inteiramente casualizado em esquema fatorial onde os fatores foram cinco concentrações de ácido indol butírico (AIB (mg L-1: 0, 250, 500, 1000 e 1500, e quatro comprimentos de estaca: 4, 6, 8 e 10 cm. As estacas tiveram a base imersa em solução de AIB e foram colocadas para enraizar em substrato comercial Mecplant®. As variáveis analisadas foram: comprimento do sistema radicular, percentagem de estacas enraizadas (%, número de brotações, massa fresca e seca da parte aérea, e massa seca das raízes. Nas condições em que o estudo foi realizado os resultados mostraram que o comprimento das estacas e concentração de AIB afetam o desenvolvimento das estacas, apresentando ajuste quadrático e linear para as variáveis analisadas. As mudas obtidas a partir de estacas com 10 cm e concentração de 1500 mg L-1 de AIB apresentaram a maior percentagem de enraizamento e as maiores médias para o comprimento do sistema radicular, número de brotações, massa fresca e seca da parte aérea.

Characterization of Fiber Optic CMM Probe System

Energy Technology Data Exchange (ETDEWEB)

K.W.Swallow

2007-05-15

This report documents a study completed on the fiber optic probe system that is a part of the Werth optical CMM. This study was necessary due to a lack of documentation from the vendor for the proper use and calibration of the fiber probe, and was performed in support of the Lithographie Galvanoformung Abformung (LIGA) development program at the FM&T. As a result of this study, a better understanding of the fiber optic probe has been developed, including guidelines for its proper use and calibration.

Evaluation of the scope and practice of oral and maxillofacial ...

African Journals Online (AJOL)

2014-11-27

Nov 27, 2014 ... that developed as a result of the need to treat servicemen injured in ... for effective organization of training, health care planning .... Similarly McNally found 5% female applicants to oral and ... maxillofacial surgeons in Australia worked in both private .... Glass ceiling, preference, prejudice or cohort effect?

Lexical Coding vs. Syntactic Marking of Homogeneity

DEFF Research Database (Denmark)

Høeg Müller, Henrik

2014-01-01

entities. However, contrasting with the leading pattern, the so-called HAVE-verbs (Borthen, 2003) actually license Spanish BNs in object position (cf., e.g., Espinal, 2010; Espinal & Mcnally, 2011), viz. Juan tiene perro [Juan has dog]. It is claimed that the occurrence of BNs in these cases is strongly...

Personality, Political Skill, and Job Performance

Science.gov (United States)

Blickle, Gerhard; Meurs, James A.; Zettler, Ingo; Solga, Jutta; Noethen, Daniela; Kramer, Jochen; Ferris, Gerald R.

2008-01-01

Based on the socioanalytic perspective of performance prediction [Hogan, R. (1991). Personality and personality assessment. In M. D. Dunnette, L. Hough, (Eds.), "Handbook of industrial and organizational psychology" (2nd ed., pp. 873-919). Chicago: Rand McNally; Hogan, R., & Shelton, D. (1998). A socioanalytic perspective on job performance.…

47 CFR 27.1208 - BTA service areas.

Science.gov (United States)

2010-10-01

.... Except for incumbent BRS licenses, BRS service areas are Basic Trading Areas (BTAs) or additional service... in places where Rand McNally has not defined BTAs: American Samoa; Guam; Gulf of Mexico Zone A; Gulf of Mexico Zone B; Gulf of Mexico Zone C; Northern Mariana Islands; Mayaguez/Aguadilla-Ponce, Puerto...

78 FR 8166 - Changes in Flood Hazard Determinations

Science.gov (United States)

2013-02-05

...., Chelsea, AL 35043. index.php/alabama/ Mayor, City of shelby-2/. Chelsea, P.O. Box 111, Chelsea, AL 35043... Ellis, Engineer's Office, www.bakeraecom.com/ County (12-04- Chairman, 506 Highway 70, index.php/alabama... McNally, 4800 West 92nd www.bakeraecom.com/ 08-0832P). Mayor, City of Avenue, Westminster, index.php...

47 CFR 27.1231 - Initiating the transition.

Science.gov (United States)

2010-10-01

... Basic Trading Area (BTA). BTAs are based on the Rand McNally 1992 Commercial Atlas & Marketing Guide...; and (C) Specify, if known, the adjacent channel D/U ratio that can be tolerated by any receiver(s) at... database; (F) The bandwidth of each channel or subchannel, the emission type for each channel or subchannel...

Preliminary thoughts on the neurobiology of innate unconscious structures and the psychodynamics of language acquisition.

Science.gov (United States)

Mizen, Susan

2017-11-01

This paper builds upon Britton's recent writing on 'models in the mind', in which he gives an account of preverbal metaphoric structures based on object relations (Britton 2015). These correspond with Jung's theory of innate unconscious structures. These innate models are considered alongside current linguistic theory following Chomsky and post-Chomskyan views about language acquisition. Neuroscience evidence linking language and abstract thinking with structures involved in tool use are presented. The implications of these findings, and our understanding of the relational context within which language, metaphor and abstract thought are acquired, will be discussed along with the failures of symbolization and verbal communication common amongst those with severe narcissistic disorders. © 2017, The Society of Analytical Psychology.

UJI VIABILITAS DAN PERKEMBANGAN SERBUK SARI BUAH NAGA PUTIH (HYLOCEREUS UNDATUS (HAW. BRITTON & ROSE, MERAH (HYLOCEREUS POLYRHIZUS (WEB. BRITTON & ROSE DAN SUPER MERAH (HYLOCEREUS COSTARICENSIS (WEB. BRITTON & ROSE SETELAH PENYIMPANAN

Directory of Open Access Journals (Sweden)

NI KADEK YUNITA SARI

2010-12-01

Full Text Available The aim of the research was to determine pollen viability, pollen tube length and pollen development of white, red and super red dragon fruit after storage at different temperatures and times. The method used to test pollen viability was hanging drop technique and to observe the development of pollen used acetolysis techniques. The results showed viability and pollen tube length of white, red and super red dragon fruit after storage at temperature of 10° C and -20° C for 1, 2 and 3 weeks decreased (66% and 25%, tended to increase (2% after 4 weeks. Viability and pollen tube length decreased (100% after storage at 30° C for 4 weeks. Pollen development of white, red and super red dragon fruit after storage at 30°C, 10°C and -20°C for 1 to 4 weeks showed the majority of pollen consists of uninucleat and binucleat.

Sources of Career Dissatisfaction among Mid-Level Coast Guard Officers.

Science.gov (United States)

1983-06-01

fulfillment than staff managers, with the largest line-staff differences occurring in the esteem and self -actualization need areas; (2) line and staff...of Industrial Psychology and Organizational Behavior, ed. Marvin Dunnette, Chicago: Rand McNally & Co., 1976. Maslow , Abraham H., Motivation and...Personality, New York: Harper and Row, Publishers, 1954. Maslow , Abraham H., "The Study of Man At His Best," Behavioral Science Concepts and

A Trapped Mercury 199 Ion Frequency Standard

Science.gov (United States)

1981-12-01

ing resul t t h a t could possibly be explained by a for tu i t ious cancel la t ion of t w o e f f ec t s : t h e second order doppler...h a t t h e helium cooling is e f f ec t ive . O the r e f f e c t s of t he helium include nar rower l ines and a la rger s ignal indicat...Desaintfuscien, K. Barjllet, J . Viennet, P. Pet i t , and C. Audoin, Appl. Phys. 24, 107 (1981). 4. R, Ifflaender and G. Werth; Metrologia 13, 167 (1977

3-D Cellular Ultrastructure Can Be Resolved by X-ray Microscopy | Center for Cancer Research

Science.gov (United States)

X-ray microscopy (XRM) is more rapid than cryoelectron tomography or super-resolution fluorescence microscopy and could fill an important gap in current technologies used to investigate in situ three-dimensional structure of cells. New XRM methods developed by first author Gerd Schneider, Ph.D., working with James McNally. Ph.D., and a team of colleagues, is capable of revealing full cellular ultrastructure without requiring fixation, staining, or sectioning.

South African Journal of Education - Vol 22, No 4 (2002)

African Journals Online (AJOL)

Analysing the role of ICT in bridging the digital divide amongst learners · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Marlien Herselman, K.G. Britton, 270-274 ...

Centrifugal Compressors, Flow Phenomena and Performance.

Science.gov (United States)

1980-11-01

r2 = 1.975 situated near diffuser exit/ collector entrance. Total temperature measure- ments have been performed at the compressor inlet and exit...non-square mesh is used in a two-dimensional flow calculation. In fact, this term is compounded of the product of a constant coefficient multiplying the...terms of the finite difference equations are evaluated from the zeroth approximation, i.e., the solution of Katsanis and McNally (1), while parabolic

Feasibility Study of a Novel Diet-Based Intervention for Prostate Cancer

Science.gov (United States)

2013-11-01

McNally D, Lee-Jones C, Brown J, Vaughan D. Fear of recurrence and possible cases of anxiety and depression in orofacial cancer patients. International...African-Americans: Relationship of patient and partner self-efficacy to quality of life. Journal of Pain and Symptom Management. 2004;18:433-444...blood. You may faint or become dizzy. You may feel a little pain or discomfort as the needle goes through the skin. Some bleeding or bruising may

78 FR 26032 - Change in Bank Control Notices; Acquisitions of Shares of a Bank or Bank Holding Company

Science.gov (United States)

2013-05-03

..., North Carolina; Frank B. Holding, Sr., Smithfield, North Carolina; Ella Ann Holding, Smithfield, North..., individually and together with Olivia Britton Holding, Raleigh, North Carolina; Frank B. Holding, Sr... Brown Holding, Jr., Raleigh, North Carolina; Frank B. Holding, Sr., Smithfield, North Carolina; Ella Ann...

Adsorptive Cathodic Stripping Voltammetric Determination of Cefoperazone in Bulk Powder, Pharmaceutical Dosage Forms, and Human Urine

Directory of Open Access Journals (Sweden)

Vu Dang Hoang

2013-01-01

Full Text Available The electroreduction behaviour and determination of cefoperazone using a hanging mercury drop electrode were investigated. Cyclic voltammograms of cefoperazone recorded in universal Britton-Robinson buffers pH 3–6 exhibited a single irreversible cathodic peak. The process was adsorption-controlled. Britton-Robinson buffer 0.04 M pH 4.0 was selected as a supporting electrolyte for quantitative purposes by differential pulse and square wave adsorptive cathodic stripping voltammetry. The experimental voltammetric conditions were optimized using Central Composite Face design. A reduction wave was seen in the range from −0.7 to −0.8 V. These voltammetric techniques were successfully validated as per ICH guidelines and applied for the determination of cefoperazone in its single and sulbactam containing powders for injection and statistically comparable to USP-HPLC. They were further extended to determine cefoperazone in spiked human urine with no matrix effect.

[The original German scholarly literature of medieval falconry and the history of its scientific research].

Science.gov (United States)

Giese, Martina

2007-01-01

German scholarly literature (Fachliteratur) of the middle ages devoted to falconry falls into two main categories: Translations, mostly of latin works, and original treatises. After a short survey of falconry in the past, this article will discuss the original treatises and the history of their analysis since the 19th century. In this context it will deal with the research of the following scholars: Joseph von Hammer-Purgstall, Anton von Perger, Ernst von Dombrowski, Hermann Werth, Christoph von Biedermann and--most importantly--Kurt Lindner. The appendix contains the editio princeps of the German Münchener Rezeptar I from the codex unicus, München, Universitätsbibliothek, 80 Cod. ms. 354, fol. 31r-33r (dating from the 15th century).

East African rarities committee report | Fisher | Scopus: Journal of ...

African Journals Online (AJOL)

East African Rarities Committee (EARC) Special Report Species included for East African countries in Britton (1980) which have since been considered unacceptable. East African Rarities Committee Report 2013–2015. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD ...

78 FR 19267 - Change in Bank Control Notices; Acquisitions of Shares of a Bank or Bank Holding Company

Science.gov (United States)

2013-03-29

... indirectly retain voting shares of First-Citizens Bank & Trust Company, both in Raleigh, North Carolina. B... Byrd Street, Richmond, Virginia 23261-4528: 1. Olivia Britton Holding, Raleigh, North Carolina; to... First-Citizens Bank & Trust Company, both in Raleigh, North Carolina. 2. Frank Brown Holding, Jr...

Confined Disposal Facility and Maintenance Dredging of the Les Cheneaux Island Federal Navigation Channels, Michigan.

Science.gov (United States)

1979-01-01

Methylation of mercury at levels > 1 mg/kg has been documented (1,2). Methyl mercury is directly available for bioaccumulation in the food chain. Elevated...White Pine, Pinus strobus L. Red Pine, Pinus resinosa Ait. Sugar Maple, Acer saccharum Marsh Yellow Birch, Betula alleghaniensis Britton Basswood

Dynamic Buffer Capacity in Acid-Base Systems.

Science.gov (United States)

Michałowska-Kaczmarczyk, Anna M; Michałowski, Tadeusz

The generalized concept of 'dynamic' buffer capacity β V is related to electrolytic systems of different complexity where acid-base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton-Robinson buffers, taken as examples.

Dynamic Buffer Capacity in Acid?Base Systems

OpenAIRE

Micha?owska-Kaczmarczyk, Anna M.; Micha?owski, Tadeusz

2015-01-01

The generalized concept of ?dynamic? buffer capacity ? V is related to electrolytic systems of different complexity where acid?base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton?Robinson buffers, taken as examples.

Book Reviews

OpenAIRE

Barlow, Colin; Harvey, D. R.; Lane, S.

1988-01-01

Books Reviewed: The Economics of Oil Palm; Agricultural Policy Formation in the European Community: The Birth of Milk Quotas and CAP Reform by M. Petit, M. de Benedictis, D. Britton, M. de Groot, W. Henrichsmeyer, and F. Lechi; Agriculture's Future: America's Food System by T. L. Wallace

Longevity Chance

Directory of Open Access Journals (Sweden)

Timon Cheng-Yi Liu

2014-03-01

Full Text Available Britton Chance pursued his research and sailing until his death at age 97. His 100th anniversary was memorialized in this paper from longevity viewpoint. His lifelong work was very creative. His life was very colorful. His aging was very successful. He has lived a longevity.

Age and size effects on seed productivity of northern black spruce

Science.gov (United States)

J. N. Viglas; C. D. Brown; J. F. Johnstone

2013-01-01

Slow-growing conifers of the northern boreal forest may require several decades to reach reproductive maturity, making them vulnerable to increases in disturbance frequency. Here, we examine the relationship between stand age and seed productivity of black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) in Yukon Territory and Alaska....

Talking and Learning in Classrooms: An Introduction.

Science.gov (United States)

Barnes, Douglas

1995-01-01

Suggests that the kinds of participation in the classroom conversation that are supported and encouraged by a teacher signals to students what learning is required of them. Introduces the articles in this special issue by discussing the ideas of Jerome Bruner, Lev Vygotsky, James Britton, and Mikhail Bakhtin. (RS)

1 Low sputum smear positive tuberculosis among pulmonary ...

African Journals Online (AJOL)

status of tuberculosis as part of the clinical case definition of AIDS in India. Postgraduate Medical Journal 81, 404–408. Bruchfeld, J., Aderaye, G., Palme, I.B., Bjorvatn, B., Britton, S., Feleke, Y., Källenius, G. & Lindquist, L. (2002) Evaluation of outpatients with suspected pulmonary tuberculosis in a high HIV prevalence ...

Fine and coarse root parameters from mature black spruce displaying genetic x soil moisture interaction in growth

Science.gov (United States)

John E. Major; Kurt H. Johnsen; Debby C. Barsi; Moira Campbell

2012-01-01

Fine and coarse root biomass, C, and N mass parameters were assessed by root size and soil depths from soil cores in plots of 32-year-old black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) from four full-sib families studied previously for drought tolerance and differential productivity on a dry and wet...

DETERMINATION OF SERUM ALBUMIN WITH ...

African Journals Online (AJOL)

The reaction of tribromoarsenazo(TB-ASA) with serum albumin in the presence of emulgent OP was studied by spectrophotometry. In a Britton-Robinson buffer solution at pH 2.9, tribromoarsenazo and bovine serum albumin can immediately form a red compound in the presence of emulgent OP with a maximum absorption ...

El género Bauhinia (Fabaceae, Caesalpinioideae, Cercideae en la península de Yucatán (México, Belice y Guatemala The genus Bauhinia (Fabaceae, Caesalpinioideae, Cercideae in Yucatán Peninsula (Mexico, Belice and Guatemala

Directory of Open Access Journals (Sweden)

Rafael Torres-Colín

2009-08-01

Full Text Available Se presenta información del género Bauhinia, tribu Cercideae en la provincia biótica de la península de Yucatán. Se reconocen 5 especies nativas: Bauhinia divaricata L., B. erythrocalyx Wunderlin, B. jenningsii P. Wilson, B. herrerae (Britton et Rose Standl. et Steyerm. y B. ungulata L., así como 2 introducidas: B. monandra Kurz y B. variegata L. Se presenta una clave para identificación, descripciones morfológicas, mapas de distribución, fotografías de las especies e información de los nombres comunes y uso en la región.General information about the genus Bauhinia in the Yucatán Peninsula Biotic Province is presented. Five native species, B. divaricata L, B. erythrocalyx Wunderlin, B. jenningsii P. Wilson, B. herrerae (Britton et Rose Standl. et Steyerm., B. ungulata L. and 2 exotic species, B. monandra Kurz and B. variegata L., are recognized. Species identification key, morphological descriptions, distribution maps, and photographs are presented. Additional information of common names and uses in the region is included.

Thermal stability of hot-wire deposited amorphous silicon

CSIR Research Space (South Africa)

Arendse, CJ

2006-04-01

Full Text Available , Utrecht, The Nether- lands, 2001. [9] D. Beeman, R. Tsu, M.F. Thorpe, Phys. Rev., B 32 (1985) 874. [10] D.T. Britton, M. Ha¨rting, M.R.B. Teemane, S. Mills, F.M. Nortier, T.N. van der Walt, Appl. Surf. Sci. 116 (1997) 53. [11] P. Willutzki, J. Sto¨rmer...

Spatial and temporal variations of wave height in shelf seas around India

Digital Repository Service at National Institute of Oceanography (India)

SanilKumar, V.; Anoop, T.R.

Science20; 87-92. Dee DP, Uppala SM, Simmons AJ, Berrisford P, Poli P, Kobayashi S, Andrae U, Balmaseda MA, Balsamo G, Bauer P, Bechtold P, Beljaars ACM, van de Berg L, Bidlot J, Bormann N, Delsol C, Dragani R, Fuentes M, Geer AJ, Haimberger L, Healy SB..., Hersbach H, Hólm EV, Isaksen L, Kållberg P, Köhler M, Matricardi M, McNally AP, Monge-Sanz BM, Morcrette J-J, Park B-K, Peubey C, de Rosnay P, Tavolato C, Thépaut J-N, Vitart F (2011) The ERA-Interim reanalysis: configuration and performance of the data...

Bookreview

OpenAIRE

Redactie KITLV

2008-01-01

Marcus Wood; Slavery, Empathy, and Pornography (Lynn M. Festa) Michèle Praeger; The Imaginary Caribbean and Caribbean Imaginary (Celia Britton) Charles V. Carnegie; Postnationalism Prefigured: Caribbean Borderlands (John Collins) Mervyn C. Alleyne; The Construction and Representation of Race and Ethnicity in the Caribbean and the World (Charles V. Carnegy) Jerry Gershenhorn; Melville J. Herskovits and the Racial Politics of Knowledge (Richard Price)...

Lichenological studies in Puerto Rico: history and current status

Science.gov (United States)

Joel A. Mercado-Diaz; Eugenio Santiago-Valentin

2010-01-01

European scientists initiated lichenology in Puerto Rico in the 19th century. Activity of the discipline increased notably on the island during the first three decades of the 20th century, primarily by the field explorations and publications of the New York Botanical Garden scientists and associates (A. A. Heller, N. L. and E. G. Britton, L. W. Riddle), and by the work...

Historia del nombre genérico Escallonia mutis ex L. Fil. Historia del nombre genérico Escallonia mutis ex L. Fil.

Directory of Open Access Journals (Sweden)

Fernández Alonso J. L.

1991-06-01

Full Text Available According with the historical context of the Real Expedición Botánica del Nuevo Reino de Granada (1783-1816, the nomenclatural history of the generic name Escallonia Mutis ex L. fiI. (Grossulariaceae is discussed. The extant misinterpretation concerning the name in the manuscript documentation of the Expedition, is brigthened; four species of diferent  families appear associated to this name in the manuscripts. Type specimens of two species, Escallonia myrtilloides L. fiI. and Dichondra evolvulacea (L. fiI. Britton are located or selected. Dentro del contexto histórico de la Real Expedición Botánica del Nuevo Reino de Granada (1783-1816, se realiza el seguimiento del nombre genérico Escallonia Mutis ex L. fiI. (Grossulariaceae. Se aclara la confusión existente acerca de este nombre en la documentación manuscrita de la Expedición (Archivos de Mutis y Linneo, donde se encuentra asociado a descripciones originales de cuatro especies de diferentes familias. Se localiza y selecciona material tipo de dos de ellas: Escallonia myrtilloides L. fil. Y Dichondra evolvulacea (L. IiI. Britton.

Notes on nesting herons and other birds of interest at Lake ...

African Journals Online (AJOL)

At high water the lake covers some 800 ha along the 520 m elevation contour. Lake Kalemawe is not included in the gazetteer in Britton (1980) and no mention can be traced of it in the bird literature of the 1980s and 1990s although it has been counted by the Tanzania Bird Atlas Project (TBAP) team in the recent past, and ...

The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands.

Science.gov (United States)

Liebherr, James K

2013-01-01

The 101 species of Mecyclothorax Sharp known to inhabit Tahiti Island, French Polynesia are taxonomically revised, including 28 species that are newly described: Mecyclothorax claridgeiae sp. n., Mecyclothorax jeanyvesi sp. n., Mecyclothorax poria sp. n., Mecyclothorax aano sp. n., Mecyclothorax papau sp. n., Mecyclothorax manina sp. n., Mecyclothorax everardi sp. n., Mecyclothorax ramagei sp. n., Mecyclothorax pitohitiensis sp. n., Mecyclothorax curtisi sp. n., Mecyclothorax hoeahiti sp. n., Mecyclothorax ninamu sp. n., Mecyclothorax kokone sp. n., Mecyclothorax paahonu sp. n., Mecyclothorax kayballae sp. n., Mecyclothorax ehu sp. n., Mecyclothorax papuhiti sp. n., Mecyclothorax tuea sp. n., Mecyclothorax taatitore sp. n., Mecyclothorax konemata sp. n., Mecyclothorax arboricola sp. n., Mecyclothorax rahimata sp. n., M. oaoa sp. n., Mecyclothorax maninapopoti sp. n., Mecyclothorax hunapopoti sp. n., Mecyclothorax fefemata sp. n., Mecyclothorax maninamata sp. n., and Mecyclothorax niho sp. n. Mecyclothorax muriauxioides Perrault, 1984 is newly synonymized with Mecyclothorax muriauxi Perrault, 1978. Lectotypes are designated for: Thriscothorax altiusculus Britton, 1938; Thriscothorax bryobius Britton, 1938; Mecyclothorax globosus Britton, 1948: and Mecyclothorax sabulicola Britton, 1948. Dichotomous identification keys augmented by dorsal habitus and male aedeagal photographs are provided to the various species-groups and all included species. The spermatophore of Mecyclothorax papau sp. n. is described, with the ampulla and collar found to correspond dimensionally to the length of the internal sac flagellar plate. Variation among characters of the female reproductive tract is presented for all newly described plus other representative species comprising the radiation. Taxa are assigned to species groups, modified from the classification of G.G. Perrault, based on derived character states polarized using the Australian outgroup taxon Mecyclothorax punctipennis (Mac

The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini of Tahiti, Society Islands

Directory of Open Access Journals (Sweden)

James Liebherr

2013-08-01

Full Text Available The 101 species of Mecyclothorax Sharp known to inhabit Tahiti Island, French Polynesia are taxonomically revised, including 28 species that are newly described: M. claridgeiae sp. n., M. jeanyvesi sp. n., M. poria sp. n., M. aano sp. n., M. papau sp. n., M. manina sp. n., M. everardi sp. n., M. ramagei sp. n., M. pitohitiensis sp. n., M. curtisi sp. n., M. hoeahiti sp. n., M. ninamu sp. n., M. kokone sp. n., M. paahonu sp. n., M. kayballae sp. n., M. ehu sp. n., M. papuhiti sp. n., M. tuea sp. n., M. taatitore sp. n., M. konemata sp. n., M. arboricola sp. n., M. rahimata sp. n., M. oaoa sp. n., M. maninapopoti sp. n., M. hunapopoti sp. n., M. fefemata sp. n., M. maninamata sp. n., and M. niho sp. n. Mecyclothorax muriauxioides Perrault, 1984 is newly synonymized with M. muriauxi Perrault, 1978. Lectotypes are designated for: Thriscothorax altiusculus Britton, 1938; T. bryobius Britton, 1938; Mecyclothorax globosus Britton, 1948: and M. sabulicola Britton, 1948. Dichotomous identification keys augmented by dorsal habitus and male aedeagal photographs are provided to the various species-groups and all included species. The spermatophore of M. papau sp. n. is described, with the ampulla and collar found to correspond dimensionally to the length of the internal sac flagellar plate. Variation among characters of the female reproductive tract is presented for all newly described plus other representative species comprising the radiation. Taxa are assigned to species groups, modified from the classification of G.G. Perrault, based on derived character states polarized using the Australian outgroup taxon Mecyclothorax punctipennis (MacLeay. Much of the species-level diversity on this small Pacific island is partitioned allopatrically over very small distributional ranges. No species is shared between Tahiti Nui and Tahiti Iti, and nearly all species in Tahiti Nui are geographically restricted to one ridgelike massif of that volcano. Cladistically

The Use of Inhibitors of Mechanosensitive Ion Channels as Local Inhibitors of Peripheral Pain

Science.gov (United States)

2015-01-01

80, 061912. Wallace, G. Q. and McNally, E. M. (2009). Mechanisms of muscle degeneration, regeneration, and repair in the muscular dystrophies . Annu...single channel traces.  6  DRG MSCs sensitivity to inflammatory agents:  We have observed that  treatment  of DRG neurons with inflammatory agents affect...indentation induced  phasic currents (Fig. 6). Similar to that reported for Piezo 2 channels after Bradykinin  treatment , we see  an increase in current

Perspectives on Suicide in the Army National Guard

Science.gov (United States)

2013-02-22

challenges.54 Maris , Berman, and Silverman55 offered several reasons for the gender associa- tion with suicide, including that males are more likely to...Person- ality and Individual Differences 48 (2009): 347-50; K. Conner , P. Britton, L. Sworts, and T. E. Joiner, ‘‘Suicide Attempts among Individuals...Theory of Suicide, 2009. 47. R. W. Maris , A. L. Berman, & M. M. Silverman, Comprehensive Textbook of Suicidality (New York, NY: Guilford, 2010). 48

Electrochemical Analysis of Antichemotherapeutic Drug Zanosar in Pharmaceutical and Biological Samples by Differential Pulse Polarography

OpenAIRE

Reddy, Chennupalle Nageswara; ReddyPrasad, Puthalapattu; Sreedhar, NeelamYughandhar

2013-01-01

The electrochemical reduction of zanosar was investigated systematically by direct current polarography, cyclic voltammetry, and differential pulse polarography (DPP). A simple DPP technique was proposed for the direct quantitative determination of anticancer drug zanosar in pharmaceutical formulation and spiked human urine samples for the first time. The reduction potential was −0.28 V versus Ag/AgCl with a hanging mercury drop electrode in Britton-Robinson buffer as supporting electrolyte. ...

Software for Avionics.

Science.gov (United States)

1983-01-01

fonctions gfinbrales et lea uti- litaires fournis en particulier grice 41 UNIX, sont intfigrfs aelon divers points de vue: - par leur accas 41 travers le...Are They Really A Problem? Proceedings, 2nd International Conference On Software Engineering, pp 91-68. Long acCA : IEEE Computer Society. Britton...CD The Hague. Nc KLEINSCIIMIDT, M. Dr Fa. LITEF. Poatfach 774. 7800 Freiburg i. Br., Ge KLEMM, R. Dr FGAN- FFM , D 5 307 Watchberg-Werthhoven. Ge KLENK

Nutrition and Resistance to Climatic Stress; With Particular Reference to Man

Science.gov (United States)

1949-11-01

metabolic rates (DuBois, 1936), which vary at the most by 20 pet. between arctic (Greenland) and tropical ( Java ) environments (equivalent to only...good nutrition." · . VanVeen (1942) calls attention to the low fat consumption in Java , 5 to 12 gms. per day per adult of 50 kgm. consuming 2600...with a possible explanation of hibernation . Am. J. Physiol. 84: 119-131. Britton, S. W. and R. F. Elire. 1945. Age, sex, carbohydrate, adrenal cortex

Voltammetric behavior of sedative drug midazolam at glassy carbon electrode in solubilized systems

OpenAIRE

Jain, Rajeev; Yadav, Rajeev Kumar

2012-01-01

Redox behavior of midazolam was studied at a glassy carbon electrode in various buffer systems, supporting electrolytes and pH using differential pulse, square-wave and cyclic voltammetry. Based on its reduction behavior, a direct differential pulse voltammetric method has been developed and validated for the determination of midazolam in parenteral dosage. Three well-defined peaks were observed in 0.1% SLS, BrittonâRobinson (BR) buffer of pH 2.5. The effect of surfactants like sodium lauryl ...

User requirements for information systems in nuclear medicine

Energy Technology Data Exchange (ETDEWEB)

Todd-Pokropek, A. (University Coll., London (United Kingdom)); Vauramo, E.; Sippo-Tujunen, I. (Helsinki City Health Dept. (Finland)); Cosgriff, P. (Pilgrim Hospital, Boston (UK)); Britton, K. (Saint Bartholomew' s Hospital, London (United Kingdom))

1992-05-01

In the field of COST cooperation (COST = European Cooperation in the Field of Scientific and Technical Research) a project B2 for Quality Assurance in Nuclear Medicine Software has been established. In a memorandum of understanding setting up this project, user requirements were to be defined for the hardware and software used for data acquisition, processing and presentation. A subgroup of the management committee of COST B2 were interested in the Advanced Informatics in Medicine, AIM, task T-734 'Quality Assurance of Medical Software', and the AIM Project 'A 1034', coordinated by Dr. K. Britton, was initiated. The initial drafts of this document were written in Helsinki during 1988-1990, and submitted for comment by the members of the management committee of COST B2. These comments were integrated in the text and this document was finalized by the UK group so as to make it available for international discussion. It is anticipated that, after appropriate international discussion, these User Requirements for Information Systems in Nuclear Medicine will be adopted by the management committee of COST B2 as a COST document. Towards these ends, a working group chaired by Dr Britton, including the British and Finnish teams and Ulrich Noelpp from Switzerland, was appointed by the management committee of COST B2 in April 1990. (Author).

User requirements for information systems in nuclear medicine

International Nuclear Information System (INIS)

Todd-Pokropek, A.; Vauramo, E.; Sippo-Tujunen, I.; Cosgriff, P.; Britton, K.

1992-01-01

In the field of COST cooperation (COST = European Cooperation in the Field of Scientific and Technical Research) a project B2 for Quality Assurance in Nuclear Medicine Software has been established. In a memorandum of understanding setting up this project, user requirements were to be defined for the hardware and software used for data acquisition, processing and presentation. A subgroup of the management committee of COST B2 were interested in the Advanced Informatics in Medicine, AIM, task T-734 'Quality Assurance of Medical Software', and the AIM Project 'A 1034', coordinated by Dr. K. Britton, was initiated. The initial drafts of this document were written in Helsinki during 1988-1990, and submitted for comment by the members of the management committee of COST B2. These comments were integrated in the text and this document was finalized by the UK group so as to make it available for international discussion. It is anticipated that, after appropriate international discussion, these User Requirements for Information Systems in Nuclear Medicine will be adopted by the management committee of COST B2 as a COST document. Towards these ends, a working group chaired by Dr Britton, including the British and Finnish teams and Ulrich Noelpp from Switzerland, was appointed by the management committee of COST B2 in April 1990. (Author)

Oil production at different stages of leaf development in Lippia alba

OpenAIRE

Diego Pandeló; Talita D. Melo; Júnya L. Singulani; Fernanda A. F. Guedes; Marco A. Machado; Cíntia M. Coelho; Lyderson F. Viccini; Marcelo O. Santos

2012-01-01

The aim of this work was to analyze terpene oil production and terpene synthases (TPS) gene expression from leaves at different developmental stages of different chemotypes of Lippia alba (Mill.) N.E. Br. ex Britton & P. Wilson, Verbenaceae. Hydro-distilled essential oil were used for chemical analysis and gene expression of three monoterpene synthase genes called LaTPS12, LaTPS23 and LaTPS25 were used for analyses of gene expression associated to oil production. The putative genes were a...

Bioconcentraciones foliares de elementos minerales en Lippia alba (salvia morada)

OpenAIRE

Schroeder, María A; Burgos, Ángela M

2013-01-01

Introducción: la salvia morada es un subarbusto aromático, que crece de modo espontáneo en América Central y del Sur. Frecuentemente es cultivada en jardines como ornamental, por su intenso aroma y sus propiedades medicinales y culinarias. No se encontraron estudios sobre parámetros nutricionales en esta especie. Objetivos: determinar las bioconcentraciones foliares de elementos minerales en Lippia alba (Mill.) N. E. Br. ex Britton & P. Wilson que crece naturalmente en el bioambiente del nort...

Interakce tenzidů a organických barviv v roztocích II

OpenAIRE

Bukatová, Helena

2010-01-01

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Helena Bukatová Supervisor: Ing. Vladimír Kubíček, CSc. Title of diploma thesis: Interaction of Tensides and Organic Dyes in Solutions II This diploma work is devoted to examination of the aqueous solutions of surfactants and organic dyes in the solution of Britton-Robinson buffer by two spectral methods: UV-VIS absorption spectrophotometry and fluorescence spectroscop...

The United States Air Force in Southeast Asia, 1961-1973: An Illustrated Account,

Science.gov (United States)

1984-01-01

control power and crashed but the only injury center and network throughout the was a sprained ankle. Eventually, the country. In April 1962 the 6-man cadre...18Oct 1970- Pinyerd Unk 624hTcia ihe ig Cal. Warner A...................... Unk-624t aciclFihtrWigBritton 12 Jan 1972 Organized at Karat AB...Major Day escaped into the jungle and began the trek toward South Vietnam. Despite injuries inflict- ed by fragments of a bomb or rocket, he continued

Comparative Study of Portland Cement-based and Zeolite-based Concretes in Terms of Hexavalent Chromium Leaching

Directory of Open Access Journals (Sweden)

Oravec Jozef

2016-12-01

Full Text Available The paper presents the results of the leaching study of Portland cement-based and zeolite-based concretes regarding water soluble hexavalent chromium. Three leaching water media (distilled water, rain water, and Britton-Robinson buffer of various pH values were under investigation. The correlation between pH and leached-out concentrations of chromium was not confirmed. The content of hexavalent water-soluble chromium in leachates of zeolite-based concretes was found to be higher than that in leachates of Portland cement-based samples.

Essential oil constituents from the aerial parts of Perilla frutescens (L.) Britton

NARCIS (Netherlands)

Dung, N.X.; Moi, La Dinh; Cu, Lu'u Dam; Leclercq, P.A.

1995-01-01

The essential oil obtained by steam distn. of the aerial parts of P. frutescens, a plant growing wild in Northwest Vietnam, was analyzed by a combination of GC and GC/MS. More than 50 compds. were detected, of which 25 components (95% of the oil) were identified. The main compds. were limonene

Highly sensitive detection of bovine serum albumin based on the aggregation of triangular silver nanoplates

Science.gov (United States)

Zhang, Ling Ling; Ma, Fang Fang; Kuang, Yang Fang; Cheng, Shu; Long, Yun Fei; Xiao, Qiu Guo

2016-02-01

A simple, fast and highly sensitive spectrophotometric method for the determination of bovine serum albumin (BSA) has been developed based on the interactions between triangular silver nanoplates (TAgNPs) and BSA in the presence of Britton-Robison buffer solution (BR). Particularly, the wavelength of absorption maximum (λmax) of TAgNPs is red shifted in the presence of BSA together with Britton-Robinson buffer solution (BR, pH = 2.56), and the color of the solution changed from blue to light blue. This may be due to the interactions between BSA molecules on the surface of TAgNPs through electrostatic forces, hydrogen bonds, hydrophobic effects and van der Waals forces at pH 2.56, which leads to the aggregation of TAgNPs. The determination of BSA was achieved by measuring the change of λmax corresponding to localized surface plasmon resonance (LSPR) from UV-visible spectrophotometry. It was found that the shift value in the wavelength of absorption maximum (Δλ, the difference in absorption maxima of the TAgNPs/BSA/BR mixture and the TAgNPs/BR mixture) was proportionate to the concentration of BSA in the range of 1.0 ng mL- 1 to 100.0 ng mL- 1 with the correlation coefficient of r = 0.9969. The detection limit (3 σ/k) for BSA was found to be as low as 0.5 ng mL- 1.

Spectroscopy and thermometry of drumhead modes in a mesoscopic trapped-ion crystal using entanglement

CSIR Research Space (South Africa)

Sawyer, BC

2012-05-01

Full Text Available -insensitive Doppler profile measurements [25], which give a minimum detectable temperature of �0:5 mK in 9Be?. Our tempera- ture measurement is mode specific and may be employed below the Doppler cooling limit, providing an alternative to Raman sideband....-D. Lin, L.-M. Duan, and C. Monroe, Nature (London) 465, 590 (2010). [13] R. Islam et al., Nature Commun. 2, 377 (2011). [14] J.W. Britton, B. C. Sawyer, A. C. Keith, C.-C. J. Wang, J. K. Freericks, H. Uys, M. J. Biercuk, and J. J. Bollinger, Nature...

Determination of free amino compounds in betalainic fruits and vegetables by gas chromatography with flame ionization and mass spectrometric detection.

Science.gov (United States)

Kugler, Florian; Graneis, Stephan; Schreiter, Pat P-Y; Stintzing, Florian C; Carle, Reinhold

2006-06-14

Amino acids and amines are the precursors of betalains. Therefore, the profiles of free amino compounds in juices obtained from cactus pears [Opuntia ficus-indica (L.) Mill. cv. Bianca, cv. Gialla, and cv. Rossa], pitaya fruits [Selenicereus megalanthus (K. Schumann ex Vaupel) Moran, Hylocereus polyrhizus (Weber) Britton & Rose, and Hylocereus undatus (Haworth) Britton & Rose], and in extracts from differently colored Swiss chard [Beta vulgaris L. ssp. cicla (L.) Alef. cv. Bright Lights] petioles and red and yellow beets (B. vulgaris L. ssp. vulgaris var. conditiva Alef. cv. Burpee's Golden) were investigated for the first time. Amino compounds were derivatized with propyl chloroformate. While gas chromatography (GC) with mass spectrometry was used for peak assignment, GC flame ionization detection was applied for quantification of individual compounds. Whereas proline was the major free amino compound of cactus pear and pitaya fruit juices, glutamine dominated in Swiss chard stems and beets, respectively. Interestingly, extremely high concentrations of dopamine were detected in Swiss chard stems and beets. Furthermore, the cleavage of betaxanthins caused by derivatization in alkaline reaction solutions is demonstrated for the first time. Amino acids and amines thus released might increase the actual free amino compound contents of the respective sample. To evaluate the contribution of betaxanthin cleavage to total amino acid and amine concentration, isolated betaxanthins were derivatized according to the "EZ:faast" method prior to quantification of the respective amino compounds released. On a molar basis, betaxanthin contribution to overall amino compound contents was always below 6.4%.

User requirements for information systems in nuclear medicine.

Science.gov (United States)

Todd-Pokropek, A; Vauramo, E; Cosgriff, P; Sippo-Tujunen, I; Britton, K

1992-05-01

In the field of COST cooperation (COST = European Cooperation in the Field of Scientific and Technical Research) a project B2 for Quality Assurance in Nuclear Medicine Software has been established. In a memorandum of understanding setting up this project, user requirements were to be defined for the hardware and software used for data acquisition, processing and presentation. A subgroup of the management committee of COST B2 were interested in the Advanced Informatics in Medicine, AIM, task T-734 'Quality Assurance of Medical Software', and the AIM Project 'A 1034', coordinated by Dr K. Britton, was initiated. The initial drafts of this document were written in Helsinki during 1988-1990, and submitted for comment by the members of the management committee of COST B2. These comments were integrated in the text and this document was finalized by the UK group so as to make it available for international discussion. It is anticipated that, after appropriate international discussion, these User Requirements for Information Systems in Nuclear Medicine will be adopted by the management committee of COST B2 as a COST document. Towards these ends, a working group chaired by Dr Britton, including the British and Finnish teams and Ulrich Noelpp from Switzerland, was appointed by the management committee of COST B2 in April 1990. While writing it we have had the pleasure of working with referees from different European hospitals in many countries. We are happy to thank all of them for their valuable contributions.

"A Myth Becomes Reality": Kaspar Hauser as Messianic Wild Child

Directory of Open Access Journals (Sweden)

Ulrich Struve

1998-06-01

Full Text Available The topos of the "Wild Child" occupies an important place in the mythic and literary imagination of the West. The European climax of a long line of wild children, Kaspar Hauser was a nineteenth-century German foundling whose fate has inspired a host of novels, dramas, novellas, poems, songs, and movies, even an opera and a ballet. It has been treated by Paul Verlaine, R. M. Rilke, and Klaus Mann, by the Dada poet Hans Arp, by the dramatist Peter Handke, and by the filmmaker Werner Herzog. This article offers a brief historical sketch of Hauser's life before discussing a key aspect of the literary Kaspar Hauser reception: the motif of the foundling as a latter-day messiah. By examining a set of twentieth-century texts that develop this motif in an exemplary manner—Jakob Wassermann's novel Caspar Hauser or The Inertia of the Heart , Georg Trakl's Kaspar Hauser Song , the anthroposophist Kaspar Hauser poems by Emma Krell-Werth, and David Constantine's Caspar Hauser: A Poem in Nine Cantos —we can gain insight into our century's desire for redemption and its ethical ramifications.

Produção de biomassa e teor do óleo essencial de cidrão em função da adubação orgânica Biomass production and essential oil content of lemon verbena in response to organic manure application

Directory of Open Access Journals (Sweden)

Renata da S Brant

2010-03-01

Full Text Available Objetivou-se com a realização deste trabalho avaliar a influência da adubação orgânica na produção de massa e no teor do óleo essencial de Aloysia triphylla (L'Hérit Britton. O experimento foi conduzido em casa de vegetação e foram aplicadas cinco doses de esterco bovino curtido: 0, 3, 6, 9 e 12 kg m-2, com quatro vasos por repetição, dispostos em delineamento inteiramente casualizado. Após 198 dias de cultivo, foi realizada a secagem em estufa e extração por hidrodestilação do óleo essencial a partir de folhas secas, em Clevenger modificado. As plantas de A. triphylla crescidas com 12 kg m-2 de esterco bovino tiveram maior rendimento de massa. Maior teor de óleo essencial foi verificado nas plantas crescidas com 9 kg m-2 de esterco bovino.This work evaluated the influence of organic manure in biomass production and in essential oil content of Aloysia triphylla (L'Hérit Britton. Plants growing under greenhouse received five tanned cattle manure rates: 0, 3, 6, 9 and 12 kg m-2 with four pots per replication, in randomized complete design. After 198 days of growth, plants were dried and the essential oil was extracted from leaves by the Clevenger's modified apparatus. The highest biomass was presented by plants cultivated with 12 kg m-2 and the highest oil yield was obtained from A. triphylla treated with 9 kg m-2 of cattle manure.

Characterization of reaction products of iron and iron salts and aqueous plant extracts

Energy Technology Data Exchange (ETDEWEB)

Jaen, J.A. [Universidad de Panama, Centro de Investigaciones con Tecnicas Nucleares/Depto. de Quimica (Panama); Garcia de Saldana, E.; Hernandez, C. [Universidad de Panama, Maestria en Ciencias Quimicas (Panama)

1999-11-15

The complexes formed in aqueous solution as a result of a reaction of iron and iron salts (Fe{sup 2+} and Fe{sup 3+}) and some plant extracts were analyzed using Moessbauer spectroscopy and Fourier transform infrared. The extracts were obtained from Opuntia elatior mill., Acanthocereus pentagonus (L.) Britton, Mimosa tenuiflora, Caesalpinia coriaria (Jacq.) Willd., Bumbacopsis quinata (Jacq.) Dugand and Acacia mangium Willd., plants growing wildly in different zones of the Isthmus of Panama. Results suggest the formation of mono- and bis-type complexes, and in some cases, the occurrence of a redox reaction. The feasibility of application of the studied extracts as atmospheric corrosion inhibitors is discussed.

The revision of Britton (1980) and the need to keep pace with all on ...

African Journals Online (AJOL)

was a landmark publication covering all known bird species occurring in Kenya,. Tanzania and ... systematics and taxonomy is continually moving forward. .... by the long blue, forked tail as a Swallow-tailed Bee-eater Merops hirundineus. I.

Looking at the vintage of 1949

Science.gov (United States)

Fifty years ago, as 1949 began, AGU dues had been raised from $5 to $7 per year. James Bernard Macelwane had just received the William Bowie Medal. Walter H. Bucher was about to become president, and H. U-.Sverdrup was vice-president.The Union's 4,500 members could choose among eight sections: Geodesy, Seismology, Meteorology, Terrestrial Magnetism and Electricity, Oceanography, Volcanology Hydrology, and Tectonophysics. Of the approximately 200 new members that joined AGU in 1949, 34 are celebrating 50 years of membership this year.The individuals listed below join the distinguished ranks of the other 50-year members. Their continuing commitment to AGU is deeply appreciated. Stephen E. Blewett, William E. Bonini, William M. Cameron, Robert A. Clark, John C. Cook, Joseph S. Cragwall, Jr., Richard C. Culler, Martin M. Fogel, Joseph B. Franzini, Thomas A. Gleeson, O. Milton Hackett, Arthur FHasbrook, James W. Hood, Shragga Irmay William W. Kellogg, Elizabeth R. King, Howard Klein, Finley B. Laverty Heinz H. Lettau, Kurt E. Lowe, Arthur R. Miller, Joseph W Mixsell, Carlo Morelli, Jack E. Oliver, B. H. Olsson, George L. Pickard, John L. Rosenfeld, Thorndike Saville, Jr., John W. Siegmund, James E. Slosson, John Summersett, Harold A. Thomas, Jr., Charles M. Weiss, and Glenn C. Werth.

THE HISTORICAL SETTING AND ORIGINAL TRAITS OF THE WORLD CRISIS

Directory of Open Access Journals (Sweden)

François Chesnais

2014-01-01

Full Text Available The most dramatic and most publicized episodes of the world crisis have been financial: the subprime mortgage market collapse in 2007, the failure of Lehmann Brothers in September 2008 and more recently the Eurozone banking and sovereign debt crisis. They have of course each time had their own impact on production, trade and employment. But this does not make the crisis a “crisis of financialisation” or of “neoliberalism”, but of capitalism tout court at a given moment of its history. Its underlying causes are overproduction and over-accumulation at world level and an effective play of the tendency of the rate of profit to fall despite the recourse by capital to the offsetting factors. The length of the crisis, which is now named not a US ‘Great Recession” but a global slump (McNally, 2011, and the end of the phase where China and Brazil appeared to be decoupled from the world crisis are expressions of this.

Fenologia reprodutiva de pitaia vermelha no município de Lavras, MG Reproductive phenology of red pitaya in Lavras, MG, Brazil

Directory of Open Access Journals (Sweden)

Virna Braga Marques

2011-06-01

Full Text Available O estudo do comportamento fenológico pode contribuir para melhorar a produtividade das culturas e a qualidade dos frutos. O trabalho foi realizado com o objetivo de avaliar a fenologia reprodutiva da pitaia vermelha em Lavras, MG, Brasil. Foram avaliados em cem plantas de pitaia vermelha (Hylocereus undatus (Haw. Britton & Rose os períodos das subfases desde a emissão das gemas até a maturação dos frutos de 2008 a 2010. O botão floral se desenvolve no período de 19 a 21 dias. A antese é noturna que dura aproximadamente 15 horas. A maturação do fruto ocorre de 30 a 40 dias após a abertura da flor, quando o fruto adquire a coloração rosa a vermelho intenso e a textura firme. Em Lavras, MG o período reprodutivo da pitaia ocorre de novembro a maio e tempo do aparecimento do botão floral até a colheita do fruto é de 50 a 60 dias.The study of phenology can contribute to improve the productivity of crops and fruit quality. The study was conducted to evaluate the reproductive phenology of red pitaya in Lavras, MG, Brazil. It was evaluated in one hundred plants of pitaya (Hylocereus undatus (Haw. Britton & Rose the subphase's periods from the issuance of buds to fruit ripening from 2008 to 2010. The bud develops from 19 to 21 days. The anthesis is nocturnal which lasts about 15 hours. The maturation occurs from 30 to 40 days after flower opening, when the fruit acquires color pink to deep red and firm texture. In Lavras, MG the reproductive period of red pitaya occurs from November to May and the time of appearance of flower buds to fruit harvest is from 50 to 60 days.

Voltammetric behavior of sedative drug midazolam at glassy carbon electrode in solubilized systems.

Science.gov (United States)

Jain, Rajeev; Yadav, Rajeev Kumar

2012-04-01

Redox behavior of midazolam was studied at a glassy carbon electrode in various buffer systems, supporting electrolytes and pH using differential pulse, square-wave and cyclic voltammetry. Based on its reduction behavior, a direct differential pulse voltammetric method has been developed and validated for the determination of midazolam in parenteral dosage. Three well-defined peaks were observed in 0.1% SLS, Britton-Robinson (BR) buffer of pH 2.5. The effect of surfactants like sodium lauryl sulfate (SLS), cetyl trimethyl ammonium bromide (CTAB) and Tween 20 was studied. Among these surfactants SLS showed significant enhancement in reduction peak. The cathodic peak currents were directly proportional to the concentration of midazolam with correlation coefficient of 0.99.

Voltammetric Determination of Ivabradine Hydrochloride Using Multiwalled Carbon Nanotubes Modified Electrode in Presence of Sodium Dodecyl Sulfate.

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Attia, Ali Kamal; Abo-Talib, Nisreen Farouk; Tammam, Marwa Hosny

2017-04-01

Purpose: A new sensitive sensor was fabricated for the determination of ivabradine hydrochloride (IH) based on modification with multiwalled carbon nanotubes using sodium dodecyl sulfate as micellar medium to increase the sensitivity. Methods: The electrochemical behavior of IH was studied in Britton-Robinson buffer (pH: 2.0-11.0) using cyclic and differential pulse voltammetry. Results: The voltammetric response was linear over the range of 3.984 x 10 -6 -3.475 x 10 -5 mol L -1 . The limits of detection and quantification were found to be 5.160 x 10 -7 and 1.720 x 10-6 mol L -1 , respectively. Conclusion: This method is suitable for determination of IH in tablets and plasma.

Voltammetric quantitation of nitazoxanide by glassy carbon electrode

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Rajeev Jain

2013-12-01

Full Text Available The present study reports voltammetric reduction of nitazoxanide in Britton–Robinson (B–R buffer by cyclic and square-wave voltammetry at glassy carbon electrode. A versatile fully validated voltammetric method for quantitative determination of nitazoxanide in pharmaceutical formulation has been proposed. A squrewave peak current was linear over the nitazoxanide concentration in the range of 20–140 µg/mL. The limit of detection (LOD and limit of quantification (LOQ was calculated to be 5.23 μg/mL and 17.45 μg/mL, respectively. Keywords: Nitazoxanide, Squarewave voltammetry, Glassy carbon electrode, Pharmaceutical formulation

Efecto del aceite esencial de Aloysia triphylla britton (cedrón sobre el Trypanosoma cruzi en ratones The effect of the essential oil from Aloysia triphylla britton (lemon verbena on Trypanosoma cruzi in mice

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Juan Rojas

2012-03-01

Full Text Available Objetivos. Determinar la actividad anti-Trypanosoma cruzi in vivo del aceite esencial de Aloysia triphylla en ratones. Materiales y Métodos. Los animales fueron asignados aleatoriamente a los siguientes grupos (n = 15 por grupo: infectados y no tratados (G1, infectados y tratados con benznidazol 100 mg/kg (G2, infectados y tratados con aceite esencial de Aloysia triphylla 100 mg/kg (G3, infectados y tratados con aceite esencial de Aloysia triphylla 250 mg/kg (G4; no infectados y no tratados (G5, y no infectados y tratados con 250 mg/kg de Aloysia triphyla (G6. La infección con T. cruzi se realizó con 104 tripomastigotes sanguíneos y el tratamiento empezó en el octavo día postinfección (dpi hasta el 28 dpi. La parasitemia se determinó con microscopía óptica cada dos días en 5 μL de sangre extraída de la cola. En el 14, 21 y 28 dpi se obtuvo sangre de la cola para el ensayo de creatina kinasa-MB (CK-MB, alanina aminotransferasa y creatinina; después, los animales fueron sacrificados y se extrajo el corazón para el estudio histopatológico. Resultados. El aceite esencial de cedrón produjo una reducción significativa de 85,4% del pico de parasitemia con la dosis de 250 mg/kg; también produjo reducción del número de amastigotes e infiltrados inflamatorios en el corazón. El nivel plasmático de CK-MB también disminuyó en el 28 dpi por efecto de dicho tratamiento. Conclusiones. En condiciones experimentales, el aceite esencial de Aloysia triphylla tiene efecto anti-Trypanosoma cruzi in vivo en ratones.Objectives. To determine the in-vivo anti-Trypanosoma cruzi activity of the essential oil from Aloysia triphylla in mice. Materials and methods. The mice (n = 15 in the study were randomly assigned to the following groups: infected and untreated (G1, infected and treated with benznidazole 100 mg/kg (G2, infected and treated with of Aloysia triphylla essential oil 100 mg/kg (G3, infected and treated with of Aloysia triphylla essential oil 250 mg/kg (G4, uninfected and untreated (G5, and uninfected and treated with 250 mg/kg of Aloysia triphyla (G6. The infection was conducted using 104 blood T. cruzi trypomastigotes and the treatment began on the 8th day post-infection (dpi through 28 dpi. The parasitemia was determined through optical microscopy every 2 days using 5 μL of blood sampled from the tail. In dpi 14, 21 and 28, the blood sample was obtained from the queue for testing creatine kinase-MB, alanine aminotransferase and creatinine, then animals were euthanized and the heart was removed for histopathological study. Results. The essential oil of lemon verbena produced a significant reduction of the parasitemia, 85.4% with the peak at a the dose of 250 mg/ kg. It was also observed a reduction in the number of amastigotes and inflammatory infiltrates in the heart. The creatine kinase-MB plasma levels also decreased at dpi 28 as a result of such treatment. Conclusions. Under experimental conditions, the essential oil of Aloysia triphylla (lemon verbena has in vivo anti-Trypanosoma cruzi effect in mice.

Effect of mycorrhizal strains in the quality of the plant Calophyllum antillanum Britton in nursery

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Yuris Rodríguez Matos

2017-12-01

Full Text Available The work was carried out in the Municipal Agricultural Interprise in the municipality of Moa in the province of Holguín, from january to May the 2016, with the objective to evaluate the effect of different mycorrhizal strains on the morphological parameters of the species Calophyllum antillanum, under nursery conditions. The treatments that were used were: T1- Soil / Glomus cubense in proportion 9: 1, T2 - Soil / Funneliformis moseae in proportion 9: 1, T3 - Soil / Rhizophagus intraradices 9: 1 and T4 - Control (Worm Humus in proportion 5: 1 "Five wagons of soil and one of organic matter", through a completely randomized design. 100 plants were used for each treatment, evaluating 25 in each of them, at 30, 60, 90 and 120 days after germination. The statistical package STATGRAPHICS Plus 5.1 was used. The results indicated T2 -Suelo/Funneliformis moseae en proporción 9:1, with the best results in the morphological parameters: plant height, stem diameter, leaf number, dry leaf mass and root, morphological attributes of the root system: long root length, number of primary roots and secundary, morphological index of plants: slenderness (H / D, shoot part ratio - RPA / RPR and Dickson quality. For the production of good quality postures T2 is also the most economically feasible, since the total expenses are 0.34.

La Bioclimatología y su utilidad en los estudios de la diversidad biológica: experiencias en la provincia Holguín, Cuba

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Elena Fornet Hernández

2010-01-01

Full Text Available Aborda un análisis sobre la importancia de la bioclimatología para los estudios de biodiversidad, se refieren reportes sobre diferentes especies vegetales y se profundiza en un endémico holguinero, Escobaria cubensis (Britton & Rose Hunt, "el cactus enano de Holguín", el cual ha sido estudiado desde hace algunos años por investigadores que han mencionado la influencia del clima sobre su comportamiento. Se concluye la utilidad demostrada de la bioclimatología en el conocimiento de la diversidad biológica y se muestra la necesidad de enfoques y acciones integradoras en este tipo de estudio y no la exposición descriptiva de las características del clima.

Voltammetric Determination of Ivabradine Hydrochloride Using Multiwalled Carbon Nanotubes Modified Electrode in Presence of Sodium Dodecyl Sulfate

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Ali Kamal Attia

2017-04-01

Full Text Available Purpose: A new sensitive sensor was fabricated for the determination of ivabradine hydrochloride (IH based on modification with multiwalled carbon nanotubes using sodium dodecyl sulfate as micellar medium to increase the sensitivity. Methods: The electrochemical behavior of IH was studied in Britton-Robinson buffer (pH: 2.0-11.0 using cyclic and differential pulse voltammetry. Results: The voltammetric response was linear over the range of 3.984 x 10-6-3.475 x 10-5 mol L-1. The limits of detection and quantification were found to be 5.160 x 10-7 and 1.720 x 10-6 mol L-1, respectively. Conclusion: This method is suitable for determination of IH in tablets and plasma.

Electrochemical Sensors for Detection of Acetylsalicylic Acid

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Rene Kizek

2006-11-01

Full Text Available Acetylsalicylic acid (AcSA, or aspirin, was introduced in the late 1890s and hasbeen used to treat a variety of inflammatory conditions. The aim of this work was to suggestelectrochemical sensor for acetylsalicylic detection. Primarily, we utilized square wavevoltammetry (SWV using both carbon paste electrode (CPE and of graphite pencilelectrode (GPE as working ones to indirect determination of AcSA. The principle ofindirect determination of AcSA bases in its hydrolysis on salicylic acid (SA, which isconsequently detected. Thus, we optimized both determination of SA and conditions forAcSA hydrolysis and found out that the most suitable frequency, amplitude, step potentialand the composition and pH of the supporting electrolyte for the determination of SA was260 Hz, 50 mV, 10 mV and Britton-Robinson buffer (pH 1.81, respectively. The detectionlimit (S/N = 3 of the SA was 1.3 ng/ml. After that, we aimed on indirect determination ofAcSA by SWV CPE. We tested the influence of pH of Britton-Robinson buffer andtemperature on yield of hydrolysis, and found out that 100% hydrolysis of AcSA wasreached after 80 minutes at pH 1.81 and 90°C. The method for indirect determination ofAcSA has been utilized to analyse pharmaceutical drug. The determined amount of AcSA in the pharmaceutical drug was in good agreement with the declared amounts. Moreover, weused GPE for determination of AcSA in a pharmaceutical drug. Base of the results obtainedfrom stationary electrochemical instrument we used flow injection analysis withelectrochemical detection to determine of salicylates (SA, AcSA, thiosalicylic acid, 3,5-dinitrosalicylic acid and 5-sulfosalicylic acid – SuSA. We found out that we are able todetermine all of detected salicylates directly without any pre-treatment, hydrolysis and so onat units of femtomoles per injection (5 μl.

Voltammetric behavior of sedative drug midazolam at glassy carbon electrode in solubilized systems

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Rajeev Jain

2012-04-01

Full Text Available Redox behavior of midazolam was studied at a glassy carbon electrode in various buffer systems, supporting electrolytes and pH using differential pulse, square-wave and cyclic voltammetry. Based on its reduction behavior, a direct differential pulse voltammetric method has been developed and validated for the determination of midazolam in parenteral dosage. Three well-defined peaks were observed in 0.1% SLS, Britton–Robinson (BR buffer of pH 2.5. The effect of surfactants like sodium lauryl sulfate (SLS, cetyl trimethyl ammonium bromide (CTAB and Tween 20 was studied. Among these surfactants SLS showed significant enhancement in reduction peak. The cathodic peak currents were directly proportional to the concentration of midazolam with correlation coefficient of 0.99. Keywords: Midazolam, Voltammetry, Surfactant, Glassy carbon electrode, Parenteral dosage form

La Historia de una especie del patrimonio holguinero: Escobaria cubensis (Cactaceae "el cactus enano". Primera parte

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Alena Reyes Fornet

2010-01-01

Full Text Available Presenta una investigación sobre la historia taxonómica y estudios sobre la ecología del "cactus enano de Holguín", Escobaria cubensis (Britton & Rose Hunt, 1978 desde 1909 hasta 1990, elementos importantes, para la conservación y como contribución al conocimiento de la historia del patrimonio natural holguinero, con datos históricos sobre visitas de personalidades del mundo y Holguín. Se estudiaron 37 materiales correspondientes a notas de viajes, cartas y publicaciones. Se señala la posibilidad de que el colector, J. Shafer estuvo en dos zonas de distribución. Las contribuciones al conocimiento de su ecología hasta 1990 se basaron en la observación y descripción.

Determination of serum albumin with tribromoarsenazo by spectrophotometry

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Qing-Zhou Zhai

2007-08-01

Full Text Available The reaction of tribromoarsenazo(TB-ASA with serum albumin in the presence of emulgent OP was studied by spectrophotometry. In a Britton-Robinson buffer solution at pH 2.9, tribromoarsenazo and bovine serum albumin can immediately form a red compound in the presence of emulgent OP with a maximum absorption wavelength at 354 nm. The presence of emulgent OP can increase the reaction sensitivity and the compound stability. The molar absorptivity of the compound is ε354 nm = 6.13 x 105 M-1•cm-1. Beer's law is obeyed over the range of 5.0-75.0 mg•L-1 for bovine serum albumin. The present method was applied to the determination of the total proteins in human serums with satisfactory results.

Efficacy and safety of venous thromboembolism prophylaxis with apixaban in major orthopedic surgery

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Werth S

2012-03-01

Full Text Available Sebastian Werth, Kai Halbritter, Jan Beyer-WestendorfCenter for Vascular Medicine and Department of Medicine III, Division of Angiology, University Hospital “Carl Gustav Carus” Dresden, Dresden, GermanyAbstract: Over the last 15 years, low-molecular-weight heparins (LMWHs have been accepted as the “gold standard” for pharmaceutical thromboprophylaxis in patients at high risk of venous thromboembolism (VTE in most countries around the world. Patients undergoing major orthopedic surgery (MOS represent a population with high risk of VTE, which may remain asymptomatic or become symptomatic as deep vein thrombosis or pulmonary embolism. Numerous trials have investigated LMWH thromboprophylaxis in this population and demonstrated high efficacy and safety of these substances. However, LMWHs have a number of disadvantages, which limit the acceptance of patients and physicians, especially in prolonged prophylaxis up to 35 days after MOS. Consequently, new oral anticoagulants (NOACs were developed that are of synthetic origin and act as direct and very specific inhibitors of different factors in the coagulation cascade. The most developed NOACs are dabigatran, rivaroxaban, and apixaban, all of which are approved for thromboprophylaxis in MOS in a number of countries around the world. This review is focused on the pharmacological characteristics of apixaban in comparison with other NOACs, on the impact of NOAC on VTE prophylaxis in daily care, and on the management of specific situations such as bleeding complications during NOAC therapy.Keywords: major orthopedic surgery, apixaban, dabigatran, edoxaban, rivaroxaban, deep vein thrombosis, venous thromboembolism, VTE prophylaxis

[School Organization: Theory and Practice; Selected Readings on Grading, Nongrading, Multigrading, Self-Contained Classrooms, Departmentalization, Team Heterogeneous Grouping. Selected Bibliographies.] Rand McNally Education Series.

Science.gov (United States)

Franklin, Marian Pope, Comp.

Over 400 journal articles, case studies, research reports, dissertations, and position papers are briefly described in a series of eight selected bibliographies related to school organization. The eight specific areas treated in the volume and the number of items listed for each include: nongraded elementary school organization, 96; nongraded…

Spectrophotometric Determination of Metoprolol Tartrate in Pharmaceutical Dosage Forms on Complex Formation with Cu(II

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Mustafa Cesme

2011-06-01

Full Text Available A new, simple, sensitive and accurate spectrophotometric method has been developed for the assay of metoprolol tartrate (MPT, which is based on the complexation of drug with copper(II [Cu(II] at pH 6.0, using Britton-Robinson buffer solution, to produce a blue adduct. The latter has a maximum absorbance at 675 nm and obeys Beer’s law within the concentration range 8.5-70 mg/mL. Regression analysis of the calibration data showed a good correlation coefficient (r = 0.998 with a limit of detection of 5.56 mg/mL. The proposed procedure has been successfully applied to the determination of this drug in its tablets. In addition, the spectral data and stability constant for the binuclear copper(II complex of MPT (Cu2MPT2Cl2 have been reported.

Voltammetric Determination of Carcinogenic Nitrobiphenyls at a Hanging Mercury Drop Electrode

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Jiří Zima

2003-02-01

Full Text Available Differential pulse voltammetry (DPV and adsorptive stripping voltammetry (AdSV at a hanging mercury drop electrode (HMDE was used for the determination of trace amounts of carcinogenic nitrobiphenyls, namely 2-nitrobiphenyl (2-NBP, 3-nitrobiphenyl (3-NBP and 4-nitrobiphenyl (4-NBP within the concentration range from 2.10-8 to 1.10-5 mol⋅L-1 for DPV and from 2.10-9 to 1.10-7 mol⋅L-1 for AdSV using a Britton-Robinson buffer – methanol (1:1 mixture with resulting pH 12 as a base electrolyte. The practical applicability of newly developed methods was verified using model samples of drinking and river water and liquid-liquid extraction for a preliminary separation and preconcentration.

Crystal structures of 2,6-dibromo-4-methylbenzonitrile and 2,6-dibromo-4-methylphenyl isocyanide

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Wayland E. Noland

2017-12-01

Full Text Available In the title crystals, C8H5Br2N, which are isomorphous, the steric bulk of the methyl group causes neighboring molecules to become mutually inclined. This prevents the formation of planar or nearly planar sheets, which were observed in the trichloro and tribromo analogs. Instead of CN/NC...Br contacts, tetrameric Br...Br contacts are observed. These contacts form tetragonally puckered sheets parallel to (001. The CN/NC and methyl groups are grouped at the peaks and troughs. Both molecules lie across crystallographic mirror planes; thus, the methyl H atoms are disordered over two sets of sites with equal occupancy. The title nitrile is a redetermination. The refinement converged at R[F2 > 2σ(F2] = 0.020, whereas the original determination [Gleason & Britton, (1976. Cryst. Struct. Commun. 5, 229–232] had R = 0.112.

STUDY OF ELECTROPOLIMERIZATION PROCESSES OF PYRROLE BY CYCLIC VOLTAMMETRIC TECHNIQUE

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Adhitasari Suratman

2010-06-01

Full Text Available Electropolymerization processes and electrochemical properties of polypyrrole as electroactive polymer have been studied by cyclic voltammetric technique. Pyrrole was electropolymerized to form polypyrrole in water-based solvent containing sodium perchlorate as supporting electrolyte in several pH values. The pH of the solutions were varied by using Britton Robinson buffer. The results showed that oxidation potential limit of electropolymerization processes of pyrrole was 1220 mV vs Ag/AgCl reference electrode. It can be seen that cyclic voltammetric respon of polypyrrole membrane that was prepared by electropolymerization processes of pyrrole at the scanning rate of 100 mV/s was stable. While the processes of pyrrole electropolymerization carried out at the variation of pH showed that the best condition was at the pH range of 2 - 6.   Keywords: polypyrolle, electropolymer, voltammetric technique

GC-MS analysis of volatile compounds of Perilla frutescens Britton var. Japonica accessions: Morphological and seasonal variability.

Science.gov (United States)

Ghimire, Bimal Kumar; Yoo, Ji Hye; Yu, Chang Yeon; Chung, Ill-Min

2017-07-01

To investigate the composition of volatile compounds in the different accessions of Perilla frutescens (P. frutescens) collected from various habitats of China and Japan. In the present study, the essential oil from the leaves of P. frutescens cultivars from China and Japan was extracted by hydro-distillation and the chemical composition and concentration of the volatile components present in the oils were determined by gas chromatography-mass spectrometry (GC-MS) analysis. Among the volatile components, the major proportion was of perilla ketone, which was followed by elemicin and beta-caryophyllene in the Chinese Perilla cultivars. The main component in the oil extracted from the Japanese accessions was myristicin, which was followed by perilla ketone and beta-caryophyllene. We could distinguish seven chemotypes, namely the perilla ketone (PK) type, perilla ketone, myristicin (PM) type, perilla ketone, unknown (PU) type, perilla ketone, beta-caryophyllene, myristicine (PB) type, perilla ketone, myristicin, unknown (PMU) type, perilla ketone, elemicine, myristicin, beta-caryophyllene (PEMB) type, and the perilla ketone, limonene, beta-cryophyllene, myristicin (L) type. Most of the accessions possessed higher essential oil content before the flowering time than at the flowering stage. The average plant height, leaf length, leaf width of the Chinese accessions was higher than those of the Japanese accessions. The results revealed that the harvest time and geographical origin caused polymorphisms in the essential oil composition and morphological traits in the Perilla accessions originating from China and Japan. Therefore, these chemotypes with desirable characters might be useful for industrial exploitation and for determining the harvest time. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Mosses as indicators of atmospheric metal deposition in an industrial area of southern Brazil Musgos como indicadores da deposição atmosférica de metais em uma área industrial do sul do Brasil

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Aline Correa Mazzoni

2012-09-01

Full Text Available Caxias do Sul hosts the second largest metal-mechanic pole in Brazil, which increases the risk of atmospheric contamination. With the aim of identifying species that might be useful as indicators of atmospheric deposition of metals, 15 species of mosses from an urban and a rural setting were analyzed and compared with specimens deposited at the Herbarium of the Universidade de Caxias do Sul. Metal concentrations (Zn, Ni, Cd, Cr, Cu and Pb were determined using Atomic Absorption Spectrometry (AAS. The Mann-Whitney test indicated concentrations of Zn, Cu, Pb and Cr that were significantly different between the urban and rural areas. Additionally, Concentrations of Zn, Cd, Cu and Pb were significantly higher in recently collected samples. The species Thuidium tomentosum Besch., Sematophyllum subpinnatum (Brid. E. Britton, Helicodontium capillare (Hedw. A. Jaeger, Schlotheimia jamesonii (W.-Arnott Brid. and Meteorium deppei (Hornsch. ex Müll. Hal. Mitt. are potential biomonitors of atmospheric metal deposition.Caxias do Sul sedia o segundo maior pólo metal mecânico do Brasil, apresentando elevado risco de contaminação atmosférica. Com o objetivo de identificar espécies úteis como indicadoras da deposição atmosférica de metais, foram analisadas 15 espécies de musgos procedentes da zona urbana e da área rural e espécimens depositados no Herbário da Universidade de Caxias do Sul. Os metais (Zn, Ni, Cd, Cr, Cu e Pb foram determinados por meio de Espectrometria de Absorção Atômica (AAS. O Teste de Mann-Whitney indicou diferenças significativas nas concentrações de Zn, Cu, Pb e Cr entre as áreas urbana e rural. Um aumento significativo na presença de Zn, Cd, Cu e Pb foi evidenciado nas amostras recentes. As espécies Thuidium tomentosum Besch., Sematophyllum subpinnatum (Brid. E. Britton, Helicodontium capillare (Hedw. A. Jaeger, Schlotheimia jamesonii (W.-Arnott Brid. e Meteorium deppei (Hornsch. ex Müll. Hal. Mitt. são indicadas

Studies on the Electrochemical Behavior of Thiazolidine and Its Applications Using a Flow–Through Chronoamperometric Sensor Based on a Gold Electrode

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Lai-Hao Wang

2011-09-01

Full Text Available The electrochemical behaviors of thiazolidine (tetrahydrothiazole on gold and platinum electrodes were investigated in a Britton-Robinson buffer (pH 2.77–11.61, acetate buffer (pH 4.31, phosphate buffer solutions (pH 2.11 and 6.38 and methanol or acetonitrile containing various supporting electrolytes. Detection was based on a gold wire electrochemical signal obtained with a supporting electrolyte containing 20% methanol-1.0 mM of phosphate buffer (pH 6.87, potassium dihydrogen phosphate and dipotassium hydrogen phosphate as the mobile phase. Comparison with results obtained with a commercial amperometric detector shows good agreement. Using the chronoamperometric sensor with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.05 to 16 mg L−1 was found. The limit of quantification (LOQ of the method for thiazolidine was found to be 1 ng.

Electrochemical Reduction of Isatin-monohydrazone on Mercury Electrode

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Ender Biçer

2015-07-01

Full Text Available Electrochemical behaviour of isatin monohydrazone (IM on a hanging mercury drop electrode in the Britton-Robinson (B-R buffer solution of pH = 2.00–9.00 has been investigated using square-wave voltammetry (SWV and cyclic voltammetry (CV techniques. In the pH range of 2.00–5.00, the voltammogram of IM exhibited a single cathodic irreversible peak. When the pH value exceeds 5.00, a new cathodic irreversible peak was also seen. According to the voltammetric data, a plausible electrode reaction mechanism of IM was proposed. The first reduction peak of IM is resulted from the reduction of =N–NH– group with consumption of 2e–/2H+. Also, its second cathodic peak is formed by the participation of 2e–/2H+ for the reduction of –N=N– group on its tautomeric form.

Determination of propylthiouracil in pharmaceuticals by differential pulse voltammetry using a cathodically pretreated boron-doped diamond electrode

Energy Technology Data Exchange (ETDEWEB)

Sartori, Elen Romao [Universidade Estadual de Londrina, PR (Brazil). Dept. de Quimica; Trench, Aline Barrios; Rocha-Filho, Romeu C.; Fatibello-Filho, Orlando, E-mail: bello@ufscar.br [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

2013-09-15

A simple procedure is described for the determination of propylthiouracil (PTU) by differential pulse voltammetry (DPV) using a cathodically pretreated boron-doped diamond (BDD) electrode. Cyclic voltammetry studies indicate that the oxidation of PTU is irreversible at a peak potential of 1.42 V (vs. Ag/AgCl (3.0 mol L{sup -1} KCl)) in a Britton-Robinson (BR) buffer solution (pH 2.0). Under optimized conditions, the obtained analytical curve was linear (r = 0.9985) for the PTU concentration range of 1.0 to 29.1 {mu}mol L{sup -1} in a BR buffer solution (pH 2.0), with a detection limit of 0.90 {mu}mol L{sup -1}. The proposed method was successfully applied in the determination of PTU in pharmaceutical samples, with results in agreement at a 95% confidence level with those obtained using an official titration method. (author)

Müzik Eğitimi Anabilim Dalı Öğrencilerinin Zaman Yönetimi Becerileri/The Time Management Skills of Music Education Students

OpenAIRE

Babacan, Yrd.Doç.Dr.Ezgi; Küçükosmanoğlu, Dr.Hayrettin Onur

2015-01-01

ÖZETBu araştırmanın amacı müzik eğitimi anabilim dalı öğrencilerinin zaman yönetimi becerilerini belirlemek ve bu becerilerin cinsiyet, yaş, sınıf ve bireysel çalgılarına göre değişkenlik gösterip göstermediğini saptamaktır. Araştırmada ilişkisel tarama modeli kullanılmıştır. Araştırmanın örneklemini 2014–2015 eğitim-öğretim yılında Necmettin Erbakan Üniversitesi A.K.E.F. Müzik Eğimi Anabilim Dalı'nda öğrenimine devam eden 128 öğrenci oluşturmaktadır. Verilerin toplanmasında Britton ve T...

Crystallization and preliminary crystallographic analysis of merohedrally twinned crystals of MJ0729, a CBS-domain protein from Methanococcus jannaschii

International Nuclear Information System (INIS)

Fernández-Millán, Pablo; Kortazar, Danel; Lucas, María; Martínez-Chantar, María Luz; Astigarraga, Egoitz; Fernández, José Andrés; Sabas, Olatz; Albert, Armando; Mato, Jose M.; Martínez-Cruz, Luis Alfonso

2008-01-01

Trigonal crystals of MJ0729 showing different degrees of merohedral twinning that may vary from perfect hemihedral twinning to perfect tetartohedral twinning were obtained upon slight variation of the pH. CBS domains are small protein motifs, usually associated in tandem, that are implicated in binding to adenosyl groups. Several genetic diseases in humans have been associated with mutations in CBS sequences, which has made them very promising targets for rational drug design. Trigonal crystals of the CBS-domain protein MJ0729 from Methanococcus jannaschii were grown by the vapour-diffusion method at acidic pH. Preliminary analysis of nine X-ray diffraction data sets using Yeates statistics and Britton plots showed that slight variation in the pH as well as in the buffer used in the crystallization experiments led to crystals with different degrees of merohedral twinning that may vary from perfect hemihedral twinning to perfect tetartohedral twinning

Surface-Enhanced Oxidation and Determination of Isothipendyl Hydrochloride at an Electrochemical Sensing Film Constructed by Multiwalled Carbon Nanotubes

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S. N. Prashanth

2012-01-01

Full Text Available The electrochemical behavior of isothipendyl hydrochloride (IPH was investigated at bare and multiwalled-carbon-nanotube modified glassy carbon electrode (MWCNT-GCE. IPH (55 μM showed two oxidation peaks in Britton-Robinson (BR buffer of pH 7.0. The oxidation process of IPH was observed to be irreversible over the pH range of 2.5–9.0. The influence of pH, scan rate, and concentration of the drug on anodic peak was studied. A differential pulse voltammetric method with good precision and accuracy was developed for the determination of IPH in pure and biological fluids. The peak current was found to be linearly dependent on the concentration of IPH in the range of 1.25–55 μM. The values of limit of detection and limit of quantification were noticed to be 0.284 and 0.949 μM, respectively.

In vivo evaluation of Aloysia triphylla britton (lemon verbena) essential oil toxicity and citral anti-Trypanosma cruzi activity.

OpenAIRE

Rojas Armas, Juan; Palacios Agüero, Olga; Ortiz Sánchez, José Manuel; López de la Peña, Leavit

2015-01-01

Introducción: Existe escasa investigación en enfermedades olvidadas. Las plantas medicinales son una potencial fuente de compuestos antimicrobianos. Objetivos: Determinar la toxicidad del aceite esencial de Aloysia triphylla y la actividad del citral contra Trypanosoma cruzi en ratones. Diseño: Estudio experimental preclínico in vivo. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material: Ratones albinos. Intervenciones: La toxicidad aguda oral a do...

Evaluation of electrochemical, UV/VIS and Raman spectroelectrochemical detection of Naratriptan with screen-printed electrodes.

Science.gov (United States)

Hernández, Carla Navarro; Martín-Yerga, Daniel; González-García, María Begoña; Hernández-Santos, David; Fanjul-Bolado, Pablo

2018-02-01

Naratriptan, active pharmaceutical ingredient with antimigraine activity was electrochemically detected in untreated screen-printed carbon electrodes (SPCEs). Cyclic voltammetry and differential pulse voltammetry were used to carry out quantitative analysis of this molecule (in a Britton-Robinson buffer solution at pH 3.0) through its irreversible oxidation (diffusion controlled) at a potential of +0.75V (vs. Ag pseudoreference electrode). Naratriptan oxidation product is an indole based dimer with a yellowish colour (maximum absorption at 320nm) so UV-VIS spectroelectrochemistry technique was used for the very first time as an in situ characterization and quantification technique for this molecule. A reflection configuration approach allowed its measurement over the untreated carbon based electrode. Finally, time resolved Raman Spectroelectrochemistry is used as a powerful technique to carry out qualitative and quantitative analysis of Naratriptan. Electrochemically treated silver screen-printed electrodes are shown as easy to use and cost-effective SERS substrates for the analysis of Naratriptan. Copyright © 2017 Elsevier B.V. All rights reserved.

Flow Injection Analysis with Electrochemical Detection for Rapid Identification of Platinum-Based Cytostatics and Platinum Chlorides in Water

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Marketa Kominkova

2014-02-01

Full Text Available Platinum-based cytostatics, such as cisplatin, carboplatin or oxaliplatin are widely used agents in the treatment of various types of tumors. Large amounts of these drugs are excreted through the urine of patients into wastewaters in unmetabolised forms. This phenomenon leads to increased amounts of platinum ions in the water environment. The impacts of these pollutants on the water ecosystem are not sufficiently investigated as well as their content in water sources. In order to facilitate the detection of various types of platinum, we have developed a new, rapid, screening flow injection analysis method with electrochemical detection (FIA-ED. Our method, based on monitoring of the changes in electrochemical behavior of analytes, maintained by various pH buffers (Britton-Robinson and phosphate buffer and potential changes (1,000, 1,100 and 1,200 mV offers rapid and cheap selective determination of platinum-based cytostatics and platinum chlorides, which can also be present as contaminants in water environments.

Perillanolides A and B, new monoterpene glycosides from the leaves of Perilla frutescens

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Yang Liu

Full Text Available Abstract Two new monoterpene glycosides, perillanolides A and B, together with a known compound reported from the genus Perilla for the first time were isolated and characterized from the leaves of Perilla frutescens (L. Britton, Lamiaceae, a garnish and colorant for foods as well as commonly used for traditional medicine. The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic evidences derived from nuclear magnetic resonance experiments, mass spectrometry and by comparing their physical and spectroscopic data of literature. These compounds, together with the previously isolated secondary metabolites of this species, were investigated for their inhibitory effects on xanthine oxidase in vitro. Of the compounds, luteolin showed the strongest inhibitory activity with an IC50 value of 2.18 µM. Esculetin and scutellarein moderately inhibited the enzyme, while perillanolides A and B, and 4-(3,4-dihydroxybenzoyloxymethylphenyl-O-β-D-glucopyranoside exerted weak activities.

Determination of antihypertensive drug moexipril hydrochloride based on the enhancement effect of sodium dodecyl sulfate at carbon paste electrode.

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Attia, Ali K

2010-04-15

Herein, an electrochemical differential pulse voltammetric method was developed for the determination of moexipril hydrochloride based on the enhancement effect of sodium dodecyl sulfate. The oxidation process has been carried out in Britton-Robinson buffer. Moexipril hydrochloride exhibits a well-defined irreversible oxidation peak over the entire pH range (2-11). The peak current varied linearly over the range from 4.0 x 10(-7) to 5.2 x 10(-6) mol L(-1). The limits of detection and quantification were 6.87 x 10(-8) mol L(-1) and 2.29 x 10(-7) mol L(-1), respectively. The recovery was found in the range from 99.65% to 100.76%. The relative standard deviation was found in the range from 0.429% to 0.845%. The proposed method possesses high sensitivity, accuracy and rapid response. Finally, this method was successfully used to determine moexipril hydrochloride in tablets. (c) 2009 Elsevier B.V. All rights reserved.

Voltammetric determination of mixtures of caffeine and chlorogenic acid in beverage samples using a boron-doped diamond electrode.

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Yardım, Yavuz; Keskin, Ertugrul; Şentürk, Zühre

2013-11-15

Herein, a boron-doped diamond (BDD) electrode that is anodically pretreated was used for the simultaneous determination of caffeine (CAF) and chlorogenic acid (CGA) by cyclic and adsorptive stripping voltammetry. The dependence of peak current and potential on pH, scan rate, accumulation parameters and other experimental variables were studied. By using square-wave stripping mode after 60 s accumulation under open-circuit voltage, the BDD electrode was able to separate the oxidation peak potentials of CAF and CGA present in binary mixtures by about 0.4V in Britton-Robinson buffer at pH 1.0. The limits of detection were 0.107 µg mL(-1) (5.51×10(-7) M) for CAF, and 0.448 µg mL(-1) (1.26×10(-6) M) for CGA. The practical applicability of this methodology was tested in commercially available beverage samples. © 2013 Elsevier B.V. All rights reserved.

Study on Cr(VI) Leaching from Cement and Cement Composites

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Palascakova, Lenka; Kanuchova, Maria

2018-01-01

This paper reports an experimental study on hexavalent chromium leaching from cement samples and cement composites containing silica fume and zeolite additions that were subjected to various leaching agents. The water-soluble Cr(VI) concentrations in cements ranged from 0.2 to 3.2 mg/kg and represented only 1.8% of the total chromium content. The presence of chromium compounds with both chromium oxidation states of III and VI was detected in the cement samples by X-ray photoelectron spectroscopy (XPS). Leaching tests were performed in a Britton-Robinson buffer to simulate natural conditions and showed increased dissolution of Cr(VI) up to 6 mg/kg. The highest amount of leached hexavalent chromium was detected after leaching in HCl. The findings revealed that the leaching of chromium from cements was higher by 55–80% than that from the cement composites. A minimum concentration was observed for all cement samples when studying the relationship between the soluble Cr(VI) and the cement storage time. PMID:29690550

Investigating Potential Toxicity of Leachate from Wood Chip Piles Generated by Roadside Biomass Operations

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John Rex

2016-02-01

Full Text Available Roadside processing of wood biomass leaves chip piles of varying size depending upon whether they were created for temporary storage, spillage, or equipment maintenance. Wood chips left in these piles can generate leachate that contaminates streams when processing sites are connected to waterways. Leachate toxicity and chemistry were assessed for pure aspen (Populus tremuloides Michx., lodgepole pine (Pinus contorta Dougl., hybrid white spruce (Picea engelmannii x glauca Parry, and black spruce (Picea mariana (Mill. Britton as well as from two wood chipping sites using mixes of lodgepole pine and hybrid or black spruce. Leachate was generated using rainfall simulation, a static 28-day laboratory assay, and a field-based exposure. Leachate generated by these exposures was analyzed for organic matter content, phenols, ammonia, pH, and toxicity. Findings indicate that all wood chip types produced a toxic leachate despite differences in their chemistry. The consistent toxicity response highlights the need for runoff management that will disconnect processing sites from aquatic environments.

Fenologia, morfologia floral e visitantes de Psychotria brachypoda (Müll. Arg. Britton (Rubiaceae em uma área de Floresta Atlântica, Sudeste do Brasil Phenology, floral morphology and visitors of Psychotria brachypoda (Müll. Arg. Britton (Rubiaceae in Atlantic Forest, southeastern Brazil

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Lorena Coutinho Nery Fonseca

2008-03-01

Full Text Available No presente estudo foram descritos o padrão fenológico, biologia floral, visitantes florais mais freqüentes e taxa de formação de frutos de Psychotria brachypoda, em uma área de Floresta Atlântica. O padrão de floração foi anual e intermediário, ocorrendo entre agosto e janeiro. A produção de frutos maduros ocorreu de março a julho/2004 e de fevereiro a maio/2005. O comprimento e o diâmetro da corola das flores brevistilas foram maiores que das longistilas. Apesar de não ter havido hercogamia recíproca exata, houve sobreposição entre as alturas dos estigmas das flores longistilas com os estames das brevistilas e vice-versa. O néctar apresentou maior concentração média de açúcares às 06:30 h (33% e menor às 14:30 h (26%. Flores cujo néctar foi coletado ao longo do dia produziram em média três vezes mais néctar que as flores que tiveram o néctar coletado apenas no final do dia. Foram encontrados 24 indivíduos brevistilos e 25 longistilos, indicando que a população é isoplética. Os principais visitantes florais foram machos e fêmeas do beija-flor Thalurania glaucopis, abelhas da tribo Trigonini e do gênero Euglossa, três espécies de lepidópteros, um díptero e um coleóptero. Houve formação de frutos verdes em 13,3% do total de flores marcadas e a taxa de produção de frutos foi similar entre os morfotipos florais. É provável que o principal polinizador de P. brachypoda seja o beija-flor T. glaucopis porque ele visita com freqüência muitas flores de diferentes indivíduos, provavelmente transferindo pólen entre eles.In this paper, the phenological pattern, floral biology, most frequent floral visitors and fruit set of Psychotria brachypoda are described. This study was carried out in Atlantic forest from October 2003 to September 2005. Flowering was annual and intermediate, occurring from August to January. Mature fruit production occurred from March to July 2004 and from February to June 2005. Corolla length and diameter of thrum flowers were larger than those of pin flowers. Although stigma length corresponded approximately to stamen length in each morph, exact reciprocal hercogamy did not occur. The nectar was more concentrated at 06:30h (33% and more diluted at 14:30h (26%. Flowers in which nectar was collected throughout the day had about three times more nectar than flowers in which nectar was collected once at the end of the day. There were 24 plants with thrum flowers and 25 plants with pin flowers, indicating an isopletic population. The main floral visitors were females and males of the hummingbird Thalurania glaucopis, bees of the tribe Trigonini and of the genus Euglossa, three Lepidoptera species, one Diptera species and one Coleoptera. Fruit was produced in 13.7% of the total number of marked flowers, with similar production in both morphs. Thalurania glaucopis is probably the most important pollinator of P. brachypoda, because it often visits many flowers from different individuals of P. brachypoda, probably transferring pollen among them.

Growth and Physiology of Senegalia senegal (L. Britton Seedlings as Influenced by Seed Origin and Salinity and Fertility Treatments

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Mame Sokhna Sarr

2017-10-01

Full Text Available Multipurpose trees such as Senegalia senegal are widespread in arid and semi-arid lands that have natural or induced saline soils and poor soil fertility. Such environmental problems impact growth and have the potential to influence plant physiological adaptations. Identifying superior genotypes better adapted to these environmental stresses will be of great importance for tree selection for reclamation of degraded drylands. The main objective of this study was to examine the growth performance, and physiological and morphological adaptations to salinity, and fertility treatments of different Senegalia senegal families. We used five families (DB16, DB14, K4B19, K17B19, NB1 selected from 60 families of a Senegalia senegal progeny trial in Dahra, Senegal. Seedlings were grown under greenhouse conditions by watering all plants for three weeks and then stopping all watering for three more weeks. In a randomized complete block design, a two-level factorial combination was used for salinity (zero and 183.1 mM NaCl added and fertility (zero and 100 kg/ha N-P-K added treatments. A significant family × salt × fertilizer interaction was found for all biomass parameters (leaf dry matter, stem dry matter, root dry matter, and leaf area. The fertilizer application resulted in a significant increase of total biomass of all families, ranging from 63% to 237% for NB1 and K17B19, respectively. In contrast, salt only decreased total biomass of NB1 and K17B19 increased growth. Despite similar net photosynthetic rates before treatment started, fertilizer and salinity induced different effects between families. Prior to drought stress, fertilizer did not affect photosynthesis of DB16, while salt significantly decreased stomatal conductance of all families. DB16 and N1B1, despite significant differences of stomata size and density, significantly decreased transpiration, and thereby increased their intrinsic water use efficiency. Under drought, relative growth rate was significantly decreased. Given that genotype differences were found, these families and salinity and fertilizer treatments need to be explored in field trials.

Text World Theory and real world readers: From literature to life in a Belfast prison.

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Canning, Patricia

2017-05-01

Cognitive stylistics offers a range of frameworks for understanding (amongst other things) what producers of literary texts 'do' with language and how they 'do' it. Less prevalent, however, is an understanding of the ways in which these same frameworks offer insights into what readers 'do' (and how they 'do' it). Text World Theory (Werth, 1999; Gavins, 2007; Whiteley, 2011) has proved useful for understanding how and why readers construct mental representations engendered by the act of reading. However, research on readers' responses to literature has largely focused on an 'idealised' reader or an 'experimental' subject-reader often derived from within the academy and conducted using contrived or amended literary fiction. Moreover, the format of traditional book groups (participants read texts privately and discuss them at a later date) as well as online community forums such as Goodreads, means that such studies derive data from post-hoc, rather than real-time textual encounters and discussions. The current study is the first of its kind in analysing real-time reading contexts with real readers during a researcher-led literary project ('read.live.learn') in Northern Ireland's only female prison. In doing so, the study is unique in addressing experimental and post hoc bias. Using Text World Theory, the paper considers the personal and social impact of reader engagement in the talk of the participants. As such, it has three interrelated aims: to argue for the social and personal benefits of reading stylistically rich literature in real-time reading groups; to demonstrate the efficacy of stylistics for understanding how those benefits come about, and to demonstrate the inter-disciplinary value of stylistics, particularly its potential for traversing traditional research parameters.

Salt Solubility Products of Diprenorphine Hydrochloride, Codeine and Lidocaine Hydrochlorides and Phosphates – Novel Method of Data Analysis Not Dependent on Explicit Solubility Equations

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Gergely Völgyi

2013-12-01

Full Text Available A novel general approach was described to address many of the challenges of salt solubility determination of drug substances, with data processing and refinement of equilibrium constants encoded in the computer program pDISOL-XTM. The new approach was illustrated by the determinations of the solubility products of diprenorphine hydrochloride, codeine hydrochloride and phosphate, lidocaine hydrochloride and phosphate at 25 oC, using a recently-optimized saturation shake-flask protocol.  The effects of different buffers (Britton-Robinson universal and Sörensen phosphate were compared. Lidocaine precipitates were characterized by X-ray powder diffraction (XRPD and polarization light microscopy. The ionic strength in the studied systems ranged from 0.25 to 4.3 M. Codeine (and possibly diprenorphine chloride were less soluble than the phosphates for pH > 2. The reverse trend was evident with lidocaine.  Diprenorphine saturated solutions showed departure from the predictions of the Henderson-Hasselbalch equation in alkaline (pH > 9 solutions, consistent with the formation of a mixed-charge anionic dimer.

Simultaneous Chronoamperometric Sensing of Ascorbic Acid and Acetaminophen at a Boron-Doped Diamond Electrode

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Ciprian Radovan

2008-06-01

Full Text Available Cyclic voltammetry (CV and chronoamperometry (CA have been used to sense and determine simultaneously L-ascorbic acid (AA and acetaminophen (AC at a boron-doped diamond electrode (BDDE in a Britton-Robinson buffer solution. The calibration plots of anodic current peak versus concentration obtained from CV and CA data for both investigated compounds in single and di-component solutions over the concentration range 0.01 mM – 0.1 mM proved to be linear, with very good correlation parameters. Sensitivity values and RSD of 2-3% were obtained for various situations, involving both individual and simultaneous presence of AA and AC. The chronoamperometric technique associated with standard addition in sequential one step and/or two successive and continuous chronoamperograms at two characteristic potential levels represented a feasible option for the simultaneous determination of AA and AC in real sample systems such as pharmaceutical formulations. The average values indicated by the supplier were confirmed to a very close approximation from chronoamperomgrams by using several additions with the application of suitable current correction factors.

Adsorptive stripping voltammetric determination of triprolidine hydrochloride in pharmaceutical tablets.

Science.gov (United States)

Zayed, S I M; Habib, I H I

2005-01-01

The electrochemical behavior of antihistaminic drug, viz. triprolidine hydrochloride (TripCl), at a hanging mercury drop electrode (HMDE) is investigated. Chemical and electrical parameters affecting the adsorptive voltammetric measurements are optimized. Different modes of sweep, viz. direct current DC, normal pulse NP, differential pulse DP and square wave SW modes, over the potential range from -800 to -1400 mV, are used in the presence of 0.04 M Britton-Robinson buffer pH 11, with accumulation time 30 s, scan rate 50 mV/s and pulse amplitude 50 mV. The reduction process is irreversible and involved the transfer of two electrons and two protons. Their responses are linear over the concentration range 15-157 ng/ml with average correlation coefficient 0.9998, while the detection limit is 2.64, 6.24, 8.80 and 2.12 ng/ml for DC, DP, SW and NP mode, respectively. The differential pulse method has been applied successfully for the determination of the drug in Egyptian pharmaceutical preparation with mean recovery 99.55+/-0.67%.

Facile preparation of molecularly imprinted polypyrrole-graphene-multiwalled carbon nanotubes composite film modified electrode for rutin sensing.

Science.gov (United States)

Yang, Lite; Yang, Juan; Xu, Bingjie; Zhao, Faqiong; Zeng, Baizhao

2016-12-01

In this paper, a novel molecularly imprinted composite film modified electrode was presented for rutin (RT) detection. The modified electrode was fabricated by electropolymerization of pyrrole on a graphene-multiwalled carbon nanotubes composite (G-MWCNTs) coated glassy carbon electrode in the presence of RT. The netlike G-MWCNTs composite, prepared by in situ hydrothermal process, had high conductivity and electrocatalytic activity. At the resulting MIP/G-MWCNTs/GCE electrode RT could produce a sensitive anodic peak in pH 1.87 Britton-Robinson buffer solution. The factors affecting the electrochemical behavior and response of RT on the modified electrode were carefully investigated and optimized. Under the selected conditions, the linear response range of RT was 0.01-1.0μmolL -1 and the detection limit (S/N=3) was 5.0nmolL -1 . The electrode was successfully applied to the determination of RT in buckwheat tea and orange juice samples, and the recoveries for standards added were 93.4-105%. Copyright © 2016 Elsevier B.V. All rights reserved.

Modification of Screen Printed Carbon Electrode (SPCE with Fe3O4 for the Determination of Nitrite (NO2- in Squarewave Voltammetry

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Erica Marista Rosida

2017-11-01

Full Text Available Nitrite is one of the food preservatives that the government permits, but on the use of over limits can cause endanger health, so it is necessary to control the content of nitrite in the food. Modification of electrodes on a screen printed carbon electrode (SPCE with Fe3O4 has been successfully done for determination of nitrite. Modification of the electrode has been done by electrodeposition with cyclic voltammetry. Electrodeposition successfully performed with an electrolyte solution of FeCl3 in ethanol. Selection of the optimum drying temperature modified electrode obtained based on the respond of the solution of nitrite in Britton Robinson buffer pH 8. The result of the modification electrode used for the determination of nitrite with squarewave voltammetry method. Reaction between Fe3+ with nitrite a basis for determining nitric indirectly measured so that the peak current is the peak current of Fe3+ of about 0,55 V vs Ag/AgCl. The results showed nitrite measurements with this method has a detection limit of 1.3 x 10-8 M.

Adsorption and electropolymerization of toluidine blue on the nanostructured octakis(hydridodimethylsiloxy)octasilsesquioxane surface

International Nuclear Information System (INIS)

Ribeiro do Carmo, Devaney; Rocha de Castro, Gustavo; Utrera Martines, Marco Antonio; Filho, Newton Luiz Dias; Ramos Stradiotto, Nelson

2008-01-01

Toluidine blue O (TBO) was adsorbed on the octakis(hydridodimethylsiloxy)octasilsesquioxane (Q 8 M 8 H ) surface. The characterization of the precursor (Q 8 M 8 H ) and resulting materials obtained by the reaction of Q 8 M 8 H and toluidine blue (CTBO) were defined using Fourier transform infrared spectra, nuclear magnetic resonance solid-state 13 C and Si 29 magic angle spinning. The electrochemical polymerization in a glassy carbon electrode was verified by means of a film silsesquioxane formation (FCTBO) using cyclic voltammetry in a potential range of -0.5 to 1.3 V (vs. saturated calomel electrode (SCE)) in a Britton Robinson (B-R) buffer solution (pH 2.0). The cyclic voltammogram of the film exhibits two redox couples with a formal potential of -0.15 and -0.02 V (B-R buffer pH 5). The formal potential shifts linearly in the cathodic direction by increasing the pH solution with a slope of 71 and 57 mV per unit for the first and second couple, respectively. The film was electrochemically very stable

Amperometric Sensor for Detection of Chloride Ions†

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Trnkova, Libuse; Adam, Vojtech; Hubalek, Jaromir; Babula, Petr; Kizek, Rene

2008-01-01

Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE) and at a CPE modified with solid AgNO3, a solution of AgNO3 and/or solid silver particles. Detection limits (3 S/N) for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO3, solution of AgNO3 and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV) we estimated the limit of detection (3 S/N) as 500 nM. PMID:27873832

Amperometric Sensor for Detection of Chloride Ions.

Science.gov (United States)

Trnkova, Libuse; Adam, Vojtech; Hubalek, Jaromir; Babula, Petr; Kizek, Rene

2008-09-15

Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE) and at a CPE modified with solid AgNO₃, a solution of AgNO₃ and/or solid silver particles. Detection limits (3 S/N) for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO₃, solution of AgNO₃ and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV) we estimated the limit of detection (3 S/N) as 500 nM.

Acid-base equilibria and solubility of loratadine and desloratadine in water and micellar media.

Science.gov (United States)

Popović, Gordana; Cakar, Mira; Agbaba, Danica

2009-01-15

Acid-base equilibria in homogeneous and heterogeneous systems of two antihistaminics, loratadine and desloratadine were studied spectrophotometrically in Britton-Robinson's buffer at 25 degrees C. Acidity constant of loratadine was found to be pK(a) 5.25 and those of desloratadine pK(a1) 4.41 and pK(a2) 9.97. The values of intrinsic solubilities of loratadine and desloratadine were 8.65x10(-6) M and 3.82x10(-4) M, respectively. Based on the pK(a) values and intrinsic solubilities, solubility curves of these two drugs as a function of pH were calculated. The effects of anionic, cationic and non-ionic surfactants applied in the concentration exceeding critical micelle concentration (cmc) on acid-base properties of loratadine and desloratadine, as well as on intrinsic solubility of loratadine were also examined. The results revealed a shift of pK(a) values in micellar media comparing to the values obtained in water. These shifts (DeltapK(a)) ranged from -2.24 to +1.24.

Study on the interaction between albendazole and eosin Y by fluorescence, resonance Rayleigh scattering and frequency doubling scattering spectra and their analytical applications

Science.gov (United States)

Tian, Fengling; Huang, Wei; Yang, Jidong; Li, Qin

In pH 3.25-3.35 Britton-Robinson (BR) buffer solution, albendazole (ABZ) could react with eosin Y (EY) to form a 1:1 ion-association complex, which not only results in the quenching of fluorescence, but also resulted in the great enhancement of resonance Rayleigh scattering (RRS) and frequency doubling scattering (FDS). Furthermore, a new RRS spectrum will appear, and the maximum RRS wavelength was located at about 356 nm. The detection limit for ABZ were 21.51 ng mL-1 for the fluorophotometry, 6.93 ng mL-1 for the RRS method and 12.89 ng mL-1 for the FDS method. Among them, the RRS method had the highest sensitivity. The experimental conditions were optimized and effects of coexisting substances were evaluated. Meanwhile, the influences of coexisting substances were tested. The methods have been successfully applied to the determination of ABZ in capsules and human urine samples. The composition and structure of the ion-association complex and the reaction mechanism were discussed.

Anti-inflammatory effects of chloroform soluble fraction from Perilla frutescens britton leaves produced by radiation breeding in RAW264.7 cells

Energy Technology Data Exchange (ETDEWEB)

Jo, Yun Ho; So, Yang Kang; Kim, Jin Baek; Jin, Chang Hyun [Advance Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Lee, Jun Soo [Dept. Food Science and Technology Graduate School, Chungbuk National University, Cheongju (Korea, Republic of); Lee, Seung Young [Freshwater Bioresources Utilization Division, Nakdonggang National Institute of Biological Resources, Sangju (Korea, Republic of)

2016-11-15

The present study aimed to determine the anti-inflammatory effects of each solvent fraction of a mutant Perilla frutescens produced by radiation breeding. Following extraction with 80% methanol, P. frutescens was fractionated in the order of hexane, chloroform, ethyl acetate, and butanol; the chloroform fraction exhibited less cytotoxicity, the greatest inhibitory effect on the production of nitric oxide (NO), and the highest rate of inhibition on the generation of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and interferon-β (IFN-β). The chloroform fraction also suppressed the mRNA and protein levels of inducible nitric oxide synthase (iNOS) and reduced the activation of nuclear factor-{sub κ}B (NF-{sub κ}B) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Finally, the presence of corosolic acid in the chloroform fraction was identifed. Taken together, the present fndings indicate that the chloroform fraction obtained from mutant P. frutescens inhibited NO production in LPSstimulated RAW264.7 cells via the suppression of iNOS expression and the inactivation of NF-{sub κ}B.

Causality in Psychiatry: A Hybrid Symptom Network Construct Model

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Gerald eYoung

2015-11-01

Full Text Available Causality or etiology in psychiatry is marked by standard biomedical, reductionistic models (symptoms reflect the construct involved that inform approaches to nosology, or classification, such as in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; American Psychiatric Association, 2013. However, network approaches to symptom interaction (i.e., symptoms are formative of the construct; e.g., McNally, Robinaugh, Wu, Wang, Deserno, & Borsboom, 2014, for PTSD (posttraumatic stress disorder are being developed that speak to bottom-up processes in mental disorder, in contrast to the typical top-down psychological construct approach. The present article presents a hybrid top-down, bottom-up model of the relationship between symptoms and mental disorder, viewing symptom expression and their causal complex as a reciprocally dynamic system with multiple levels, from lower-order symptoms in interaction to higher-order constructs affecting them. The hybrid model hinges on good understanding of systems theory in which it is embedded, so that the article reviews in depth nonlinear dynamical systems theory (NLDST. The article applies the concept of emergent circular causality (Young, 2011 to symptom development, as well. Conclusions consider that symptoms vary over several dimensions, including: subjectivity; objectivity; conscious motivation effort; and unconscious influences, and the degree to which individual (e.g., meaning and universal (e.g., causal processes are involved. The opposition between science and skepticism is a complex one that the article addresses in final comments.

Abcc9 is required for the transition to oxidative metabolism in the newborn heart.

Science.gov (United States)

Fahrenbach, John P; Stoller, Douglas; Kim, Gene; Aggarwal, Nitin; Yerokun, Babatunde; Earley, Judy U; Hadhazy, Michele; Shi, Nian-Qing; Makielski, Jonathan C; McNally, Elizabeth M

2014-07-01

The newborn heart adapts to postnatal life by shifting from a fetal glycolytic metabolism to a mitochondrial oxidative metabolism. Abcc9, an ATP-binding cassette family member, increases expression concomitant with this metabolic shift. Abcc9 encodes a membrane-associated receptor that partners with a potassium channel to become the major potassium-sensitive ATP channel in the heart. Abcc9 also encodes a smaller protein enriched in the mitochondria. We now deleted exon 5 of Abcc9 to ablate expression of both plasma membrane and mitochondria-associated Abcc9-encoded proteins, and found that the myocardium failed to acquire normal mature metabolism, resulting in neonatal cardiomyopathy. Unlike wild-type neonatal cardiomyocytes, mitochondria from Ex5 cardiomyocytes were unresponsive to the KATP agonist diazoxide, consistent with loss of KATP activity. When exposed to hydrogen peroxide to induce cell stress, Ex5 neonatal cardiomyocytes displayed a rapid collapse of mitochondria membrane potential, distinct from wild-type cardiomyocytes. Ex5 cardiomyocytes had reduced fatty acid oxidation, reduced oxygen consumption and reserve. Morphologically, Ex5 cardiac mitochondria exhibited an immature pattern with reduced cross-sectional area and intermitochondrial contacts. In the absence of Abcc9, the newborn heart fails to transition normally from fetal to mature myocardial metabolism.-Fahrenbach, J. P., Stoller, D., Kim, G., Aggarwal, N., Yerokun, B., Earley, J. U., Hadhazy, M., Shi, N.-Q., Makielski, J. C., McNally, E. M. Abcc9 is required for the transition to oxidative metabolism in the newborn heart. © FASEB.

Study on the interaction between three benzimidazole anthelmintics and eosin Y by high performance liquid chromatography associating with resonance light scattering and its application.

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Pan, Ziyu; Peng, Jingdong; Zang, Xu; Lei, Gang; He, Yan; Liu, Di

2016-07-01

A novel, highly selective, and sensitive resonance light scattering (RLS) detection approach coupled with high performance liquid chromatography (HPLC) was researched and developed for the synchronous analysis of three kinds of benzimidazole anthelmintics, including mebendazole (MBZ), albendazole (ABZ), and fenbendazole (FBZ) for the first time. In the pH range of 3.5-3.7 Britton-Robinson buffer medium, three kinds of anthelmintics, which were separated by HPLC, reacted with eosin Y (EY) to form 1:1 ion-association complexes, resulting in significantly enhanced RLS signals and the maximum peak located at 335 nm. The enhanced RLS intensity was in proportion to the MBZ, ABZ, and FBZ concentration in the range 0.2-25, 0.2-23, and 0.15-20 μg/mL, respectively. The limit of detection was in the range of 0.064-0.16 μg/mL. In addition, human urine was determined to validate the proposed method by spiked samples and real urine samples. Satisfactory results were obtained by HPLC-RLS method. Graphical Abstract The diagram mechanism of generating resonance between emitted light and scattered light.

A COMPARISON ON THE TIME MANAGEMENT UNDERSTANDINGS OF UNIVERSITY ACADEMIC STAFF

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Kubilay Çimen

2017-10-01

Full Text Available The aim of this study was to investigate time management understandings of university academic staff with their participation or not participation in the sports activities, gender and their work year. The sample of the study consisted of 93 university academic staff who Works at Dumlupinar University (37 women and 56 men. As data collection tool in addition to a questionary, which consists 10 items developed by the researchers, “Time Management Scale”, which was developed by Britton and Tesser (1991 and Turkish adaptation was done by Koçak and Alay (2002 was used. The obtained data were analyzed by using SPSS for windows. In addition to descriptive statistics, Mann Whitney U and Kruskal Wallis test were done in order to determine significant differences between time management understandings of the academic staff. As a result, although, there was no significant difference between participants’ time management understanding according to gender (p>.05 there were significant differences between participants’ time management understandings in the “time attitudes” subscale according to their work year and in “time management” and “time attitudes” subscales according to participation /or not participation in sport activities (p<.05.

Study on the ternary mixed ligand complex of palladium(II)-aminophylline-fluorescein sodium by resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectrum and its analytical application.

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Chen, Peili; Liu, Shaopu; Liu, Zhongfang; Hu, Xiaoli

2011-01-01

The interaction between palladium(II)-aminophylline and fluorescein sodium was investigated by resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectrum. In pH 4.4 Britton-Robinson (BR) buffer medium, aminophylline (Ami) reacted with palladium(II) to form chelate cation([Pd(Ami)]2+), which further reacted with fluorescein sodium (FS) to form ternary mixed ligand complex [Pd(Ami)(FS)2]. As a result, resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering spectrum (FDS) were enhanced. The maximum scattering wavelengths of [Pd(Ami)(FS)2] were located at 300 nm (RRS), 650 nm (SOS) and 304 nm (FDS). The scattering intensities were proportional to the Ami concentration in a certain range and the detection limits were 7.3 ng mL(-1) (RRS), 32.9 ng mL(-1) (SOS) and 79.1 ng mL(-1) (FDS), respectively. Based on it, the new simple, rapid, and sensitive scattering methods have been proposed to determine Ami in urine and serum samples. Moreover, the formation mechanism of [Pd(Ami)(FS)2] and the reasons for enhancement of RRS were fully discussed. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

New contribution in the study of phase formation in mixed alkanethiol self-assembled monolayers: a powerful tool for transducers design

International Nuclear Information System (INIS)

Coelho, Dyovani; Machado, Sergio A.S.

2014-01-01

Here, the formation of distinct 3-mercaptopropionic acid (MPA) and 11-mercaptoundecanoic acid (MUA) domains on polycrystalline gold surfaces was investigated by cyclic voltammetry and electrochemical quartz crystal nanobalance. Voltammetric experiments with the [Fe(CN) 6 ] 4-/3− redox couple showed that the MPA SAM allowed electron transference at the same rate as the bare gold surface, while the MUA SAM blocked the entire electrode surface. The chemical nature of mixed SAMs is discussed by evaluating the mass variations and the respective molecular weight in the desorption potential regions for each thiol by electrochemical quartz crystal nanobalance. Different domains containing MUA, MPA and their mixtures were identified in the massograms, thus demonstrating MPA island domains and the electrochemical response obtained for the [Fe(CN) 6 ] 4-/3− redox couple. The modified surfaces, as well as bare Au electrode, were used for electroanalysis of the flavonoid fisetin in Britton-Robinson buffer solution, pH 5. Depending on the modification, detection limits as low as 3.35 ×10 −10 mol L −1 , which attests the possibility of use such surfaces in electroanalysis

Voltammetric Quantification of Paraquat and Glyphosate in Surface Waters

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William Roberto Alza-Camacho

2016-09-01

Full Text Available The indiscriminate use of pesticides on crops has a negative environmental impact that affects organisms, soil and water resources, essential for life. Therefore, it is necessary to evaluate the residual effect of these substances in water sources. A simple, affordable and accessible electrochemical method for Paraquat and Glyphosate quantification in water was developed. The study was conducted using as supporting electrolyte Britton-Robinson buffer solution, working electrode of glassy carbon, Ag/AgCl as the reference electrode, and platinum as auxiliary electrode. Differential pulse voltammetry (VDP method for both compounds were validated. Linearity of the methods presented a correlation coefficient of 0.9949 and 0.9919 and the limits of detection and quantification were 130 and 190 mg/L for Paraquat and 40 and 50 mg/L for glyphosate. Comparison with the reference method showed that the electrochemical method provides superior results in quantification of analytes. Of the samples tested, a value of Paraquat was between 0,011 to 1,572 mg/L and for glyphosate it was between 0.201 to 2.777 mg/L, indicating that these compounds are present in water sources and that those may be causing serious problems to human health.

Amperometric Sensor for Detection of Chloride Ions

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Rene Kizek

2008-09-01

Full Text Available Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE and at a CPE modified with solid AgNO3, a solution of AgNO3 and/or solid silver particles. Detection limits (3 S/N for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO3, solution of AgNO3 and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV we estimated the limit of detection (3 S/N as 500 nM.

Laccase-based biosensor for the determination of polyphenol index in wine.

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Di Fusco, Massimo; Tortolini, Cristina; Deriu, Daniela; Mazzei, Franco

2010-04-15

In this work we have developed and characterized the use of Laccases from Trametes versicolor (TvL) and Trametes hirsuta (ThL) as biocatalytic components of electrochemical biosensors for the determination of polyphenol index in wines. Polyazetidine prepolimer (PAP) was used as immobilizing agent, multi-walled and single-walled carbon nanotubes screen-printed electrodes as sensors (MWCNTs-SPE and SWCNTs-SPE) and gallic acid as standard substrate. The amperometric measurements were carried out by using a flow system at a fixed potential of -100 mV vs. silver/silver chloride electrode in Britton-Robinson buffer 0.1 mol L(-1), pH 5. The results were compared with those obtained with the Folin-Ciocalteau reference method. The results obtained in the analysis of twelve Italian wines put in evidence the better suitability of ThL-MWCNTs-based biosensor in the determination of the polyphenol index in wines. This biosensor shows fast and reliable amperometric responses to gallic acid with a linear range 0.1-18.0 mg L(-1) (r(2)=0.999). The influence of the interferences on both spectrophotometric and electrochemical measurements have been carefully evaluated. (c) 2009 Elsevier B.V. All rights reserved.

DNA-binding, DNA cleavage and cytotoxicity studies of two anthraquinone derivatives.

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Gholivand, M B; Kashanian, S; Peyman, H

2012-02-15

The interaction of native calf thymus DNA (CT-DNA) with two anthraquinones including quinizarin (1,4-dihydroxy anthraquinone) and danthron (1,8-dihydroxy anthraquinone) in a mixture of 0.04M Brittone-Robinson buffer and 50% of ethanol were studied at physiological pH by spectrofluorometric and cyclic voltammetry techniques. The former technique was used to calculate the binding constants of anthraquinones-DNA complexes at different temperatures. Thermodynamic study indicated that the reactions of both anthraquinone-DNA systems are predominantly entropically driven. Furthermore, the binding mechanisms on the reaction of the two anthraquinones with DNA and the effect of ionic strength on the fluorescence property of the system have also been investigated. The results of the experiments indicated that the binding modes of quinizarin and danthron with DNA were evaluated to be groove binding. Moreover, the cytotoxic activity of both compounds against human chronic myelogenous leukemia K562 cell line and DNA cleavage were investigated. The results indicated that these compounds slightly cleavage pUC18 plasmid DNA and showed minor antitumor activity against K562 (human chronic myeloid leukemia) cell line. Copyright © 2011 Elsevier B.V. All rights reserved.

Electroanalytical Determination of Gemifloxacin Mesylate in Bulk, Tablets and Human Urine Using Gold Nanoparticles Modified Carbon Paste Electrode

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Ali Attia

2014-12-01

Full Text Available A simple, precise, inexpensive and sensitive voltammetric method has been developed for the determination of gemifloxacin mesylate (GEM in the presence of tween 80 in the bulk, farmaceutical dosage forms and human urine at gold nanoparticles modified carbon paste electrode (GNCPE. The electrochemical behavior of GEM has been investigated by using cyclic voltammetry (CV and differential pulse voltammetry (DPV techniques. The electrochemical oxidation of GEM was an irreversible process which exhibited adsorption-diffusion controlled process behavior in Britton-Robinson (BR buffer over the entire pH range of values from 2 to 9. The adsorptive stripping response was evaluated as a function of some variables such as pH, type of surfactant, scan rate and accumulation time. The anodic peak current varied linearly over the range from 8.0 × 10-7 to 2.8 × 10-5 M. The limits of detection and quantification were 7.32 × 10-8 M and 2.44 × 10-7 M, respectively. The relative standard deviations and the percentage recoveries were found in the following ranges: 0.58-1.35% and 99.37-101.76%, respectively.

Quantitative inheritance of crop timing traits in interspecific hybrid Petunia populations and interactions with crop quality parameters.

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Warner, Ryan M; Walworth, Aaron E

2010-01-01

The leaf unfolding rate (i.e., development rate) and the number of nodes forming prior to floral initiation are 2 factors determining production times for floriculture crops. Wild relative species of the cultivated petunia (Petunia x hybrida Vilm.) that exhibited faster development rates than modern cultivars and may therefore be useful genetic sources to develop cultivars with decreased production time were identified. Three interspecific F(2) families, Petunia exserta Stehmann x P. axillaris (Lam.) Britton et al., P. x hybrida 'Mitchell' x P. axillaris, and P. axillaris x P. integrifolia (Hook.) Schinz & Thell. all exhibited transgressive segregation for development rate and node number below the first flower. Development rate and time to flower segregated independently in all families. Leaf number below the first flower was positively correlated with leaf unfolding rate in all families except P. axillaris x P. integrifolia. Time to flower was positively correlated with flower bud number in the P. x hybrida 'Mitchell' x P. axillaris and P. axillaris x P. integrifolia families only. Based on these results, wild Petunia germplasm should be useful for developing petunia cultivars with reduced crop production times, but some negative effects on crop quality parameters may need to be overcome.

Electrochemistry of moexipril: experimental and computational approach and voltammetric determination.

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Taşdemir, Hüdai I; Kiliç, E

2014-09-01

The electrochemistry of moexipril (MOE) was studied by electrochemical methods with theoretical calculations performed at B3LYP/6-31 + G (d)//AM1. Cyclic voltammetric studies were carried out based on a reversible and adsorption-controlled reduction peak at -1.35 V on a hanging mercury drop electrode (HMDE). Concurrently irreversible diffusion-controlled oxidation peak at 1.15 V on glassy carbon electrode (GCE) was also employed. Potential values are according to Ag/AgCI, (3.0 M KCI) and measurements were performed in Britton-Robinson buffer of pH 5.5. Tentative electrode mechanisms were proposed according to experimental results and ab-initio calculations. Square-wave adsorptive stripping voltammetric methods have been developed and validated for quantification of MOE in pharmaceutical preparations. Linear working range was established as 0.03-1.35 microM for HMDE and 0.2-20.0 microM for GCE. Limit of quantification (LOQ) was calculated to be 0.032 and 0.47 microM for HMDE and GCE, respectively. Methods were successfully applied to assay the drug in tablets by calibration and standard addition methods with good recoveries between 97.1% and 106.2% having relative standard deviation less than 10%.

Bijdrage tot de kennis van den groei van Pseudotsuga taxifolia Britton in Nederland in verband met zijn beteekenis voor den Nederlandschen boschbouw

NARCIS (Netherlands)

Hoogh, de J.

1925-01-01

Development of the green Douglas fir in the Netherlands in different places with different methods of planting was studied by enquiry, personal research and from the literature. The climate and soil types seemed suitable. Game, insects and fungi caused little damage. The stands studied all derived

„Ich fordre so viel Freiheit und Musse, als nötig ist, über mich selbst, über meine Bestimmung und meinen Werth als mensch zu denken“ (Moritz, 1962, 17. Zur Kunstund Freiheitskonzeption bei Karl Philipp Moritz. „Ich fordre so viel Freiheit und Musse, als nötig ist, über mich selbst, über meine Bestimmung und meinen Werth als mensch zu denken“ (Moritz, 1962, 17. On Karl Philipp Moritz’s concept of art and freedom

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Krzysztof Tkaczyk

2008-01-01

Full Text Available In 1786 in Rome, Johann Wolfgang Goethe wrote about him: “He is my younger brother; we art cut from the same mould. However, fate was against him, whereas I was fortune’s favourite.” He meant Karl Phillip Moritz (1756-1793, a German writer and art critic, Greek mythology historian, precursor of modern psychology and the author of psychological novel. If we assume that Goethe’s comments concern Moritz’s material and social status only, we would have to admit that Goethe was right. However, if we apply these judgments to the quality of his (Moritz’s works, we would be inclined to saying that in this case the great Goethe was wrong. In his aesthetic, Moritz is far more interesting and progressive than his “elder brother”; in his literary criticism – more consistent than Schiller, and in perceiving society and politics – more radical than Kant. This article is mainly on key concept regarding Moritz’s aesthetic works: the concept of beauty and its functionalism. Definition of “the work of art” as a closed, specified unity enables Moritz to get out of the frame of aesthetics itself and to enter the sphere of politics. Moritz liberates man from the restraints of utility and treats him as a noble individual who possesses the artistic value in himself.

DETERMINAÇÃO RÁPIDA E SIMPLES DE CITRATO DE SILDENAFILA (VIAGRA® E GENÉRICOS EMPREGANDO ELETRODO IMPRESSO DE CARBONO EM SISTEMAS FIA E BIA COM DETECÇÃO AMPEROMÉTRICA

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Rafael S. Backes

Full Text Available This work presents two amperometric methods for Sildenafil Citrate (SC determination in erectile dysfunction drugs (Viagra® and Generics, using Batch Injection Analysis (BIA and Flow Injection Analysis (FIA systems with a cell for Screen Printed Electrodes (SPE. In Britton- Robinson buffer solution (pH 2, the SC presented an irreversible anodic peak at around +1.0 V vs. Ag pseudo-reference electrode, using five different working electrodes of commercial SPE. The carbon SPE (unmodified was selected as the best working electrode, providing good sensitivity, precision and low-cost. The SC amperometric detection for two proposed methods was performed at +1.1 V. The best conditions for SC determination by hydrodynamic systems were obtained through injection volumes of 50 and 150 µL at flow rates of 100 and 75 µL s-1, for BIA and FIA respectively. In these conditions, BIA system showed the best sensitivity (0.188 µA mol-1 L and theoretical analytical frequency (360 h-1 for SC determination. The repeatability studies were similar for both systems with relative standard deviation of approximately 3.0%. The SC analyses in pharmaceutical samples obtained by two proposed methods were compared to HPLC-UV method.

An erythrosin B-based "turn on" fluorescent sensor for detecting perfluorooctane sulfonate and perfluorooctanoic acid in environmental water samples.

Science.gov (United States)

Cheng, Zhen; Du, Lingling; Zhu, Panpan; Chen, Qian; Tan, Kejun

2018-05-04

Because of the serious harm to animals and the environment associated with perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), a rapid, sensitive and low-cost method for detecting PFOS and PFOA is of great importance. In this paper, a novel sensing method has been proposed for the highly sensitive detection of PFOS and PFOA in environmental water samples based on the "turn-on" switch of erythrosine B (EB)-hexadecyltrimethylammonium bromide (CTAB) system. In pH 8.55 Britton-Robinson (BR) buffer, EB can react with CTAB by electrostatic attraction, resulting in a strong fluorescence quenching of EB. With a subsequent addition of the CTAB, a red-shift occurred (11 nm), followed by a significant increase in fluorescence at high surfactant concentrations. It was found that PFOS and PFOA can obviously enhance fluorescence intensity of EB-CTAB system. The enhanced fluorescence intensity is proportional to the concentration of PFOS and PFOA in the range of 0.05-10 μM with detection limit of 12.8 nM and 11.8 nM (3σ), respectively. The presented assay has been successfully applied to sensing PFOS and PFOA in real water samples with RSD ≤ 4.3% and 2.9%, respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

Extending the capability of forensic electrochemistry to the novel psychoactive substance benzylpiperazine

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S.A. Waddell

2017-04-01

Full Text Available Benzylpiperazine (BZP is a novel psychoactive substance that is commonly abused in tablet form as an “ecstasy-type” drug. Electroanalysis offers genuine potential for field testing of bulk drug samples. This research is the first to investigate the viability of voltammetric analysis of BZP. Initial cyclic voltammetry in 0.1 M KCl showed an oxidative peak at a glassy carbon electrode for BZP at approximately 0.8 V (scan rate 205 mV s−1. Next an optimised electrode/electrolyte combination (viz. 80:20 W:W glassy carbon beads:nujol and pH 9.5, 40 mM, Britton-Robinson buffer was developed using K3Fe(CN6 to test the electrode material. The oxidation of BZP involves two electrons and two protons and a mechanism has been proposed. An anodic stripping square wave voltammetric method was optimised by factorial design with the conditions of deposition: −0.8 V for 135 s, and stripping: step height 10 mV, amplitude 50 mV and frequency 13 Hz. A limit of detection of 6 μM was achieved. The resolution against 3,4-methylenedioxymethylamphetamine (MDMA was also verified. Keywords: Voltammetry, Forensic, Controlled drugs, Benzylpiperazine, Ecstasy

Oil production at different stages of leaf development in Lippia alba

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Diego Pandeló

2012-06-01

Full Text Available The aim of this work was to analyze terpene oil production and terpene synthases (TPS gene expression from leaves at different developmental stages of different chemotypes of Lippia alba (Mill. N.E. Br. ex Britton & P. Wilson, Verbenaceae. Hydro-distilled essential oil were used for chemical analysis and gene expression of three monoterpene synthase genes called LaTPS12, LaTPS23 and LaTPS25 were used for analyses of gene expression associated to oil production. The putative genes were associated to TPS-b gene class. Semi-quantitative PCR and quantitative PCR (qPCR analysis were used to investigate the expression profile of those three putative genes in different leaf stages and different chemotypes. Additionally, total oil production and gene expression of putative TPS genes cloned from L. alba chemotype linalool were evaluated at different stages of leaf development. The expression level of those three genes was higher when the highest oil production was observed, mainly in young leaves at the fourth nodal segment for all evaluated chemotypes. Total oil production was higher at leaves that had unopened trichomes. We also observed that the 1mM of MeJA treatment increased the gene expression in all chemotypes after 24 h elicitation.

Oil production at different stages of leaf development in Lippia alba

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Diego Pandeló

2012-01-01

Full Text Available The aim of this work was to analyze terpene oil production and terpene synthases (TPS gene expression from leaves at different developmental stages of different chemotypes of Lippia alba (Mill. N.E. Br. ex Britton & P. Wilson, Verbenaceae. Hydro-distilled essential oil were used for chemical analysis and gene expression of three monoterpene synthase genes called LaTPS12, LaTPS23 and LaTPS25 were used for analyses of gene expression associated to oil production. The putative genes were associated to TPS-b gene class. Semi-quantitative PCR and quantitative PCR (qPCR analysis were used to investigate the expression profile of those three putative genes in different leaf stages and different chemotypes. Additionally, total oil production and gene expression of putative TPS genes cloned from L. alba chemotype linalool were evaluated at different stages of leaf development. The expression level of those three genes was higher when the highest oil production was observed, mainly in young leaves at the fourth nodal segment for all evaluated chemotypes. Total oil production was higher at leaves that had unopened trichomes. We also observed that the 1mM of MeJA treatment increased the gene expression in all chemotypes after 24 h elicitation.

Electrochemical behavior of labetalol at an ionic liquid modified carbon paste electrode and its electrochemical determination

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Zhang Yan-Mei

2013-01-01

Full Text Available Electrochemical behavior of labetalol (LBT at carbon paste electrode (CPE and an ionic liquid1-benzyl-3-methylimidazolehexafluorophosphate([BnMIM]PF6modified carbon paste electrode([BnMIM]PF6/CPEin Britton-Robinson buffer solution (pH 2.0 was investigated by cyclic voltammetry (CV and square wave voltammetric (SWV. The experimental results showed that LBT at both the bare CPE and [BnMIM]PF6/CPEshowed an irreversible oxidation process, but at [BnMIM]PF6/CPE its oxidation peak current increased greatly and the oxidation peak potential shifted negatively. The electrode reaction process is a diffusion-controlled process involving one electron transferring accompanied by a participation of one proton at [BnMIM]PF6/CPE. At the same time, the electrochemical kinetic parameters were determined. Under the optimized electrochemical experimental conditions, the oxidation peak currents were proportional to LBT concentration in the range of 7.0 x 10-6-1.0 x 10-4 mol L-1 with the limit of detection(LOD, S/N=3 of 4.810 x 10-8 mol L-1and the limit of quantification(LOQ, S/N=10 of 1.60 x 10-7 mol L-1, respectively. The proposed method was successfully applied in the determination of LBT content in commercial tablet samples.

Electrochemical Analysis of Antichemotherapeutic Drug Zanosar in Pharmaceutical and Biological Samples by Differential Pulse Polarography

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Chennupalle Nageswara Reddy

2013-01-01

Full Text Available The electrochemical reduction of zanosar was investigated systematically by direct current polarography, cyclic voltammetry, and differential pulse polarography (DPP. A simple DPP technique was proposed for the direct quantitative determination of anticancer drug zanosar in pharmaceutical formulation and spiked human urine samples for the first time. The reduction potential was −0.28 V versus Ag/AgCl with a hanging mercury drop electrode in Britton-Robinson buffer as supporting electrolyte. The dependence of the intensities of currents and potentials on pH, concentration, scan rate, deposition time, and nature of the supporting electrolyte was investigated. The calibration curve was found to be linear with the following equation: y=0.4041x+0.012, with a correlation coefficient of 0.992 (R2 over a concentration range from 1.0×10-7 M to 1.0×10-3 M. In the present investigation, the achieved limit of detection (LOD and limit of quantization (LQD were 7.42×10-8 M and 2.47×10-8 M; respectively. Excipients did not interfere with the determination of zanosar in pharmaceutical formulation and spiked urine samples. Precision and accuracy of the developed method were checked by recovery studies in pharmaceutical formulation and spiked human urine samples.

Remote sensing of changes in morphology and physiology of trees under stress

Science.gov (United States)

Olson, C. E., Jr.; Rohde, W. G.; Ward, J. M.

1970-01-01

Results of continuing studies of forest trees subjected to varying types of stress are reported. Both greenhouse and field studies are included. Greenhouse work with tree seedlings exposed to varying levels of NaCl and CaCl2 in the soil indicated that, in the initial stages, palisade cells shrink and the amount of air space in the leaf increases. As the severity of damage increases, the cells of the spongy mesophyll shrink and flatten, and the amount of air space in the leaf decreases. Statistical analysis of foliar reflectance and associated moisture content data led to a series of regression equations for predicting foliar moisture content from reflectance data. Equations were calculated for three species, yellow birch (Betula alleghaniensis Britton), sugar maple (Acer saccharum Marsh.) and white ash (Fraxinus americana L.) having multiple correlation coefficients of 0.98, 0.94 and 0.93 respectively. Interpretation of multispectral imagery of the Ann Arbor Forestry Test Site (NASA Site 190) provided evidence that infections of Fomes annosus can be detected in the early stages. Infections of two needle cast diseases were also detected in conifer plantations in the test site. A study of automatic interpretation of multispectral scanner imagery for tree species recognition provided encouraging results.

Electrochemical analysis of antichemotherapeutic drug zanosar in pharmaceutical and biological samples by differential pulse polarography.

Science.gov (United States)

Reddy, Chennupalle Nageswara; Reddyprasad, Puthalapattu; Sreedhar, Neelamyughandhar

2013-01-01

The electrochemical reduction of zanosar was investigated systematically by direct current polarography, cyclic voltammetry, and differential pulse polarography (DPP). A simple DPP technique was proposed for the direct quantitative determination of anticancer drug zanosar in pharmaceutical formulation and spiked human urine samples for the first time. The reduction potential was -0.28 V versus Ag/AgCl with a hanging mercury drop electrode in Britton-Robinson buffer as supporting electrolyte. The dependence of the intensities of currents and potentials on pH, concentration, scan rate, deposition time, and nature of the supporting electrolyte was investigated. The calibration curve was found to be linear with the following equation: y = 0.4041x + 0.012, with a correlation coefficient of 0.992 (R (2)) over a concentration range from 1.0 × 10(-7) M to 1.0 × 10(-3) M. In the present investigation, the achieved limit of detection (LOD) and limit of quantization (LQD) were 7.42 × 10(-8) M and 2.47 × 10(-8) M; respectively. Excipients did not interfere with the determination of zanosar in pharmaceutical formulation and spiked urine samples. Precision and accuracy of the developed method were checked by recovery studies in pharmaceutical formulation and spiked human urine samples.

Double-wavelength overlapping resonance Rayleigh scattering technique for the simultaneous quantitative analysis of three β-adrenergic blockade

Science.gov (United States)

Tan, Xuanping; Yang, Jidong; Li, Qin; Yang, Qiong; Shen, Yizhong

2016-05-01

Four simple and accurate spectrophotometric methods were proposed for the simultaneous determination of three β-adrenergic blockade, e.g. atenolol, metoprolol and propranolol. The methods were based on the reaction of the three drugs with erythrosine B (EB) in a Britton-Robinson buffer solution at pH 4.6. EB could combine with the drugs to form three ion-association complexes, which resulted in the resonance Rayleigh scattering (RRS) intensity that is enhanced significantly with new RRS peaks that appeared at 337 nm and 370 nm, respectively. In addition, the fluorescence intensity of EB was also quenched. The enhanced scattering intensities of the two peaks and the fluorescence quenched intensity of EB were proportional to the concentrations of the drugs, respectively. What is more, the RRS intensity overlapped with the double-wavelength of 337 nm and 370 nm (so short for DW-RRS) was also proportional to the drugs concentrations. So, a new method with highly sensitive for simultaneous determination of three bisoprolol drugs was established. Finally, the optimum reaction conditions, influencing factors and spectral enhanced mechanism were investigated. The new DW-RRS method has been applied to simultaneously detect the three β-blockers in fresh serum with satisfactory results.

Fabrication of an electrochemical sensor for determination of doxorubicin in human plasma and its interaction with DNA

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Reza Hajian

2017-02-01

Full Text Available In this work, an electrochemical sensor was fabricated for determination of an anthracycline, doxorubicin (DOX as a chemotherapy drug in plasma based on multi-walled carbon nanotubes modified platinum electrode (Pt/MWCNTs. DOX was effectively accumulated on the surface of modified electrode and generated a pair of redox peaks at around 0.522 and 0.647 V (vs. Ag/AgCl in Britton Robinson (B-R buffer (pH 4.0, 0.1 M. The electrochemical parameters including pH, type of buffer, accumulation time, amount of modifier and scan rate were optimized. Under the optimized conditions, there was a linear correlation between cathodic peak current and concentration of DOX in the range of 0.05–4.0 µg/mL with the detection limit of 0.002 µg/mL. The number of electron transfers (n and electron transfer-coefficient (α were estimated as 2.0 and 0.25, respectively. The constructed sensor displayed excellent precision, sensitivity, repeatability and selectivity in the determination of doxorubicin in plasma. Moreover, cyclic voltammetry studies of DOX in the presence of DNA showed an intercalation mechanism with binding constant (Kb of 1.12×105 L/mol.

Botanicals as Modulators of Neuroplasticity: Focus on BDNF

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Enrico Sangiovanni

2017-01-01

Full Text Available The involvement of brain-derived neurotrophic factor (BDNF in different central nervous system (CNS diseases suggests that this neurotrophin may represent an interesting and reliable therapeutic target. Accordingly, the search for new compounds, also from natural sources, able to modulate BDNF has been increasingly explored. The present review considers the literature on the effects of botanicals on BDNF. Botanicals considered were Bacopa monnieri (L. Pennell, Coffea arabica L., Crocus sativus L., Eleutherococcus senticosus Maxim., Camellia sinensis (L. Kuntze (green tea, Ginkgo biloba L., Hypericum perforatum L., Olea europaea L. (olive oil, Panax ginseng C.A. Meyer, Rhodiola rosea L., Salvia miltiorrhiza Bunge, Vitis vinifera L., Withania somnifera (L. Dunal, and Perilla frutescens (L. Britton. The effect of the active principles responsible for the efficacy of the extracts is reviewed and discussed as well. The high number of articles published (more than one hundred manuscripts for 14 botanicals supports the growing interest in the use of natural products as BDNF modulators. The studies reported strengthen the hypothesis that botanicals may be considered useful modulators of BDNF in CNS diseases, without high side effects. Further clinical studies are mandatory to confirm botanicals as preventive agents or as useful adjuvant to the pharmacological treatment.

The natural diatomite from caldiran-van (Turkey): electroanalytical application to antimigraine compound naratriptan at modified carbon paste electrode.

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Calışkan, Necla; Sögüt, Eda; Saka, Cafer; Yardım, Yavuz; Sentürk, Zuhre

2010-09-01

This paper is the first report describing the characterization of local diatomite of Caldiran-Van region (Eastern Anatolia, Turkey). Special attention was paid to the ability of its electroanalytical performance at modified electrodes and to the potential application of diatomite-modified electrode. For this purpose, the determination of Naratriptan which is a novel oral triptan (5-hydroxytryptamine receptor agonist) in migraine treatment, by means of a carbon paste electrode modified with 10% (w/w) of diatomite was studied using cyclic and square-wave voltammetry. The experimental conditions that affect the electrode reaction process were studied in terms of pH of the supporting electrolyte, scan rate, accumulation variables, modifier composition and square-wave parameters. Using square-wave stripping mode, the drug yielded a well-defined voltammetric response in Britton-Robinson buffer, pH 4.0 at 0.84 V (vs. Ag/AgCl) (a pre-concentration step being carried out with an open circuit at 120 s). The process could be used to determine Naratriptan concentrations in the range 5x10(-7)-9x10(-7) M, with a detection limit of 1.25x10(-7) M (46.5 mug L(-1)). The applicability of the method to spiked human urine samples was illustrated.

Are waves of relational assumptions eroding traditional analysis?

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Meredith-Owen, William

2013-11-01

The author designates as 'traditional' those elements of psychoanalytic presumption and practice that have, in the wake of Fordham's legacy, helped to inform analytical psychology and expand our capacity to integrate the shadow. It is argued that this element of the broad spectrum of Jungian practice is in danger of erosion by the underlying assumptions of the relational approach, which is fast becoming the new establishment. If the maps of the traditional landscape of symbolic reference (primal scene, Oedipus et al.) are disregarded, analysts are left with only their own self-appointed authority with which to orientate themselves. This self-centric epistemological basis of the relationalists leads to a revision of 'analytic attitude' that may be therapeutic but is not essentially analytic. This theme is linked to the perennial challenge of balancing differentiation and merger and traced back, through Chasseguet-Smirgel, to its roots in Genesis. An endeavour is made to illustrate this within the Journal convention of clinically based discussion through a commentary on Colman's (2013) avowedly relational treatment of the case material presented in his recent Journal paper 'Reflections on knowledge and experience' and through an assessment of Jessica Benjamin's (2004) relational critique of Ron Britton's (1989) transference embodied approach. © 2013, The Society of Analytical Psychology.

Floração e frutificação em diferentes tipos de cladódios de pitaia-vermelha em Lavras -MG

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Ana Claudia Costa

2014-03-01

Full Text Available Recentemente, algumas espécies de cactáceas têm-se destacado quanto ao potencial como frutíferas, sendo suas frutas utilizadas como alimento para o homem. dentre essas, a pitaia tem despertado grande interesse. O presente trabalho teve como objetivo estudar a floração e a frutificação em diferentes tipos de cladódios (tamanho e presença ou ausência de frutificação em safras anteriores de pitaia-vermelha em Lavras-MG. As observações foram realizadas em plantas de pitaia-vermelha [Hylocereus undatus (haw. Britton & Rose], com quatro anos de idade, tutoradas em mourões de eucalipto com 1,80 m de altura, no espaçamento de 3 x 3 m. Do surgimento do botäo floral até a abertura da flor, decorreram cerca de 21 dias, e da antese até a colheita do fruto, cerca de 35 dias. Cladódios que já haviam produzido frutos em anos anteriores e com tamanho entre 40 e 60 cm de comprimento apresentaram maior porcentagem de cladódios com frutos e maior número de frutos por cladódio.

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

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

2011-06-01

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

Levantamento etnobotânico das espécies vegetais em quintais de bairro na cidade de Mossoró, Rio Grande do Norte

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Maria de Fatima Barbosa Coelho

2016-11-01

Full Text Available Os quintais são conhecidos por diferentes denominações em vários lugares e podem ser definidos como uma área de produção localizada perto da casa, onde são cultivadas espécies agrícolas e florestais, com a criação de pequenos animais domésticos. O presente trabalho teve como objetivo realizar um levantamento etnobotânico das espécies vegetais existentes nos quintais do bairro Alto Sumaré em Mossoró, Rio Grande do Norte. A seleção de quinze informantes foi feita usando a técnica de bola de neve e a coleta dos dados foi efetuada com observação direta e participante, turnê guiada, e entrevistas semiestruturadas. Foram observadas 65 espécies pertencentes a 38 famílias botânicas. A família com maior número de espécies foi Lamiaceae e as espécies mais frequentes foram Carica papaya L. e Mangifera indica L. Alocasia macrorrhizos (L. G. Don e Carica papaya L. foram as espécies mais abundantes. Dos entrevistados, 80% declararam utilizar plantas medicinais para tratamentos de doenças e 24 espécies têm uso medicinal. As categorias de uso predominantes foram alimentícia, medicinal e ornamental. Mentha X piperita L. e Lippia alba (Mill. N. E. Br. ex Britton & P. Wilson foram as mais citadas como medicinal, Carica papaya e Mangifera indica como frutífera e Dieffenbachia picta Schott como ornamental.Ethnobotanical survey of plant species in neighborhood quintals in the city of Mossoró, Rio Grande do NorteAbstract: Homegardens are known by different denominations in various places and can be defined as a production area located near the house, where agricultural and forestry species are grown, with the creation of small domestic animals. The present work had as objective to carry out an ethnobotanical survey of the vegetal species existing in the homegardens of the Alto Sumaré neighborhood in Mossoró, Rio Grande do Norte. The selection of fifteen informants was done using the snowball technique and the data collection was

Flora cactológica y especies asociadas en el área natural protegida Sierra Corral de los Bandidos, Nuevo León, México Cactus list and asociated plants of the protected natural area Sierra Corral de Los Bandidos, Nuevo Leon, Mexico

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María del Pilar Carmona-Lara

2008-12-01

Full Text Available El área natural protegida (ANP Sierra Corral de los Bandidos ubicada en la sierra Madre Oriental, al noroeste de Monterrey, sufre el impacto de actividades antropológicas asociadas al matorral submontano (ganadería, agricultura, colecta y urbanismo, disminuyendo sus recursos naturales y amenazando sus especies endémicas, principalmente cactáceas. El propósito del estudio fue conocer la diversidad de cactáceas y especies asociadas en zonas de amortiguamiento y núcleo. Para ello se determinaron índices de riqueza y similitud utilizando un muestreo estratificado con cuadrantes a lo largo de transectos orientados por gradientes altitudinales según su zonificación. En total se registraron 112 taxa (30 cactáceas, 87 (24 cactáceas en zona de amortiguamiento y 80 (19 cactáceas en zona núcleo. Por su densidad, frecuencia y abundancia sobresalieron Echinocereus stramineus (Engelm. Engelm. ex F. Seitz, Cylindropuntia leptocaulis F. M. Knuth in Backeb et F. M. Knuth, Mammillaria melanocentra Poselg., Neolloydia conoidea (DC Britton et Rose, (Cactaceae; Erioneuron avenaceum (H. B et K. Tateoka, (Poaceae; Viguiera stenoloba S. F. Blake; Zexmenia hispida (Kunth A. Gray, (Asteraceae y Agave lechuguilla Torr, (Agavaceae. Existe diferencia significativa entre las poblaciones de cactus de las zonas del ANP, según Jacquard (13%, Sörensen (38% y Morisita (0.44. Ocho cactáceas (7 endémicas están registradas en algún estatus de la NOM-ECOL-059, 2001.The Sierra Corral de los Bandidos is a natural protected area located in the Sierra Madre Oriental mountain range northwest of Monterrey city. This preserve suffers the impact of human activities in the form of cattle ranching, agriculture, harvest of wild plants, and urbanism, diminishing its natural resources and threatening its endemic species, especially from the cactaceae family. The purpose of this study was to obtain information on the diversity of cacti and associated species in the buffer and

Surface wave site characterization at 27 locations near Boston, Massachusetts, including 2 strong-motion stations

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Thompson, Eric M.; Carkin, Bradley A.; Baise, Laurie G.; Kayen, Robert E.

2014-01-01

The geotechnical properties of the soils in and around Boston, Massachusetts, have been extensively studied. This is partly due to the importance of the Boston Blue Clay and the extent of landfill in the Boston area. Although New England is not a region that is typically associated with seismic hazards, there have been several historical earthquakes that have caused significant ground shaking (for example, see Street and Lacroix, 1979; Ebel, 1996; Ebel, 2006). The possibility of strong ground shaking, along with heightened vulnerability from unreinforced masonry buildings, motivates further investigation of seismic hazards throughout New England. Important studies that are pertinent to seismic hazards in New England include source-parameter studies (Somerville and others, 1987; Boore and others, 2010), wave-propagation studies (Frankel, 1991; Viegas and others, 2010), empirical ground-motion prediction equations (GMPE) for computing ground-motion intensity (Tavakoli and Pezeshk, 2005; Atkinson and Boore, 2006), site-response studies (Hayles and others, 2001; Ebel and Kim, 2006), and liquefaction studies (Brankman and Baise, 2008). The shear-wave velocity (VS) profiles collected for this report are pertinent to the GMPE, site response, and liquefaction aspects of seismic hazards in the greater Boston area. Besides the application of these data for the Boston region, the data may be applicable throughout New England, through correlations with geologic units (similar to Ebel and Kim, 2006) or correlations with topographic slope (Wald and Allen, 2007), because few VS measurements are available in stable tectonic regions.Ebel and Hart (2001) used felt earthquake reports to infer amplification patterns throughout the greater Boston region and noted spatial correspondence with the dominant period and amplification factors obtained from ambient noise (horizontal-to-vertical ratios) by Kummer (1998). Britton (2003) compiled geotechnical borings in the area and produced a

Limited magnetic resonance imaging in low back pain instead of plain radiographs: Experience with first 1000 cases

International Nuclear Information System (INIS)

McNally, Eugene G.; Wilson, David J.; Ostlere, Simon J.

2001-01-01

AIM: We report our experience with the first 1000 patients with non-traumatic low back pain (LBP) without radiculopathy undergoing limited sequence magnetic resonance imaging (MRI) instead of plain radiography. METHODS: Between January 1996 and December 1998, 1042 patients with low back pain unresponsive to conservative treatment were examined using a limited MR protocol comprising sagittal T1-weighted and STIR imaging. Plain radiographs were not performed. RESULTS: Malignancy, infection, vertebral fracture, spondylitis, pars defects and cord tumours were detected in 20%. Of the 82 osteoporotic vertebral fractures detected, 51 (62%) were recent and 31 had normal marrow signal indicating that they were old. Eighty pars defects were identified, 45(56%) had spondylolisthesis, 29(37%) were undisplaced and 6 (7%) had pars oedema only. Neoplastic disease was found in 17(8%) of which none was suspected before imaging. Benign neoplastic diseases such as vertebral AVM/haemangiomata were excluded. Twenty-one patients had a variety of disorders including ankylosing spondylitis (7), large vessel aneurysm (3), discitis (2), ovarian cyst (2), sequestered disc (2), sacral insufficiency fracture (2) and one patient each with burst fracture, retroperitoneal haematoma and a previously unsuspected horseshoe kidney. CONCLUSION: The majority of patients with LBP are best assessed clinically and imaging is usually not required. In patients with worrying symptoms, MRI with a limited protocol detects a greater number of abnormalities than previously reported studies using plain radiographs and has replaced plain radiography in our hospital. We report our experience with the first 1000 patients and highlight issues such as protocols, detection rates and communication issues. McNally E.G. et al. (2001)

Polyaniline–bismuth oxide nanocomposite sensor for quantification of anti-parkinson drug pramipexole in solubilized system

International Nuclear Information System (INIS)

Jain, Rajeev; Tiwari, Dinesh Chandra; Shrivastava, Swati

2014-01-01

Graphical abstract: - Highlights: • PANI–Bi 2 O 3 nanocomposite has been synthesized first time and effectively used for the electrochemical studies. • PANI–Bi 2 O 3 /GCE modified sensors have a large surface area greatly enhancing the sensitivity of electroactive species. • Modified sensor was successfully used for the detection of pramipexole utilizing enhancement effect of surfactant. • The reported method showed very good stability as well as reproducibility for the voltammetric analysis of pramipexole. - Abstract: In this study, a new sensor polyaniline–bismuth oxide (PANI–Bi 2 O 3 ) nanocomposite has been fabricated and characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). SEM was used to provide information about the morphology of the PANI–Bi 2 O 3 nanocomposite. Cyclic voltammetric studies of electroactive species i.e. K 3 Fe(CN) 6 demonstrate almost reversible electrochemical behaviour, with diffusion controlled mass transfer process in the double layer region of the electrode. EIS studies revealed that PANI–Bi 2 O 3 /GCE having lower charge transfer resistance which leads to higher electrocatalytic activity. This modified electrode was successfully used for the detection of pramipexole in pharmaceutical formulation in sodium lauryl sulphate (SLS) in Britton Robinson (BR) buffer at pH 4.5. The ease of fabrication, excellent electrochemical performance and high electroactive surface area are the promising features of the fabricated sensor

Electrochemical study of varenicline adsorptive behaviour and its interaction with DNA

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Radulović Valentina

2012-01-01

Full Text Available The electrochemical behaviour of novel nicotinic α4β2 subtype receptor partial agonist varenicline (VAR which is used for smoking cessation, was investigated in Britton-Robinson buffers (pH 2.0-12.0 by cyclic, differential pulse and square wave voltammetry at a hanging mercury drop elctrode. The influence of pH, scan rate, concentration, accumulation potential and time on peak current and potential suggested that in alkaline media the redox process was adsorption controlled. Also, the experimental value of surface coverage, G = 1.03´10-10 mol cm-2, was used to determine the conditions when VAR was fully adsorbed at the electrode surface. Having in mind potential high toxicity of VAR due to the presence of quinoxaline structure, its interaction with DNA was postulated, and studied when both compounds were in the adsorbed state at modified HMDE. Using adsorptive transfer technique, the changes in potential and decrease in normalized peak currents were observed. The estimated value of the ratio of surface-binding constants indicated that the reduced form of VAR interacted with dsDNA more strongly than the oxidized form. Subtle DNA damage under conditions of direct DNA-VAR interaction at room temperature was observed. The proposed type of interaction was an intercalation. This study used simple electroanalytical methodology and showed the potential of DNA/HMDE biosensor for investigation of genotoxic effects.

Adsorptive stripping voltammetric methods for determination of aripiprazole

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Derya Aşangil

2012-06-01

Full Text Available Anodic behavior of aripiprazole (ARP was studied using electrochemical methods. Charge transfer, diffusion and surface coverage coefficients of adsorbed molecules and the number of electrons transferred in electrode mechanisms were calculated for quasi-reversible and adsorption-controlled electrochemical oxidation of ARP at 1.15 V versus Ag/AgCl at pH 4.0 in Britton–Robinson buffer (BR on glassy carbon electrode. Voltammetric methods for direct determination of ARP in pharmaceutical dosage forms and biological samples were developed. Linearity range is found as from 11.4 μM (5.11 mg/L to 157 μM (70.41 mg/L without stripping mode and it is found as from 0.221 μM (0.10 mg/L to 13.6 μM (6.10 mg/L with stripping mode. Limit of detection (LOD was found to be 0.11 μM (0.05 mg/L in stripping voltammetry. Methods were successfully applied to assay the drug in tablets, human serum and human urine with good recoveries between 95.0% and 104.6% with relative standard deviation less than 10%. Keywords: Adsorptive stripping voltammetry, Aripiprazole, Electrochemical behavior, Human serum and urine, Pharmaceuticals

Abortion foe convicted and sentenced for murders of women's health clinic workers.

Science.gov (United States)

1996-03-22

On March 18, after deliberating for approximately nine hours over two days, a Dedham, Massachusetts, jury found John Salvi guilty of two counts of first-degree murder for the December 1994 shooting deaths of Shannon Lowney and Lee Ann Nichols, receptionists at two Brookline, Massachusetts, women's health care clinics. Salvi was also convicted of five counts of assault with intent to murder (see RFN IV/1). Almost immediately, Norfolk Superior Court Judge Barbara Dortch-Okara ordered Salvi to serve the maximum sentence--two consecutive life terms in prison without parole--for the murders and an additional 90-100 years for the five assaults. Under Massachusetts law, the first-degree murder convictions will be automatically appealed. In reaching their verdict, the jury of six men and six women rejected Salvi's plea of not guilty by reason of insanity. The five-week trial included testimony from more than 100 witnesses. In the past two years, two other men have been convicted for the first-degree murders of abortion providers: Michael Griffin, who was convicted of murdering Dr. David Gunn in March 1994, is now serving a life sentence; and Paul Hill, who was convicted of murdering Dr. John Britton and James Barrett in November 1995, is on Florida's death row while his sentence is pending mandatory appeal (see RFN III/19, 22). full text

Alternative methods of synthesizing 99Tcm-labelled ciprofloxacin

International Nuclear Information System (INIS)

Kumar, V.; Choong, K.K.L.; Evans, S.; Olma, T.R.

1999-01-01

Full text: 99 Tc m -labelled ciprofloxacin (Infecton) is a new class of radiopharmaceutical designed for imaging live bacterial infection. We synthesized Infecton by modifying the procedure described by Keith Britton's group (Lancet 1996; 347: 233-235) and reported our findings at the ANZSNM meeting last year. Since the methodology was cumbersome, we investigated simpler alternative ways of labelling ciprofloxacin with 99 Tc m -pertechnetate for routine imaging. There were several limitations in the previously described method: (1) Need to prepare pure ciprofloxacin which was unstable on storage. (2) Synthetic procedure using formimidine sulphinic acid (FSA) was complicated and required boiling step. (3) The radiochemical purity (RCP) of the product was low (45-50%) requiring purification. (4) Biodistribution studies showed a marked uptake by the liver which could interfere with scan interpretation in this region. The results of our present studies showed that Infecton could be prepared by a simple two-step method: (1) Reduce 99 Tc m -pertechnetate with stannous salt (SnCl 2 or Sn-tartrate). (2) Mix with Ciproxin IV-100. The RCP of the product was up to 98%, which obviates the need for further purification. Infecton synthesized by the above method showed avid localization in abscesses induced with Staphylococcus aureus in rats. The biodistribution studies showed that Infecton was renally excreted with minimal accumulation in the liver or other organs

Electrochemical study and flow injection analysis of paracetamol in pharmaceutical formulations based on screen-printed electrodes and carbon nanotubes

International Nuclear Information System (INIS)

Fanjul-Bolado, Pablo; Lamas-Ardisana, Pedro Jose; Hernandez-Santos, David; Costa-Garcia, Agustin

2009-01-01

Acetaminophenol or paracetamol is one of the most commonly used analgesics in pharmaceutical formulations. Acetaminophen is electroactive and voltammetric mechanistic studies for the electrode processes of the acetaminophenol/N-acetyl-p-quinoneimine redox system are presented. Carbon nanotubes modified screen-printed electrodes with enhanced electron transfer properties are used for the study of the electrochemical-chemical oxidation mechanism of paracetamol at pH 2.0. Quantitative analysis of paracetamol by using its oxidation process (in a Britton-Robinson buffer solution pH 10.0) at +0.20 V (vs. an Ag pseudoreference electrode) on an untreated screen-printed carbon electrode (SPCE) was carried out. Thus, a cyclic voltammetric based reproducible determination of acetaminophen (R.S.D., 2.2%) in the range 2.5 x 10 -6 M to 1 x 10 -3 M, was obtained. However, when SPCEs are used as amperometric detectors coupled to a flow injection analysis (FIA) system, the detection limit achieved for paracetamol was 1 x 10 -7 M, one order of magnitude lower than that obtained by voltammetric analysis. The repeatability of the amperometric detection with the same SPCE is 2% for 15 successive injections of 10 -5 M acetaminophen and do not present any memory effect. Finally, the applicability of using screen-printed carbon electrodes for the electrochemical detection of paracetamol (i.e. for quality control analysis) was demonstrated by using two commercial pharmaceutical products.

Time Management and Its Relation To Students’ Stress, Gender and Academic Achievement Among Sample of Students at Al Ain University of Science and Technology, UAE

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Ahmad Saleh Al Khatib

2014-05-01

Full Text Available The objective of the present study was to investigate the relationship between time management, perceived stress, gender and academic achievement among United Arab Emirates college students. The respondents were 352 college students from Al Ain University of Science and Technology. The sample was stratified by sex. Among the respondents, 52.5% were female students and 47.5% were male students. The mean age of the sample was 23.4 years ranging from 18 to 39. Time management was measured by Time Management Questionnaire” developed by Britton and Tesser (1991, while perceived stress was measured by The Perceived Stress Scale developed by Cohen (1985. The findings of the study showed that there was statistically significant negative relationship between time management and perceived stress. Females reported higher time management compared to their males counter mates. Higher time management and lower perceived stress were associated with high levels of academic achievement. However, time management was the most significant predictor of academic achievement accounting for 26 % of the variance while perceived stress accounted for an additional 11.2% of the variance in academic achievement. All three predictors explained 29.4% (R = .543 of total variance. The implications and limitations are reviewed as are the suggestions for future research.   Keywords: Time management, perceived stress, academic achievement, college students.

Silver-choline chloride modified graphene oxide: Novel nano-bioelectrochemical sensor for celecoxib detection and CCD-RSM model.

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Parsaee, Zohreh; Karachi, Nima; Abrishamifar, Seyyed Milad; Kahkha, Mohammad Reza Rezaei; Razavi, Razieh

2018-07-01

In this study, silver nanoparticles modified choline chloride functionalized graphene oxide (AgNPs-ChCl-GO) was synthesized using sonochemical method and utilized as a bioelectrochemical sensor for detection of celecoxib (CEL). The characterization studies were ultimately performed in order to acheive a more complete understanding of the morphological and structural features of the AgNPs-ChCl-GO using different techniques including FT-IR, AFM, FE-SEM, EDX, and XRD. AgNPs-ChCl-GO demonstrated a significant improvement in the reduction activity of CEL due to the enhancement in the current response compared to the bare carbon paste electrode (CPE). The optimum experimental conditions, were optimized using central composite design (CCD) methodology. The differential pulse voltammetry (DPVs) showed an expanded linear dynamic ranges of 9.6 × 10 -9 -7.4 × 10 -7  M for celecoxib in Britton-Robinson buffer in pH 5.0 with. LOD (S/N = 3) and LOQ (S/N = 10) were obtained 2.51 × 10 -9  M and 6.58 × 10 -9  M respectively. AgNPs-ChCl-GO-carbon paste electrode exhibited suitable properties and high accuracy determination of celecoxib in the human plasma sample. Copyright © 2018 Elsevier B.V. All rights reserved.

Rhizobial inoculation increases soil microbial functioning and gum arabic production of 13-years old Senegalia senegal (L. Britton, trees in the North part of Senegal

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Dioumacor FALL

2016-09-01

Full Text Available Abstract Rhizobial inoculation has been widely used in controlled conditions as a substitute for chemical fertilizers to increase plants growth and productivity. However, very little is known about such effects on mature trees in natural habitats. In this study, we investigated the effect of rhizobial inoculation on soil total microbial biomass, mineral nitrogen content, potential CO2 respiration, fluorescein diacetate (FDA, acid phosphatase activities and gum arabic production by 13-years old Senegalia senegal (Syn. Acacia senegal under natural conditions in the north part of Senegal during two consecutive years. Rhizobial inoculation was performed at the beginning of the rainy season (July for both years with a cocktail of four strains (CIRADF 300, CIRADF 301, CIRADF 302 and CIRADF 303. Rhizospheric soils were collected in both dry and rainy seasons to a depth of 0-25 cm under uninoculated (UIN and inoculated (IN trees. Trees were tapped in November (beginning of dry season using traditional tools. Gum arabic was harvested every 15 days from December to March. The results obtained from both years demonstrated that rhizobial inoculation increased significantly the percentage of trees producing gum arabic, gum arabic production per tree, soil microbial biomass, FDA and acid phosphatase activities. However, there was no significant effect on C mineralization and mineral nitrogen (N content. Gum arabic production was positively correlated to rainfall, soil microbial biomass and mineral nitrogen content. Our results showed a positive effect of rhizobial inoculation on soil microbial functioning and gum arabic production by mature S. senegal trees. These important findings deserve to be conducted in several contrasting sites in order to improve gum arabic production and contribute to increase rural population incomes.

Rhizobial Inoculation Increases Soil Microbial Functioning and Gum Arabic Production of 13-Year-Old Senegalia senegal (L.) Britton, Trees in the North Part of Senegal.

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Fall, Dioumacor; Bakhoum, Niokhor; Nourou Sall, Saïdou; Zoubeirou, Alzouma Mayaki; Sylla, Samba N; Diouf, Diegane

2016-01-01

Rhizobial inoculation has been widely used in controlled conditions as a substitute for chemical fertilizers to increase plants growth and productivity. However, very little is known about such effects on mature trees in natural habitats. In this study, we investigated the effect of rhizobial inoculation on soil total microbial biomass, mineral nitrogen content, potential CO2 respiration, fluorescein diacetate (FDA), acid phosphatase activities, and gum arabic production by 13-year-old Senegalia senegal (synonym: Acacia senegal) under natural conditions in the north part of Senegal during two consecutive years. Rhizobial inoculation was performed at the beginning of the rainy season (July) for both years with a cocktail of four strains (CIRADF 300, CIRADF 301, CIRADF 302, and CIRADF 303). Rhizospheric soils were collected in both dry and rainy seasons to a depth of 0-25 cm under uninoculated and inoculated trees. Trees were tapped in November (beginning of dry season) using traditional tools. Gum arabic was harvested every 15 days from December to March. The results obtained from both years demonstrated that rhizobial inoculation increased significantly the percentage of trees producing gum arabic, gum arabic production per tree, soil microbial biomass, FDA, and acid phosphatase activities. However, there was no significant effect on C mineralization and mineral nitrogen (N) content. Gum arabic production was positively correlated to rainfall, soil microbial biomass, and mineral nitrogen content. Our results showed a positive effect of rhizobial inoculation on soil microbial functioning and gum arabic production by mature S. senegal trees. These important findings deserve to be conducted in several contrasting sites in order to improve gum arabic production and contribute to increase rural population incomes.

Effect of essential oils of medicinal plants on leaf blotch in Tanzania grass Efeito de óleos essenciais de plantas medicinais sobre a helmintosporiose do capim Tanzânia

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Gil Rodrigues dos Santos

2013-09-01

Full Text Available Leaf spots caused by phyto-pathogenic fungi, can reduce the production of forage plants. The essential oils of medicinal plants have antimicrobial potential. The objective here was to evaluate the fungotoxicity in vitro of the essential oils of lemongrass (Cymbopogon citratus (DC. Stapf (Poaceae, citronella (Cymbopogon nardus (L. Rendle (Poaceae, lemon balm (Lippia alba (Mill. NE Br ex Britton & P. Wilson (Verbenaceae and peppermint (Mentha piperita L. (Lamiaceae on the fungus Helminthosporium sp. and the in vivo effect of these oils and of commercial neem oil (Azadirachta indica A. Juss. (Meliaceae on leaf blotch in Panicum maximum Jacq. cv. Tanzania-1. The mycelial growth of the fungus was evaluated over five periods (2; 4; 6; 8 and 10 days from incubation and with five concentrations of essential oils (C1 = 250 ppm; C2 = 500 ppm; C3 = 750 ppm; C4 = 1,000 ppm e C5 = 1,250 ppm. As an alternative control, the preventative and curative effect on leaf blotch of five oil-based treatments were evaluated: lemongrass, citronella, lemon balm, peppermint and neem in four concentrations (2,500; 5,000; 7,500 and 10,000 ppm. The essential oils of lemongrass and citronella were the most effective in reducing mycelial growth of Helminthosporium sp. With the essential oil of lemongrass, the pathogen presented the highest growth concentration (1.250 ppm. The results obtained showed that all the essential oils and concentrations tested presented a preventive and curative effect, reducing the severity of leaf blotch.Manchas foliares, causadas por fungos fitopatogênicos, podem reduzir a produção de forrageiras. Óleos essenciais de plantas medicinais apresentam potencial antimicrobiano. Objetivou-se avaliar a fungitoxicidade in vitro dos óleos essenciais de capim-limão (Cymbopogon citratus (DC. Stapf (Poaceae, citronela (Cymbopogon nardus (L. Rendle (Poaceae, erva-cidreira (Lippia alba (Mill. N.E. Br. ex Britton & P. Wilson (Verbenaceae e hortel

Novo método espectrofotométrico para determinação de Hg (II em amostras de peixe New spectrophotometric method for the determination of Hg (II in fish samples

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Lorena Carvalho Martiniano

2008-06-01

Full Text Available Um novo método espectrofotométrico simples, sensível e com boa seletividade é apresentado para a determinação rápida de mercúrio (II em nível de traços com 2-mercapto-5-metilbenzilimidazol (MMBI como um novo reagente espectrofotométrico (lambda max = 320 nm, em um meio aquoso ligeiramente alcalino (tampão Britton-Robinson (BR 0,04 M, pH 8,0. A reação é instantânea e a absorbância permanece estável por mais de 24 horas. O coeficiente de absorção molar encontrado foi de 2,71 x 10(4 L mol-1 cm-1. A composição estequiométrica do complexo é de 1:1 (Hg:MMBI. Considerável excesso dos íons cobre, zinco, chumbo e cádmio não interfere na determinação. O método desenvolvido permitiu a determinação de mercúrio na faixa de 2 x 10-6 a 4 x 10-5 mol.L-1 com boa precisão e exatidão, e o limite de detecção para Hg foi de 9,9 x 10-7 mol.L-1. O método foi aplicado com sucesso a amostras de peixe e os resultados foram avaliados com o clássico método de espectrometria de absorção atômica (EAA. Os desvios padrão relativos para as amostras analisadas foram de 7,2 e 33% (n = 5, enquanto os erros foram de 1,63 e 11,6. O método mostrou-se sensível, seletivo e foi aplicado para a determinação de mercúrio em amostras de peixe com resultados satisfatórios.A simple, sensitive and selective spectrophotmetric method is presented for the rapid determination of mercury (II at trace levels using 2-mercapto-5-methylbenzimidazole (MMBI as a new spectrophotometric reagent (lambdamax = 320 nm in a slightly basic (0.04 M Britton-Robinson (BR buffer, pH 8.0 aqueous solution. The reaction is instantaneous and the absorbance remains stable for over 24 hours. The average molar absorption coefficient was found to be 2.71 x 10(4 L mol-1 cm-1. The stoichiometric composition of the chelate is 1:1 (Hg:MMBI. Considerable excesses of copper, zinc, lead and cadmium do not interfere in the determination. The method developed allowed the

Network pharmacology-based screening of the active ingredients and potential targets of the genus of Pithecellobium marthae (Britton & Killip) Niezgoda & Nevl for application to Alzheimer's disease.

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Zhang, Han; Yan, Zhi-Yang; Wang, Yu-Xi; Bai, Ming; Wang, Xiao-Bo; Huang, Xiao-Xiao; Song, Shao-Jiang

2018-02-16

Alzheimer's disease (AD) is a progressive neurodegenerative disorder associated with synaptic dysfunction, pathological accumulation of β-amyloid (Aβ), and neuronal loss. Given the prevalence of AD and the lack of effective long-term therapies, there is a pressing need to discover viable leads that can be developed into clinically approved drugs with disease-modifying effects. The analysis of current reported literatures confirms the importance of the plants of Pithecellobium genus as candidate against AD. Hence, it is necessary to identify selective anti-dementia agents from this genus. To explore potential compounds with marked effect on AD in Pithecellobium genus, a compound database based on the methods of network pharmacology prediction was established in this paper by constructing the compound-disease target network. The result showed that the most effective compound in the plants of this genus might be (7'R,8'R)-7'-methoxyl strebluslignanol, and the most potential target might be Macrophage colony-stimulating factor 1 receptor.

Voltammetric determination of heparin based on its interaction with malachite green

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Xueliang Niu

2008-08-01

Full Text Available In this paper malachite green (MG was used as a bioprobe to determine heparin concentration by linear sweep voltammetry on the dropping mercury working electrode (DME. In Britton-Robinson (B-R buffer solution of pH 1.5, MG had a well-defined second order derivative linear sweep voltammetric reductive peak at –0.618 V (vs. SCE. After the addition of heparin into the MG solution, the reductive peak current decreased apparently without the movement of peak potential. Based on the difference of the peak current, a new voltammetric method for the determination of heparin was established. The conditions for the binding reaction and the electrochemical detection were optimized. Under the selected experimental conditions the difference of peak current was directly proportional to the concentration of heparin in the range from 0.3 to 10.0 mg/L with the linear regression equation as ∆ip″ (nA = 360.19 C (mg/L + 178.88 (n = 15, γ = 0.998 and the detection limit as 0.28 mg/L (3σ. The effects of coexisting substances such as metal ions, amino acids on the determination of heparin were investigated and the results showed that this method had good selectivity. This method was further applied to determine the heparin content in heparin sodium injection samples with satisfactory results and good recovery. The stoichiometry of the biocomplex was calculated by the electrochemical method and the binding mechanism was further discussed.

Electrochemical Behaviour of Tinidazole at 1,4-Benzoquinone Modified Carbon Paste Electrode and Its Direct Determination in Pharmaceutical Tablets and Urine by Differential Pulse Voltammetry

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Yosef Nikodimos

2017-01-01

Full Text Available A simple and highly sensitive electrochemical method based on a 1,4-benzoquinone modified carbon paste electrode (1,4-BQMCPE was described for the determination of tinidazole (TDZ. In Britton Robinson buffer solution, TDZ yields well-defined irreversible reduction peak at −0.344 V on a 1,4-BQMCPE. Compared with that on a bare CPE, the reduction peak of TDZ increased significantly on the modified CPE and the effects of different parameters on the voltammetric responses were also investigated. Differential pulse voltammetric method was proposed and optimized for TDZ determination and its reductive peak current response at 1,4-BQMCPE was found to show linear dependence on the concentration of TDZ in the range of 1.0 × 10−6 to 5.0 × 10−4 M with a linear regression equation, correlation coefficient, limit of detection (LOD, and limit of quantification (LOQ of IPC (μA = 0.19958 + 0.02657C (μM, 0.99486, 1.10 × 10−7 M, and 3.77 × 10−7, respectively. Excellent recovery results for spiked TDZ in pharmaceutical tablet samples ranging within 97.44–97.51% and in urine ranging within 95.37–96.91% were observed. The selectivity of the method for TDZ was further studied in the presence of selected potential interferents and confirmed the potential applicability of the developed method for the determination of TDZ.

Adsorptive stripping differential pulse voltammetric determination of venlafaxine and desvenlafaxine employing Nafion-carbon nanotube composite glassy carbon electrode

Energy Technology Data Exchange (ETDEWEB)

Sanghavi, Bankim J. [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400 098, Maharashtra (India); Srivastava, Ashwini K., E-mail: aksrivastava@chem.mu.ac.i [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400 098, Maharashtra (India)

2011-04-15

A Nafion-carbon nanotube-modified glassy carbon electrode (NAF-CNT-GCE) was developed for the determination of venlafaxine (VF) and desvenlafaxine (DVF). The electrochemical behavior of both these molecules was investigated employing cyclic voltammetry (CV), chronocoulometry (CC), electrochemical impedance spectroscopy (EIS) and adsorptive stripping differential pulse voltammetry (AdSDPV). The surface morphology of the electrodes has been studied by means of scanning electron microscopy (SEM). These studies revealed that the oxidation of VF and DVF is facilitated at NAF-CNT-GCE. After optimization of analytical conditions employing this electrode at pH 7.0 in Britton-Robinson buffer (0.05 M) for VF and pH 5.0 in acetate buffer (0.1 M) for DVF, the peak currents for both the molecules were found to vary linearly with their concentrations in the range of 3.81 x 10{sup -8}-6.22 x 10{sup -5} M for VF and 5.33 x 10{sup -8}-3.58 x 10{sup -5} M for DVF. The detection limits (S/N = 3) of 1.24 x 10{sup -8} and 2.11 x 10{sup -8} M were obtained for VF and DVF, respectively, using AdSDPV. The prepared modified electrode showed several advantages, such as simple preparation method, high sensitivity, very low detection limits and excellent reproducibility. The proposed method was employed for the determination of VF and DVF in pharmaceutical formulations, urine and blood serum samples.

Assessing the Potential Stem Growth and Quality of Yellow Birch Prior to Restoration: A Case Study in Eastern Canada

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Alexis Achim

2013-09-01

Full Text Available Past silvicultural treatments have resulted in the high-grading mixed temperate forests of Québec, Canada. Despite recognition of this issue, the low occurrence of yellow birch (Betula alleghaniensis Britton within current stands raises questions about the potential of the species to grow and eventually constitute a high-quality forest resource. The objective of this study was to assess this potential using tree characteristics, forest structure and additional site and climatic conditions as predictors. A total of 145 trees were sampled in two areas located in the same bioclimatic zone. Lower-Saguenay-Charlevoix was chosen as an area where a restoration plan could be implemented, whereas Portneuf was selected as a reference. We used nonlinear mixed models to investigate which environmental factors are likely to influence the radial growth and stem quality of yellow birch sample trees. Our results suggest that topographic and climatic conditions, as well as the competitive environment of the trees, are important factors to consider in the evaluation of yellow birch production. Despite the limited occurrence of yellow birch, the potential for growth and quality was high in the Lower-Saguenay-Charlevoix area. For equivalent topographic, climatic, and competitive environment conditions, there was no significant difference in either radial growth or stem quality with Portneuf. We suggest that the economic interest of producing high quality timber should be used to justify the implementation of a restoration strategy in the Lower-Saguenay-Charlevoix area.

Application of o-tolidine as substrate for the electrochemical determination of hemoglobin or hydrogen peroxide

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Wei Sun

2007-08-01

Full Text Available In this paper hemoglobin (Hb was used to catalyze the oxidative reaction of ο-tolidine (OT with H2O2. The oxidative product of OT with H2O2 was an azo substrate, which was electroactive and had a sensitive linear sweep voltammetric reductive peak at -0.52 V (vs. SCE on hanging mercury drop working electrode (HMDE in pH 5.0 Britton-Robinson (B-R solution. The conditions of Hb catalytic reaction and voltammetric detection were optimized. Under the optimal conditions, the electrochemical behaviour of the oxidative product was carefully investigated and the electrode process of the product on mercury electrode was proposed. Based on the increase of the reductive peak current of the oxidative product with the concentration of the H2O2 or Hb, a new electrochemical method for the determination of trace amount of H2O2 or Hb was proposed. The calibration graph had a linear range of 6.0 x 10-8 to 4.0 x 10-5 M for H2O2 and 1.0 x 10-9 to 7.0 x 10-7 M for Hb with the detection limit of 1.0 x 10-8 M H2O2 and 5.0 x 10-10 M Hb (3σ, respectively. This new proposed method was further attempted to determine the content of H2O2 in fresh rainwater with satisfactory results.

Electrochemical studies of quinine in surfactant media using hanging mercury drop electrode: a cyclic voltammetric study.

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Dar, Riyaz Ahmad; Brahman, Pradeep Kumar; Tiwari, Sweety; Pitre, Krishna Sadashiv

2012-10-01

The electrochemical behavior of quinine was investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV) using surfactant. The reduction peak current of quinine increases remarkably in presence of 1% CTAB. Its electrochemical behavior is quasi-reversible in the Britton-Robinson buffers of pH 10.38 by exhibiting the well-defined single cathodic and anodic waves and the ratio of I(p)(a)/I(p)(c) approaching one at the scan rate of 500 mVs(-1). On the basis of CV, SWV and Coulometry, electrochemical reduction mechanism of quinine has been proposed which has shown that protonation occurs on the nitrogen of the quinoline moiety. Linearity was obtained when the peak currents (I(p)) were plotted against concentrations of quinine in the range of 30.0-230.0 ng mL(-1) with a detection limit of 0.132 ng mL(-1) in SWV and 90.0-630.0 ng mL(-1) with a detection limit of 0.238 ng mL(-1) in DPV. Fast and sensitive SWV has been applied for the quantitative analysis of quinine in bark of Cinchona sp. and in soft drinks and a good recovery was obtained. The accuracy and precision of the method are determined and validated statistically. No interferences from other food additives were observed. The relative standard deviation for intraday and interday assay was 0.89 and 0.73% (n=3) respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

Development and Validation of Chronopotentiometric Method for Imidacloprid Determination in Pesticide Formulations and River Water Samples

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Ana Đurović

2016-01-01

Full Text Available A new electrochemical method for determination of imidacloprid using chronopotentiometry on thin film mercury and glassy carbon electrode was presented. The most important experimental parameters of chronopotentiometry were examined and optimized with respect to imidacloprid analytical signal. Imidacloprid provided well-defined reduction peak in Britton-Robinson buffer on thin film mercury electrode at −1.0 V (versus Ag/AgCl (KCl, 3.5 mol/L and on glassy carbon electrode at −1.2 V (versus Ag/AgCl (KCl, 3.5 mol/L. The reduction time was linearly proportional to concentrations from 0.8 to 30.0 mg/L on thin film mercury electrode and from 7.0 to 70.0 mg/L on glassy carbon electrode. The detection limits were 0.17 mg/L and 0.93 mg/L for thin film mercury and glassy carbon electrode, respectively. The estimation of method precision as a function of repeatability and reproducibility showed relative standard deviations values lower than 3.73%. Recovery values from 97.3 to 98.1% confirmed the accuracy of the proposed method, while the constancy of the transition time with deliberated small changes in the experimental parameters indicated a very good robustness. A minor influence of possible interfering compounds proved good selectivity of the method. Developed method was applied for imidacloprid determination in commercial pesticide formulations and river water samples.

Novel fiber optic-based needle redox imager for cancer diagnosis

Science.gov (United States)

Kanniyappan, Udayakumar; Xu, He N.; Tang, Qinggong; Gaitan, Brandon; Liu, Yi; Li, Lin Z.; Chen, Yu

2018-02-01

Despite various technological advancements in cancer diagnosis, the mortality rates were not decreased significantly. We aim to develop a novel optical imaging tool to assist cancer diagnosis effectively. Fluorescence spectroscopy/imaging is a fast, rapid, and minimally invasive technique which has been successfully applied to diagnosing cancerous cells/tissues. Recently, the ratiometric imaging of intrinsic fluorescence of reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD), as pioneered by Britton Chance and the co-workers in 1950-70's, has gained much attention to quantify the physiological parameters of living cells/tissues. The redox ratio, i.e., FAD/(FAD+NADH) or FAD/NADH, has been shown to be sensitive to various metabolic changes in in vivo and in vitro cells/tissues. Optical redox imaging has also been investigated for providing potential imaging biomarkers for cancer transformation, aggressiveness, and treatment response. Towards this goal, we have designed and developed a novel fiberoptic-based needle redox imager (NRI) that can fit into an 11G clinical coaxial biopsy needle for real time imaging during clinical cancer surgery. In the present study, the device is calibrated with tissue mimicking phantoms of FAD and NADH along with various technical parameters such as sensitivity, dynamic range, linearity, and spatial resolution of the system. We also conducted preliminary imaging of tissues ex vivo for validation. We plan to test the NRI on clinical breast cancer patients. Once validated this device may provide an effective tool for clinical cancer diagnosis.

Spectroscopic determination of succinylcholine in dosage forms using eosin Y.

Science.gov (United States)

Ayad, Magda M; Belal, Fathalla; Hosney, Mervet M; Abo El Abass, Samah; Elsayed, Nora

2018-03-01

Two simple and sensitive analytical assay methods using spectrophotometry and spectrofluorimetry techniques were developed for the estimation of succinylcholine chloride (SUC) in pharmaceutical preparations. The suggested methods are based on the formation of an ion pair complex formed between the drug and eosin Y spectrophotometrically (Method I), or the suppressive effect of succinylcholine on the native fluorescence property of eosin Y (Method II). The spectrophotometric method (Method I) involves measuring the absorbance of the complex between succinylcholine and eosin Y at 550 nm in Britton Robinson buffer of pH 3. However, the spectrofluorimetric method (Method II) involves measuring the quenching effect of the studied drug on the native fluorescence property of eosin Y at the same pH at 550 nm after excitation at 480 nm. The absorbance versus concentration of the drug is rectilinear over the range of 0.5 to 15 μg/ml. The formation constant was 3.5 × 10 4 and the Gibb's free energy change was -2.5 × 10 4  J/mol. In Method II, the relative fluorescence intensity was directly proportional to SUC concentration over the range of 0.05 to 1 μg/ml. The proposed methods allowed a successful application to the estimation of succinylcholine ampoules. An explanation of the reaction pathway was postulated. Copyright © 2017 John Wiley & Sons, Ltd.

Polyaniline–bismuth oxide nanocomposite sensor for quantification of anti-parkinson drug pramipexole in solubilized system

Energy Technology Data Exchange (ETDEWEB)

Jain, Rajeev, E-mail: rajeevjain54@yahoo.co.in [School of Studies in Chemistry, Jiwaji University, Gwalior, 474011 (India); Tiwari, Dinesh Chandra [School of Studies in Physics, Jiwaji University, Gwalior, 474011 (India); Shrivastava, Swati [School of Studies in Chemistry, Jiwaji University, Gwalior, 474011 (India)

2014-07-01

Graphical abstract: - Highlights: • PANI–Bi{sub 2}O{sub 3} nanocomposite has been synthesized first time and effectively used for the electrochemical studies. • PANI–Bi{sub 2}O{sub 3}/GCE modified sensors have a large surface area greatly enhancing the sensitivity of electroactive species. • Modified sensor was successfully used for the detection of pramipexole utilizing enhancement effect of surfactant. • The reported method showed very good stability as well as reproducibility for the voltammetric analysis of pramipexole. - Abstract: In this study, a new sensor polyaniline–bismuth oxide (PANI–Bi{sub 2}O{sub 3}) nanocomposite has been fabricated and characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). SEM was used to provide information about the morphology of the PANI–Bi{sub 2}O{sub 3} nanocomposite. Cyclic voltammetric studies of electroactive species i.e. K{sub 3}Fe(CN){sub 6} demonstrate almost reversible electrochemical behaviour, with diffusion controlled mass transfer process in the double layer region of the electrode. EIS studies revealed that PANI–Bi{sub 2}O{sub 3}/GCE having lower charge transfer resistance which leads to higher electrocatalytic activity. This modified electrode was successfully used for the detection of pramipexole in pharmaceutical formulation in sodium lauryl sulphate (SLS) in Britton Robinson (BR) buffer at pH 4.5. The ease of fabrication, excellent electrochemical performance and high electroactive surface area are the promising features of the fabricated sensor.

Polarographic study of acrolein and its determination by flow injection with amperometric detection at a mercury electrode.

Science.gov (United States)

Naranjo Rodríguez, I; Muñoz Leyva, J A; Hidalgo Hidalgo de Cisneros, J L

1996-07-01

A study of the electrochemical behavior of acrolein at a dropping mercury electrode using different polarographic techniques is described. Theoretical studies of the reversibility of the wave of acrolein were carried out using two different polarographic techniques: direct current tast and differential pulse. Differential pulse polarography may be used to determine acrolein concentration in a Britton-Robinson buffer solution of pH 10 in the ranges 2 x 10(-7)10(-8) and 5 x 10(-8)-10(-4) mol dm(-3) and a coefficient of variation of 1.7% for a concentration of 10(-5)mol dm(-3). A flow injection method with amperometric detection at a potential of -1.4V using a mercury electrode is also described. Before each injection, any drop hanging from the tip of the capillary needs to be dislodged and a new electrode drop dispensed; three different drop sizes were tested. A linear relationship between peak intensity and acrolein concentration was obtained in the range 10(-5)-10(-7) mol dm(-3), with a detection limit of 9.8 x 10(-8) mol dm(-) 3 and a coefficient of variation of 2.9% for a 2 x 10(-7) mol dm(-3) concentration. Several organic and inorganic species were tested in order to ascertain whether they interfered with the signal for acrolein. The proposed methods were applied to the determination of acrolein in seawater samples.

[Social aspects of epilepsy: marriage, pregnancy, driving, antiepileptic drug withdrawal and against social stigma].

Science.gov (United States)

Tsuji, Sadatoshi

2004-11-01

Persons with epilepsy need adequate advice and effective counselling about issues such as marriage, pregnancy, risks of inheriting epilepsy, driving, employment and antiepileptic drug withdrawal, because these persons are not receiving important information and education about their condition and possible adverse effects of treatment. Furthermore, women with epilepsy have increased rates of pregnancy complications and poor fetal outcomes including congenital malformations and developmental delay related to both their epilepsy and antiepileptic drugs. However, approximately 90% of all women with epilepsy undergo normal pregnancy and give birth to children free of birth defects. Pregnancy is generally safe in women with epilepsy. The study of long-term prognosis of childhood-onset epilepsy in Japan shows that the majority of these patients have lower levels of educational background as well as employment and marital status compared with the general population (Wakamoto H. et al). Of patients with epilepsy, 60% to 70% achieve control with antiepileptic medication. However, several antiepileptic drug withdrawal studies show variable rates of success, with relapse rates ranging from 12% to 63% (Britton J.W.). Driving is listed as major problem in persons with epilepsy. However, the patients with seizure-free more than two years have been able to get the driver's license since June, 2002. Social attitudes towards epilepsy cause more distress to the patient than the disease itself. We should realize that persons with epilepsy are normal or near-normal. To ameliorate the social stigma against epilepsy, continuous and repetitive educational efforts would be needed.

Conditioning of renewable silver amalgam film electrode for the characterization of clothianidin and its determination in selected samples by adsorptive square-wave voltammetry.

Science.gov (United States)

Brycht, Mariola; Skrzypek, Sławomira; Guzsvány, Valéria; Berenji, Janoš

2013-12-15

A new square-wave adsorptive stripping voltammetric (SWAdSV) method was developed for the determination of the neonicotinoid insecticide clothianidin (Clo), based on its reduction at a renewable silver amalgam film electrode (Hg(Ag)FE). The key point of the procedure is the pretreatment of the Hg(Ag)FE by applying the appropriate conditioning potential (-1.70 V vs. Ag/AgCl reference electrode). Under the optimized voltammetric conditions, such pretreatment resulted in the peak for the Clo reduction in Britton-Robinson buffer pH 9.0 at about -0.60 V, which was used for the analytical purpose. The developed SWAdSV procedure made it possible to determine Clo in the concentration range of 6.0×10(-7)-7.0×10(-6) mol L(-1) (LOD=1.8×10(-7) mol L(-1), LOQ=6.0×10(-7) mol L(-1)) and 7.0×10(-6)-4.0×10(-5) mol L(-1) (LOD=1.3×10(-6) mol L(-1), LOQ=4.2×10(-6) mol L(-1)). The repeatability, precision, and the recovery of the method were determined. The effect of common interfering pesticides was also investigated. Standard addition method was successfully applied and validated for the determination of Clo in spiked Warta River water, corn seeds samples, and in corn seeds samples treated with the commercial formulation PONCHO 600 FS. © 2013 Elsevier B.V. All rights reserved.

Efecto de la fertilización nitrogenada en el rendimiento y la composición de los aceites esenciales de especies y accesiones de Lippia

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érika Leonor Zambrano M

2013-04-01

Full Text Available En el Centro Experimental de la Universidad Nacional de Colombia sede Palmira (CEUNP se evaluó el efecto de la aplicación de nitrógeno (N en la producción de materia seca y aceites esenciales de dos especies de Lippia. Se utilizaron las accesiones Cítrica y Típica de Lippia alba (Miller N.E.Brown ex Britton & Wilson y Patía, Típica y Cítrica de L. origanoides H.B.K. Como fuentes de N se aplicaron gallinaza y urea en dosis equivalentes de 50 y 100 kg/ha de N. Se utilizó un diseño experimental de bloques completos al azar, con cinco tratamientos y tres repeticiones para cada accesión. Se evaluaron los rendimientos de biomasa fresca y seca (MS y de los aceites esenciales y su composición por arrastre de vapor en hojas secas. Los mayores rendimientos de MS y de aceite esencial (3.318 kg/ha y 82.9 lt/ha, respectivamente se obtuvieron con las accesiones de L origanoides. La mayor concentración de aceite esencial (4 ml/100 g se registró en L. origanoides Patía con la aplicación de 100 kg/ha de N como urea. Las diferencias en la composición química de los aceites estuvieron más asociadas con la especie y accesión que con la aplicación de N.

Binding of several anti-tumor drugs to bovine serum albumin: Fluorescence study

Energy Technology Data Exchange (ETDEWEB)

Bi Shuyun [College of Chemistry, Changchun Normal University, Changchun 130032 (China)], E-mail: sy_bi@sina.com; Sun Yantao [College of Chemistry, Jilin University, Changchun 130023 (China); College of Chemistry, Jilin Normal University, Siping 136000 (China); Qiao Chunyu; Zhang Hanqi [College of Chemistry, Jilin University, Changchun 130023 (China); Liu Chunming [College of Chemistry, Changchun Normal University, Changchun 130032 (China)

2009-05-15

The interactions of mitomycin C (MMC), fluorouracil (FU), mercaptopurine (MP) and doxorubicin hydrochloride (DXR) with bovine serum albumin (BSA) were studied by spectroscopic method. Quenching of fluorescence of serum albumin by these drugs was found to be a static quenching process. The binding constants (K{sub A}) were 9.66x10{sup 3}, 2.08x10{sup 3}, 8.20x10{sup 2} and 7.50x10{sup 3} L mol{sup -1} for MMC-, FU-, MP- and DXR-BSA, respectively, at pH 7.4 Britton-Robinson buffer at 28 deg. C. The thermodynamic functions such as enthalpy change ({delta}H), entropy change ({delta}S) and Gibbs free-energy change ({delta}G) for the reactions were also calculated according to the thermodynamic equations. The main forces in the interactions of these drugs with BSA were evaluated. It was found that the interactions of MMC and FU with BSA were exothermic processes and those of MP and DXR with BSA were endothermic. In addition, the binding sites on BSA for the four drugs were probed by the changes of binding properties of these drugs with BSA in the presence of two important site markers such as ibuprofen and indomethacin. Based on the Foester theory of non-radiation energy transfer, the binding distances between the drugs and tryptophane were calculated and they were 3.00, 1.14, 2.85, and 2.79 nm for MMC, FU, MP and DXR, respectively.

The ego according to Klein: return to Freud and beyond.

Science.gov (United States)

Blass, Rachel B

2012-02-01

This paper explores fundamental dimensions of Melanie Klein's concept of the ego through a detailed study of the writings of Klein and her early colleagues (Paula Heimann, Susan Isaacs and Joan Riviere). The study examines three central issues: (a) the basic theoretical framework for Klein's conceptualization of the ego, and specifically how her conceptualization builds on Freud's structural and dual instinct models; (b) the processes involved in the development of the ego and its capacities (including the development from id to ego and from ego to superego); and (c) the view of the ego as an object of phantasy. Through this examination, the study demonstrates that Klein's conceptualization of the ego is firmly grounded both in Freud's formulations about the ego and in his theoretical and metapsychological approach to thinking about the ego. This counters the prevalent view that Klein was only focused on clinical understandings, unconcerned with theory and fuzzy in her abstract thinking. More specifically, it counters the view that Klein did not really have a concept of the ego in any well-structured sense of the term (Britton, 2003; Hinshelwood, 1994; Segal, 2001). The study considers the sources of these misconceived views. Finally, it argues that discarding such views allows us to appreciate better the richness of Klein's thinking, her theoretical affinities to Freud, and the role of theory in the development and justification of psychoanalysis. Copyright © 2011 Institute of Psychoanalysis.

Nutritional ecology of the formosan subterranean termite (Isoptera: Rhinotermitidae): feeding response to commercial wood species.

Science.gov (United States)

Morales-Ramos, J A; Rojas, M G

2001-04-01

The feeding preferences of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were tested in three separate experiments on 28 different wood species. Experiment 1 was a multiple-choice test designed to test relative preferences among 24 wood species commercially available in New Orleans, LA. Experiment 2 was a similar study designed to test relative preferences among 21 wood species shown or reported to be unpalatable to the Formosan subterranean termite. Experiment 3 was a no-choice test to examine the feeding deterrence of the 10 least preferred wood species. Preference was determined by consumption rates. Birch (Betula alleghaniensis Britton), red gum (Liquidambar styraciflua L.), Parana pine [Araucaria angustifolia (Bert.) 1, sugar maple (Acer saccharum Marsh.), pecan (Carya illinoensis Wangenh.), and northern red oak (Quercus rubra L.) were the most preferred species by C. formosanus in order of consumption rate. All of these species were significantly more preferred than southern yellow pine (Pinus taeda L.), widely used for monitoring. Sinker cypress [ = old growth bald cypress, Taxodium distichum (L.)], western red cedar (Thuja plicata Donn), Alaskan yellow cedar (Chamaecyparis nootkatensis D. Don), eastern red cedar (Juniperus virginiana L.), sassafras [Sassafras albidum (Nutt.)], Spanish cedar (Cedrella odorata L.), Honduras mahogany (Swietenia macrophyla King), Indian rosewood (Dalbergia latifolia Roxb.), Honduras rosewood (D. stevensonii Standl.), and morado (Machaerium sp.) induced significant feeding deterrence and mortality to C. formosanus. The last eight species produced 100% mortality after 3 mo.

Iridium Oxide-reduced Graphene Oxide Nanohybrid Thin Film Modified Screen-printed Electrodes as Disposable Electrochemical Paper Microfluidic pH Sensors.

Science.gov (United States)

Yang, Jiang; Kwak, Tae-Joon; Zhang, Xiaodong; McClain, Robert; Chang, Woo-Jin; Gunasekaran, Sundaram

2016-11-22

A facile, controllable, inexpensive and green electrochemical synthesis of IrO2-graphene nanohybrid thin films is developed to fabricate an easy-to-use integrated paper microfluidic electrochemical pH sensor for resource-limited settings. Taking advantages from both pH meters and strips, the pH sensing platform is composed of hydrophobic barrier-patterned paper micropad (µPAD) using polydimethylsiloxane (PDMS), screen-printed electrode (SPE) modified with IrO2-graphene films and molded acrylonitrile butadiene styrene (ABS) plastic holder. Repetitive cathodic potential cycling was employed for graphene oxide (GO) reduction which can completely remove electrochemically unstable oxygenated groups and generate a 2D defect-free homogeneous graphene thin film with excellent stability and electronic properties. A uniform and smooth IrO2 film in nanoscale grain size is anodically electrodeposited onto the graphene film, without any observable cracks. The resulting IrO2-RGO electrode showed slightly super-Nernstian responses from pH 2-12 in Britton-Robinson (B-R) buffers with good linearity, small hysteresis, low response time and reproducibility in different buffers, as well as low sensitivities to different interfering ionic species and dissolved oxygen. A simple portable digital pH meter is fabricated, whose signal is measured with a multimeter, using high input-impedance operational amplifier and consumer batteries. The pH values measured with the portable electrochemical paper-microfluidic pH sensors were consistent with those measured using a commercial laboratory pH meter with a glass electrode.

Electrochemical study and flow injection analysis of paracetamol in pharmaceutical formulations based on screen-printed electrodes and carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Fanjul-Bolado, Pablo [DropSens, S.L., Edificio Severo Ochoa, Campus El Cristo, 33006 Oviedo, Asturias (Spain); Lamas-Ardisana, Pedro Jose [Departamento de Quimica Fisica y Analitica, Universidad de Oviedo, Julian Claveria 8, 33006 Oviedo, Asturias (Spain); Hernandez-Santos, David [DropSens, S.L., Edificio Severo Ochoa, Campus El Cristo, 33006 Oviedo, Asturias (Spain); Costa-Garcia, Agustin, E-mail: costa@fq.uniovi.es [Departamento de Quimica Fisica y Analitica, Universidad de Oviedo, Julian Claveria 8, 33006 Oviedo, Asturias (Spain)

2009-04-13

Acetaminophenol or paracetamol is one of the most commonly used analgesics in pharmaceutical formulations. Acetaminophen is electroactive and voltammetric mechanistic studies for the electrode processes of the acetaminophenol/N-acetyl-p-quinoneimine redox system are presented. Carbon nanotubes modified screen-printed electrodes with enhanced electron transfer properties are used for the study of the electrochemical-chemical oxidation mechanism of paracetamol at pH 2.0. Quantitative analysis of paracetamol by using its oxidation process (in a Britton-Robinson buffer solution pH 10.0) at +0.20 V (vs. an Ag pseudoreference electrode) on an untreated screen-printed carbon electrode (SPCE) was carried out. Thus, a cyclic voltammetric based reproducible determination of acetaminophen (R.S.D., 2.2%) in the range 2.5 x 10{sup -6} M to 1 x 10{sup -3} M, was obtained. However, when SPCEs are used as amperometric detectors coupled to a flow injection analysis (FIA) system, the detection limit achieved for paracetamol was 1 x 10{sup -7} M, one order of magnitude lower than that obtained by voltammetric analysis. The repeatability of the amperometric detection with the same SPCE is 2% for 15 successive injections of 10{sup -5} M acetaminophen and do not present any memory effect. Finally, the applicability of using screen-printed carbon electrodes for the electrochemical detection of paracetamol (i.e. for quality control analysis) was demonstrated by using two commercial pharmaceutical products.

Flow injection analysis of sulphide based on its photoelectrocatalytic oxidation at poly-methylene blue modified glassy carbon electrode

International Nuclear Information System (INIS)

Dilgin, Yusuf; Canarslan, Seda; Ayyildiz, Onder; Ertek, Bensu; Nişli, Gürel

2012-01-01

A new approach for photoelectrocatalytic determination of sulphide in a flow injection analysis (FIA) system was studied using a poly-methylene blue modified glassy carbon electrode (poly-MB/GCE). Results from electrochemical measurements have revealed that poly-MB/GCE is capable of signalling electrocatalytic and photoelectrocatalytic activity towards sulphide oxidation. When the surface of poly-MB/GCE was irradiated with a light source (250 W Halogen lamp), the electrocatalytic current increased substantially. A homemade flow electrochemical cell with a suitable transparent window for the irradiation of the electrode surface was used to perform the photoelectrocatalytic determination of sulphide in FIA system. The currents obtained from the photoamperometric measurements in the FIA system at optimum conditions (carrier solution: pH 9.0 Britton Robinson buffer solution containing 0.1 M KCl; flow rate: 1.3 mL min −1 ; transmission tubing length: 10 cm; injection volume: 100 μL; and constant applied potential: +150 mV vs. Ag/AgCl/KCl sat ) were linearly correlated with the sulphide concentration. The calibration curves were obtained for sulphide concentrations in a range of 0.5–500 μM. The detection limits were found to be 0.27 and 0.15 μM for amperometric and photoamperometric methods, respectively. The proposed method was successfully applied to different wastewaters such as municipal sewage or tannery wastewater. Finally, results from the sulphide measurements by poly-MB/GCE were in good agreement with those attained using spectrophotometric method.

Active site intermediates in the reduction of O(2) by cytochrome oxidase, and their derivatives.

Science.gov (United States)

Wikström, Mårten

2012-04-01

The mechanism of dioxygen activation and reduction in cell respiration, as catalysed by cytochrome c oxidase, has a long history. The work by Otto Warburg, David Keilin and Britton Chance defined the dioxygen-binding heme iron centre, viz. das Atmungsferment, or cytochrome a(3). Chance brought the field further in the mid-1970's by ingenious low-temperature studies that for the first time identified the primary enzyme-substrate (ES) Michaelis complex of cell respiration, the dioxygen adduct of heme a(3), which he termed Compound A. Further work using optical, resonance Raman, EPR, and other sophisticated spectroscopic techniques, some of which with microsecond time resolution, has brought us to the situation today, where major principles of how O(2) reduction occurs in respiration are well understood. Nonetheless, some questions have remained open, for example concerning the precise structures, catalytic roles, and spectroscopic properties of the breakdown products of Compound A that have been called P, F (for peroxy and ferryl), and O (oxidised). This nomenclature has been known to be inadequate for some time already, and an alternative will be suggested here. In addition, the multiple forms of P, F and O states have been confusing, a situation that we endeavour to help clarifying. The P and F states formed artificially by reacting cytochrome oxidase with hydrogen peroxide are especially scrutinised, and some novel interpretations will be given that may account for previously unexplained observations. Copyright © 2011 Elsevier B.V. All rights reserved.

A dual-wavelength overlapping resonance Rayleigh scattering method for the determination of chondroitin sulfate with nile blue sulfate

Science.gov (United States)

Cui, Zhiping; Hu, Xiaoli; Liu, Shaopu; Liu, Zhongfang

2011-12-01

A dual-wavelength overlapping resonance Rayleigh scattering (DWO-RRS) method was developed to detect chondroitin sulfate (CS) with nile blue sulfate (NBS). At pH 3.0-4.0 Britton-Robinson (BR) buffer medium, CS interacted with NBS to form an ion-association complex. As a result, the new spectra of resonance Rayleigh scattering (RRS), second order scattering (SOS) and frequence doubling scattering (FDS) appeared and their intensities were enhanced greatly. Their maximum wavelengths were located at 303 nm (RRS), 362 nm (RRS), 588 nm (SOS) and 350 nm (FDS), respectively. The scattering intensities of the three methods were proportional to the concentration of CS in certain ranges. The methods had high sensitivity and the detection limits were between 1.5 and 7.1 ng mL -1. The DWO-RRS method had the highest sensitivity with the detection limit being 1.5 ng mL -1. The characteristics of the spectra and optimal reaction conditions of RRS method were investigated. The effects of coexistent substances on the determination of CS were evaluated. Owing to the high sensitivity, RRS method had been applied to the determination of CS in eye drops with satisfactory results. The recovery range was between 99.4% and 104.6% and the relative standard deviation (RSD) was between 0.4% and 0.8%. In addition, the reasons for RRS enhancement were discussed and the shape of ion-association complex was characterized by atomic force microscopy (AFM).

Growth and gas exchange in white pitaya under different concentrations of potassium and calcium

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João Paulo Cajazeira

Full Text Available ABSTRACT Agriculture in Brazil has improved at a fast pace in recent years, given the growing demand for quality and the need for new products. In this respect, white pitaya [Hylocereus undatus (Haw. Britton & Rose] has become a feasible alternative for Northeast farmers. The limiting factors include a small amount of data on plant mineral nutrition and crop growth (phenology. Therefore, this study goal was to evaluate the effect of different concentrations of potassium (K and calcium (Ca on crop development and gas exchange in white pitaya grown in the coastal region of the state of Ceará, in Brazil. Sixteen treatments with three repetitions were organized in a completely randomized block design and a 4 × 4 factorial arrangement. Treatments consisted of various concentrations of K (0; 125; 250 and 375 mg dm-3 and Ca (0, 53, 106, and 159 mg dm-3. Biometric characteristics and gas exchange were determined after 270 and 240 days of treatment, respectively. For morphometric characteristics, the most significant nutrient combination was 250 mg dm-3 of K and 159 mg dm-3 of Ca. Net photosynthesis was higher at the dose of 125 mg dm-3 of K and 0 mg dm-3 of Ca. Our results indicate that, for the environmental conditions under which the test was conducted, an optimum nutrient combination for the analyzed variables was 250 mg dm-3 K and 159 mg dm-3 Ca.

Use and knowledge of Cactaceae in Northeastern Brazil.

Science.gov (United States)

Lucena, Camilla Marques de; Lucena, Reinaldo Farias Paiva de; Costa, Gabriela Maciel; Carvalho, Thamires Kelly Nunes; Costa, Gyslaynne Gomes da Silva; Alves, Rômulo Romeu da Nóbrega; Pereira, Daniel Duarte; Ribeiro, João Everthon da Silva; Alves, Carlos Antônio Belarmino; Quirino, Zelma Glebya Maciel; Nunes, Ernane Nogueira

2013-08-28

This study aimed to record the use, and knowledge that residents from São Francisco community (Paraiba, Brazil) have regarding the Cactaceae. Semi-structured interviews were carried out with 118 informants; 50 men and 68 women. The cacti cited in this study were organised into use categories and use values were calculated. Differences in the values applied to species and use categories by men and women were compared via a G test (Williams). The nine species identified were: Cereus jamacaru DC., Melocactus bahiensis (Brtitton & Rose) Luetzelb., Nopalea cochenillifera (L.) Salm-Dyck., Opuntia ficus indica (L.) Mill, Opuntia stricta (Haw.) Haw., Pilosocereus gounellei (F.A.C. Weber) Byles & Rowley, Pilosocereus pachycladus F. Ritter, Tacinga inamoena (K. Schum) N.P. Taylor & Stuppy, Tacinga palmadora (Britton & Rose) N.P. Taylor & Stuppy. In total, 1,129 use citations were recorded, divided into 11 categories. The use value categories with the highest scores were forage (0.42), food (0.30) and construction (building) (0.25). P. pachycladus showed the greatest use value, versatility and number of plant parts used. The survey showed that the Cactaceae is extremely important for several uses and categories attributed to different species. Apart from contributing to the ethnobotanical knowledge of the Cactaceae, another important focus of this study was to reinforce the necessity for further studies that record the traditional knowledge about this plant family, which has been lost in younger generations.

Evaluación de la toxicidad del aceite esencial de Aloysia triphylla Britton (cedrón y de la actividad anti-Trypanosoma cruzi del citral, in vivo

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Juan Rojas Armas

2015-04-01

Full Text Available Introducción: Existe escasa investigación en enfermedades olvidadas. Las plantas medicinales son una potencial fuente de compuestos antimicrobianos. Objetivos: Determinar la toxicidad del aceite esencial de Aloysia triphylla y la actividad del citral contra Trypanosoma cruzi en ratones. Diseño: Estudio experimental preclínico in vivo. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material: Ratones albinos. Intervenciones: La toxicidad aguda oral a dosis única fue evaluada en ratas albinas. Para la actividad tripanocida se utilizaron ratones asignados a los siguientes grupos: infectados y no tratados (G1, infectados y tratados con citral en dosis de 50, 150 y 300 mg/kg/día (G2, G3 y G4, respectivamente, infectados y tratados con benznidazol 100 mg/kg (G5 y no infectados y no tratados (G6. La parasitemia fue determinada individualmente cada 2 días por microscopia directa. En los días 14, 21 y 28 post infección, cinco ratones de cada grupo fueron sacrificados y los corazones procesados para análisis histopatológico. Principales medidas de resultados: Signos de toxicidad y mortalidad, y parasitemia. Resultados: La dosis límite de 2 000 mg/kg no provocó signos ni síntomas de toxicidad y los estudios anatomopatológicos macroscópicos y microscópicos no mostraron alteración de los órganos estudiados. La parasitemia fue reducida significativamente con la dosis de 300 mg/kg en los días 16° 18° y 20° post infección (p < 0,05. El número de nidos de amastigotes y de infiltrados inflamatorios en corazón fueron reducidos en 67,7% y 51,7%, respectivamente, con 300 mg/kg en el día 28°. Conclusiones: El aceite esencial de Aloysia triphylla es calificado como no tóxico y el citral en dosis de 300 mg/kg tuvo actividad contra Trypanosoma cruzi en ratones.

Polymeric bionanocomposite cast thin films with in situ laccase-catalyzed polymerization of dopamine for biosensing and biofuel cell applications.

Science.gov (United States)

Tan, Yueming; Deng, Wenfang; Li, Yunyong; Huang, Zhao; Meng, Yue; Xie, Qingji; Ma, Ming; Yao, Shouzhuo

2010-04-22

We report here on the facile preparation of polymer-enzyme-multiwalled carbon nanotubes (MWCNTs) cast films accompanying in situ laccase (Lac)-catalyzed polymerization for electrochemical biosensing and biofuel cell applications. Lac-catalyzed polymerization of dopamine (DA) as a new substrate was examined in detail by UV-vis spectroscopy, cyclic voltammetry, quartz crystal microbalance, and scanning electron microscopy. Casting the aqueous mixture of DA, Lac and MWCNTs on a glassy carbon electrode (GCE) yielded a robust polydopamine (PDA)-Lac-MWCNTs/GCE that can sense hydroquinone with 643 microA mM(-1) cm(-2) sensitivity and 20-nM detection limit (S/N = 3). The DA substrate yielded the best biosensing performance, as compared with aniline, o-phenylenediamine, or o-aminophenol as the substrate for similar Lac-catalyzed polymerization. Casting the aqueous mixture of DA, glucose oxidase (GOx), Lac, and MWCNTs on a Pt electrode yielded a robust PDA-GOx-Lac-MWCNTs/Pt electrode that exhibits glucose-detection sensitivity of 68.6 microA mM(-1) cm(-2). In addition, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS) was also coimmobilized to yield a PDA-Lac-MWCNTs-ABTS/GCE that can effectively catalyze the reduction of O(2), and it was successfully used as the biocathode of a membraneless glucose/O(2) biofuel cell (BFC) in pH 5.0 Britton-Robinson buffer. The proposed biomacromolecule-immobilization platform based on enzyme-catalyzed polymerization may be useful for preparing many other multifunctional polymeric bionanocomposites for wide applications.

Validated stability indicating liquid chromatographic determination of ebastine in pharmaceuticals after pre column derivatization: Application to tablets and content uniformity testing

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Eid Manal

2011-05-01

Full Text Available Abstract An accurate, simple, sensitive and selective reversed phase liquid chromatographic method has been developed for the determination of ebastine in its pharmaceutical preparations. The proposed method depends on the complexation ability of the studied drug with Zn2+ ions. Reversed phase chromatography was conducted using an ODS C18 (150 × 4.6 mm id stainless steel column at ambient temperature with UV-detection at 260 nm. A mobile phase containing 0.025%w/v Zn2+ in a mixture of (acetonitril/methanol; 1/4 and Britton Robinson buffer (65:35, v/v adjusted to pH 4.2, has been used for the determination of ebastine at a flow rate of 1 ml/min. The calibration curve was rectilinear over the concentration range of 0.3 - 6.0 μg/ml with a detection limit (LOD of 0.13 μg/ml, and quantification limit (LOQ of 0.26 μg/ml. The proposed method was successfully applied for the analysis of ebastine in its dosage forms, the obtained results were favorably compared with those obtained by a comparison method. Furthermore, content uniformity testing of the studied pharmaceutical formulations was also conducted. The composition of the complex as well as its stability constant was also investigated. Moreover, the proposed method was found to be a stability indicating one and was utilized to investigate the kinetics of alkaline and ultraviolet induced degradation of the drug. The first-order rate constant and half life of the degradation products were calculated.

Functionalized Multiwalled Carbon Nanotube Electrochemical Sensor for Determination of Anticancer Drug Flutamide

Science.gov (United States)

Farias, Julianna Santos; Zanin, Hudson; Caldas, Adriana Silva; dos Santos, Clenilton Costa; Damos, Flavio Santos; de Cássia Silva Luz, Rita

2017-10-01

An electrochemical sensor based on functionalized multiwalled carbon nanotubes (MWCNTf) has been developed and applied for determination of anticancer drug flutamide in pharmaceutical and artificial urine samples. The electrode was prepared by modifying a glassy carbon electrode with MWCNTf, denoted herein as MWCNTf/GCE. The MWCNTf/GCE electrode exhibited high catalytic activity, high sensitivity, and high stability and was applicable over a wide concentration range for flutamide. The effects of the scan rate, pH, and nature of the electrolyte on the electrochemical behavior of flutamide on the MWCNTf/GCE were investigated. The results showed that this electrode presented the best square-wave voltammetric response to flutamide in Britton-Robinson buffer solution at pH 5.0 at frequency of 50 Hz and amplitude of 0.06 V. The proposed sensor presents a wide linear response range from concentration of 0.1 μmol L-1 up to 1000 μmol L-1 (or 27.6 μg L-1 up to 0.27 g L-1), with limit of detection, limit of quantification, and sensitivity of 0.03 μmol L-1, 0.1 μmol L-1, and 0.30 μA μmol-1 L, respectively. The MWCNTf/GCE electrode was successfully applied for determination of flutamide in pharmaceutical formulations and artificial urine samples, giving results in agreement with those obtained by a comparative method described in literature. A paired Student's t-test revealed no statistical difference between the reference and proposed method at 95% confidence level. The average recovery for fortified samples was 101 ± 1%.

EVALUACIÓN DEL USO DE ENZIMAS Y FILTRACIÓN POR GRAVEDAD PARA LA CLARIFICACIÓN DE UNA MEZCLA DILUIDA DE PULPA DE FRUTOS DE CACTUS (OPUNTIA BOLDINGHII BRITTON & ROSE, JUGOS DE NARANJA Y TORONJA EVALUATION OF THE USE OF ENZYMES AND GRAVITY FILTRATION FOR CLARIFICATION OF DILUTED MIXTURE OF CACTUS (OPUNTIA BOLDINGHII BRITTON & ROSE FRUITS PULP, ORANGE AND GRAPEFRUIT JUICES

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Carlos Alberto Padrón Pereira

2010-06-01

Full Text Available En Venezuela los frutos de cactus (Opuntia boldinguii son de escasa utilidad comercial. Para su aprovechamiento se evaluó el efecto del uso combinado de enzimas fibrolíticas y filtración por gravedad en la clarificación de una mezcla diluida de pulpa de frutos de cactus, jugos de naranja y toronja. Se compararon los valores de las curvas de flujo de filtrado de las mezclas hidrolizada y sin hidrolizar mediante la prueba t de Welch. La concentración óptima de enzimas fue 0,76% (v/v. La hidrólisis enzimática previa a la pasteurización no afectó el color de la mezcla. Durante los ensayos de pasteurización (62 ± 1 ºC por 30 min hubo grandes cambios de coloración, solo en la mezcla hidrolizada, por degradación de las betalaínas y la adición de ácido ascórbico (0,5% p/v permitió preservar el color. Hubo diferencias altamente significativas entre los valores de las curvas de flujo de filtrado (PIn Venezuela the fruits of cactus (Opuntia boldinguii are of scarce commercial usefulness. For its utilization the effect of combined use of fibrolytic enzymes and gravity filtration for clarification of diluted mixture of cactus fruits pulp, orange and grapefruit juices was evaluated. The values of filtered-flow curves of hydrolyzed and not hydrolyzed mixtures were compared by means of Welch’s t-test. The optimal enzymes concentration was 0.76% (v/v. The prior enzymatic hydrolysis to the pasteurization does not affect the color of the mixture. During the pasteurization assays (62 ± 1 ºC for 30 min there were large changes of coloring, only in the hydrolyzed mixture, by betalains degradation and the addition of ascorbic acid (0.5% w/v permitted to preserve the color. There were highly significant differences between the filtered-flow curves values (P<0.01. The filtered-flow of the hydrolyzed mixture elapsed 110 min (0.159 mL·min-1 was greater to the not hydrolyzed mixture (control flow to the 8 min (0.100 mL·min-1. The juice production yield during the filtration of hydrolyzed mixture was 38.3% greater than that obtained with the control mixture. The elaboration of citric beverages pigmented with fruits of cactus represents an alternative of utilization of these species and the prior enzymatic hydrolysis to the elaboration constitutes a treatment to improve the quality.

Biogenic volatile organic compound emissions from a lowland tropical wet forest in Costa Rica

Energy Technology Data Exchange (ETDEWEB)

Geron, C. [United States Environmental Protection Agency, Research Triangle Park, NC (United States). National Risk Management Research Lab.; Guenther, A.; Greenberg, J. [National Center for Atmospheric Research, Boulder, CO (United States); Loescher, H.W. [University of Florida, Gainesville, FL (United States). School of Forest Resources and Conservation; Clark, D. [University of Missouri-St. Louis, MS (United States). Dept. of Biology; Baker, B. [South Dakota School of Mines and Technology, Rapid City, SD (United States)

2002-08-01

Twenty common plant species were screened for emissions of biogenic volatile organic compounds (BVOCs) at a lowland tropical wet forest site in Costa Rica. Ten of the species examined emitted substantial quantities of isoprene. These species accounted for 35-50% of the total basal area of old-growth forest on the major edaphic site types, indicating that a high proportion of the canopy leaf area is a source of isoprene. A limited number of canopy-level BVOC flux measurements were also collected by relaxed eddy accumulation (REA). These measurements verify that the forest canopy in this region is indeed a significant source of isoprene. In addition, REA fluxes of methanol and especially acetone were also significant, exceeding model estimates and warranting future investigation at this site. Leaf monoterpene emissions were non-detectable or very low from the species surveyed, and ambient concentrations and REA fluxes likewise were very low. Although the isoprene emission rates reported here are largely consistent with phylogenetic relations found in other studies (at the family, genus, and species levels), two species in the family Mimosaceae, a group previously found to consist largely of non-isoprene emitters, emitted significant quantities of isoprene. One of these, Pentaclethra macroloba (Willd.) Kuntze, is by far the most abundant canopy tree species in the forests of this area, composing 30-40% of the total basal area. The other, Zygia longifolia (Humb. and Bonpl.) Britton and Rose is a common riparian species. Our results suggest that the source strength of BVOCs is important not only to tropical atmospheric chemistry, but also may be important in determining net ecosystem carbon exchange.(author)

Differential pulse cathodic stripping voltammetric determination of uranium with arsenazo-III at the hanging mercury dropping electrode

Energy Technology Data Exchange (ETDEWEB)

Kadi, M.W.; El-Shahawi, M.S. [Chemistry Dept., King Abdulaziz Univ., Jeddah (Saudi Arabia)

2009-07-01

An accurate, inexpensive and less laborious controlled adsorptive accumulation of uranium(VI)-arsenazo-III on a hanging mercury drop electrode (HMDE) has been developed for uranium(VI) determination. The method is based upon the collection of uranium(VI)-arsenazo-III complex at pH 5-6 at the HMDE and subsequent direct stripping measurement of the element in the nanomolar concentration level. The cathodic peak current (i{sub p,c}) of the adsorbed complex ions of uranium(VI) was measured at -0.35 V vs. Ag/AgCl reference electrode by differential pulse cathodic stripping voltammetry (DP-CSV), proceeded by an accumulation period of 150s2.5 in Britton-Robinson buffer of pH 5. The plot of the resulting i{sub p,c} vs. uranium(VI) concentration was linear in the range 2.1 x 10{sup -9} to 9.60 x 10{sup -7} mol L{sup -1} uranium(VI) and tended to level off at above 9.6 x 10{sup -7} mol L{sup -1}. The limits of detection and quantification of uranium(VI) were found to be 4.7 x 10{sup -10} and 1.5 x 10{sup -9} mol L{sup -1}, respectively. A relative standard deviation of {+-}2.39% (n = 5) at 8.5 x 10{sup -7} mol L{sup -1} uranium(VI) was obtained. The method was validated by comparing the results with that obtained by ICP-MS method with RSD less than {+-}3.3%. The method was applied successfully for the analysis of uranium in certified reference material (IAEA soil-7), and in phosphate fertilizers. (orig.)

Continued selenium biofortification of carrots and broccoli grown in soils once amended with Se-enriched S. pinnata

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Gary S. Bañuelos

2016-08-01

Full Text Available Selenium (Se biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton three and four years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0-30 cm were 1.65 mg kg-1 and 88 µg L-1, and 0.92 mg kg-1 and 48.6 µg L-1 at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg-1 and 3.15 to 6.25 mg kg-1 in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid analyses (PLFA showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi, actinomycetes and Gram-positive and bacterial PLFA at both 0-5 and 0-30 cm, respectively, three years later. Successfully producing Se-enriched broccoli and carrots three and four years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions.

The development of environmental awareness through a proposal for promoting intercomprehension in romance languages among high school seniors

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Bibiana Amado

2015-09-01

Full Text Available This work aims to analyze the treatment of environmental issues in an educational proposal for Intercomprehension in Romance Languages (hereinafter called IC developed by InterRom, a research team from Universidad Nacional de Córdoba, in Argentina. This proposal, aimed at developing high school seniors’ language skills from the perspective of teaching and learning IC from text genres, integrates pluralistic approaches to languages with contributions from socio-discursive interactionism (BRONCKART, 2007, from the sociocultural theory of human development (BRUNER, 1994; NELSON, 1996; ROGOFF, 1993; VYGOTSKY, 1962, 1988 and from cognitive approaches to text comprehension and production (BRITTON and GRAESSER, 1996; HAYES and FLOWERS, 1980, HAYES, 1996; SCARDAMALIA and BEREITER, 1992. Through the convergence of these theoretical perspectives, the proposal promotes IC in French, Italian, Spanish and Portuguese, related to environmental conservation, as well as actions for writing texts in Spanish. The planned language activities involve working with different text genres on environmental issues, such as the extinction of animal species, the production of genetically modified foods and the use of agrochemicals that contaminate the biosphere and threaten the life of all living species, including human beings. The exercises related to these topics, at the same time, encourage students to reflect on critical environmental issues and to develop strategies for writing texts in Spanish. To conclude, it can be argued that the IC proposal is based on social and intercultural approaches that integrate teaching actions, text production processes and science issues regarding the environment. As a result, students are regarded as subjects with competencies to understand discourses from different cultures and to think, write and act within their natural, social and cultural environments.

Unconscious phantasy as a structural principle and organizer of mental life: The evolution of a concept from Freud to Klein and some of her successors.

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Weiss, Heinz

2017-06-01

Starting with Freud's discovery of unconscious phantasy as a means of accessing his patients' internal world, the author discusses the evolution of the concept in the work of Melanie Klein and some of her successors. Whereas Freud sees phantasy as a wish fulfilling imagination, dominated by primary process functioning and kept apart from reality testing, Klein understands phantasies as a structural function and organizer of mental life. From their very beginnings they involve object relations and gradually evolve from primitive body-near experiences to images and symbolic representations. With her concept of projective identification in particular, Klein anticipates the communicative function of unconscious phantasies. They are at the basis of processes of symbolization, but may also be put into the service of complex defensive operations. The author traces the further evolution of the concept from the contributions of S. Isaacs, the theories of thinking proposed by W.R. Bion and R. Money-Kyrle, Hanna Segal's ideas on symbolization and reparation all the way to the latest approaches by R. Britton, J. Steiner and others, including the understanding of transference and counter-transference as a 'total situation'. Points of contact with Freud are to be found particularly in connection with his concept of 'primal phantasies'. In the author's view, the idea of the transmission and communicative potential of unconscious phantasies enabled these authors to overcome the solipsistic origins of drive theory in favour of a notion in which unconscious phantasies both set down the coordinates of the inner world and form and reflect the matrix of inter-subjective relations. Copyright © 2017 Institute of Psychoanalysis.

A note on notes: note taking and containment.

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Levine, Howard B

2007-07-01

In extreme situations of massive projective identification, both the analyst and the patient may come to share a fantasy or belief that his or her own psychic reality will be annihilated if the psychic reality of the other is accepted or adopted (Britton 1998). In the example of' Dr. M and his patient, the paradoxical dilemma around note taking had highly specific transference meanings; it was not simply an instance of the generalized human response of distracted attention that Freud (1912) had spoken of, nor was it the destabilization of analytic functioning that I tried to describe in my work with Mr. L. Whether such meanings will always exist in these situations remains a matter to be determined by further clinical experience. In reopening a dialogue about note taking during sessions, I have attempted to move the discussion away from categorical injunctions about what analysis should or should not do, and instead to foster a more nuanced, dynamic, and pair-specific consideration of the analyst's functioning in the immediate context of the analytic relationship. There is, of course, a wide variety of listening styles among analysts, and each analyst's mental functioning may be affected differently by each patient whom the analyst sees. I have raised many questions in the hopes of stimulating an expanded discussion that will allow us to share our experiences and perhaps reach additional conclusions. Further consideration may lead us to decide whether note taking may have very different meanings for other analysts and analyst-patient pairs, and whether it may serve useful functions in addition to the one that I have described.

Molecularly imprinted polymer solid-phase extraction coupled to square wave voltammetry at carbon fibre microelectrodes for the determination of fenbendazole in beef liver.

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Guzmán-Vázquez de Prada, A; Loaiza, Oscar A; Serra, B; Morales, D; Martínez-Ruiz, P; Reviejo, A J; Pingarrón, J M

2007-05-01

A molecularly imprinted polymer was developed and used for solid-phase extraction (MISPE) of the antihelmintic fenbendazole in beef liver samples. Detection of the analyte was accomplished using square wave voltammetry (SWV) at a cylindrical carbon fibre microelectrode (CFME). A mixture of MeOH/HAc (9:1) was employed both as eluent in the MISPE system and as working medium for electrochemical detection of fenbendazole. The limit of detection was 1.9x10(-7) mol L-1 (57 microg L-1), which was appropriate for the determination of fenbendazole at the maximum residue level permitted by the European Commission (500 microg kg-1 in liver). Given that the SW voltammetric analysis could not be directly performed in the sample extract as a consequence of interference from some sample components, a sample clean-up with a MIP for selectively retaining fenbendazole was performed. The MIP was synthesized using a 1:8:22 template/methacrylic acid/ethylene glycol dimethacrylate ratio. A Britton-Robinson Buffer of pH 9.0 was selected for retaining fenbendazole in the MIP cartridges, and an eluent volume of 5.0 mL at a flow rate of 2.0 mL min-1 was chosen in the elution step. Cross-reactivity with the MIP was observed for other benzimidazoles. The synthesized MIP exhibited a good selectivity for benzimidazoles with respect to other veterinary drugs. The applicability of the MISPE-SWV method was tested with beef liver samples, spiked with fenbendazole at 5,000 and 500 microg kg-1. Results obtained for ten different liver samples yielded mean recoveries of (95+/-12)% and (96+/-11)% for the upper and lower concentration level, respectively.

Voltammetric Behaviour of Sulfamethoxazole on Electropolymerized-Molecularly Imprinted Overoxidized Polypyrrole

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Yücel Sahin

2008-12-01

Full Text Available In this work, preparation of a molecularly imprinted polymer (MIP film and its recognition properties for sulfamethoxazolewere investigated. The overoxidized polypyrrole (OPPy film was prepared by the cyclic voltammetric deposition of pyrrole (Py in the presence of supporting electrolyte (tetrabutylammonium perchlorate-TBAP with and without a template molecule (sulfamethoxazole on a pencil graphite electrode (PGE. The voltammetric behaviour of sulfamethoxazole on imprinted and non-imprinted (NIP films was investigated by differential pulse voltammetry (DPV in Britton-Robinson (BR buffer solutions prepared in different ratio of acetonitrile-water binary mixture, between the pH 1.5 and 7.0. The effect of the acetonitrile-water ratio and pH, monomer and template concentrations, electropolymerization cycles on the performance of the MIP electrode was investigated and optimized. The MIP electrode exhibited the best reproducibility and highest sensitivity. The results showed that changing acetonitrile-water ratio and pH of BR buffer solution changes the oxidation peak current values. The highest anodic signal of sulfamethoxazole was obtained in BR buffer solution prepared in 50% (v/v acetonitrile-water at pH 2.5. The calibration curve for sulfamethoxazole at MIP electrode has linear region for a concentration range of 25.10-3 to 0.75 mM (R2=0.9993. The detection limit of sulfamethoxazole was found as 3.59.10-4 mM (S/N=3. The same method was also applied to determination of sulfamethoxazole in commercial pharmaceutical samples. Method precision (RSD87% were satisfactory. The proposed method is simple and quick. The polypyrrole (PPy electrodes have low response time, good mechanical stability and are disposable simple to construct.

Evaluación in vivo de la actividad antimalárica de 25 plantas provenientes de una Reserva de Conservación Biológica de Costa Rica In vivo evaluation of the antimalarial activity of 25 plants from a Biological Conservation Reserve of Costa Rica

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MISAEL CHINCHILLA-CARMONA

2011-03-01

Full Text Available Se realizó una evaluación in vivo de la actividad antimalárica de las hojas, flores, frutos, corteza y raíz de 25 plantas de la Reserva Biológica Alberto Manuel Brenes (REBAMB, situada en San Ramón, Alajuela, Costa Rica. Las plantas estudiadas fueron Aphelandra aurantiaca (Scheidw. Lindl., Aphelandra tridentata Hemsl. (Acanthaceae, Xanthosoma undipes (K. Koch & C.D. Bouché K. Koch. (Araceae, Iriartea deltoidea Ruiz & Pav. (Arecaceae, Neurolaena lobata (L. Cass. (Asteraceae, Lonchocarpus pentaphyllus (Poir. Kunth ex DC., Pterocarpus hayesii Hemsl., Senna papillosa (Britton & Rose H.S. Irwin & Barneby., Cinnamomum chavarrianum (Hammel Kosterm. (Fabaceae, Nectandra membranacea (Sw. Griseb., Persea povedae W.C. Burger. (Lauraceae, Hampea appendiculata (Donn. Sm. Standl. (Malvaceae, Guarea glabra Vahl., Ruagea glabra Triana & Planch. (Meliaceae, Psidium guajava L. (Myrtaceae, Bocconia frutescens L. (Papaveraceae, Piper friedrichsthalii C. DC. (Piperaceae, Clematis dioica L. (Ranunculaceae, Prunus annularis Koehne. (Rosaceae, Siparuna thecaphora (Poepp. & Endl. A. DC. (Siparunaceae, Solanum arboreum Dunal., Witheringia solanacea L'Hér. (Solanaceae, Ticodendron incognitum Gómez-Laur. & L.D. Gómez. (Ticodendraceae, Heliocarpus appendiculatus Turcz. (Tiliaceae y Myriocarpa longipes Liebm. (Urticaceae. Los extractos alcohólicos frescos y secos, fueron evaluados por su actividad inhibitoria de la parasitemia causada por Plasmodium berghei en ratones Swiss. Al realizar las prueba de CI50 las plantas en que esa actividad fue muy relevante fueron (en mg kg-1 de peso: 12 para la corteza de B. frutescens, 18 para la raíz de H. appendiculata, 14 para la raíz de I. deltoidea, 4 para el fruto inmaduro de M. longipes, 21 para la raíz de N. membranacea, 19 para las hojas tiernas de P. povedae y 16 para el fruto inmaduro de S. tecaphora. Los extractos frescos presentaron una mayor actividad antimalárica que los sometidos a desecación. Este estudio es

Inundation downscaling for the development of a long-term and global inundation database compatible to SWOT mission

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Aires, Filipe; Prigent, Catherine; Papa, Fabrice

2014-05-01

-term, high-resolution wetland dataset over the Amazon basin, downscaled from a multi-wavelength retrieval using SAR, J. of Hydrometeorology, 14, 594-6007, 2013. - Prigent, C., F. Papa, F. Aires, C. Jimenez, W.B. Rossow, and E. Matthews. Changes in land surface water dynamics since the 1990s and relation to population pressure. Geophys. Res. Lett., 39(L08403), 2012. - Frappart, F.; F. Papa, A. Guntner, S. Werth, J. Santos da Silva, J. Tomasella, F. Seyler, C. Prigent, W.B. Rossow, S. Calmant, and M.-P. Bonnet. Satellite-based estimates of groundwater storage variations in large drainage basins with extensive floodplains. Remote Sens. Environ., 115 :1588-1594, 2011.

In This Issue

Science.gov (United States)

1996-04-01

acquisition of data has made these techniques desirable even at the high school level. Students who are used to surfing the Internet on their home computer are ready to collect information via PC in their school labs as well. Bindel (page 356) takes advantage of the Personal Science Laboratory, an affordable package of probes and software for PC interfacing, to provide an experiment using the eye-catching lightstick as its object. Students use two methods to determine the activation energy of the reaction that produces the luminescence and explore concepts of kinetics as well as learn about computer-interfaced experimentation. Addendum. The engaging photgraph of Linus Pauling on the cover of the January issue was taken by Joseph McNally and is copyright Joseph McNally Photography, 52 Villard Avenue, Hastings-on-Hudon, NY 10706.

Estudos sobre a atividade dos extratos da suprarenal

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Maria Isabel Mello

1947-03-01

Full Text Available Studies have been carried out on the method of Britton and Silvette modified by Reinecke and Kendall, for the evaluation of cortico-adrenal extracts, based on the deposition of glycogen in the liver of adrenaletomized rats. The test was performed in a total of 180 normal and adrenalectomized rats. The extracts tested were: a an aqueous extract of cortico-adrenal cortex prepared by the Swingle and Pfiffner technique; b the same extract added with ascorbic acid (Supracortin Labor; c desoxycorticosterone acetate (Percortol Ciba and Syncortyl Roussell. Male rats were used, ranging from 40-200g, fed since the 18 th days old with a special diet, in which they were maintained until the day before the injection. Adrenalectomy was performed under urethane anesthesia. The fourth day after operation, food was removed and they were fasted for 24 hours. In the morning of the fifth day, injections of the material to be assayed were given at hourly and two hours intervals, during four to eight hours. One or two hours after the last injection, the animals were sacrified, the livers removed and dropped into a hot 30% solution of potassium hydroxide, and worked by Good, Kramer and Somogyi method. The glycogen was calculated as milligrams per lOOg of body and liver weight. The results obtained are shown in the tables I, II, and III. When several dosages of the same sample of extract were made (5 animals each dose, the amount of glycogen deposited in the liver per lOOg of body and liver weight, was found to be a positive function of the dose injected. The graph 2, shows these results. The synthetic compounds were ineffective. Our results are in agreement with those of Reinecke and Kendall and of Olson et al.

Subinhibitory concentrations of perilla oil affect the expression of secreted virulence factor genes in Staphylococcus aureus.

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Jiazhang Qiu

Full Text Available BACKGROUND: The pathogenicity of staphylococcus aureus is dependent largely upon its ability to secrete a number of virulence factors, therefore, anti-virulence strategy to combat S. aureus-mediated infections is now gaining great interest. It is widely recognized that some plant essential oils could affect the production of staphylococcal exotoxins when used at subinhibitory concentrations. Perilla [Perilla frutescens (L. Britton], a natural medicine found in eastern Asia, is primarily used as both a medicinal and culinary herb. Its essential oil (perilla oil has been previously demonstrated to be active against S. aureus. However, there are no data on the influence of perilla oil on the production of S. aureus exotoxins. METHODOLOGY/PRINCIPAL FINDINGS: A broth microdilution method was used to determine the minimum inhibitory concentrations (MICs of perilla oil against S. aureus strains. Hemolysis, tumour necrosis factor (TNF release, Western blot, and real-time RT-PCR assays were performed to evaluate the effects of subinhibitory concentrations of perilla oil on exotoxins production in S. aureus. The data presented here show that perilla oil dose-dependently decreased the production of α-toxin, enterotoxins A and B (the major staphylococcal enterotoxins, and toxic shock syndrome toxin 1 (TSST-1 in both methicillin-sensitive S. aureus (MSSA and methicillin-resistant S. aureus (MRSA. CONCLUSIONS/SIGNIFICANCE: The production of α-toxin, SEA, SEB, and TSST-1 in S. aureus was decreased by perilla oil. These data suggest that perilla oil may be useful for the treatment of S. aureus infections when used in combination with β-lactam antibiotics, which can increase exotoxins production by S. aureus at subinhibitory concentrations. Furthermore, perilla oil could be rationally applied in food systems as a novel food preservative both to inhibit the growth of S. aureus and to repress the production of exotoxins, particularly staphylococcal enterotoxins.

Cathodic adsorptive stripping voltammetric determination of Ribavirin in pharmaceutical dosage form, urine and serum

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Ahmed A. Abdel Gaber

2017-05-01

Full Text Available A sensitive, simple and rapid square-wave adsorptive stripping voltammetric method was developed and validated for the determination of Ribavirin in pharmaceutical formulations. The proposed method was based on the electrochemical reduction of Ribavirin at a hanging mercury drop electrode in Britton Robinson buffer at pH 10. A well-defined peak was observed at 880 mV with 30 s of accumulation time and 50 mV of accumulation potential. Under these optimized conditions, the square-wave adsorptive stripping voltammetric peak current showed a linear correlation on drug concentration over the range of 1 × 10−10–2 × 10−7 mol L−1 with a correlation coefficient of 0.9995 for the proposed method. The detection and quantitation limits for this method were 2.02 × 10−10 and 6.80 × 10−10 mol L−1, respectively. The results obtained for intra-day and inter-day precision (as RSD % were between 0.447% and 1.024%. This method was applied successfully for the determination of Ribavirin in its pharmaceutical dosage forms with mean recoveries of 99.68 ± 0.13 with RSD % of 0.81% and 99.20 ± 0.24 with RSD % of 0.49% for two concentrations 5 × 10−9 and 5 × 10−8 mol L−1, respectively for 200 mg capsules. The results obtained from the developed square-wave adsorptive stripping voltammetric method were compared with those obtained by the analytical method reported in the literature.

Diversidade genética intra e interespecífica de pitaya com base nas características físico-químicas de frutos

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Cristiane Andréa de Lima

2013-12-01

Full Text Available Neste trabalho, objetivou-se avaliar a diversidade genética intra e interespecífica de 21 acessos de duas espécies de pitaya, Hylocereus undatus (Haw Britton & Rose e Selenicereus setaceus Salm-Dyck. A. Bereger ex Werderm., com base nas características físico-químicas dos frutos. Foram avaliadas as características: comprimento, diâmetro, sólidos solúveis, massa total da casca e da polpa dos frutos. Com base na média das características físico-químicas de cada acesso, foram calculados índices de distância genética entre cada par de acessos com base na distância euclidiana média padronizada. A partir da matriz de distâncias genéticas, realizaram-se análises de agrupamento por meio de dendograma e dispersão gráfica baseada em escalas multidimensionais. As variáveis analisadas apresentaram diferentes contribuições relativas para a diversidade genética. O diâmetro do fruto foi a variável que teve maior contribuição no índice de diversidade genética (27,45 %, seguido pela massa total do fruto (25,43 % e pela massa da polpa do fruto (24,67 %. As distâncias genéticas entre os 21 acessos de pitaya variaram entre 2,2 e 540,1. A análise de agrupamento permitiu subdividir os 21 acessos em dois grupos de similaridade genética, Hylocereus e Selenicereus, a uma distância genética relativa de 100. As características físico-químicas dos frutos evidenciaram alta diversidade genética entre os acessos das espécies H. undatus e S. setaceus.

Calorific Value and Chemical Composition of Five Semi-Arid Mexican Tree Species

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Maginot Ngangyo-Heya

2016-03-01

Full Text Available The current global energy crisis has generated growing interest in looking for alternatives to traditional fossil fuels, presenting lignocellulosic materials as a promising resource for sustainable energy production. In this paper, the calorific values and chemical composition of the trunks, branches, twigs and leaves of five timber species of the semi-arid land of Mexico (Helietta parvifolia (Gray Benth., Ebenopsis ebano (Berl. Barneby, Acacia berlandieri (Benth., Havardia pallens (Benth. Britton & Rose and Acacia wrightii (Benth. were determined according to international standards. The results highlighted the calorific value ranges of 17.56 to 18.61 MJ kg−1 in trunks, 17.15 to 18.45 MJ kg−1 in branches, 17.29 to 17.92 MJ kg−1 in twigs, and 17.35to 19.36 MJ kg−1 in leaves. The pH presented an acidic trend (3.95–5.64. The content of mineral elements varied in trunks (1.09%–2.29%, branches (0.86%–2.75%, twigs (4.26%–6.76% and leaves (5.77%–11.79%, showing the higher proportion in Ca (57.03%–95.53%, followed by K (0.95%–19.21% and Mg (0.88%–13.47%. The highest amount of extractives was obtained in the methanolic solvent (3.96%–17.03%. The lignin recorded values of 28.78%–35.84% for trunks, 17.14%–31.39% for branches and 20.61%–29.92% for twigs. Lignin showed a moderately strong correlation (r = 0.66 with calorific value, but the best mathematical model was registered with the calorific value depending on the pH and lignin (R2 = 58.86%.

A Different Kind of Physics Competition-the 12th International Young Physicists Tournament

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Haskell, Hugh

1999-11-01

This May, five seniors from the North Carolina School of Science and Mathematics and their adult leaders, Hugh Haskell and Chuck Britton, were the first US team to compete in the International Young Physicists Tournament (IYPT), which took place in Vienna, Austria. They challenged and were challenged by eighteen similar teams from sixteen other countries. The IYPT differs from the Physics Olympiad, which is an examination, whereas the Tournament is a debate on the solution of seventeen open-ended problems published in October, on the IYPT website . The five students, Adriane Boyd, Dahl Clark, Mark Blevins, Zach Keane, and Adam Simpkins spent from mid-January until our departure on May 20, preparing their responses to the questions. In Vienna, the team was joined by Ron Edge, of the University of South Carolina, who served as jurist for the tournament. Each team pays for transportation, but once there, the host country bears all other costs. For each event, called a "physics fight," three teams are assigned their roles-reporter, opponent and reviewer. First, the opposing team selects a question. The reporters have twelve minutes to present a report. The opposing team then has five minutes to critique the report. After a rebuttal by the reporter, the reviewers discuss effectiveness of both presentations . Finally, the jurors ask questions and score each team. This year's overall winner was Germany. Taking second was the team from the Republic of Georgia. The US team did not make the semifinal round, but did well enough for a first-time competitor. Will there be another United States Team? This is an open question. Efforts are being made to find a school that can send a team to next year's competition which is scheduled for Budapest, Hungary.

Group-based social skills interventions for adolescents with higher-functioning autism spectrum disorder: a review and looking to the future

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McMahon CM

2013-01-01

Full Text Available Camilla M McMahon,1 Matthew D Lerner,2,3 Noah Britton41Department of Curriculum and Instruction, Indiana University Bloomington, Bloomington, IN, USA; 2Department of Psychology, University of Virginia, Charlottesville, VA, USA; 3Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA; 4Behavorial Sciences Department, Bunker Hill Community College, Charleston, MA, USAAbstract: In this paper, we synthesize the current literature on group-based social skills interventions (GSSIs for adolescents (ages 10–20 years with higher-functioning autism spectrum disorder and identify key concepts that should be addressed in future research on GSSIs. We consider the research participants, the intervention, the assessment of the intervention, and the research methodology and results to be integral and interconnected components of the GSSI literature, and we review each of these components respectively. Participant characteristics (eg, age, IQ, sex and intervention characteristics (eg, targeted social skills, teaching strategies, duration and intensity vary considerably across GSSIs; future research should evaluate whether participant and intervention characteristics mediate/moderate intervention efficacy. Multiple assessments (eg, parent-report, child-report, social cognitive assessments are used to evaluate the efficacy of GSSIs; future research should be aware of the limitations of current measurement approaches and employ more accurate, sensitive, and comprehensive measurement approaches. Results of GSSIs are largely inconclusive, with few consistent findings across studies (eg, high parent and child satisfaction with the intervention; future research should employ more rigorous methodological standards for evaluating efficacy. A better understanding of these components in the current GSSI literature and a more sophisticated and rigorous analysis of these components in future research will lend clarity to key questions

Size-mediated tree transpiration along soil drainage gradients in a boreal black spruce forest wildfire chronosequence.

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Angstmann, J L; Ewers, B E; Kwon, H

2012-05-01

Boreal forests are crucial to climate change predictions because of their large land area and ability to sequester and store carbon, which is controlled by water availability. Heterogeneity of these forests is predicted to increase with climate change through more frequent wildfires, warmer, longer growing seasons and potential drainage of forested wetlands. This study aims at quantifying controls over tree transpiration with drainage condition, stand age and species in a central Canadian black spruce boreal forest. Heat dissipation sensors were installed in 2007 and data were collected through 2008 on 118 trees (69 Picea mariana (Mill.) Britton, Sterns & Poggenb. (black spruce), 25 Populus tremuloides Michx. (trembling aspen), 19 Pinus banksiana Lamb. (jack pine), 3 Larix laricina (Du Roi) K. Koch (tamarack) and 2 Salix spp. (willow)) at four stand ages (18, 43, 77 and 157 years old) each containing a well- and poorly-drained stand. Transpiration estimates from sap flux were expressed per unit xylem area, J(S), per unit ground area, E(C) and per unit leaf area, E(L), using sapwood (A(S)) and leaf (A(L)) area calculated from stand- and species-specific allometry. Soil drainage differences in transpiration were variable; only the 43- and 157-year-old poorly-drained stands had ∼ 50% higher total stand E(C) than well-drained locations. Total stand E(C) tended to decrease with stand age after an initial increase between the 18- and 43-year-old stands. Soil drainage differences in transpiration were controlled primarily by short-term physiological drivers such as vapor pressure deficit and soil moisture whereas stand age differences were controlled by successional species shifts and changes in tree size (i.e., A(S)). Future predictions of boreal climate change must include stand age, species and soil drainage heterogeneity to avoid biased estimates of forest water loss and latent energy exchanges.

Effects of Climate and Fuels Management on Wildfire Occurrence, Size, Severity and Emissions in the Sierra Nevada

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Westerling, A. L.; Fites, J. A.; Keyser, A.

2015-12-01

Annual wildfire burned area in federally managed Sierra Nevada forests has increased by more than 10,000 ha per decade since the early 1970s. At the same time, recent years have seen some extremely large fires compared to the historical record, with significant areas of moderate to high severity fire (e.g., McNally 2002, Rim 2013, King 2014 fires). Changes to fuels and fire regimes due to fire suppression and land use, as well as warming temperatures and the occurrence of drought, are thought to be significant factors contributing to increased risks of large, severe fires in Sierra Nevada forests. Over 70% of the vegetated area in federally managed forests in the Sierra Nevada is classified as having altered fuels and fire regimes, while average annual temperature in the Sierra Nevada has been above the long term mean for all but four years in the past two decades. As climate is expected to continue warming for decades to come, we explored fuels management scenarios as the primary tools available to modify risks of large, severe wildfires. We developed experimental statistical models of fire occurrence, fire size, and high severity burned area, to explore the interaction between climate and altered fuels conditions. These models were applied to historical climate conditions, a sample of future climate projections, and to both current fuels conditions and a range of scenarios for fuels treatments. Emissions from wildfires were estimated using the Fire Inventory from the National Center for Atmospheric Research. Our models project that average annual burned area in the Sierra Nevada will more than double by mid-century. Similarly, particulate and other pollution emissions from Sierra Nevada wildfires are projected to more than double, even if future fire severity does not change. Fuels treatment scenarios significantly reduced simulated future burned area and emissions below untreated projections. High severity burned area responded to both climate and fuels

The role of hRev7, the accessory subunit of hPolζ, in translesion synthesis past DNA damage induced by benzo[a]pyrene diol epoxide (BPDE

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Maher Veronica M

2010-12-01

Full Text Available Abstract Background DNA polymerase zeta (Polζ is a specialized DNA polymerase that, unlike classical replicative polymerases, is capable of replicating past DNA lesions, i.e. of performing translesion synthesis (TLS. The catalytic subunit of hPolζ, hRev3, has been shown to play a critical role in DNA damage-induced mutagenesis in human cells, but less is known about the role of hRev7, the accessory subunit of hPolζ, in such mutagenesis. To address this question, we recently generated human fibroblasts with very significantly reduced levels of hRev7 protein and demonstrated that hRev7 is required to protect cells from ultraviolet(254 nm (UV radiation-induced cytotoxicity and mutagenesis (McNally et al., DNA Repair 7 (2008 597-604. The goal of the present study was to determine whether hRev7 is similarly involved in the tolerance of DNA damage induced by benzo[a]pyrene diol epoxide (BPDE, the reactive form of the widespread environmental carcinogen benzo[a]pyrene. Methods To determine whether hRev7 also plays a role in protecting human cells from the cytotoxicity and mutagenesis induced by benzo[a]pyrene diol epoxide (BPDE, cell strains with reduced hRev7 were compared to their parental strain and a vector control strain for the effect of BPDE on cell survival, induction of mutations, and the ability to progress through the cell cycle. Results The results show that cell strains with reduced hRev7 are more sensitive to the cytotoxic effect of BPDE than the control strains, and progress through S-phase at a slower rate than the control cells following BPDE treatment, indicating that hRev7, and likely hPolζ, is required for efficient bypass of BPDE-induced DNA lesions. However, neither the frequency nor kinds of mutations induced by BPDE in cells with reduced hRev7 differ significantly from those induced in the control strains, suggesting that hPolζ is not essential for inserting nucleotides opposite BPDE-induced DNA damage. Conclusions Taken

Variation in chromosome number and breeding systems: implications for diversification in Pachycereus pringlei (Cactaceae

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Carina Gutiérrez-Flores

2018-02-01

Full Text Available Polyploidy, the possession of more than two sets of chromosomes, is a major biological process affecting plant evolution and diversification. In the Cactaceae, genome doubling has also been associated with reproductive isolation, changes in breeding systems, colonization ability, and speciation. Pachycereus pringlei (S. Watson, 1885 Britton & Rose, 1909, is a columnar cactus that has long drawn the attention of ecologists, geneticists, and systematists due to its wide distribution range and remarkable assortment of breeding systems in the Mexican Sonoran Desert and the Baja California Peninsula (BCP. However, several important evolutionary questions, such as the distribution of chromosome numbers and whether the diploid condition is dominant over a potential polyploid condition driving the evolution and diversity in floral morphology and breeding systems in this cactus, are still unclear. In this study, we determined chromosome numbers in 11 localities encompassing virtually the entire geographic range of distribution of P. pringlei. Our data revealed the first diploid (2n = 22 count in this species restricted to the hermaphroditic populations of Catalana (ICA and Cerralvo (ICE Islands, whereas the tetraploid (2n = 44 condition is consistently distributed throughout the BCP and mainland Sonora populations distinguished by a non-hermaphroditic breeding system. These results validate a wider distribution of polyploid relative to diploid individuals and a shift in breeding systems coupled with polyploidisation. Considering that the diploid base number and hermaphroditism are the proposed ancestral conditions in Cactaceae, we suggest that ICE and ICA populations represent the relicts of a southern diploid ancestor from which both polyploidy and unisexuality evolved in mainland BCP, facilitating the northward expansion of this species. This cytogeographic distribution in conjunction with differences in floral attributes suggests the distinction of

Quality by design in the chiral separation strategy for the determination of enantiomeric impurities: development of a capillary electrophoresis method based on dual cyclodextrin systems for the analysis of levosulpiride.

Science.gov (United States)

Orlandini, S; Pasquini, B; Del Bubba, M; Pinzauti, S; Furlanetto, S

2015-02-06

Quality by design (QbD) concepts, in accordance with International Conference on Harmonisation Pharmaceutical Development guideline Q8(R2), represent an innovative strategy for the development of analytical methods. In this paper QbD principles have been comprehensively applied in the set-up of a capillary electrophoresis method aimed to quantify enantiomeric impurities. The test compound was the chiral drug substance levosulpiride (S-SUL) and the developed method was intended to be used for routine analysis of the pharmaceutical product. The target of analytical QbD approach is to establish a design space (DS) of critical process parameters (CPPs) where the critical quality attributes (CQAs) of the method have been assured to fulfil the desired requirements with a selected probability. QbD can improve the understanding of the enantioseparation process, including both the electrophoretic behavior of enantiomers and their separation, therefore enabling its control. The CQAs were represented by enantioresolution and analysis time. The scouting phase made it possible to select a separation system made by sulfated-β-cyclodextrin and a neutral cyclodextrin, operating in reverse polarity mode. The type of neutral cyclodextrin was included among other CPPs, both instrumental and related to background electrolyte composition, which were evaluated in a screening phase by an asymmetric screening matrix. Response surface methodology was carried out by a Doehlert design and allowed the contour plots to be drawn, highlighting significant interactions between some of the CPPs. DS was defined by applying Monte-Carlo simulations, and corresponded to the following intervals: sulfated-β-cyclodextrin concentration, 9-12 mM; methyl-β-cyclodextrin concentration, 29-38 mM; Britton-Robinson buffer pH, 3.24-3.50; voltage, 12-14 kV. Robustness of the method was examined by a Plackett-Burman matrix and the obtained results, together with system repeatability data, led to define a method

Interval cancer peer review in East Anglia: Implications for monitoring doctors as well as the NHS breast screening programme

International Nuclear Information System (INIS)

Britton, P.D.; McCann, J.; O'Driscoll, D.; Hunnam, G.; Warren, R.M.L.

2001-01-01

AIM: To devise a method for reviewing interval cancers that will both educate radiologists and facilitate improvement of breast screening practice. To evaluate different methods for case classification to find one that best serves this purpose. METHOD: The method of peer review and the means by which interval cancers are classified is described. The way in which cases are designated false-negative is an issue of acceptability for radiologists, and so three different methods are evaluated. Each is applied to the data set collected in this region over a 3-year period. RESULTS: For cases read by five readers, when a consensus method was used for classifying cases, the proportion of cases classified as false-negative was 14%. Using a method in which only one of the five readers had to classify a case as false-negative for it to be categorized as such, the proportion of false-negative cases rose to a maximum of 38%. The minimum proportion of cases that could be considered to be false-negative was 6% and was obtained when all five readers had to classify a case as false-negative for it to be so categorized. Consistent with its majority viewpoint, the consensus method gave results for proportions of total cases classified as false-negative which were similar to those given by methods in which cases are classified as false-negative if either three of five readers, or at least 60% of readers, classified it as such. CONCLUSION: For the peer review method to achieve its dual aims of educating radiologists and auditing performance, the participating radiologists must share ownership of the results and view the analysis as fair. The method used to classify interval cancers as false-negative will influence the number so classified. A consensus method has been found to give a result that is both fair and acceptable to our radiologist. Using this method 16% of all reviewed cases were classified as false-negative and 60% as true interval cancers. Britton, P.D. (2001)

Rapid and sensitive electrochemical determination of codeine in pharmaceutical formulations and human urine using a boron-doped diamond film electrode

International Nuclear Information System (INIS)

Švorc, Ľubomír; Sochr, Jozef; Svítková, Jana; Rievaj, Miroslav; Bustin, Dušan

2013-01-01

Highlights: ► Novel electrochemical sensor for the determination of codeine is presented. ► Codeine provided a single oxidation peak at +1.0 V vs. Ag/AgCl in BRBS at pH 7. ► Detection limit of 0.08 μM was achieved without electrode surface modification. ► Benefits of method: rapidity, low cost, low elaborateness and high repeatability. ► Possibility for drug quality control and drug analysis of biological samples. - Abstract: An unmodified boron-doped diamond film electrode was used for the first time as a sensitive and selective electrochemical sensor for the determination of codeine by the use of differential pulse voltammetry. Codeine provided a single well-defined oxidation peak at +1.0 V vs. Ag/AgCl in Britton-Robinson buffer solution at pH 7.0. Using the optimal differential pulse voltammetric conditions (modulation amplitude of 50 mV, modulation time of 40 ms and scan rate of 50 mV s −1 ), the detection limit of 0.08 μM, the linear response of peak current on codeine concentration in the range from 0.1 to 60 μM (R 2 = 0.998, n = 6) and relative standard deviation of 0.9% at 10 μM concentration level (n = 10) were achieved without any electrode surface modification. The influence of potential interfering agents on the current response was also studied and the results indicated that the proposed method was sufficiently selective. The method was successfully applied in the determination of codeine in real samples including pharmaceutical tablets and human urine with results similar to those declared by manufacturer and obtained by reference high-performance liquid chromatography method, respectively. The typical benefits of the method may be summarized as: rapidity (20 determinations per hour), sensitivity and selectivity, low cost and elaborateness, simplicity, wide linear concentration range, low detection limit and excellent repeatability. It might also represent the competitive alternative to the existing analytical methods in monitoring of

Variation in chromosome number and breeding systems: implications for diversification in Pachycereus pringlei (Cactaceae).

Science.gov (United States)

Gutiérrez-Flores, Carina; la Luz, José L León-de; León, Francisco J García-De; Cota-Sánchez, J Hugo

2018-01-01

Polyploidy, the possession of more than two sets of chromosomes, is a major biological process affecting plant evolution and diversification. In the Cactaceae, genome doubling has also been associated with reproductive isolation, changes in breeding systems, colonization ability, and speciation. Pachycereus pringlei (S. Watson, 1885) Britton & Rose, 1909, is a columnar cactus that has long drawn the attention of ecologists, geneticists, and systematists due to its wide distribution range and remarkable assortment of breeding systems in the Mexican Sonoran Desert and the Baja California Peninsula (BCP). However, several important evolutionary questions, such as the distribution of chromosome numbers and whether the diploid condition is dominant over a potential polyploid condition driving the evolution and diversity in floral morphology and breeding systems in this cactus, are still unclear. In this study, we determined chromosome numbers in 11 localities encompassing virtually the entire geographic range of distribution of P. pringlei . Our data revealed the first diploid (2n = 22) count in this species restricted to the hermaphroditic populations of Catalana (ICA) and Cerralvo (ICE) Islands, whereas the tetraploid (2n = 44) condition is consistently distributed throughout the BCP and mainland Sonora populations distinguished by a non-hermaphroditic breeding system. These results validate a wider distribution of polyploid relative to diploid individuals and a shift in breeding systems coupled with polyploidisation. Considering that the diploid base number and hermaphroditism are the proposed ancestral conditions in Cactaceae, we suggest that ICE and ICA populations represent the relicts of a southern diploid ancestor from which both polyploidy and unisexuality evolved in mainland BCP, facilitating the northward expansion of this species. This cytogeographic distribution in conjunction with differences in floral attributes suggests the distinction of the diploid

Plantas medicinais cultivadas em quintais de comunidades rurais no domínio do cerrado piauiense (Município de Demerval Lobão, Piauí, Brasil Medicinal plants cultivated in homegardens of rural communities in the domain of Cerrado in Piaui (Demerval Lobão Municipality, Piauí State, Brazil

Directory of Open Access Journals (Sweden)

L.C.G.G. Aguiar

2012-01-01

Full Text Available O conhecimento terapêutico acumulado por populações rurais através de séculos de estreito contato com o meio possibilita a obtenção de informações acerca do uso dos recursos naturais. O objetivo do presente trabalho foi realizar um inventário das plantas medicinais cultivadas em quintais do município de Demerval Lobão, Piauí, bem como, conhecer o emprego e a importância dessas espécies na comunidade. Foram amostrados 21 quintais em nove comunidades da zona rural do município de Demerval Lobão com vegetação de cerrado. O trabalho foi conduzido com os mantenedores dos quintais a partir de entrevistas semi-estruturadas e observação direta, associada à técnica de turnê-guiada. As plantas medicinais coletadas foram catalogadas, identificadas, e depositadas no Herbário Graziela Barroso (TEPB da Universidade Federal do Piauí (UFPI. Foram referidas 100 espécies botânicas, predominantemente herbáceas e cultivadas, distribuídas em 49 famílias, sendo Leguminosae, Euphorbiaceae e Lamiaceae as mais representativas em número de espécies. Na preparação dos remédios, as folhas foram as mais utilizadas, sendo a decocção a principal forma de preparo. As doenças mais frequentes tratadas por remédios caseiros referem-se ao sistema respiratório e digestivo. Observou-se que não há rigidez quanto à posologia e a duração do tratamento, ficando este a critério do hábito de cada pessoa entrevistada. As plantas que apresentaram índice de importância relativa e concordância de uso (CUP acima de 60% foram cansansão (Cnidosculus urens, boldo (Plectranthus barbatus Andrews, jurema-preta (Mimosa verrucosa Benth e cidreira (Lippia alba (Mill. N.E.Br. ex Britton & P.Wilson. P. barbatus foi a mais citada e também a que apresentou os índices mais altos de CUP (100%, fator de correção - FC (1,00 e concordância de uso corrigido - CUPc (100% para dores no estômago e problemas no fígado. Observou-se a necessidade de resgatar o

BOOK REVIEW: Mastering Physics (4th edn) Macmillan Master Series

Science.gov (United States)

Sugden, Chris

2000-01-01

The preface to the first edition of this book, in 1982, stated the aim as `presenting ideas with a directness and simplicity that will enable students to achieve maximum comprehension in the shortest possible time'. The fourth edition remains true to this aim, whilst paying some attention to the possibility of using the book alongside classroom work as well as a revision aid. However, it is as a clear concise summary of GCSE level physics (and a little bit beyond) that this book excels. I would recommend it to students as a revision aid at the end of the course and as a reference book during it. There should certainly be a few copies in the school library. Since I see the book's main role as being for the individual use of students it seemed sensible to ask one for his impression of the book having completed GCSE Physics a few months ago, and this is appended below. Philip Britton The book is split into many small, precise subsections and so allows easy reference to the topic you want to know about. The major equations are all included and explained well. The text is quite detailed and includes helpful examples. Concepts are explained in simple stages and in a way that is easy to understand; for example, the phases of the moon and ray diagrams. Resistors, which had been a little difficult for me, are very well explained. A simple detail like putting the names of the circuit symbols beside them on diagrams helps a lot. Throughout the book there are plenty of diagrams used to assist understanding rather than just illustrate the book. Overall I think that it would be best used as a revision aid. It reads very much like a syllabus with added explanation and examples. Perhaps it would be possible for a class to read a section before a lesson so less basic explanation is required during the lesson and other work can be done. The sections are brief enough to allow even the apathetic to complete such a homework assignment.

Electroanalysis of formetanate hydrochloride by a cobalt phthalocyanine functionalized multiwalled carbon nanotubes modified electrode: characterization and application in fruits

International Nuclear Information System (INIS)

Ribeiro, Francisco Wirley Paulino; Souza Lucas, Francisco Willian de; Mascaro, Lucia H.; Morais, Simone; Naftali da Silva Casciano, Paulo; Lima-Neto, Pedro de; Correia, Adriana N.

2016-01-01

Highlights: • A Co-phthalocyanine functionalized MWCNT modified carbon electrode was developed. • Formetanate (FMT) electroanalytical behavior is consistent with an ECE mechanism. • CoPc-fMWCNT/GCE exhibited good analytical performance to quantify FMT. • CoPc-fMWCNT/GCE was successfully applied to fruits (recoveries ≥ 94.2%). - Abstract: This study characterizes the electroanalytical behavior of the carbamate pesticide formetanate hydrochloride (FMT) at a cobalt phthalocyanine (CoPc) functionalized multiwalled carbon nanotubes (fMWCNT) modified glassy carbon electrode (CoPc-fMWCNT/GCE). Nafion ® was used to improve solubility and dispersibility of fMWCNT. The construction of the developed electrode was characterized by high-resolution field-emission gun scanning electron microscopy, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. FMT exhibited a behavior consistent with a three-step reaction of the electrochemical-chemical-electrochemical mechanistic type at CoPc-fMWCNT/GCE (three anodic peaks at 0.26, 0.55 and 1.2 V, and two cathodic peaks at 0.35 and 0.50 V vs. Ag/AgCl/3 M KCl). Highly reproducible and well-defined peaks were obtained at the optimum experimental conditions (Britton-Robinson buffer at pH 5.0, accumulation potential 1.55 V, accumulation time 5 s, frequency 100 s −1 , amplitude 30 mV, and scan increment 3 mV). Peak currents were found to be proportional to the FMT concentrations in the range of 9.80 × 10 −8 to 3.92 × 10 −6 mol dm −3 with a detection limit (LOD) of 9.7 × 10 −8 mol dm −3 . The modification of GCE with CoPc-fMWCNT enhanced the electrocatalytic activity and provided high sensitivity (3.51 A mol −1 dm 3 ). The developed electroanalytical methodology was successfully applied to FMT residue analysis in mango and grape samples with recoveries in the range of 94.2 ± 4.5 to 105.7 ± 1.8%. The proposed electroanalytical approach represents a reliable, sensitive and environmental

Regional Instability in the Abundance of Open Stands in the Boreal Forest of Eastern Canada

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Rija Rapanoela

2016-05-01

Full Text Available Fires are a key disturbance of boreal forests. In fact, they are the main source of renewal and evolution for forest stands. The variability of fire through space and time results in a diversified forest mosaic, altering their species composition, structure and productivity. A resilient forest is assumed to be in a state of dynamic equilibrium with the fire regime, so that the composition, age structure and succession stages of forests should be consistent with the fire regime. Dense spruce-moss stands tend, however, to diminish in favour of more open stands similar to spruce-lichen stands when subjected to more frequent and recurring disturbances. This study therefore focused on the effects of spatial and temporal variations in burn rates on the proportion of open stands over a large geographic area (175,000 km2 covered by black spruce (Picea mariana (Mill. Britton, Sterns, Poggenb.. The study area was divided into 10 different zones according to burn rates, as measured using fire-related data collected between 1940 and 2006. To test if the abundance of open stands was unstable over time and not in equilibrium with the current fire regime, forest succession was simulated using a landscape dynamics model that showed that the abundance of open stands should increase progressively over time in zones where the average burn rate is high. The proportion of open stands generated during a specific historical period is correlated with the burn rate observed during the same period. Rising annual burn rates over the past two decades have thereby resulted in an immediate increase in the proportion of open stands. There is therefore a difference between the current proportion of open stands and the one expected if vegetation was in equilibrium with the disturbance regime, reflecting an instability that may significantly impact the way forest resources are managed. It is apparent from this study that forestry planning should consider the risks associated

PREFACE: Preface

Science.gov (United States)

Luo, Qingming; Wang, Lihong V.; Tuchin, Valery V.

2011-02-01

and imaging from all over the world, including the United States, Russia, Australia, Canada, Israel, France, Ireland, Japan, Korea and China. The major topics covered at the conference and presented in this volume include: Photonic Therapeutics, Diagnostics and Instrumentations; Tissue Optics and Laser Tissue Interaction; Biomedical Spectroscopy and Microscopy; Multimodal and Hybrid Biomedical Imaging; and Optical Molecular Imaging. The conference voted for the three best student papers; awards were presented to the participant students whose posters were recognized as excellent and who took part in the oral presentation competition. The conference received 133 submitted abstracts, and this volume of the Journal of Physics: Conference Series includes a selection of 53 excellent submissions. The Conference Secretariat and Local Organizing Committee deserve recognition for planning a smoothly run and productive conference with comprehensive, instructive lectures and innovative work displayed in poster presentations. The faculties and students from Britton Chance Center for Biomedical Photonics were dedicated to their work in reception and service during the conference. It is a pleasure to thank all of them for their efficient and hard work. We are also grateful for the financial support from 111 Project (B07038), and the assistance in organization and coordination from Wuhan National Laboratory for Optoelectronics and Huazhong University of Science and Technology. Finally, we would like to thank all the authors for their contributions to PIBM 2010 and all the members of the Committees for their cooperation and time spent reviewing submissions. Special thanks are due to the Advisory Committee members Shu Chien, Aaron Ciechanover, Steve Dahms, Da Hsuan Feng, Steven R Goodman, Brian Salzberg, Fujia Yang, Jianquan Yao, Baoyong Zheng and Olivia Ho Cheng for their participation on-site, and their significant contributions to the conference. Wuhan, PR ChinaDecember, 2010

Japan - UK Conference: Trends in Physics and Chemistry Education in Secondary Schools

Science.gov (United States)

1998-11-01

This conference, held in Tokyo between 3-5 April 1998, was the most recent product of a now longstanding involvement between British and Japanese physics teachers which has grown out of a personal friendship between Brenda Jennison (Cambridge University and Vice Chair of the Education Group) and Tae Ryu (Sophia University). For a number of years British teachers have hosted Japanese counterparts at the annual ASE meetings and in visits to schools following the conference. For this conference a team of four physicists, Brenda Jennison, lan Lawrence (King's School Worcester), Philip Britton (Leeds Grammar School) and Phil Scott (University of Leeds) travelled to Japan to contribute to a conference and visit schools and University Departments. Feelings on reading a conference report can too often resemble the experience of being shown a friend's holiday snaps. They are clearly very interesting but equally clearly your friend is enjoying it more than you are, because the snaps are rekindling memories and thoughts. This set of reflections is an attempt to report on just four of those memories and thoughts rather than describe the pictures. Why organize an international conference? The conference was an event that almost took more months of tireless organization than it lasted in hours. It was conceived and brought to fruition amongst a welter of e-mail communications between Brenda Jennison, Tae Ryu and Maurice Jenkins of the British Council, who sponsored the event. Given this immense organizational task, just why did we bother? What can be gained by holding such an international event? The significant benefit of discussing issues between two cultures is clarifying which are the issues that are intrinsically due to the nature of physics teaching rather than the extrinsic effects of educational systems and customs. Unsurprisingly pupil motivation, pupil numbers, relevance, `up-to-date-ness' and the role of mathematics emerged as concerns in both cultures. Also there are

Facile one-step direct electrodeposition of bismuth nanowires on glassy carbon electrode for selective determination of folic acid

International Nuclear Information System (INIS)

Ananthi, Arjunan; Kumar, Shanmugam Senthil; Phani, Kanala Lakshminarasimha

2015-01-01

Highlights: • BiNWs prepared through simple, fast one step electrochemical route. • BiNWs showed more catalytic activity and sensitivity than GC towards FA reduction. • Selective detection of FA was achieved with low limit of detection (9.53 × 10 −9 mol L −1 ). • Real sample analysis was successfully demonstrated using FA pharmaceutical tablets. • BiNWs based sensor matrix is inexpensive, and more suitable for FA real application. - Abstract: In the present work, we have developed a facile one step route to electrodeposition of stabilizer-free bismuth nanowires (BiNWs) on glassy carbon (GC) substrates by using a simple potentiostatic method. Formation of BiNWs on GC substrate was confirmed by field emission scanning electron microscopy (FE-SEM). The growth of BiNWs on the GC substrate was monitored by cyclic voltammetry and found that continuous in-situ generation of hydrogen bubbles during electrodeposition provides a stagnant template for the formation of BiNWs on the GC substrate. Phase-purity of the deposited BiNWs on GC substrate studied by XRD indicates no other oxide formation. The electrodeposited BiNWs on GC substrate was used for electro-reduction of folic acid (FA) and its quantitative determination in Britton-Robinson buffer of pH 4.5 solutions. The observed cyclic voltammetric reduction current of FA on BiNWs/GC is almost 15 times higher with 0.015 V less negative overpotential compared to bare GC substrate alone. This result clearly reveals the electrocatalytic activity of the deposited BiNWs. In addition, square wave voltammetry (SWV) showed a perfectly linear response in the concentration range of 1 × 10 −8 –15 × 10 −8 mol L −1 with a correlation coefficient of 0.9956. The limit of detection (LOD) and limit of quantitation (LOQ) are determined to be 9.53 × 10 −9 and 31.68 × 10 −9 mol L −1 respectively. The response of the BiNWs/GC sensor matrix is not affected by any usual interference from excess concentrations of

An ethnobotany of the Lukomir Highlanders of Bosnia & Herzegovina.

Science.gov (United States)

Ferrier, Jonathan; Saciragic, Lana; Trakić, Sabina; Chen, Eric C H; Gendron, Rachelle L; Cuerrier, Alain; Balick, Michael J; Redžić, Sulejman; Alikadić, Emira; Arnason, John T

2015-11-25

This aim of this study is to report upon traditional knowledge and use of wild medicinal plants by the Highlanders of Lukomir, Bjelašnica, Bosnia and Herzegovina (B&H). The Highlanders are an indigenous community of approximately 60 transhumant pastoralist families who speak Bosnian (Bosanski) and inhabit a highly biodiverse region of Europe. This paper adds to the growing record of traditional use of wild plants within isolated communities in the Balkans. An ethnobotanical study using consensus methodology was conducted in Lukomir in Bjelašnica's mountains and canyons. Field work involved individual semi-structured interviews during which informants described plants, natural product remedies, and preparation methods on field trips, garden tours, while shepherding, or in settings of their choice. Plant use categories were ranked with informant consensus factor and incorporated into a phylogenetic tree. Plants cited were compared to other ethnobotanical surveys of the country. Twenty five people were interviewed, resulting in identification of 58 species (including two subspecies) from 35 families, which were cited in 307 medicinal, 40 food, and seven material use reports. Individual plant uses had an average consensus of five and a maximum consensus of 15 out of 25. There were a number of rare and endangered species used as poisons or medicine that are endemic to Flora Europaea and found in Lukomir. Ten species (including subspecies) cited in our research have not previously been reported in the systematic ethnobotanical surveys of medicinal plant use in B&H: (Elymus repens (L.) Gould, Euphorbia myrsinites L., Jovibarba hirta (L.) Opiz, Lilium bosniacum (Beck) Fritsch, Matricaria matricarioides (Less.) Porter ex Britton, Phyllitis scolopendrium (L.) Newman, Rubus saxatilis L., Silene uniflora Roth ssp. glareosa (Jord.) Chater & Walters, Silene uniflora Roth ssp. prostrata (Gaudin) Chater & Walters, Smyrnium perfoliatum L.). New uses not reported in any of the

Bookreview

Directory of Open Access Journals (Sweden)

Redactie KITLV

2008-12-01

Full Text Available Marcus Wood; Slavery, Empathy, and Pornography (Lynn M. Festa Michèle Praeger; The Imaginary Caribbean and Caribbean Imaginary (Celia Britton Charles V. Carnegie; Postnationalism Prefigured: Caribbean Borderlands (John Collins Mervyn C. Alleyne; The Construction and Representation of Race and Ethnicity in the Caribbean and the World (Charles V. Carnegy Jerry Gershenhorn; Melville J. Herskovits and the Racial Politics of Knowledge (Richard Price Sally Cooper Coole; Ruth Landes: A Life in Anthropology (Olivia Maria Gomes Da Cunha Maureen Warner Lewis; Central Africa in the Caribbean: Transcending Time, Transforming Cultures (Robert W. Slenes Gert Oostindie (ed.; Facing up to the Past: Perspectives on the Commemoration of Slavery from Africa, the Americas and Europe (Gad Heuman Gert Oostindie, Inge Klinkers; Decolonising the Caribbean: Dutch Policies in a Comparative Perspective (Paul Sutton Kirk Peter Meigho; Politics in a ‘Half-Made Society’: Trinidad and Tobago, 1925-2001 (Douglas Midgett Linden Lewis (ed.; The Culture of Gender and Sexuality in the Caribbean (David A.B. Murray Gertrude Aub-Buscher, Beverly Ormerod Noakes (eds.; The Francophone Caribbean Today: Literature, Language, Culture (Elizabeth Walcott-Hackshaw Sally Lloyd-Evans, Robert B. Potter; Gender, Ethnicity and the Iinformal Sector in Trinidad (Katherine E. Browne STeve Striffler, Mark Moberg (eds.; Banana Wars: Power, Production and History in the Americas (Peter Clegg Johannes Postma, Victor Enthoven (eds.; Riches from Atlantic Commerce: Dutch Transatlantic Trade and Shipping, 1585-1817 (Gert J. Oostindie Phil Davison; Volcano in Paradise: Death and Survival on the Caribbean Island of Montserrat (Bonham C. Richardson Ernest Zebrowski jr; The Last Days of St. Pierre: The Volcanic Disaster that Claimed Thirty Thousand Lives (Bernard Moitt Beverley A. Steele; Grenada: A History of Its People (Jay R. Mandle Walter C

Social anxiety and fear of negative evaluation: construct validity of the BFNE-II.

Science.gov (United States)

Carleton, R Nicholas; Collimore, Kelsey C; Asmundson, Gordon J G

2007-01-01

disorder. Psychological Assessment, 17, 179-190]; however [Carleton, R. N., McCreary, D., Norton, P. J., & Asmundson, G. J. G. (in press-a). The Brief Fear of Negative Evaluation Scale, Revised. Depression & Anxiety; Collins, K. A., Westra, H. A., Dozois, D. J. A., & Stewart, S. H. (2005). The validity of the brief version of the fear of negative evaluation scale. Journal of Anxiety Disorders, 19, 345-359] recommend that these items be reworded to maintain scale sensitivity. The present study examined the reliability and validity of the BFNE-II, a version of the BFNE evaluating revisions of the reverse-worded items in a community sample. A unitary model of the BFNE-II resulted in excellent confirmatory factor analysis fit indices. Moderate convergent and discriminant validity were found when BFNE-II items were correlated with additional independent measures of social anxiety [i.e., Social Interaction Anxiety & Social Phobia Scales; Mattick, R. P., & Clarke, J. C. (1998). Development and validation of measures of social phobia scrutiny fear and social interaction anxiety. Behaviour Research and Therapy, 36, 455-470], and fear [i.e., Anxiety Sensitivity Index; Reiss, S., & McNally, R. J. (1985). The expectancy model of fear. In S. Reiss, R. R. Bootzin (Eds.), Theoretical issues in behaviour therapy (pp. 107--121). New York: Academic Press. and the Illness/Injury Sensitivity Index; Carleton, R. N., Park, I., & Asmundson, G. J. G. (in press-b). The Illness/Injury Sensitivity Index: an examination of construct validity. Depression & Anxiety). These findings support the utility of the revised items and the validity of the BFNE-II as a measure of the fear of negative evaluation. Implications and future research directions are discussed.

Book reviews

Directory of Open Access Journals (Sweden)

Redactie KITLV

2010-12-01

úa, by Allen Wells (reviewed by Michael R. Hall Downtown Ladies: Informal Commercial Importers, a Haitian Anthropologist, and Self-Making in Jamaica, by Gina A. Ulysse (reviewed by Jean Besson Une ethnologue à Port-au-Prince: Question de couleur et luttes pour le classement socio-racial dans la capitale haïtienne, by Natacha Giafferi-Dombre (reviewed by Catherine Benoît Haitian Vodou: Spirit, Myth, and Reality, edited by Patrick Bellegarde-Smith & Claudine Michel (reviewed by Susan Kwosek Cuba: Religion, Social Capital, and Development, by Adrian H. Hearn (reviewed by Nadine Fernandez "Mek Some Noise": Gospel Music and the Ethics of Style in Trinidad, by Timothy Rommen (reviewed by Daniel A. Segal Routes and Roots: Navigating Caribbean and Pacific Island Literatures, by Elizabeth M. DeLoughrey (reviewed by Anthony Carrigan Claude McKay, Code Name Sasha: Queer Black Marxism and the Harlem Renaissance, by Gary Edward Holcomb (reviewed by Brent Hayes Edwards The Sense of Community in French Caribbean Fiction, by Celia Britton (reviewed by J. Michael Dash Imaging the Chinese in Cuban Literature and Culture, by Ignacio López-Calvo (reviewed by Stephen Wilkinson Pre-Columbian Jamaica, by P. Allsworth-Jones (reviewed by William F. Keegan Underwater and Maritime Archaeology in Latin America and the Caribbean, edited by Margaret E. Leshikar-Denton & Pilar Luna Erreguerena (reviewed by Erika Laanela

Signing off

Science.gov (United States)

2001-01-01

another favourite. Recognizing the need for customer support the What button brings up a help menu explaining the concept of social interaction from first principles. Another set of four buttons controls the class's hands. As you would expect of this top-of-the-range technology it includes hands up, down, on the head and off. Slide controls allow the teacher to set both the volume and tone of the voice (from loud and scary to quiet and caring) And so that even the most clumsy user makes no mistake a set of three buttons makes it quiet clear physics is fun, fun, fun. Today many talk of the possibility of a digital teacher. In prototype models sampling rates are so low that there are long gaps between intervals when the teacher notices what is happening. Although some say this resembles real life practical use remains some way off. However, ... The new breakthrough comes with the 'auto marking' feature for which the anticipated demand is colossal. Philip Britton Head of Physics, Leeds Grammar School, UK

Voltammetric behavior and determination of the macrolide antibiotics azithromycin, clarithromycin and roxithromycin at a renewable silver – amalgam film electrode

International Nuclear Information System (INIS)

Vajdle, Olga; Guzsvány, Valéria; Škorić, Dušan; Csanádi, János; Petković, Miloš; Avramov-Ivić, Milka; Kónya, Zoltán; Petrović, Slobodan

2017-01-01

Highlights: • Voltammetric characterization of AZI, CLA and ROX at Hg(Ag)FE was performed. • AZI, CLA and ROX were determined via optimized SWV and SW-AdSV procedures. • Protonated forms of AZI, CLA and ROX favored their adsorption on Hg(Ag)FE. • 1 H NMR chemical shift dependence of N-methyl proton signals from pH. • Optimized SW-AdSV procedure was applied to determine ROX in Runac ® tablet. - Abstract: The renewable silver-amalgam film electrode (Hg(Ag)FE) was applied for voltammetric characterization and determination of semi-synthetic macrolide antibiotics azithromycin (AZI), clarithromycin (CLA) and roxithromycin (ROX) in the Britton-Robinson buffer as supporting electrolyte ranging the pH from 4.0 to 11.9. All three macrolides showed reduction signals in fairly negative potential range. During direct cathodic square wave voltammetric (SWV) investigations conducted over the potential range from −0.75 V to −2.00 V vs SCE, either one or two reduction peaks were obtained in the potential range from −1.5 to −1.9 V. The shapes and intensities of the signals depend on the applied pH values in wider pH ranges. For analytical purposes concerning the development of direct cathodic SWV and adsorptive stripping SWV (SW-AdSV) methods the neutral and slightly alkaline media were suitable as pH 7.2, pH 7.4 and pH 7.0 for AZI, CLA and ROX, respectively. Based on the cyclic voltammograms recorded at these pH values, adsorption-controlled electrode kinetics process can be proposed for all three macrolides. Furthermore, the water suppressed 1 H NMR measurements in the pH range between 6.0 and 10.5 indicated that the macrolide molecules at the optimal analytical conditions are predominantly in protonated form via their tertiary amino groups which supported in all three cases their adsorption on the appropriately polarized Hg(Ag)FE electrode. The optimized direct cathodic SWV methods showed good linearity in concentration ranges 4.81–23.3 μg mL −1 , 1.96�

Voltammetric behavior of erythromycin ethylsuccinate at a renewable silver-amalgam film electrode and its determination in urine and in a pharmaceutical preparation

International Nuclear Information System (INIS)

Vajdle, Olga; Guzsvány, Valéria; Škorić, Dušan; Anojčić, Jasmina; Jovanov, Pavle; Avramov-Ivić, Milka; Csanádi, János; Kónya, Zoltán

2016-01-01

Highlights: • Voltammetric characterization of erythromycin ethylsuccinate (EES) on Hg(Ag)FE. • Trace level determination of EES by electroreduction based SWV and SW-AdSV methods. • Protonation of the tertiary amino group supports the adsorption of EES on Hg(Ag)FE. • 1 H NMR confirms chemical shifting of tertiary amine methyl proton signals with pH. • Comparative HPLC-DAD measurements were performed for the validation of the methods. - Abstract: Erythromycin, a macrolide antibiotic, has similar antimicrobial spectrum to penicillin and it is widely used, especially in the treatment of patients who are allergic to penicillin. In this work, the application of a renewable silver-amalgam film electrode (Hg(Ag)FE) for the characterization and determination of erythromycin ethylsuccinate (EES), a widely used esterified form of this antibiotic, by means of cyclic voltammetry (CV) and square wave voltammetry (SWV) is presented. In the aqueous Britton-Robinson buffer (pH 5.0–9.0) that served as the supporting electrolyte, one reduction peak of EES was observed in the investigated potential range between −0.75 V and −1.80 V vs SCE, with peak potential maxima ranging from −1.59 V to −1.70 V, which strongly depended on the applied pH, as did the peak shape. For the analytical purposes the pH of 7.0 was selected, since in this electrolyte the EES peak was well-shaped and separated from the background current of the supporting electrolyte in both cases; in the direct cathodic SWV and in the case of square wave adsorptive stripping voltammetry (SW-AdSV). It was established, by the E p -pH correlation, that protons strongly influenced the electrochemical reduction of EES. The CVs recorded between 0.025–0.50 V s −1 at pH 7.0 confirmed that the electrode reaction is adsorption-controlled. Based on the series of 1 H NMR measurements it is proved that the tertiary amino group of EES is mainly in its protonated form at pH 7.0 which may lead, at appropriate

Signing off

Science.gov (United States)

2001-03-01

Munchkins were to be on performance related pay things might improve? And what are you thinking? What is the conductance of the Tin man? Would it vary measured from head to toe or hand to hand? Students could do extended investigations into the conductance of different body parts. There are surely some great opportunities for projects and science fairs. Students could investigate the suitability of different materials for making Tin man suits. They could do a special display... So you are thinking again, but so are they. Everyone sees the world from their own perspective. Perhaps people think the perspective of a physics teacher is a bit strange. We must stand up for ourselves and fight back. It is time to tell the world what good people we are to know - far more interesting than road engineers or school principals. After all, look at what they think about when they watch The Wizard of Oz! If this positive image projection fails to recruit more physics teachers I can propose an alternative. There are about as many giant pandas in the world as physics teachers in the UK. There is a breeding programme for pandas. Now there's an idea ... . What good people we are to know - far more interesting than road engineers or school principals. After all, look at what they think about when they watch The Wizard of Oz! Philip Britton Head of Physics, Leeds Grammar School, UK

Christmas in Physics Land

Science.gov (United States)

1999-01-01

, but no-one thanked him. Oh no, they were all just annoyed that he had dismantled the lights at all. That was the real world for you. Conversation had been difficult. People kept asking questions, but then didn't appear to be interested in the answer. One host had commented on the weather and then very rudely drifted off to another guest just as the physicist was making a clear distinction between rotating and inertial reference frames as the fundamental cause of the geostrophic wind. Another guest had made an equally bad impression by being clearly uninterested in a small digression on energy balance which seemed the obvious response to his comment about how warm the room had become as people began to dance. The physicist came out of his day dream. An old man was walking a dog on the end of a light inextensible string. A young girl on a swing was executing simple harmonic motion using a small-angle approximation in the park. Two older boys were investigating moments on a see-saw. A boisterous teenager was having a great time with the centripetal force on a roundabout. Yes, this was the life. In Physics Land, it would be a very merry Christmas. Philip Britton

This Is So NP!

Directory of Open Access Journals (Sweden)

Elizaveta Bylinina

2010-12-01

.Kennedy, C. 2007. ‘Vagueness and grammar: The semantics of relative and absolute gradable predicates’. Linguistics and Philosophy 30: 1–45.http://dx.doi.org/10.1007/s10988-006-9008-0Kennedy, C. & McNally, L. 2005. ‘Scale structure, degree modification, and the semantics of gradable predicates’. Language 81.2: 345–381.http://dx.doi.org/10.1353/lan.2005.0071Maling, J. 1983. ‘Transitive adjective: a case of categorial reanalysis’. In F. Heny & B. Richards (eds. ‘Linguistic Categories: Auxiliaries and Related Puzzles’, 253–289. Dordrecht: Reidel.Matushansky, O. 2002. ‘Tipping the scales: The syntax of scalarity in the complement of ‘seem”. Syntax 5: 219–276.http://dx.doi.org/10.1111/1467-9612.00052Matushansky, O. 2008. ‘On the Linguistic Complexity of Proper Names’. Linguistics and Philosophy 31, no. 5: 573–627.http://dx.doi.org/10.1007/s10988-008-9050-1Morzycki, M. 2009a. ‘Degree modification of gradable nouns: Size adjectives and adnominal degree morphemes’. Natural Language Semantics 17, no. 2: 175–203.http://dx.doi.org/10.1007/s11050-009-9045-7Morzycki, M. 2009b. ‘Degree modification of extreme adjectives’. To appear in proceedings of CLS 45.Neeleman, A., van de Koot, H. & Doetjes, J. 2004. ‘Degree expressions’. The Linguistic Review 21: 1–66.http://dx.doi.org/10.1515/tlir.2004.001Osherson, D. N. & Smith, E. E. 1981. ‘On the adequacy of prototype theory as a theory of concepts’. Cognition 9, no. 1: 35–58.http://dx.doi.org/10.1016/0010-0277(8190013-5Paradis, C. 2001. ‘Adjectives and boundedness’. Cognitive Linguistics 12: 47–65.http://dx.doi.org/10.1515/cogl.12.1.47Partee, B. 1986. ‘Ambiguous pseudoclefts with unambiguous ‘be”. Proceedings of NELS 16: 354–366.Peterson, P. 1991. ‘Problems with constraints on coordination’. Linguistic Analysis 8: 449–460.Recanati, F. 1997. Direct reference: From language to thought. Oxford: Blackwell.Rett, J. 2008. Degree modification in natural language. Ph.D. thesis

Proceedings of the 2015 WAO Symposium on Food Allergy and the Microbiome

Directory of Open Access Journals (Sweden)

Raúl Lázaro Castro Almarales

2016-10-01

Full Text Available Table of contents A1 Characterization of the immunoallergic profile towards the proteins of the wheat flour in Cuban population Raúl Lázaro Castro Almarales, Mary Carmen Reyes Zamora, Beatriz Tamargo, Damaris Torralba Averoff, Raysa Cruz, Yunia Oliva Diaz, Mirta Alvarez Castello, Alexander Ciria, Alexis Labrada, Maytee Mateo A2 Are peanuts causing food allergy in Cuba? Maytee Mateo, Damaris Torralba Averoff, Raysa Cruz, Yunia Oliva Diaz, Mirta Alvarez Castello, Alexander Ciria, Mary Carmen Reyes Zamora, Beatriz Tamargo, Alexis Labrada A3 Prick test and immunoallergic profile to soy allergens in Cuban population Omar Herrera, Maytee Mateo, Raysa Cruz, Mirta Alvarez Castello, Alexander Ciria, Raúl Lázaro Castro Almarales, Mary Carmen Reyes Zamora, Alexis Labrada A4 Skin sensitization and immunoallergic profile to hen's egg in Cuban population José Severino Rodríguez Canosa, Raysa Cruz, Maytee Mateo, Mirta Alvarez Castello, Alexander Ciria, Raúl Lázaro Castro Almarales, Mary Carmen Reyes Zamora, Alexis Labrada A5 Sensitization to three domestic mites in patients with adverse food events to shellfish Mirta Alvarez Castello, Raúl Lázaro Castro Almarales, Alexis Labrada, Biocen A6 Diagnostic efficacy by skin prick test with allergenic extracts of legumes in Cuban patients Yamilet Ibizate Novales, Ilonka Estruch Fajardo, Alexis Labrada, Maytee Mateo, Armando Ginard A7 Baked egg goods without wheat flour carry an increased risk of reaction Bruce Lanser, Anna Faino, Erwin Gelfand, Pia Hauk A8 Prevalence, incidence and associated risk factors of adverse reaction to food in Cuban infants - a population-based prospective study Silvia Venero Fernández, Julia Urbina, Mirta Alvarez Castello, Raúl Lázaro Castro Almarales, Ramón Suárez Medina, Hermes Fundora Hernández, John Britton, Andrew William Fogarty A9 Microbiome in ice machines and assessing the plasma nanotechnology in breaking the biofilm and improving air quality Nabarun Ghosh, Clinton

Post-16 update

Science.gov (United States)

1999-11-01

(Post-16 Initiative) Engineering Physics? Many A-level physics students do not go on to study physics. For them physics is a support subject, either just for fun or just for the grade. Where physics is a lead subject some students go on to study physics but many more go on to study engineering. So can we deliberately give some aspects of an A-level course an engineering flavour? Electromagnetism would seem a good place to start. There is a clear `physics' route into this topic, a microscopic forces and fields view of the situation. But do our students really need to look at it this way? All electromagnetic machines are linked magnetic and electric circuits. The design idea is to link these circuits as closely as possible. The electric circuits must be as good as possible, with a high conductivity. The magnetic circuits must be as good as possible, with high permeance. Conductivity depends on area/length. So does permeance. The goodness of an electromagnetic machine (how good it is at its job, which is linking electric and magnetic circuits) scales as the square of its linear dimensions. That means small electromagnetic machines are harder to make, and so the very smallest nanomotors are electrostatic. None of this is new, but many teachers are uncomfortable with it. We are thinking like physicists. Many of our students are not. They deserve us to take the trouble every now and again to encourage them to think a bit differently about a topic, to look at practical ways of discussing design and to give their course an engineering flavour. Philip Britton Coursework in A-level Physics The criteria for the new AS and A-levels have provided the teams developing the specifications with an opportunity to think creatively about how internal assessment is used within post-16 physics courses. Teachers may be concerned that allowing 30% of the marks to be internally assessed will create a burden for them. However, it is possible to look at this in a much more positive light

World Radiopharmaceutical Therapy Council: A report on the 5th International Radiopharmaceutical Therapy Colloquium and the Final Planning Meeting of the World Radiopharmaceutical Therapy Council held at Santiago, Chile, 29 September, 2002

International Nuclear Information System (INIS)

Turner, J.V.

2003-01-01

incorporated body according to a resolution put forward by Henry Wagner and Keith Britton and adopted at the Final Planning Meeting. A final draft of the Charter will be prepared and submitted for ratification at the Establishment Meeting of the World Radiopharmaceutical Therapy Council to be held during the Annual Scientific Meeting of the Society of Nuclear Medicine in New Orleans in June 2003. All physicians, physicists, chemists, oncologists, biological scientists and prospective corporate members, active in the field of therapeutic nuclear medicine, are invited to participate in this global collaborative enterprise to foster worldwide cooperation in research and development and clinical practice of nuclear medicine therapy. (author)

Book Reviews

Directory of Open Access Journals (Sweden)

Redactie KITLV

2004-07-01

, and modernity in Dominican history. Stanford CA: Stanford University Press, 2003. x + 384 pp. -Eric Paul Roorda, Bernardo Vega, Almoina, Galíndez y otros crímenes de Trujillo en el extranjero. Santo Domingo: Fundación Cultural Dominicana, 2001. 147 pp.''Diario de una misión en Washington. Santo Domingo: Fundación Cultural Dominicana, 2002. 526 pp. -Gerben Nooteboom, Aspha Bijnaar, Kasmoni: Een spaartraditie in Suriname en Nederland. Amsterdam: Uitgeverij Bert Bakker, 2002. 378 pp. -Dirk H.A. Kolff, Chan E.S. Choenni ,Hindostanen: Van Brits-Indische emigranten via Suriname tot burgers van Nederland. The Hague: Communicatiebureau Sampreshan, 2003. 224 pp., Kanta Sh. Adhin (eds -Dirk H.A. Kolff, Sandew Hira, Het dagboek van Munshi Rahman Khan. The Hague: Amrit/Paramaribo: NSHI, 2003. x + 370 pp. -William H. Fisher, Neil L. Whitehead, Dark Shamans: Kanaimà and the poetics of violent death. Durham NC: Duke University Press, 2002. 309 pp. -David Scott, A.J. Simoes da Silva, The luxury of nationalist despair: George Lamming's fiction as decolonizing project. Amsterdam: Rodopi, 2000. 217 pp. -Lyn Innes, Maria Cristina Fumagalli, The flight of the vernacular. Amsterdam: Rodopi, 2001. xvi + 303 pp. -Maria Cristina Fumagalli, Tobias Döring, Caribbean-English passages: Intertextuality in a postcolonial tradition. London: Routledge, 2002. xii + 236 pp. -A. James Arnold, Celia Britton, Race and the unconscious: Freudianism in French Caribbean thought. Oxford: Legenda, 2002. 115 pp. -Nicole Roberts, Dorothy E. Mosby, Place, language, and identity in Afro-Costa Rican literature. Columbia: University of Missouri Press, 2003. xiii + 248 pp. -Stephen Steumpfle, Philip W. Scher, Carnival and the formation of a Caribbean transnation. Gainesville: University Press of Florida, 2003. xvi + 215 pp. -Peter Manuel, Frances R. Aparicho ,Musical migrations: transnationalism and cultural hybridity in Latin/o America, Volume 1. With Maria Elena Cepeda. New York: Palgrave Macmillan, 2003. 216

Book Reviews

Directory of Open Access Journals (Sweden)

Redactie KITLV

2000-07-01

: The Press University of the West Indies, 1998. xviii + 152 pp. -Kris Lane, Hans Turley, Rum, sodomy, and the lash: Piracy, sexuality, and masculine identity. New York: New York University Press, 1999. lx + 199 pp. -Jonathan Schorsch, Eli Faber, Jews, slaves, and the slave trade: Setting the record straight. New York: New York University Press, 1998. xvii + 367 pp. -Bonham C. Richardson, Bridget Brereton ,The Colonial Caribbean in transition: Essays on postemancipation social and cultural history. Barbados: The Press University of the West Indies; Gainesville: University Press of Florida, 1999. xxiii + 319 pp., Kevin A. Yelvington (eds -Ransford W. Palmer, Thomas Klak, Globalization and neoliberalism: The Caribbean context. New York: Rowman and Littlefield, 1998. xxiv + 319 pp. -Susan Saegert, Robert B. Potter ,Self-help housing, the poor, and the state in the Caribbean. Knoxville: University of Tennessee Press, 1997. xiv + 299 pp., Dennis Conway (eds -Peter Redfield, Michèle-Baj Strobel, Les gens de l'or: Mémoire des orpailleurs créoles du Maroni. Petit-Bourg, Guadeloupe: Ibis Rouge, 1998. 400 pp. -Donald R. Hill, Louis Regis, The political calypso: True opposition in Trinidad and Tobago 1962-1987. Gainesville: University Press of Florida, 1999. xv + 277 pp. -A. James Arnold, Christiane P. Makward, Mayotte Capécia ou l'aliénation selon Fanon. Paris: Karthala, 1999. 230 pp. -Chris Bongie, Celia M. Britton, Edouard Glissant and postcolonial theory: Strategies of language and resistance. Charlottesville: University Press of Virginia, 1999. xiv + 224 pp. -Chris Bongie, Anne Malena, The negotiated self: The dynamics of identity in Francophone Caribbean narrative. New York: Peter Lang, 1999. x + 192 pp. -Catherine A. John, Kathleen M. Balutansky ,Caribbean creolization: Reflections on the cultural dynamics of language, literature, and identity., Marie-Agnès Sourieau (eds -Leland Ferguson, Jay B. Haviser, African sites archaeology in the Caribbean. Princeton NJ: Markus

Editorial: Focus on Atom Optics and its Applications

Science.gov (United States)

Schmidt-Kaler, F.; Pfau, T.; Schmelcher, P.; Schleich, W.

2010-06-01

Frequency stability of optical lattice clocks Jérôme Lodewyck, Philip G Westergaard, Arnaud Lecallier, Luca Lorini and Pierre Lemonde Ultracold quantum gases in triangular optical lattices C Becker, P Soltan-Panahi, J Kronjäger, S Dörscher, K Bongs and K Sengstock Cold atoms near superconductors: atomic spin coherence beyond the Johnson noise limit B Kasch, H Hattermann, D Cano, T E Judd, S Scheel, C Zimmermann, R Kleiner, D Koelle and J Fortágh Focusing a deterministic single-ion beam Wolfgang Schnitzler, Georg Jacob, Robert Fickler, Ferdinand Schmidt-Kaler and Kilian Singer Tuning the structural and dynamical properties of a dipolar Bose-Einstein condensate: ripples and instability islands M Asad-uz-Zaman and D Blume Double-resonance lineshapes in a cell with wall coating and buffer gas Svenja Knappe and Hugh G Robinson Transport and interaction blockade of cold bosonic atoms in a triple-well potential P Schlagheck, F Malet, J C Cremon and S M Reimann Fabrication of a planar micro Penning trap and numerical investigations of versatile ion positioning protocols M Hellwig, A Bautista-Salvador, K Singer, G Werth and F Schmidt-Kaler Laser cooling of a magnetically guided ultracold atom beam A Aghajani-Talesh, M Falkenau, V V Volchkov, L E Trafford, T Pfau and A Griesmaier Creation efficiency of nitrogen-vacancy centres in diamond S Pezzagna, B Naydenov, F Jelezko, J Wrachtrup and J Meijer Top-down pathways to devices with few and single atoms placed to high precision Jessica A Van Donkelaar, Andrew D Greentree, Andrew D C Alves, Lenneke M Jong, Lloyd C L Hollenberg and David N Jamieson Enhanced electric field sensitivity of rf-dressed Rydberg dark states M G Bason, M Tanasittikosol, A Sargsyan, A K Mohapatra, D Sarkisyan, R M Potvliege and C S Adams

Abstracts from the 15th International Myopia Conference

Directory of Open Access Journals (Sweden)

Alexandra Benavente-Perez

2016-11-01

Full Text Available Table of contents O1 Changes in peripheral refraction associated with decreased ocular axial growth rate in marmosets Alexandra Benavente-Perez, Ann Nour, Tobin Ansel, Kathleen Abarr, Luying Yan, Keisha Roden, David Troilo O2 PPARα activation suppresses myopia development by increasing scleral collagen synthesis--a new drug target to suppress myopia development Chanyi Lu, Miaozhen Pan, Min Zheng, Jia Qu, Xiangtian Zhou O3 Evidence and possibilities for local ocular growth regulating signal pathways Christine F Wildsoet O4 Myopia researches at Eye Hospital of Wenzhou Medical University Fan Lu, Xiangtian Zhou, Jie Chen, Jinhua Bao, Liang Hu, Qinmei Wang, Zibing Jin, Jia Qu O5 Color, temporal contrast and myopia Frances Rucker, Stephanie Britton, Stephan Hanowsky, Molly Spatcher O6 The impact of atropine usage on visual function and reading performance in myopic school children in Taiwan Hui-Ying Kuo, Ching-Hsiu Ke, I-Hsin Kuo, Chien-Chun Peng, Han-Yin Sun O7 Increased time outdoors prevents the onset of myopia: evidence from randomised clinical trials Ian G Morgan O8 Environmental risk factors and gene-environment interactions for myopia in the ALSPAC cohort Jeremy A. Guggenheim, Rupal L. Shah, Cathy Williams O9 Retinal metabolic profiling identifies declines in FP receptor-linked signaling as contributors to form-deprived myopic development in guinea pigs Jinglei Yang, Peter S. Reinach, Sen Zhang, Miaozhen Pan, Wenfeng Sun, Bo Liu, Xiangtian Zhou O10 The study of peripheral refraction in moderate and high myopes after one month of wearing orthokeratology lens Jun Jiang, Haoran Wu, Fan Lu O11 Axial length of school children around the earth’s equatorial area and factors affecting the axial length Kazuo Tsubota, Hiroko Ozawa, Hidemasa Torii, Shigemasa Takamizawa, Toshihide Kurihara, Kazuno Negishi O12 Processing of defocus in the chicken retina by retinal ganglion cells Klaus Graef, Daniel Rathbun, Frank Schaeffel O13 Blue SAD light protects

Commentary: Photothermal effects of laser tissue soldering

International Nuclear Information System (INIS)

Menovsky, T.; Beek, J.F.; Gemert, M.J.C. van

1999-01-01

Full text: Laser tissue welding is the process of using laser energy to join tissues without sutures or with a reduced number of sutures. Recently, diode lasers have been added to the list of fusion lasers (Lewis and Uribe 1993, Reali et al 1993). Typically, for tissue welding, deep penetrating diode lasers emitting at 800-810 nm are used, in combination with a strong absorbing protein solder containing the dye indocyanine green. Indocyanine green has a maximum absorption coefficient at 805 nm and binds preferentially with proteins (Sauda et al 1986). The greatest advantage of diode lasers is their compact size, easy use and low cost. In this issue of Physics in Medicine and Biology (pp 983-1002, 'Photothermal effects of laser tissue soldering'), in an in vitro study, McNally et al investigate the optimal laser settings and welding temperatures in relation to the tensile strength and thermal damage of bovine aorta specimens. An interesting statement in their introduction is that the low strength of laser produced anastomoses can lead to aneurysm formation. The increased chance of aneurysm formation may merely be due to the thermal effect of the laser on the vascular wall, especially on the adventitia and media layers, which become necrotic after thermal injury. Subsequent haemodynamic stress exerted on a damaged vascular wall is a significant contributing factor for aneurysmal initiation. Also interesting is the remark that 'by the application of wavelength-specific chromophores in tissue welding ... the requirement for precise focusing and aiming of the laser beam may be removed'. Though perhaps not yet fully justified, this statement, if true, would facilitate surgical procedures. While the experiments are conducted in a proper manner, the use of bovine aorta specimens, which were stored at -70 deg. C and subsequently thawed for the tissue welding experiments, may not be the most appropriate for studying tissue effects or tensile strength measurements, as the

Revolution or flight from reality? The IoP Education Group Conference 1999

Science.gov (United States)

Dobson, Ken

1999-09-01

The 1999 Education Group Conference attracted some 60 teachers and educationalists to the salubrious outskirts of the city of Leicester on 2 3 July. The title of the conference was The ICT revolution: just how will ICT change my physics teaching? For those not au courant with current jargon ICT stands for Information and Communications Technology, or, in short, computers. ICT was certainly to the fore from the presenters, who practised what they preached. Every talk was delivered using Microsoft PowerPoint, obsolescent overhead projectors serving only as laptop stands. Animated slides, computer generated and controlled, were projected on to a screen and supplemented as required by (fairly) instant live excerpts from relevant computer programs. The theme of the conference was set by the opening discussion led by the trio PowerPoint, Ian Lawrence (chairman of the Institute of Physics Education Group) and Philip Britton (vice-chair). They gave us the slogan Physics first! with technology, however brilliant or politically correct, only significant and valuable insofar as it helped students learn physics. And learning is a social activity: any system that places one child in front of a computer screen for hours on end should be suspect. Much the same could be said of a voltmeter, of course, and the minimal situation must include a pair of students and a teacher as well as the apparatus. Another message: think of the computer system as just another piece of equipment whose use is determined by the learning task, not as an item that determines the task. Figure 1. Jason Wye, Secretary of the Education Group, opening the Conference. It may not be surprising that the level-headed delegates agreed whole-heartedly with these sentiments, but they were also supported and reinforced by all the speakers as the conference went on. The first speaker was Jerry Wellington, ex-physics teacher, now at the University of Sheffield. In his presentation `Multimedia in science teaching

Experimental investigations regarding the use of sand as an inhibitor of air convection in deep seismic boreholes

Science.gov (United States)

Holcomb, L. Gary; Sandoval, Leo; Hutt, Bob

1998-01-01

Tilt has been the nemesis of horizontal long period seismology since its inception. Modern horizontal long period seismometers with their long natural periods are incredibly sensitive to tilt. They can sense tilts smaller than 10-11 radians. To most readers, this is just a very very small number, so we will begin with an example, which should help to illustrate just how small 10-11 radians is.Suppose we have an absolutely rigid rod which is approximately 4170 kilometers long; this just happens to be the Rand McNally map scaled crow flight distance between Los Angeles and Boston. Tilting this rod 10-11 radians corresponds to raising one end of the rod 0.0000417 meters. Alas, this is just another very very small number! However, this corresponds to slipping a little less than one third a sheet of ordinary copying paper under one end of this perfectly rigid rod. To clarify, we mean, take a sheet of paper just like the paper this report is printed on and split it a little less than one third in the thickness direction, then put it under the end of the 4170 kilometer long rod! This will tilt the rod 10-11 radians.Real world seismometers are nowhere near the length of this rod. A KS-54000 is about two meters long. Tilting a rod only two meters long 10~n radians corresponds to moving one end of this rod a mere 0.00000000002 meters or 0.02 millimicrons. As one of the authors old math teachers used to say, "That's PDS" (PDS = Pretty Damn Small). Unfortunately, the long period seismologist does not have the luxury of ignoring PDS numbers when it suits him as the mathematician frequently does. He must live in the real world in which tilts this small create severe contamination of long period seismic data.At periods longer than 20 seconds, tilt noise contaminates the long period data from all instruments installed on or near the earth's surface. Many years of experimentation revealed that installing the sensors at depth in deep mines drastically reduced the level of tilt noise

Two Types of Belief Report

Directory of Open Access Journals (Sweden)

Michael Hegarty

2010-12-01

��, 49–79. Oxford: Oxford University Press.Hintikka, J. 1969. ‘Semantics of propositional attitudes’. In J. W. Davis, D. J. Hockney & W. K. Wilson (eds. ‘Philosophical Logic’, 21–45. Dordrecht: D. Reidel.Horn, L. 1989. A Natural History of Negation. Chicago: The University of Chicago Press.Katz, G. 2000. ‘Anti neo-Davidsonianism’. In C. Tenny & J. Pustejovsky (eds. ‘Events as Grammatical Objects: The Converging Perspectives of Lexical Semantics and Syntax’, 393–414. Stanford, CA: CSLI Publications.Katz, G. 2003. ‘Event arguments, adverb selection, and the Stative Adverb Gap’. In E. Lang, C. Maienbron & C. Fabricius-Hansen (eds. ‘Modifying Adjuncts. (Interface Explorations 4’, 455–474. Berlin: Mouton de Gruyter.Katz, G. 2008. ‘Manner modification of state verbs’. In L. McNally & C. Kennedy (eds. ‘Adjective and Adverbs’, 220–248. Oxford: Oxford University Press.Kratzer, A. 1979. ‘Conditional necessity and possibility’. In R. Bäuerle, U. Egli & A. von Stechow (eds. ‘Semantics from Different Points of View’, 117–147. Berlin: SpringerVerlag.Kratzer, A. 1981. ‘The notional category of modality’. In H. Eikmeyer & H. Rieser (eds. ‘Words, Worlds, and Contexts: New Approaches in Word Semantics’, 38–74. Berlin: Walter de Gruyter.Kratzer, A. 1989. ‘Stage-level and individual-level predicates’. In G. N. Carlson & F. J. Pelletier (eds. ‘The Generic Book’, 125–175. Chicago: Chicago University Press.Kratzer, A. 1991. ‘Modality’. In A. von Stechow & D. Wunderlich (eds. ‘Semantik: Ein internationales Handbuch der eitgenössischen Forschung / Semantics: An International Handbook of Contemporary Research,’, 639–650. Berlin: Walter de Gruyter.Lewis, D. 1975. ‘Adverbs of quantification’. In E. L. Keenan (ed. ‘Formal Semantics of Natural Language’, 3–15. Cambridge: Cambridge University Press. Reprinted in Portner, P. & Partee, B. H. (eds., Formal Semantics: The Essential Readings, pp. 178

Nanotechnology in paper electronics

Science.gov (United States)

Demming, Anna; Österbacka, Professor Ronald; Han, Jin-Woo, Dr

2014-03-01

devices. If 'writing is thinking on paper' [15], it seems researchers are finding yet more powerful means of putting their ideas on paper. References [1] Barquinha P, Martins R, Pereira L and Fortunato E 2012 Transparent Oxide Electronics: From Materials to Devices (Chichester: Wiley) [2] Zocco A T, You H, Hagen J A and Steckl A J 2014 Pentacene organic thin film transistors on flexible paper and glass substrates Nanotechnology 25 094005 [3] Pereira L, Gaspar D, Guerin D, Delattre A, Fortunato E and Martins R 2014 The influence of fibril composition and dimension on the performance of paper gated oxide transistors Nanotechnology 25 094007 [4] Wu G, Wan C, Zhou J, Zhu L and Wan Q 2014 Low-voltage protonic/electronic hybrid indium-zinc-oxide synaptic transistors on paper substrates Nanotechnology 25 094001 [5] Shin H, Yoon B, Park I S and Kim J-M 2014 An electrothermochromic paper display based on colorimetrically reversible polydiacetylenes Nanotechnology 25 094011 [6] Ihalainen P, Pettersson F, Pesonen M, Viitala T, Määttänen A, Österbacka R and Peltonen J 2014 An impedimetric study of DNA hybridization on paper supported inkjet-printed gold electrodes Nanotechnology 25 094009 [7] Wang Y, Shi Y, Zhao C X, Wong J I, Sun X W and Yang H Y 2014 Printed all-solid flexible microsupercapacitors: towards the general route for high energy storage device Nanotechnology 25 094010 [8] Andersson H A, Manuilskiy A, Haller S, Hummelgård M, Sidén J, Hummelgård C, Olin H and Nilsson H-E 2014 Assembling surface mounted components on ink-jet printed double sided paper circuit board Nanotechnology 25 094002 [9] Gaspar D, Fernandes S N, de Oliveira A G, Fernandes J G, Grey P, Pontes R V, Pereira L, Martins R, Godinho M H and Fortunato E 2014 Nanocrystalline cellulose applied simultaneously as gate dielectric and substrate on flexible field effect transistors Nanotechnology 25 094008 [10] Männl U, van den Berg C, Magunje B, Härting M, Britton D T, Jones S, Mvan Staden M J and Scriba M

Without 'Focus'

Directory of Open Access Journals (Sweden)

Aldo Sevi

2010-12-01

��Contrastive focus, givenness and the unmarked status of discourse-new’.Sevi, A. 2005. Exhaustivity: A Semantic Account of ’Quantity’ Implicatures. Ph.D. thesis, Tel Aviv University.Truckenbrodt, H. 1995. Phonological Phrases: Their Relation to Syntax, Focus and Prominence. Ph.D. thesis, MIT.Valduví, E. & Vilkuna, M. 1998. ‘On Rheme and Kontrast’. In P. Cullicover & Louise McNally (eds. ‘Syntax and Semantics29: The Limits of Syntax’, 79–108. Academic Press.van Rooij, R. & Schulz, K. 2006. ‘Pragmatic meaning and non-monotonic reasoning: the case of exhaustive interpretation’. Linguistics and Philosophy 29: 205–250.von Stechow, A. 1981. ‘Topic, focus and local relevance’. In W. Klein and W. Levelt (eds., Crossing the Boundaries in Linguistics, Reidel.von Stechow, A. 1982. ‘Structured propositions’. Technical Report 59, Sonder-forschungsbereich 99, Universität Konstanz.von Stechow, A. 1989. ‘Focusing and backgrounding operators’. Technical Report 6, Fachgruppe Sprachwissenschaft, Universität Konstanz.Wagner, M. 2006. ‘Givenness and locality’. In M. Gibson & J. Howell (eds. ‘Proceedings of SALT XVI’, 295–312. Ithaca, NY: CLC Publications.Zeevat, H. 2007. ‘Exhaustivity, questions and plurals in update semantics’. In M. Aloni, A. Butler & P. Dekker (eds. ‘Questions in Dynamic semantics’, 161–92. Elsevier.Zimmermann, M. 2008. ‘Contrastive focus and emphasis’. Acta Linguistica Hungarica 55: 347–360.http://dx.doi.org/10.1556/ALing.55.2008.3-4.9

Institute news

Science.gov (United States)

1999-11-01

celebrate the Group's 50th anniversary by examining what has been done, focusing on why and how it was done, with lessons and ambitions for the future. The meeting will be held at Institute Headquarters and the programme is as follows: 10.45 - 11.00 Welcome and introduction (Philip Britton: Chair of the Education Group) 11.00 - 11.45 Examinations and assessment through the ages (Tim Akrill, Chief Examiner for A-level Physics with Edexcel) 11.45 - 12.30 Curriculum reform in physics, past, present and future (Professor Jon Ogborn, Director of the Post-16 Physics Initiative) 14.00 - 14.15 Physics education and the Institute of Physics, some personal reflections (speaker to be announced) 14.15 - 15.00 Connecting with Advancing Physics: the first year in HE physics (Professor Mick Brown, University of Cambridge) 15.15 - 15.35 Physics education, the next 50 years! (Ken Dobson, Honorary Editor of Physics Education) The day should hold something for everyone, so reserve your place if you can. Schools and Colleges lecture Dr Zbig Sobiesierski of the University of the West of England is the 1999 - 2000 Institute of Physics Schools and Colleges lecturer, touring the country with his talk `Seeing is believing?'. He will demonstrate the different physical ways in which we can both make and mix colour and will then proceed to discuss why our eyes respond to light in the way they do. The lecture will be aimed primarily at students aged 14 and above, but it will also be suitable for older audiences. The intention, as with previous series, will be to show the relevance of the physics concepts to the members of the audience and the world in which they live. To find out more about the lecture in your area and to make a booking, contact should be made with the local organizer (full details of the list can be obtained from Catherine Wilson at Institute Headquarters). The dates and venues planned so far are as follows: 1 Nov: Northern College, Aberdeen 2 Nov: University of St Andrews 3 Nov

Backwards and Forwards: 50 years of the Education Group

Science.gov (United States)

2000-01-01

The Education Group of the Institute of Physics celebrated its 50th anniversary by dedicating its annual 16 - 19 Day to a conference entitled Post-16 Physics: Looking forward, learning from the past. This attracted an audience of 50 or so nostalgia-seekers on Saturday 13 November at the Portland Place HQ. Philip Britton (Chair of the Education Group) began the proceedings in his usual pawky way by challenging members to identify the year in which some hardy topics were first addressed. A key trend in titles was the movement from problem to challenge . He looked forward to the time when success was a keynote word. Few identified Physics in Industry with the year of the deepest recession of the Thatcher Era. Tim Akrill (Chief A-level Physics Examiner for Edexcel) reminded us that A-levels were just about as old as the Education Group before taking us on an informative and entertaining tour of Assessment and Examinations through the Ages . Things have indeed become more complex since the very first written examination of 6th century China, when the only question, set every year, was: `Write down everything you know'. In 1951 an A-level physics paper gave a choice of six out of twelve questions and appeared in an A5 booklet of perhaps as many as four pages. The satisfying thump of a kilogram mass of current Edexcel A-level physics papers resounded through the room as he dropped them on a table. In those innocent days all questions followed the DDC format: define, describe, calculate . `Question spotting' was an art (or science) assiduously developed by teachers, as Lees' Disk alternated with Searle's Bar with less than exciting regularity. Have standards fallen? He thought not. At Edexcel they still get about 4000 candidates getting the higher grades, a number that has stayed the same for some 20 years. He singled out Nuffield Advanced Physics as being responsible for the greatest innovations in exam style since, well, the Chinese really. Styles such as Practical

Where were you when the sun went out?

Science.gov (United States)

1999-11-01

train from St Ives to Lelant in order to climb to the highest point for miles around - Trencrom hill where (on a clear day) there was a good view of the north and south Cornish coasts. We were not alone, however. Hundreds of others had the same idea and it was pretty crowded up there. As we waited on the crowed hill top the weather got wetter and wetter, and I wasn't very impressed with the New Age contingent who chanted and drummed to encourage the clouds to retreat - their `music' sounded more like a rain dance to me! The only comfort was the sight of the Radio 1 roadshow revellers, who were down the road at Marazion, getting a soaking too - the wonders of modern technology enabled us to watch them on top of the hill on a miniature TV! Well, it did get very dark and it was strange to see the flashes of hundreds of cameras going off all over the surrounding countryside. But I must admit that as I got soaked to the skin (I discovered that my rainproof jacket isn't!) and as the rain turned to hail as the temperature fell, I wondered what all the fuss was about. I was very glad to return to our friends' cottage and dry off. The real the highlight of the day was watching the latest Austin Powers film at the local cinema - so you can tell that the eclipse was a pretty disappointing experience! Norman Fancey writes: I was on a camp site in Austria just inside the boundary of totality. As a physicist, I was familiar with the theory and knew what to expect. Nevertheless, even in the period leading up to the total eclipse, I found the slowly increasing section being eaten out of the Sun's disc to be most interesting and the few seconds of totality and almost complete darkness to be an experience I will never forget. My previous reading about eclipses did not prepare me for the beautiful colours reflected from the clouds near to the line of sight to the Sun for the few minutes on either side of the few seconds of complete darkness. Philip Britton writes: What do I remember most

Proceedings of the 25th Annual Stirling Physics Meeting 1999

Science.gov (United States)

McVey, Michael

1999-09-01

length standard for imports and exports!) resulted in the establishment of the Convention Du Mètre, an agreement on the definition of a standard metre to which all signatories would adhere. This now has 48 signatories and has given rise to the International Bureau of Weights and Measures located near Paris but technically not in France (merely surrounded by it). The French Government has accorded its couple of acres international status. The Bureau is the Secretariat to the International Committee on Weights and Measures and it is this committee which has overall responsibility for international standards. Dr Berry described a proposed international agreement which all national standards institutions will be required to sign. This will result in the production of a database listing the standards being used in all the participating countries and will be totally transparent. Uncertainties were touched on. A draft NPL document entitled `A Beginner's Guide to The Uncertainty of Measurement' already exists and will be made available to the profession in due course. The Scottish Branch was invited to have an input to this publication. Dr Berry concluded by describing a number of interesting everyday examples in which measurement was critically important. These ranged from calibration of aircraft altimeters by pressure measurement to the equalisation of National Lottery balls to a paltry 1/1000 inch (more non-SI units!). The audience was left with much to take back to the classroom from a valuable and entertaining presentation. Advancing Physics Philip Britton set the scene in a light-hearted and often hilarious introduction, e.g. `when you're in a room full of physicists you don't feel so awkward because everybody else is weird'. The Advancing Physics initiative, he explained, was an Institute of Physics response to a deteriorating situation within physics education in England and Wales, particularly in the following areas: too few young people south of the border are