240 research outputs found
Scientometric Portrait of Homi Jehangir Bhabha: The Father of Indian Nuclear Research Programme
No full textQuantitative and qualitative analysis with graphic representation of the publication productivity of a scientist facilitates easy and clear perception about the work of a scientist. Bhabha’s scientific work spanned over more than three decades (1933-1967) during which he published 104 publications, which could be classified into nine fields: Interaction of Radiation with Matter (4), Quantum Electrodynamics (5), Mathematical Physics (2), Cosmic Ray Physics (18), Elementary Particle Physics (14), Field Theory (15), General Physics (2), Nuclear Physics (4) and General (40). The highest number of publications (6) were published in 1941, 1945 and 1964 respectively. The average number of publications published per year was 3.05. His productivity coefficient was 0.05 which is a clear indicates that his publication productivity was quite consistent throughout his scientific career. He was single author in 79 of his publications and the main author in 24 publications indicates that he always preferred to work himself and lead the team as ‘mentor’. Bhabha had 22 collaborators during the period. Team of research collaborators working with a successful scientist documents the sociological aspect of history of science while generating knowledge by a leader in a domain.
Bhabha became a citable author in 1937. Bhabha received 1211 citations to his 30 publications out of 104 publications. Out of 104, 74 publications did not receive any citations. Out of 74 publications, 40 publications dealt subjects mainly of general interest. Bhabha’s 86.66 percent of cited publications received their first citations within four years of their publication indicates that his publications were noticed immediately and had direct impact among the fellow researchers working all over the world. His overall citation rate was 11.64 per cited publication. The highest citations 389 were received to the domain ‘Cosmic ray physics’. The highest number of citations received were 45 in 1938. His self-citations were only 24 (1.98%) and citations by others were 1187 (98.02%). The highest self citations were six in 1946. Bhabha’s mean diachronous self-citation rate was 1.98. The highest citation rate 28.4 was to the domain ‘Quantum electrodynamics. His single authored publications have received the highest number 863 (71.26%) of citations. Bhabha’s five publications have been cited more than 100 times each. His publications have been cited by the authors working in various diverse fields like nuclear physics, mathematical physics, instrumentation, optics, geophysics and geochemistry, condensed matter physics, applied physics, electrical and electronic engineering, mechanical engineering etc., indicating a very diverse influence and impact of Bhabha’s publications. Bhabha’s publications have also been cited by the Nobel laureates like V. L. Ginzberg, Wolfgang Pauli, H. A. Bethe, M. Born, W. Bothe, E. P. Wigner, H. Yukawa, P. M. S. Blackett and C. N. Yang which is an indication of his originality of ideas and high quality of publications
A Hamiltonian Reduction Method for Nonlinear Dynamics
No full textNonlinear analysis of dynamic problems has become important for modern industrial design applications. The increasing pressure on airlines to decrease fuel costs demands the design of more efficient aircraft. This requires aircraft manufacturing companies to design lighter structural components. The result is the need for more realistic and accurate modelling of critical structural components. Over the years, more powerful finite element discretization methods and improved numerical methods and programming techniques for dynamic analyses of structures have been introduced. Despite these advances and the increase in available computer power, the analysis of nonlinear dynamic problems is yet a computationally demanding task, implying it is very expensive. To reduce the computational time of nonlinear finite element analyses, reduction methods have been developed. These methods have as aim to reduce the number of degrees of freedom, while retaining sufficient accuracy of the solution.Recently, a new reduction method, applicable to nonlinear static stability problems, has been developed at Delft University of Technology. The aim of this thesis is to extend the reduction method for statics to nonlinear dynamics. This is achieved by using the Hamiltonian formulation to describe the motion of a system. A reduced order model (ROM) is constructed for free vibrations, forced vibrations and damped vibrations, using Hamilton’s equations of motion. These are integrated to obtain the response of the ROM, in terms of displacements and momenta. The displacements of the full finite element model are computed by back-substituting the reduced response into the displacement expansion. The ROM is implemented in a finite element framework.The ROM is applied to beams, to plates as well as to shells. Overall, good agreement is found between the ROM and Abaqus. The big advantage of the ROM is found when the computational times for beams and plates are compared to that of Abaqus. A drastic reduction in time is observed for the ROM, while still maintaining accurate results. The ROM thus saves valuable computational time.Aerospace Engineering | Structures and Material
Analysis of Blast Pattern to Evaluate Extent and Causes of Overbreak in Large Cavern
No full textDamage is classified as loss in the integrity or deterioration in the quality of rock mass and is influenced by methodology of excavation on the geo-technical properties of rock mass. Overbreak, on the other hand, is the result of damage and is quantified in either of the terms viz., extra mucking, shot-creting, application of extra support system and extension of scheduled completion time. Damage or overbreak in rock mass by the impact of blasting, is generally unavoidable but, the magnitude can be minimized so that it does not deteriorate the quality or integrity of structure. The paper, here, analyses magnitude of overbreak of a powerhouse cavern with respect to different blast patterns implemented at the site. The magnitude of overbreak was analyzed in terms of profile measurement with the help of laser profiler and percentage of half-cast markings observed on the periphery rock wall. The paper revealed the impact of decoupling ratio, blast pattern and geometry of blasting patch on the magnitude of overbreak. The author observed that presence of un-favourable joint pattern or foliation plane along the periphery rock wall couldn’t contain magnitude of overbreak within allowable limit. The analyses revealed that percentage of half-cast markings on periphery rock wall was influenced by response of rock towards detonation of explosive and cannot be a single parameter to assess the effectiveness of a blast. The analyses also revealed that magnitude of overbreak for down-stream wall was more than that observed in up-stream wall
An investigation into the experiences of managers who work flexibly
No full textThis thesis explores the experiences of managers who work flexibly. Flexible working
policies are prevalent in all organizations in the UK because of the legislation giving
specific groups of parents and carers the right to request flexible working. Many
organizations extend the policies to all employees, yet the take-up is not as high as
expected, particularly among staff at managerial levels. This thesis explores how
managers construe and experience flexible working arrangements while successfully
fulfilling their roles as managers of people.
The exploratory study consisted of interviews with eight managers with unique flexible
working patterns. Analysis of the interview transcripts identified concepts of
consistency and adaptability. Consistency refers to meeting fixed needs from the work
and non-work domains, and adaptability refers to the adjustment of schedules to meet
the changing demands from those domains. The concepts of consistency and
adaptability were further explored in the main study which is based on interviews with
24 women and 10 men who held managerial positions and had a flexible working
arrangement which reduced their face time in the workplace.
The research offers three main contributions to the literature. At a theoretical level, I
propose a model which demonstrates how individuals use consistency and adaptability
to meet the fixed and changing demands from the work and non-work domains. This
model extends understanding of the complexity of the segmentation/integration
continuum of boundary theory, explaining how and why managers use flexible working
arrangements as a means of managing boundaries and achieving desired goals in both
domains. Four distinct clusters emerged among the managerial participants in terms of
the type and direction of adaptability, indicating the range of strategies used by
managers to ensure the success of their flexible working arrangements. A detailed
description of managers’ flexible working experiences is provided, adding to what is
known about the role of manager through the exploration of the enactment of that role
when working flexibly
Avaliação da especiação química de cobre nas águas de chuva de Florianópolis e magnitude da sua reposição utilizando a voltametria de redissolução catódica
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em QuímicaUma vez que um metal é emitido na atmosfera, este pode ser transportado por longas distâncias, e interagir com compostos orgânicos e inorgânicos nesse meio antes de ser precipitado na forma de aerossóis e chuva. Este estudo avaliou as diferentes espécies metálicas do cobre por voltametria de redissolução catódica, em águas de chuva com o objetivo de identificar as principais fontes de cobre para a atmosfera na região de Florianópolis, avaliar a magnitude da deposição atmosférica de metais nos ambientes aquáticos e identificar a origem (terrestre ou marinha) da matéria orgânica presente nas águas de chuva
Anti-neurofascin antibodies
No full textNeurofascin (NF) is a cell-adhesion molecule that is found at the nodes of Ranvier. The 186
kDa isoform of neurofascin (NF186) is expressed on the axon in the exposed node, and the
155 kDa isoform (NF155) is expressed on myelinating glia at the paranode. NF186 is essential
for clustering of sodium channels to the nodes while NF155 is needed for close paranodal interactions
between myelinating glia and axons. The neurofascins are found in both the peripheral
and central nervous system (PNS and CNS).
NF-specific autoantibodies were identified in serum of multiple sclerosis (MS) patients using
a proteomics approach with two-dimensional Western blotting of human myelin glycoproteins.
A monoclonal antibody (mAb) specific for NF was shown to induce axonal injury in an animal
model of MS, experimental autoimmune encephalomyelitis. This indicated that NF is a relevant
autoantibody target in patients with inflammatory diseases of the nervous system (central and
peripheral), but actual abundance of anti-NF autoantibodies is unknown.
The objectives of the thesis were the following: 1) Develop assays to detect autoantibodies
against human NF. 2) Determine the prevalence in patients with MS and with inflammatory
diseases of the PNS. 3) Characterize the reactivity by immunoglobulin isotyping, serial dilution,
epitope mapping, and staining of nodal structures in tissue sections. 4) Affinity purify anti-NF
antibodies from plasma exchange material. 5) Determine possible in vivo effects of anti-NF
antibodies in the PNS using a neuritis animal model.
First, we expressed the complete human NF155 and NF186 on the surface of stable human cell
lines, produced the complete extracellular portion of the NFs in HEK293 cells, and expressed
truncated variants of the NFs in E. coli. With these reagents, we set up three antibody detection
assays: cell-based assay by flow cytometry, ELISA, and Western blot. These assays were
validated using NF-specific monoclonal and polyclonal antibodies, and optimized with a test
cohort of serum samples.
We screened 687 serum and 48 plasma exchange samples from patients with MS (n = 233),
inflammatory diseases in the PNS (n = 294), and controls (n = 208). From serum analysis,
we observed low prevalence of anti-NF reactivity (3%) by flow cytometry and/or ELISA despite
broad reactivity in almost half of the serum samples analyzed by Western blot. Reactivity observed
by flow cytometry and by ELISA were congruent only in the patients with the highest
reactivities. The anti-NF antibodies were NF-isoform specific, mainly IgG subclasses, and at
high titres in some cases. Using truncated variants of NF fused to super green fluorescence
protein (sGFP), we showed that reactivity of anti-NF Abs was largely directed towards the membrane
proximal extracellular domains that are unique to each isoform, while the membrane
distal immunoglobulin-like domains and fibronectin domains were not recognized.
A small proportion (3%; 8/254) of patients with GBS and CIDP showed reactivity to human NF
by ELISA. A few showed a particularly high reactivity (up to 1:10 000 dilution) to NF. Two CIDP
patients showed a particularly high (up to 1:10 000 dilution) anti-NF155 reactivity by FACS and
ELISA, recognized paranodes in tissue sections, and exhibited dominant IgG4 subclass usage.
Another CIDP patient who benefited from plasma exchange had a persistent anti-NF155
reactivity by ELISA in serum, and after affinity purification, anti-NF186 and -NF155 reactivity by
FACS and ELISA were detected in addition. These antibodies were mainly IgG3, with minor
contribution of IgM and IgA. To investigate possible functions of anti-NF antibodies in inflammatory
PNS diseases, we injected two different monoclonal antibodies (mAbs) into a P2-peptide
induced experimental autoimmune neuritis (EAN) animal model at disease onset. We found
that while the anti-NF mAbs prolonged and exacerbated clinical disease in these animals, they
could not induce disease on their own.
We detected NF-reactivity in a small proportion of MS samples (3%; 7/225) by ELISA and flow
cytometry. We obtained follow-up material from two NF-reactive patients and saw a persistent
NF reactivity in one of them. To increase detection sensitivity, we affinity purified anti-NF antibodies
from plasma exchange material of patients with MS (n = 8). IgG, IgM, and IgA were
isolated from most of the samples; they were found to recognize NF155 and to a lower extent
NF186 by ELISA and in a few also by flow cytometry. This indicates that low levels of anti-NF
antibodies exist in a proportion of MS patients.
In conclusion, 3% of serum samples from patients with PNS inflammatory neuropathies (GBS
and CIDP) showed reactivity by ELISA and none of the controls. In an animal model of autoimmune
peripheral nerve inflammation, we showed, using two anti-NF mAbs, that antibody
targeting of NF can enhance and prolong disease course. This suggests that antibodies to NF
may be relevant for a small group of patients with peripheral inflammatory neuropathies. In MS
patients, 3% showed anti-NF reactivity by flow cytometry and ELISA. Furthermore, low levels of
anti-NF antibodies that could be detected by ELISA and flow cytometry after affinity purification
were additionally found in some MS patient samples that were unreactive by serum screening.
This raises the possibility that low levels of antibodies to NF are present in some MS patients
and may contribute to the pathogenesis of this chronic disease
Water rights, conflict and policy: Proceedings of a workshop held in Kathmandu, Nepal, January 22-24, 1996
No full textIrrigationIrrigation managementWater rightsWater lawConflictFarmers' associations
Blockade of endothelin ETA, but not thromboxane, receptors offsets the cyclosporine-evoked hypertension and interrelated baroreflex and vascular dysfunctions
No full textThe impairment of arterial baroreceptor and vasodilator functions are two major contributors to the hypertensive action of cyclosporine (CSA). In this study, in vivo and in vitro pharmacological studies were performed to investigate whether these effects of CSA are differentially modulated by endothelin and thromboxane signaling. The treatment of rats with CSA (25 mg-kg-day i.p.) for 7 consecutive days caused significant increases in blood pressure (BP), attenuated reflex heart rate (HR) responses to vasopressor (phenylephrine, PE) and vasodepressor (sodium nitroprusside, SNP) agents, and reduced cumulative vasorelaxant responses elicited by acetylcholine (Ach, 1×10-9-1×10-5 M) in PE-precontracted isolated aortas. These effects of CSA were blunted after concurrent i.p. administration of atrasentan (selective ETA blocker, 10 mg-kg-day), but not terutroban (thromboxane receptor blocker, 10 mg-kg-day). Moreover, atrasentan reversed the reductions in aortic protein expression of eNOS caused by CSA whereas terutroban was without effect. We also report that the favorable effect of atrasentan on CSA-evoked impairment in aortic Ach responsiveness disappeared in rats treated simultaneously with L-NAME (NOS inhibitor, 10 mg-kg-day) but not BQ 788 (ETB receptor blocker, 0.1 mg-kg-day) or indomethacin (cycloxygenase inhibitor, 5 mg-kg-day). Together, the data implicate endothelin ETA receptors in baroreflex and vascular derangements which predispose to the hypertensive effect of CSA. 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Remoção de espécies de cromo em águas contaminadas utilizando alga marinha como adsorvente
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Engenharia Quimica.Cromo e seus compostos são utilizados em diversas indústrias. Como resultados dessas aplicações industriais, grandes quantidade de compostos de cromo são despejados para o meio ambiente, podendo causar efeitos ecológicos e biológicos adversos. Recentemente, os processos de biossorção mostraram ter um bom potencial para a remoção de metais, substituindo os métodos convencionais. Neste trabalho, a macroalga marinha Laminaria digitata, na forma protonada, foi utilizada como biossorvente no tratamento de águas contaminadas com cromo. A alga marrom L. digitata foi coletada na costa norte de Portugal. A biomassa seca foi cortada em pequenas partículas e, subsequentemente, protonada por imersão em HNO3 sob agitação constante durante 3 h ou 6 h. Este procedimento foi repetido duas vezes. A biomassa foi então, lavada várias vezes com água destilada até pH 4 e seca em estufa. Estudos cinéticos de biossorção de Cr (VI) foram realizados em reatores de vidro com capacidade de 1 L contendo 800 mL da solução de metal (10, 50 ou 300 mg L-1). As condições otimizadas foram a concentração de biomassa de 4 g L-1 e o pH de 2,5 em 20 ºC. O efeito da temperatura também foi avaliado. A cinética de redução de Cr (VI) em regime contínuo foi avaliada em diferentes vazões (1; 2,5; 5 e 10 mL min-1), com uma solução de alimentação de 10 mg L-1 de Cr (VI), utilizando uma coluna de leito fixo. O equilíbrio de biossorção de Cr (III) pela alga protonada foi estudado em diferentes pH (1 a 4) sob condições de temperatura constante (25 ºC e 40 ºC) usando um refrigerador termostático. Os experimentos foram realizados em duplicata com concentração inicial de Cr na faixa de 5 a 250 e 2 g L-1 de biomassa. O equilíbrio de biossorção do Cr (III) proveniente do processo de redução também foi avaliado com concentrações iniciais de 5 a 100 mg L-1 e 1 g L-1 de biomassa. Durante o contato com o adsorvente, observou-se uma redução do Cr (VI) a Cr (III) pela matéria orgânica do sólido e a completa remoção de Cr (VI) foi obtida em 48 h para um pH de 2,5. Foi verificado que a concentração da biomassa, temperatura e o pH são fatores que exercem bastante influência na redução do Cr (VI); para maiores valores de concentrações de biomassa e de temperatura, obteve-se maior taxa de remoção e, para menores valores de pH, maior foi a taxa de remoção obtida. A concentração inicial do Cr (VI), por outro lado, não apresentou influência na taxa de remoção para baixas concentrações, entretanto, foi verificada uma diminuição na cinética, devido a maior defasagem dos compostos orgânicos oxidados. Os resultados experimentais foram ajustados a uma cinética química de primeira ordem sendo o valor da constante cinética de 0,061 ± 0,002 h-1. A capacidade de redução de Cr (VI) obtida foi de 120 mg g-1 para pH 2,5. Foi observado que os sítios ativos envolvidos no processo de adsorção do Cr (VI) são, em parte, os mesmos envolvidos no processo de adsorção do Cr (III). A energia de ativação obtida para a remoção de Cr (VI) pela alga Laminaria d. foi de 42,9 kJ mol-1. Nos ensaios realizados em coluna a diferentes vazões de alimentação, foi obtido um efluente final com concentração nula de Cr (VI) e uma concentração de cromo total de 4,5 ± 0,3 mg L-1, para a vazão de 1 mL min-1. Foi verificada a capacidade da alga Laminaria na adsorção de Cr (III). Dados cinéticos foram satisfatoriamente descritos por uma cinética de pseudo-segunda ordem. Para uma concentração inicial de Cr (III) de 232 mg L-1, os parâmetros do modelo cinético de pseudo-segunda ordem são k2,ads= 0,01 g mg-1 h?1; qeq= 43,0 ± 0,9 mg g?1. A biossorção de Cr (III) foi fortemente dependente do pH do meio, sendo que a temperatura apresentou pouca influência. O aumento do pH gerou um aumento na capacidade de biossorção do Cr (III) na alga. Os modelos de Langmuir e Freundlich foram selecionados para descrever as isotermas do Cr (III). O modelo de Langmuir ajustou melhor os resultados, segundo teste-F aplicado para um nível de confiança de 95%. Os parâmetros qL e kL do modelo de equilíbrio de Langmuir são 41 ± 1 mg g-1 e 0,31 ± 0,04 L mg-1, respectivamente. Análises de FTIR indicaram a participação de grupos carboxílicos e amida na interação com metalChromium and its related compounds are used in several industries. As result of these industrial applications, large quantities of chromium compounds are discharged into the environment and may cause adverse biological and ecological effects. Recently, biosorption processes showed to have a good potential for metals removal, replacing conventional methods. In this work, the seaweed Laminaria, in a protonated form, has been used as biosorbent for treatment of water contaminated with chromium. The brown seaweed L. digitata was collected from the north coast of Portugal. The dried biomass was then cut to small particles and subsequently protonated by soaking into HNO3 under constant shaking for 3 h or 6 h. This procedure was repeated twice. After that, the biomass was rinsed several times with distilled water until pH 4 and then it was dried in an oven. Biosorption kinetic studies of Cr (VI) were carried out in a batch system using a 1 L capacity glass vessel containing 800 mL of metal solution (10, 50 or 300 mg L-1). The optimized conditions were the biomass concentration of 4 g L-1 and pH 2.5 at 20 ºC. The effect of temperature was also evaluated. The kinetic studies of reduction of Cr (VI) were also evaluated in continuous flows using a fixed bed column at different flows (1; 2.5; 5 and 10 mL min-1) and initial solution of 10 mg L-1 of Cr (VI). Biosorption equilibrium of Cr (III) by protonated seaweed was studied at different pH (1 to 4) under constant temperature (25 °C and 40 °C) using a thermostatic refrigerator. The experiments were carried out in duplicate with initial concentration of chromium in the range of 5 to 250 mg L-1 and 2 g L-1 of biomass concentration. Biosorption equilibrium of Cr (III) was also studied with initial concentration of 5 to 100 mg L-1 and 1 g L-1 of biomass concentration. During the contact with the adsorbent, it was observed a reduction of Cr (VI) to Cr (III) by organic matter of the solid and the complete removal of Cr (VI) was obtained in 48 h at pH 2.5. It was found that the biomass concentration, temperature and pH are factors that show considerable influence on reduction of Cr (VI). Higher biomass concentrations and temperature increase the removal rate and lower pH values increase the removal rate. The initial concentration of Cr (VI), on the other hand, had no effect on removal rate at low concentrations, however a decrease was observed in the kinetics due to a larger quantity of oxidized organic compounds. The experimental results were fitted to a first-order chemical kinetics and the value of the kinetic constant was 0.061 ± 0.002 h-1. The capacity of algae to reduce Cr (VI) was 120 mg g-1 at pH 2.5. It was observed that the active sites involved in adsorption of Cr (VI) are, in part, the same involved in the process of adsorption of Cr (III). The activation energy obtained for removal of Cr (VI) by algae Laminaria d. was 42.9 kJ mol-1. Tests in a continuous flow were conducted at different flow rates and proved to be a final effluent with zero concentration of Cr (VI) and total chromium concentration of 4.5 ± 0.3 mg L-1, for flow rate of 1 mL min-1. It was verified the capacity of the algae Laminaria on the adsorption of Cr (III). Kinetic data were satisfactorily described by a kinetic of pseudo-second order. For an initial concentration of Cr (III) of 232 mg L-1 the parameters of the kinetic model of pseudo-second order are K2, ads= 0.01 mg g-1 h-1; qeq = 43 ± 0.9 mg g-1. The chromium adsorption was strongly dependent of the pH solution and less dependent of the temperature. And with increasing pH increases the adsorption capacity of Cr (III) in seaweed. The Langmuir and Freundlich models were selected to describe the isotherms of Cr (III). The Langmuir model fitted better the results, according of F-test applied to a confidence level of 95%. The parameters qL and kL of the Langmuir equilibrium model are 41 ± 1 mg g-1 and 0.31 ± 0.04 mg L-1, respectively. FTIR analysis indicated the participation of amide and carboxylic groups in the interaction with meta
Investigação fitoquímica do extrato etanólico de Hedyosmum brasiliense Miq., Chloranthaceae
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-graduação em Farmácia, Florianópolis, 2011Hedyosmum brasiliense é um arbusto aromático que pertence à família Chloranthaceae e é popularmente usado como calmante e antiinflamatório, para tratar frieiras, enxaquecas e doenças de ovário. Este trabalho visou continuar a análise fitoquímica desta espécie que é conhecida popularmente como "Cidrão". Foi possível isolar e identificar treze substâncias oriundas só das frações hexano e diclorometano do extrato etanólico. Dessas substâncias, quatro são inéditas na literatura e pertencem à classe das lactonas sesquiterpênicas 15-acetilisogermafurenolídeo (H622), 1-hidroxi-10,15-metilenopodoandina (HB 212), 15-hidroxi-isogermafurenolídeo (HB 21) e brasiliensolídeo (HL 33) que é uma lactona sesquiterpênica dimérica. Seis estão sendo descritas pela primeira vez para a espécie (monoglicerídeo de ácido esteárico, éster etílico do ácido linolênico, éster etílico do ácido linoléico, ácido 3-metoxi-4-hidroxibenzoico, escopoletina e vanilina), e três (podoandina, 13-hidroxi-8,9-diidroshizukanolídeo (13HDS) e ß- sitosterol) já foram descritas previamente para H. brasiliense. Quanto aos estudos farmacológicos, a podoandina mostrou atividade antidepressiva agindo sobre as vias adrenérgicas, dopaminérgicas e serotonérgicas; o extrato bruto e as lactonas, podoandina e 13HDS exibiram a atividade vasodilatadora e as lactonas sesquiterpênicas (H622, HB 212 e HB 21) não tiveram atividade antimicrobiana contra Mycobacterium tuberculosis. As substâncias foram identificadas pela espectroscopia de ressonância magnética nuclear de 1D, 2D, espectrometria de massas e dados da literatura.Hedyosmum brasiliense is an aromatic shrub that belongs to the Chloranthaceae family and is popularly used as a calmative and ntiinflammatory, for treating athlete's foot, migraines and diseases of the ovary. This work was done to continue the phytochemical analysis of this species which is popularly known as "Cidrão". It was possible to isolate and identify thirteen substances which were obtained from the hexane and dichloromethane fractions of the ethanol extract. Out of these substances, four are new and belong to the class of sesquiterpene lactones: 15-acetyl-isogermafurenolide (H622), 1-hydroxy-10 ,15-methylenepodoandin (HB 212), 15-hydroxy-isogermafurenolide (HB21) and brasiliensolide (HL 33) which is a dimeric sesquiterpene lactone. Six are being described for the first time for this species (stearic acid monoglyceride, linolenic acid ethyl ester, linoleic acid ethyl ester, 3-methoxy-4- hydroxybenzoic acid, scopoletin and vanillin), and three (podoandin, 13-hydroxy-8,9-dehydroshizukanolide (13HDS) and ß-sitosterol) were previously described for H. brasiliense. With regards to pharmacological studies, podoandin exhibited antidepressant activity by acting on adrenergic, dopaminergic and serotonergic pathways; the crude extract and the lactones podoandin and 13HDS exhibited vasodilator activity and the sesquiterpene lactones (H622, HB 212 and HB 21) showed no antimicrobial activity against Mycobacterium tuberculosis. The substances were identified by Nuclear magnetic resonance spectroscopy 1D, 2D, mass spectrometry and already published data
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