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1.
Phys Rev Lett ; 112(16): 162701, 2014 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-24815644

RESUMO

Coulomb-excitation experiments to study electromagnetic properties of radioactive even-even Hg isotopes were performed with 2.85 MeV/nucleon mercury beams from REX-ISOLDE. Magnitudes and relative signs of the reduced E2 matrix elements that couple the ground state and low-lying excited states in Hg182-188 were extracted. Information on the deformation of the ground and the first excited 0+ states was deduced using the quadrupole sum rules approach. Results show that the ground state is slightly deformed and of oblate nature, while a larger deformation for the excited 0+ state was noted in Hg182,184. The results are compared to beyond mean field and interacting-boson based models and interpreted within a two-state mixing model. Partial agreement with the model calculations was obtained. The presence of two different structures in the light even-mass mercury isotopes that coexist at low excitation energy is firmly established.

2.
Sci Total Environ ; 874: 162599, 2023 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-36871730

RESUMO

The Kvarken Archipelago is Finland's World Heritage site designated by UNESCO. How climate change has affected the Kvaken Archipelago remains unclear. This study was conducted to investigate this issue by analyzing air temperature and water quality in this area. Here we use long-term historical data sets of 61 years from several monitoring stations. Water quality parameters included chlorophyll-a; total phosphorus; total nitrogen; coliform bacteria thermos tolerant; temperature; nitrate as nitrogen; nitrite-nitrate as nitrogen, and Secchi depth and correlations analysis was conducted to identify the most relevant parameters. Based on the correlation analysis of weather data and water quality parameters, air temperature showed a significant correlation with water temperature (Pearson's correlations = 0.89691, P < 0.0001). The air temperature increased in April (R2 (goodness-of-fit) = 0.2109 &P = 0.0009) and July (R2 = 0.1207 &P = 0.0155) which has indirectly increased the chlorophyll-a level (e.g. in June increasing slope = 0.39101, R2 = 0.4685, P < 0.0001) an indicator of phytoplankton growth and abundance in the water systems. The study concludes that there might be indirect effects of the likely increase in air temperature on water quality in the Kvarken Archipelago, in particular causing water temperature and chlorophyll-a concentration to increase at least in some months.


Assuntos
Nitratos , Qualidade da Água , Temperatura , Nitratos/análise , Monitoramento Ambiental , Clorofila A/análise , Clorofila/análise , Fitoplâncton , Nitrogênio/análise , Fósforo/análise
3.
Phys Rev Lett ; 109(1): 012501, 2012 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-23031099

RESUMO

The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin of 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of neighboring nuclei and it is shown that the kinematic and dynamic moments of inertia are sensitive to the underlying single-particle shell structure and the specific location of high-j orbitals. The moments of inertia therefore provide a sensitive test of shell structure and pairing in superheavy nuclei which is essential to ensure the validity of contemporary nuclear models in this mass region. The data obtained show that there is no deformed shell gap at Z=104, which is predicted in a number of current self-consistent mean-field models.

4.
Biochem Pharmacol ; 35(16): 2671-5, 1986 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-3091030

RESUMO

[Carboxyl-14C] labelled 1,2,3,4-tetrahydro-beta-carboline-1-carboxylic acid (I) and 1-methyl-1,2,3,4-tetrahydro-beta-carboline-1-carboxylic acid (II) were synthesized and their decarboxylation was studied in mouse brain homogenate and buffer. The decarboxylation rates of (I) and (II) in the homogenate were about 6-fold and 4-fold, respectively, as compared with the rates in phosphate buffer. The increase could not be prevented by preheating the homogenate, but was partially abolished by addition of 1 mM EDTA. The decarboxylation was increased dose-dependently when pyridoxal-5'-phosphate was included in the buffer, 400 microM being sufficient to exceed the rate in homogenate for both (I) and (II). Mass spectrometric examination of the decarboxylation products indicated that both (I) and (II) were degraded mainly to corresponding 1,2,3,4-tetrahydro-beta-carbolines, but some 3,4-dihydro analogues also were detectable. In conclusion, the results outline a way through which these pharmacologically active beta-carbolines are readily formed under conditions that may be regarded as physiological.


Assuntos
Encéfalo/metabolismo , Carbolinas/metabolismo , Fosfato de Piridoxal/metabolismo , Animais , Relação Dose-Resposta a Droga , Ácido Edético/farmacologia , Espectrometria de Massas , Mercúrio/farmacologia , Camundongos
5.
Pharmacol Biochem Behav ; 17(4): 831-6, 1982 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7178191

RESUMO

Voluntary alcohol intake has been reported to increase in rats after the repeated intracerebroventricular (ICV) administration of 1,2,3,4-tetrahydro-beta-carboline (THBC) and some tetrahydroisoquinolines, although negative results have also been reported. THBC is a normal constituent in human plasma and platelets; 1-methyl-1,2,3,4-tetrahydro-beta-carboline (1-Me-THBC), however, occurs in the blood after a person drinks alcohol. We have evaluated the effects of two doses of THBC and 1-Me-THBC on voluntary alcohol consumption in rats. ICV infusions were given with Alzet minipumps for 14 days rather than giving repeated ICV injections. Stability of the drugs in the pump was verified using mass spectrometry. On each day the rats chose between water, alcohol (increasing concentrations from 3 to 30%) and an empty bottle. Alcohol intake increased by about 100% (p less than 0.05) during the last six days when 47 nmoles/hr of either THBC or 1-Me-THBC was infused. At the end of the experiment elevated blood concentrations of alcohol (0.02-0.78(0)/00) were found in rats belonging to the THBC or 1-Me-THBC groups and drinking 30% alcohol. The infusion of 0.47 nmoles/hr of either drug did not increase alcohol intake as compared to control.


Assuntos
Consumo de Bebidas Alcoólicas , Carbolinas/farmacologia , Indóis/farmacologia , Animais , Peso Corporal , Carbolinas/administração & dosagem , Feminino , Injeções Intraventriculares , Masculino , Ratos , Ratos Endogâmicos , Especificidade da Espécie
6.
Pharmacol Biochem Behav ; 18 Suppl 1: 525-9, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-6634862

RESUMO

Some beta-carbolines, such as tetrahydro-beta-carboline (THBC) and 6-methoxy-THBC, occur normally in mammalian tissues, and 1-methyl-THBC has been found in human blood after alcohol intake. Continuous intraventricular (ICV) infusion of THBC and 1-methyl-THBC for 14 days was shown to increase voluntary alcohol intake in rats during the second week of infusion. In this study the experimental arrangement was slightly modified. Alcohol was offered for 7 days before the start of the 14 days of ICV infusion with Alzet minipumps and alcohol concentration (3-30% v/v) was increased every second day. The rats consumed less alcohol in the second day with the same concentration. Also, the dose of 47 nmoles/hr of 1-Me-THBC increased the voluntary alcohol intake over the controls, but only during the last 7 days. The same dose of 6-MeO-THBC, a serotonergic beta-carboline, was ineffective. Neither drug changed the total fluid intake. This study suggests that the increased voluntary alcohol intake by THBC's is not due to their serotonergic effect. A hypothesis concerning a possible involvement of opiate receptors is presented.


Assuntos
Consumo de Bebidas Alcoólicas , Carbolinas/farmacologia , Indóis/farmacologia , Animais , Comportamento de Escolha/efeitos dos fármacos , Etanol/sangue , Injeções Intraventriculares , Masculino , Ratos , Ratos Endogâmicos
7.
J Pharm Biomed Anal ; 6(6-8): 821-5, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-16867349

RESUMO

Tryptamine (TA) occurs in trace levels in the brain, but its role in the central nervous system is not clear. However, there is evidence that TA may be a neuromodulator since it binds to specific binding sites in the brain. TA was measured as a diheptafluorobutyryl derivative in rat whole brain by capillary gas chromatography-mass spectrometry using negative chemical ionization (NCI) and single ion monitoring (SIM). d(4)-TA was used as the internal standard. The ions m/z 532 and m/z 536 were monitored to identify TA and d(4)-TA, respectively and to calculate the concentration of TA in rat whole brain which was found to be 0.19 +/- 0.08 ng g(-1) (n = 8). The results confirm the earlier TA concentrations measured by GC-MS using positive electron impact ionization. However, NCI improved the signal/noise ratio of the method increasing its sensitivity for TA.

8.
J Pharm Biomed Anal ; 9(9): 737-45, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1821151

RESUMO

New alkyl and aralkyl pilocarpic acid diesters, prodrugs of pilocarpine, were synthesized with the aim of improving the bioavailability of pilocarpine by increasing its corneal permeability. These esters were several orders of magnitude more lipophilic than pilocarpine as determined by their apparent partition coefficients between 1-octanol and phosphate buffer (pH 7.40) (log P). Good correlation between log P and HPLC capacity factors of the compounds was observed. All the compounds are stable in acidic aqueous solution; in serum, however, pilocarpic acid diesters are hydrolysed enzymatically to pilocarpic acid monoester, which undergoes spontaneous cyclization to active pilocarpine and inactive isopilocarpine. The half-lives of the diesters in serum varied from 6-232 min. In addition to the direct effects of the R2, R1 moiety had a remarkable effect on the rate of enzyme-catalysed hydrolysis taking place in moiety R2. The formed pilocarpine was analysed with a new HPLC method which allowed good resolution of pilocarpine, isopilocarpine, pilocarpic acid and isopilocarpic acid. Rates for pilocarpine formation were both determined by experiment and calculated using the STELLA simulation programme with known degradation rate constants of pilocarpic acid diesters and monoesters. Since the simulations were in good agreement with the experimental results, it is concluded that STELLA simulation programme is useful in predicting pilocarpine formation.


Assuntos
Pilocarpina/análogos & derivados , Cromatografia Líquida de Alta Pressão/métodos , Ésteres/sangue , Ésteres/química , Humanos , Hidrólise , Cinética , Pilocarpina/sangue , Pilocarpina/química , Relação Estrutura-Atividade
9.
J Pharm Biomed Anal ; 10(2-3): 153-61, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1391095

RESUMO

As a part of a series of studies to develop prodrug derivatives of pilocarpine, the O,O'-succinyl (dibenzyl), O,O-adipoyl (dibenzyl), O,O-fumaryl (dibenzyl), and O,O-terephthaloyl (dibenzyl) bispilocarpate fumarates were synthesized as a new class of pilocarpine prodrugs. The compounds were prepared from pilocarpic acid benzyl monoester by coupling two pilocarpic acid benzyl monoesters together with spacer chains by usual esterification methods. Liquid chromatography, thermospray liquid chromatography-mass spectrometry, high-resolution mass spectrometry, and NMR spectroscopy were applied to the identification and the purity evaluation of the synthetic products.


Assuntos
Pilocarpina/análogos & derivados , Pró-Fármacos/síntese química , Cromatografia Líquida , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Pilocarpina/síntese química , Pilocarpina/química , Pilocarpina/isolamento & purificação , Pró-Fármacos/química , Pró-Fármacos/isolamento & purificação
10.
J Pharm Biomed Anal ; 9(6): 457-64, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1747398

RESUMO

A series of new pilocarpic acid diesters were synthesized to obtain prodrugs for pilocarpine with varying physico-chemical properties. Thermospray liquid chromatography-mass spectrometry (TSP-LC-MS), liquid chromatography with UV-detection (LC-UV) and NMR-spectroscopy were used for the identification of the synthetic products and for evaluation of their purity including typical impurities (pilocarpic acid monoester, pilocarpine). TSP-LC-MS-analysis was performed in the reversed-phase mode using acetonitrile (60%)-0.2 M ammonium acetate (40%) as mobile phase. In LC-UV-analysis chromatographic separation was carried out on a reversed-phase column and the mobile phase consisted of methanol (71%) and 0.02 M potassium dihydrogen phosphate, pH 4.5 (29%). Electron ionization-mass spectrometry (EI-MS) was used for elucidation of structures. Elemental compositions of the substances were verified with high resolution-mass spectrometry (HR-MS). The complete establishment of structures presented was based on 1H-, and COSY-NMR-spectroscopy joined to TSP-LC-MS-analysis.


Assuntos
Pilocarpina/análogos & derivados , Pró-Fármacos/síntese química , Cromatografia Líquida , Ésteres/síntese química , Ésteres/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Pilocarpina/química , Pró-Fármacos/isolamento & purificação
11.
Environ Pollut ; 87(2): 235-42, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-15091598

RESUMO

Fifteen or 18-month-old Aleppo pine seedlings were fumigated with different concentrations and doses of ozone over a period of 2-16 days in controlled-environmental growth chambers. The total fatty acid content and ultrastructure of the current year needles were subsequently analysed. In acute, high concentration exposures, significant reductions in the levels of linolenic acid were detected. Increases in myristic or palmitic acid were common in needles exposed to lower concentrations of ozone. Ultrastructural studies revealed reductions in chloroplast size and a darkening of stroma at low ozone exposures while at high concentrations disruption of the chloroplast membranes was also identified.

12.
J Ethnopharmacol ; 18(3): 273-96, 1986 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3821142

RESUMO

The use of natural plants as emergency food in Finland and northern Europe has been described. The chemical contents of the commonly used "pettu" (pine bark), lichen (Cetraria islandica, Cladonia sp.) and water plants (Calla palustris, Menyathes trifoliata, Nymphea sp. and Nuphar luteum) are described and their toxicity after traditional pretreatments were studied in mice and rats. As 50% w/w mixture in normal food none of them were tolerated by mice. However, rats tolerated 25% of "pettu" and ash-treated C. islandica in 3-month tests rather well, although the body weight did not increase as much as in controls. At the end of experiment in the lichen group, the rats had proteinuria, and on autopsy some tubular changes were found probably due to high concentrations of lead in the lichen and kidneys. All the rhizomes studied contain toxic compounds, but they, particularly calla, would be nutritionally valuable. Boiling poorly eliminated their toxicity, but after baking at 180-200 degrees C the most toxic Nuphar and calla were well tolerated as 25% mixture during a 6-week test. It is possible that poorly selected or poorly pretreated emergency food have sometimes contributed to the death of famine victims in the olden times. Unqualified simplification of the traditional precautions for their treatment may be dangerous.


Assuntos
Alimentos , Plantas Comestíveis/análise , Plantas Tóxicas , Inanição , Animais , Feminino , Finlândia , Líquens , Masculino , Camundongos , Plantas Tóxicas/análise , Ratos , Árvores
13.
Health Technol Assess ; 16(7): 1-186, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22361003

RESUMO

BACKGROUND: Sepsis is a syndrome characterised by a systemic inflammatory response to infection that leads to rapid acute organ failure and potentially rapid decline to death. Intravenous immunoglobulin (IVIG), a blood product derived from human donor blood, has been proposed as an adjuvant therapy for sepsis. OBJECTIVES: To describe current practice in the management of adult patients severely ill with sepsis (severe sepsis or septic shock) in the UK; to assess the clinical effectiveness of IVIG for severe sepsis and septic shock and to obtain the appropriate inputs for the relative efficacy parameters, and the key uncertainties associated with these parameters, required to populate the decision model; to develop a decision-analytic model structure and identify key parameter inputs consistent with the decision problem and relevant to an NHS setting; and to populate the decision model and determine the cost-effectiveness of IVIG and to estimate the value of additional primary research. DATA SOURCES: Existing literature on IVIG and severe sepsis. Existing case-mix and outcome data on critical care admissions. Survey data on management of admissions with severe sepsis. Databases searched for clinical effectiveness were Cochrane Infectious Diseases Group Specialized Trials Register, the Cochrane Trials Register, MEDLINE and EMBASE. Dates searched were 1 January 2002 to 2 October 2009 to update previous Cochrane review. Databases searched for cost-effectiveness were NHS Economic Evaluation Database (NHS EED) to 2 October 2009, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations and EMBASE to 20 October 2009. REVIEW METHODS: Systematic literature searching with data extraction, descriptive analysis and clinical effectiveness and cost-effectiveness modelling of IVIG in severe sepsis. Additional primary data analysis. Expected value of information (EVI) analysis. RESULTS: Our meta-analysis, the first to simultaneously allow for type of IVIG (IVIG or immunoglobulin M-enriched polyclonal IVIG), choice of control (no treatment or albumin), study quality/publication bias and other potential covariates, indicated that the treatment effect of IVIG on mortality for patients with severe sepsis is borderline significant with a large degree of heterogeneity in treatment effect between individual studies. Modelling indicated that there were issues with bias associated with trial methodology, publication and small-study effects with the current evidence. The large degree of heterogeneity in treatment effects between studies, however, could be explained (best-fitting model) by a measure of study quality (i.e. use of albumin as control - as an indicator of proper blinding to treatment as a proxy for study quality - associated with decreased effect) and duration of IVIG therapy (longer duration associated with increased effect). In-depth discussion within the Expert Group on duration of IVIG therapy, with daily dose and total dose also clearly inter-related, indicated no clear clinical rationale for this association and exposed a lack of evidence on the understanding of the mechanism of action of IVIG in severe sepsis. Although the EVI analyses suggested substantial expected net benefit from a large, multicentre randomised controlled trial (RCT) evaluating the clinical effectiveness of IVIG, the remaining uncertainties around the design of such a study mean that we are unable to recommend it at this time. LIMITATIONS: As has been identified in previous meta-analyses, there are issues with the methodological quality of the available evidence. CONCLUSIONS: Although the results highlight the value for money obtained in conducting further primary research in this area, the biggest limitation for such research regards the uncertainties over the mechanism of action of IVIG and the heterogeneous nature of severe sepsis. Resolving these would allow for better definition of the plausibility of the effectiveness scenarios presented and, consequently, a better understanding of the cost-effectiveness of this treatment. This information would also inform the design of future, primary evaluative research. Our recommendations for future research focus on filling the knowledge gaps to inform a future multicentre RCT prior to recommending its immediate design and conduct. FUNDING: The National Institute for Health Research Health Technology Assessment programme.


Assuntos
Imunoglobulinas Intravenosas/economia , Imunoglobulinas Intravenosas/uso terapêutico , Sepse/tratamento farmacológico , Sepse/economia , Adulto , Idoso , Quimioterapia Adjuvante/economia , Quimioterapia Adjuvante/normas , Análise Custo-Benefício , Técnicas de Apoio para a Decisão , Feminino , Humanos , Imunoglobulinas Intravenosas/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Anos de Vida Ajustados por Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Sepse/mortalidade , Medicina Estatal/economia , Medicina Estatal/normas , Análise de Sobrevida , Reino Unido
14.
Appl Radiat Isot ; 70(2): 392-6, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22037206

RESUMO

Aerosol samples have been studied under different background conditions using gamma-ray coincidence and low-background gamma-ray singles spectrometric techniques with High-Purity Germanium detectors. Conventional low-background gamma-ray singles counting is a competitive technique when compared to the gamma-gamma coincidence approach in elevated background conditions. However, measurement of gamma-gamma coincidences can clearly make the identification of different nuclides more reliable and efficient than using singles spectrometry alone. The optimum solution would be a low-background counting station capable of both singles and gamma-gamma coincidence spectrometry.


Assuntos
Contaminação Radioativa do Ar/análise , Raios gama , Espectrometria gama/métodos , Aerossóis , Radiação de Fundo , Germânio , Física Nuclear/legislação & jurisprudência
15.
Health Technol Assess ; 14(Suppl. 2): 11-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21047486

RESUMO

This paper presents a summary of the evidence review group (ERG) report into capecitabine for advanced gastric cancer (aGC). Capecitabine is an oral prodrug of 5-fluorouracil (5-FU). The decision problem addressed was the use of capecitabine (X) compared to 5-FU (F), in combination regimens with platinum agents [cisplatin (C) or oxaliplatin (O)] with or without epirubicin (E), in patients with inoperable aGC. Approximately 7000 new cases of gastric cancer are diagnosed in England and Wales every year. Of these, 80% are candidates for palliative chemotherapy and around 2900 receive such treatment. The standard UK practice for patients with aGC who are considered fit enough has consisted of a triplet regimen comprising intravenous 5-FU in combination with a platinum agent (capecitabine or oxaliplatin) and epirubicin. The manufacturer's submission (MS) focused on direct evidence from two phase III non-inferiority randomised controlled trials (RCTs), REAL-2 (Randomized ECF for Advanced and Locally advanced oesophagogastric cancer-2; n = 1002) and ML17032 (n = 316). REAL-2 randomised patients to four regimens (ECF, ECX, EOF and EOX) to compare 5-FU with capecitabine and cisplatin with oxaliplatin, whereas ML17032 compared CX with CF. Efficacy outcomes from these trials were pooled in an individual patient data (IPD) meta-analysis. Both RCTs demonstrated statistically significant non-inferiority of capecitabine on the outcome of overall survival (OS) assessed in the per-protocol population; equivalent results were also demonstrated for progression-free survival (PFS). The IPD meta-analysis found a statistically significant benefit in OS for capecitabine compared with 5-FU [unadjusted hazard ratio (HR): 0.87; 95% confidence interval (CI) 0.77 to 0.98, p = 0.027]. There was no evidence of a poorer safety profile for capecitabine overall, nor of any difference in quality of life (QoL) between the two fluoropyrimidines. The MS included a de novo economic evaluation based on a cost-minimisation analysis (CMA), where the costs of capecitabine-based regimens were compared with their equivalent 5-FU-based regimens in aGC. A time horizon of 5.5 cycles (each lasting for 21 days) was used in the base-case analysis, representing the duration of treatment. The results of the manufacturer's base-case analysis showed that capecitabine regimens are associated with mean net cost savings of 1620 pounds (ECX vs ECF), 1572 pounds (EOX vs EOF) and 4210 pounds (CX vs CF). The manufacturer failed to comment explicitly on the uncertainty around the estimates of efficacy and on the fact that the IPD meta-analysis suggests that capecitabine may actually be more effective on average. Further analyses exploring additional costs incurred by the UK NHS from extending survival duration showed that these are unlikely to have a material effect on conclusions. A full probabilistic analysis was not performed; however, the evidence explored by the MS and ERG is consistent in suggesting that capecitabine has a lower mean cost than 5-FU-based regimens. The submission was considered to contain convincing evidence of the non-inferiority of capecitabine to 5-FU on survival; this evidence was considered to be applicable to UK practice. Although some uncertainty remains, the ERG deemed CMA to be an appropriate framework with which to analyse this decision problem. Overall cost estimates for the CMA were generated appropriately and were robust to uncertainties regarding assumptions and sources. At the time of writing, the guidance document issued by NICE on 28 July 2010 states that capecitabine in combination with a platinum-based regimen is recommended for the first-line treatment of inoperable advanced gastric cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Capecitabina , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Fluoruracila/administração & dosagem , Fluoruracila/análogos & derivados , Fluoruracila/economia , Humanos , Cuidados Paliativos/métodos , Pró-Fármacos/administração & dosagem
16.
Rev Sci Instrum ; 81(2): 02A302, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20192323

RESUMO

Time-resolved helium ion production and bremsstrahlung emission from JYFL 14 GHz ECRIS is presented with different radio frequency pulse lengths. rf on times are varied from 5 to 50 ms and rf off times from 10 to 1000 ms between different measurement sets. It is observed that the plasma breakdown occurs a few milliseconds after launching the rf power into the plasma chamber, and in the beginning of the rf pulses a preglow transient is seen. During this transient the ion beam currents are increased by several factors compared to a steady state situation. By adjusting the rf pulse separation the maximum ion beam currents can be maintained during the so-called preglow regime while the amount of bremsstrahlung radiation is significantly decreased.

17.
Phys Rev Lett ; 102(21): 212501, 2009 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-19519098

RESUMO

The rotational band structure of 255Lr has been investigated using advanced in-beam gamma-ray spectroscopic techniques. To date, 255Lr is the heaviest nucleus to be studied in this manner. One rotational band has been unambiguously observed and strong evidence for a second rotational structure was found. The structures are tentatively assigned to be based on the 1/2-[521] and 7/2-[514] Nilsson states, consistent with assignments from recently obtained alpha decay data. The experimental rotational band dynamic moment of inertia is used to test self-consistent mean-field calculations using the Skyrme SLy4 interaction and a density-dependent pairing force.

18.
Med Biol ; 65(2-3): 105-12, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-2888927

RESUMO

The basic mechanism or mechanisms of the alcohol withdrawal syndrome (AWS) are still unknown despite extensive research on alcoholism. There are, however, two major hypotheses or groups of hypotheses. Increasing experimental evidence supports adaptive changes in membrane lipids and/or proteins in response to prolonged high alcohol concentrations which might cause abnormal function after withdrawal of alcohol in general or more specifically in certain receptor sites. Changes in the formation or concentration of some receptor ligands as a consequence of alcohol metabolism are, however, also possible. Both can cause changes in neurotransmission, and these have been found in several systems. Although all studies do not agree, there seems to be some reduction in gabaergic, enkephalinergic, and possibly in dopaminergic function and increase in glutaminergic, adrenergic, cholinergic and possibly in serotoninergic and tryptaminergic activity at least in some neurons during AWS. These may be involved in producing some symptoms, but the variable whole AWS, particularly its two phases, remains to be explained.


Assuntos
Etanol/efeitos adversos , Neurotransmissores/fisiologia , Síndrome de Abstinência a Substâncias/fisiopatologia , Transmissão Sináptica , Etanol/metabolismo , Humanos
19.
Int J Clin Pharmacol Ther Toxicol ; 28(11): 471-4, 1990 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2272707

RESUMO

Doxycycline (DC) is used either as solid form hydrochloride capsules, or as monohydrate tablets, which may be taken either as solid form tablets or dissolved in water. In this single dose (150 mg), crossover study on 15 healthy volunteers, the pharmacokinetic properties of DC from hydrochloride tablets taken either in dissolved or in solid form were compared with those observed after taking dissolved DC as a monohydrate tablet. The results of this study show that DC is absorbed rapidly (tmax 3.3-3.8 h) and with equal bioavailability (AUC values 52.9-58.5 mg/l x h) from both hydrochloride and monohydrate tablets. It can be concluded that taking the DC hydrochloride tablets in dissolved form does not affect the pharmacokinetics of DC, moreover the bioavailability of DC is comparable to that achieved after taking DC monohydrate tablets in dissolved form.


Assuntos
Doxiciclina/farmacocinética , Disponibilidade Biológica , Biofarmácia , Doxiciclina/administração & dosagem , Doxiciclina/sangue , Composição de Medicamentos , Humanos , Fatores de Tempo
20.
Arch Toxicol Suppl ; 9: 406-9, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3468923

RESUMO

Iceland lichen (Cetraria islandica) is sold in health food stores to prevent various disorders. In olden times it and sometimes also reindeer lichen (Cladonia sp.) have been used as emergency food. Lichen contains bitter and potentially toxic lichen acids and it also concentrates heavy metals. Therefore lichen toxicity was studied with traditional pretreatment methods (boiling, ash-soaking or both). Untreated and only shortly boiled lichens were lethally toxic to mice in 50 and 25% w/w mixtures in food, but when ash-soaking was added mice tolerated Cetraria (but not Cladonia) reasonably well for 3 weeks. In a 3 month test in rats 25% mixture of Cladonia was tolerated well and blood tests were normal at the end. However, urinary protein was increased, the autopsies revealed kidney changes corresponding to a mild heavy metal poisoning, as the lead concentrations in kidney and lichen were high.


Assuntos
Líquens/análise , Intoxicação por Plantas/etiologia , Plantas Comestíveis/análise , Plantas Tóxicas/análise , Animais , Feminino , Manipulação de Alimentos , Rim/patologia , Masculino , Metais/análise , Camundongos , Ratos
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