RESUMO
Isotope shifts in dielectronic recombination spectra were studied for Li-like (A)Nd(57+) ions with A=142 and A=150. From the displacement of resonance positions energy shifts deltaE(142 150)(2s-2p(1/2))=40.2(3)(6) meV [(stat)(sys)] and deltaE(142 150)(2s-2p(3/2))=42.3(12)(20) meV of 2s-2p(j) transitions were deduced. An evaluation of these values within a full QED treatment yields a change in the mean-square charge radius of (142 150)deltar(2)=-1.36(1)(3) fm(2). The approach is conceptually new and combines the advantage of a simple atomic structure with high sensitivity to nuclear size.
RESUMO
In recent years, a single ion hit facility has been constructed at the IFJ ion microprobe. The setup is used for the precise irradiations of living cells by a controlled number of ions. Investigations of such type have two very important requirements: (1) cells must be examined in their natural state and environment (i.e. without previously being killed, preferentially neither fixed nor stained) and (2) the possibility of automatic irradiation of large number of cells (including computer recognition of cells positions) must be provided. This work presents some of the crucial features of the off-line and on-line optical systems, including self-developed software responsible for automatic cell recognition.
Assuntos
Técnicas de Cultura de Células/instrumentação , Separação Celular/instrumentação , Íons Pesados , Interpretação de Imagem Assistida por Computador/métodos , Microscopia/instrumentação , Aceleradores de Partículas/instrumentação , Radiometria/instrumentação , Técnicas de Cultura de Células/métodos , Separação Celular/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Alemanha , Interpretação de Imagem Assistida por Computador/instrumentação , Íons , Microscopia/métodos , Miniaturização , Sistemas On-Line , Doses de Radiação , Radiometria/métodos , Sensibilidade e Especificidade , Avaliação da Tecnologia BiomédicaRESUMO
The 2s(1/2)-2p(1/2) energy splittings DeltaE(L) of the lithiumlike ions 19779Au76+, 20882Pb79+, and 23892U89+ have been measured at the Experimental Storage Ring, utilizing low energy dielectronic recombination. The resonance energies in total 41 different 1s(2) 2p(1/2)nl(j(')) (n > or =20) autoionizing Rydberg states populated in the dielectronic capture process have been determined. The 2s(1/2)-->2p(1/2) excitation energies have been obtained by extrapolation of these resonance energies to the associated series limits n--> infinity. The combined analysis of the experimental data for all three ions yields DeltaE(L)=216.134(96) eV for Au76+, 230.650(81) eV for Pb79+, and 280.516(99) eV for U89+.
RESUMO
Dielectronic recombination resonances of Pb (79+) associated with 2s(1/2)-->2p(1/2) excitations were measured at the heavy-ion storage ring ESR at GSI. The fine structure of the energetically lowest resonance manifold Pb (78+)(1s(2)2p(1/2)20l(j)) at around 18 eV could partially be resolved, and rate coefficients on an absolute scale were obtained. A comparison of the experimental data with results of a fully relativistic theoretical approach shows that high-angular-momentum components up to j=31/2 significantly contribute to the total resonance strength demonstrating the necessity to revise the widespread notion of negligible high-angular-momentum contributions at least for very highly charged ions.
RESUMO
The cell's cytoskeleton together with the cell membrane and numerous accessory proteins determines the mechanical properties of cell. Any factors influencing cell organization and structure can cause alterations in mechanical properties of cell (its ability for deformation and adhesion). The determination of the local elastic properties of cells in their culture conditions has opened the possibility for the measurement of the influence of different factors on the mechanical properties of the living cells. The effect of the chitosan on the stiffness of the non-malignant transitional epithelial cells of ureter (HCV 29) and the transitional cell cancer of urine bladder (T24) was determined using scanning force microscopy. The investigations were performed in the culture medium (RPMI 1640) containing 10% fetal calf serum in the presence of the microcrystalline chitosan of the three different deacetylation degrees. In parallel, the effect of chitosan on production of lactate and ATP level was determined. The results showed the strong correlation between the decrease of the energy production and the increase in Young's modulus values obtained for the cancer cells treated with chitosan.
Assuntos
Quitina/farmacologia , Bexiga Urinária/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Células Cultivadas , Quitina/análogos & derivados , Quitosana , Citoesqueleto/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Humanos , Microscopia de Força Atômica , Células Tumorais CultivadasRESUMO
Radiative electron capture, the time-reversed photoionization process occurring in ion-atom collisions, provides presently the only access to photoionization studies for very highly charged ions. By applying the deceleration mode of the ESR storage ring, we studied this process in low-energy collisions of bare uranium ions with low- Z target atoms. This technique allows us to extend the current information about photoionization to much lower energies than those accessible for neutral heavy elements in the direct reaction channel. The results prove that for high- Z systems, higher-order multipole contributions and magnetic corrections persist even at energies close to the threshold.
RESUMO
Strong evidence has been found for enhanced multiple electron capture into 46 MeV/u Pb81+ with a significant contribution from the entrance surface of thin carbon foils. Capture of up to five electrons has been observed. The multiple electron capture yield is found to increase with decreasing target thickness for thin targets. A simple model describing the data and showing the importance of capture from surfaces is discussed. Further evidence is found for a pronounced asymmetry between electron capture at the entrance and the exit surfaces. Absolute yields for multiple electron capture and projectile ionization are presented. The experimental total cross sections for single capture and ionization agree well with theory.
RESUMO
The Lyman- alpha transitions of hydrogenlike uranium associated with electron capture were measured in collisions of stored bare U (92+) ions with gaseous targets at the storage ring ESR. By applying the deceleration technique, the experiment was performed at slow collision energies in order to reduce the uncertainties associated with Doppler corrections. From the measured centroid energies, a ground state Lamb shift of 468 eV+/-13 eV is deduced which gives the most precise test of quantum electrodynamics for a single electron system in the strong field regime. In particular, the technique applied paves the way towards the 1 eV precision regime.
RESUMO
The study aimed to evaluate the effect of acute and 14-day haloperidol treatment (2 mg/kg ip) on release of neuropeptide Y-like immunoreactivity (NPY-LI) in non-anesthetized, freely moving rats by means of push-pull perfusion of the lateral cerebral ventricle. Twenty four hours after a single haloperidol injection NPY-LI release decreased by 15% (p < 0.05). No alterations were detected after 14-day haloperidol treatment. The study has confirmed that haloperidol alters the activity of neuropeptide Y system in the rat brain and suggested that acute haloperidol treatment inhibits the activity of the neuropeptide Y system at least in some brain structures surrounding the cerebral ventricles. The presented results have been discussed in view of our previous findings describing the haloperidol-induced changes in NPY-LI and NPY mRNA levels in the rat brain.
Assuntos
Antipsicóticos/farmacologia , Encéfalo/efeitos dos fármacos , Haloperidol/farmacologia , Neuropeptídeo Y/metabolismo , Animais , Encéfalo/metabolismo , Relação Dose-Resposta a Droga , Injeções Intraperitoneais , Masculino , RNA/metabolismo , Ratos , Ratos WistarRESUMO
We report a rare case of spontaneous epidural accumulation of air in the occipital region resulting from an unusual hyperpneumatization of the cranium in a 37-year-old miner. For suspected subarachnoid haemorrhage the patient was admitted to neurological department. Performed computed tomography (CT) revealed extensive hyperpneumatization of the cranium, involving also the upper part of the cervical vertebral column, and epidural pneumocephalus. To the authors knowledge, so much pneumatization of the cranium seems to be very rare and when present, however, can cause spontaneous pneumocephalus. Based on the two years follow-up of this patient, conservative therapy showed to be sufficient for him, despite this, we have suggested him periodically perform CT of the head.
Assuntos
Doenças Profissionais/diagnóstico , Pneumocefalia/diagnóstico , Adulto , Encéfalo/diagnóstico por imagem , Diagnóstico Diferencial , Seguimentos , Cefaleia/etiologia , Humanos , Masculino , Mineração , Pneumocefalia/complicações , Hemorragia Subaracnóidea/diagnóstico , Tomografia Computadorizada por Raios XRESUMO
Immunotherapy is one of the experimental methods used in the treatment of brain tumours. The development of astrocytomas is accompanied by decreased activity of lymphocytes, namely inhibition of mitogen-induced proliferation and decreased cytokine secretion, which is an adverse event in the course of disease. In the present study, astrocytoma cells obtained from human tumours and cocultured with autologous lymphocytes inhibited cytokine secretion by those lymphocytes.
Assuntos
Astrocitoma/metabolismo , Neoplasias Encefálicas/metabolismo , Citocinas/deficiência , Citocinas/metabolismo , Linfócitos do Interstício Tumoral/metabolismo , Humanos , Células Tumorais CultivadasRESUMO
Scanning force microscopy was used for the determination of the elastic properties of living cells in their culture conditions. The studies were carried out on human epithelial cells. Two similar lines of normal cells (Hu609 and HCV29) and three cancerous ones (Hu456, T24, BC3726) were measured using the scanning force microscope in order to collect the force versus indentation curves. The BC3726 line originates from the HCV29 cell line which was transformed by the v-ras oncogene. To evaluate their elastic properties, Young's modulus values were determined. The present study has shown that normal cells have a Young's modulus of about one order of magnitude higher than cancerous ones. Such a change might be attributed to a difference in the organisation of cell cytoskeletons and requires further studies.
Assuntos
Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/fisiopatologia , Bexiga Urinária/citologia , Bexiga Urinária/fisiologia , Fenômenos Biofísicos , Biofísica , Linhagem Celular , Transformação Celular Neoplásica/genética , Elasticidade , Células Epiteliais/fisiologia , Genes ras , Humanos , Microscopia de Força Atômica , Estresse Mecânico , Células Tumorais CultivadasRESUMO
A case of neurofibromatosis type II in a 19-year-old man is described with clinical and neuroimaging (MRI) findings. The diagnostic criteria of neurofibromatosis type I (NF1) and type II (NF2) and the optimal management options are still controversial. The authors suggest that this patient fulfills criteria of neurofibromatosis type II as well as partially neurofibromatosis type I. At present, without molecular analysis of DNA, this assumption can not be verified.
Assuntos
Neurofibromatose 1/patologia , Neurofibromatose 2/patologia , Neuroma Acústico/patologia , Osteoma/patologia , Neoplasias Cranianas/patologia , Adulto , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/patologia , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Cromossomos Humanos Par 22/genética , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias Primárias Múltiplas , Neurofibromatose 1/complicações , Neurofibromatose 1/genética , Neurofibromatose 2/complicações , Neurofibromatose 2/genética , Neuroma Acústico/complicações , Neoplasias Cranianas/complicações , Neoplasias da Medula Espinal/complicações , Neoplasias da Medula Espinal/patologiaRESUMO
We studied head-injured patients assessed after admission to the hospital according to the Glasgow coma scale (3-8 points). All of them underwent surgical procedure after neuroradiological examination. Due to therapeutic problems, some of these patients had lumbar puncture on the fourth day following surgery. The control group consisted of patients with lumbosacral discopathy in whom lumbar puncture was performed during radiculography. The level of neuropeptide Y (NPY) was examined in 5 ml of cerebrospinal fluid (CSF). The concentration of NPY in CSF was assayed radioimmunologically. Taking into account our results and the clinical course of disease we suggest that high concentration of NPY in lumbar fluid in severe head-injured patients may contribute to poor clinical outcome.
Assuntos
Traumatismos Craniocerebrais/líquido cefalorraquidiano , Neuropeptídeo Y/líquido cefalorraquidiano , Neuropeptídeo Y/imunologia , Adulto , Idoso , Sistema Nervoso Central/irrigação sanguínea , Reações Cruzadas , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Radioimunoensaio , Punção Espinal , Vasoconstrição/fisiologiaRESUMO
We studied head-injured patients treated at the Department of Neurosurgery, Silesian University School of Medicine, Katowice. The patients underwent lumbar puncture on days 1, 4 and 7 for diagnostic reasons. The levels of leu-enkephalin (LENK) and met-enkephalin (MENK) were examined in 4.5 ml of cerebrospinal fluid (CSF). The control group included patients with lumbar discopathy from whom CSF fluid was collected during myelography. Enkephalins were extracted by column chromatography and their levels were assayed radioimmunologically. The results indicate that enkephalins may play a certain role in the pathophysiological response of nervous tissue to traumatic injury. Constantly elevated MENK levels together with decreasing LENK levels in patients with a Glasgow coma scale score < or = 8 may be useful as a poor prognostic factor. It is also suggested that LENK and MENK play different pathophysiological roles.
Assuntos
Traumatismos Craniocerebrais/líquido cefalorraquidiano , Encefalinas/líquido cefalorraquidiano , Adulto , Idoso , Concussão Encefálica/líquido cefalorraquidiano , Concussão Encefálica/fisiopatologia , Traumatismos Craniocerebrais/fisiopatologia , Feminino , Hematoma Epidural Craniano/líquido cefalorraquidiano , Hematoma Epidural Craniano/fisiopatologia , Hematoma Subdural/líquido cefalorraquidiano , Hematoma Subdural/fisiopatologia , Humanos , Deslocamento do Disco Intervertebral/líquido cefalorraquidiano , Deslocamento do Disco Intervertebral/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fraturas Cranianas/líquido cefalorraquidiano , Fraturas Cranianas/fisiopatologiaRESUMO
The SFM setup has been used to image the three-dimensional surface structures of various biological specimens in air and in liquid cell. The samples like red blood cell (RBC), lymphocytes, aggregates of pronase, and surface of bone measured in air, and macrophage surface measured in PBS solution are presented.
Assuntos
Osso e Ossos/ultraestrutura , Células/ultraestrutura , Microscopia de Força Atômica , Pronase/ultraestrutura , Manejo de Espécimes/métodos , Humanos , Propriedades de SuperfícieRESUMO
Male Wistar rats were treated with morphine (MP) or pentazocine (PT) subcutaneously (sc) and then intrathecally (it) with a specific kappa receptor agonist spiradoline (U62066E). In another series of experiments methionine-(MENK) or leucine-enkephalin (LENK) were injected it with U62066E simultaneously. Then antinociceptive effect on thermal stimulus was measured 1 h using the tail immersion test. MP or LENK induced analgesia was enhanced by U62066E during the first 30 min of observation. MENK analgesic activity was potentiated by kappa receptor agonist only up to 5 min. U62066E acted biphasically on PT antinociceptive effect. These results suggest that kappa opioid receptors may participate in antinociceptive action of MP and LENK and in small degree for analgesic effect of PT and MENK at the spinal level.
Assuntos
Analgésicos/farmacologia , Morfina/farmacologia , Pentazocina/farmacologia , Pirrolidinas/farmacologia , Analgesia , Analgésicos/administração & dosagem , Animais , Sinergismo Farmacológico , Encefalina Leucina/administração & dosagem , Encefalina Leucina/farmacologia , Encefalina Metionina/administração & dosagem , Encefalina Metionina/farmacologia , Injeções Espinhais , Injeções Subcutâneas , Masculino , Morfina/administração & dosagem , Pentazocina/administração & dosagem , Pirrolidinas/administração & dosagem , Ratos , Ratos Wistar , Receptores Opioides kappa/agonistasRESUMO
Male Wistar rats were treated with pethidine (PT) or fentanyl (FN) subcutaneously (sc) followed by intrathecal (ith) non analgesic doses of methionine- (MENK) or leucine-enkephalin (LENK), neurotensin, (NT), substance P (SP) or cholecystokinin octapeptide 26-33 (CCK-8). Then the antinociceptive effect was measured during 1 h using tail-immersion test. LENK potentiated strongly PT and FN analgesia. MENK antagonized PT analgesia only transiently 30 min after administration and transiently potentiated FN analgesia. SP and CCK-8 potentiated significantly PT analgesia, whereas NT acted biphasically: increasing and then decreasing PT analgesia. SP, CCK-8 and NT augmented FN analgesia. Naloxone inhibited analgesia elicited by the studied opioids and neuropeptides. These data show that LENK affects similarly the analgesic effects of both studied opioids, whereas MENK acted differently on PT and FN analgesia. This may suggest that individual enkephalins have different pharmacological features when interacting with different analgesics. Also NT interacted differently with pethidine and fentanyl.