RESUMO
We report on experimentally measured light shifts of superconducting flux qubits deep-strongly coupled to LC oscillators, where the coupling constants are comparable to the qubit and oscillator resonance frequencies. By using two-tone spectroscopy, the energies of the six lowest levels of each circuit are determined. We find huge Lamb shifts that exceed 90% of the bare qubit frequencies and inversions of the qubits' ground and excited states when there are a finite number of photons in the oscillator. Our experimental results agree with theoretical predictions based on the quantum Rabi model.
RESUMO
We derive the Hamiltonian of a superconducting circuit that comprises a single-Josephson-junction flux qubit inductively coupled to an LC oscillator, and we compare the derived circuit Hamiltonian with the quantum Rabi Hamiltonian, which describes a two-level system coupled to a harmonic oscillator. We show that there is a simple, intuitive correspondence between the circuit Hamiltonian and the quantum Rabi Hamiltonian. While there is an overall shift of the entire spectrum, the energy level structure of the circuit Hamiltonian up to the seventh excited states can still be fitted well by the quantum Rabi Hamiltonian even in the case where the coupling strength is larger than the frequencies of the qubit and the oscillator, i.e., when the qubit-oscillator circuit is in the deep-strong-coupling regime. We also show that although the circuit Hamiltonian can be transformed via a unitary transformation to a Hamiltonian containing a capacitive coupling term, the resulting circuit Hamiltonian cannot be approximated by the variant of the quantum Rabi Hamiltonian that is obtained using an analogous procedure for mapping the circuit variables onto Pauli and harmonic oscillator operators, even for relatively weak coupling. This difference between the flux and charge gauges follows from the properties of the qubit Hamiltonian eigenstates.
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A high-dispersion spectrum of Comet C/1999S4 (LINEAR) was obtained in the optical region with the high-dispersion spectrograph on the Subaru telescope when the comet was 0.863 astronomical units from the Sun before its disintegration. We obtained high signal-to-noise ratio emission lines of the cometary NH2 bands from which an ortho-to-para ratio (OPR) of 3.33 +/- 0.07 was derived on the basis of a fluorescence excitation model. Assuming that cometary NH2 mainly originates from ammonia through photodissociation, the derived OPR of NH2 molecules should reflect that of ammonia, which provides information on the environment of molecular formation or condensation and of the thermal history of cometary ices. Assuming that the OPR of ammonia in comets was unchanged in the nucleus, the derived spin temperature of ammonia (28 +/- 2 kelvin) suggests that a formation region of the cometary ammonia ice was between the orbit of Saturn and that of Uranus in the solar nebula.
Assuntos
Amônia , Meteoroides , Gelo , Análise Espectral , TemperaturaRESUMO
The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu's shape, mass, and geomorphology. Ryugu has an oblate "spinning top" shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu's shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.
RESUMO
The in vivo activity of depolymerized holothurian glycosaminoglycan (DHG), a newly developed polysaccharide anticoagulant, on neointimal formation induced by a balloon catheter in the left common carotid artery of rats was investigated. In every Sprague-Dawley rat weighing approximately 400 g, a Forgaty 2Fr balloon catheter was inserted from the left femoral artery to the left common carotid artery, and was passed through three times in order to denude the endothelium of the artery. These rats were divided into four groups by the following treatment protocols; DHG was given to rats by daily subcutaneous injection into their abdomens at a dose of 3 mg/kg or 10 mg/kg (D3 or D10 group). For controls, 250 microl saline was injected daily (C group). Furthermore, 1 mg/kg of unfractionated heparin was also injected daily as a comparison to DHG (H group). Each treatment was performed in six rats, and the injections were continued for two weeks after the catheterization. The area ratio of thickened intima/media (I/M ratio) treated with DHG decreased in a dose-dependent manner compared to the control. In addition, the ratio in the D10 group was significantly lower than in the control (P < 0.01). However, the ratio in the H group did not decrease. By anti-a smooth muscle actin antibody staining the intimal thickening layers were seen to be completely occupied by proliferated smooth muscle cells, and their amount in these layers was attenuated by the DHG treatment. This indicated that DHG has an inhibitory effect on intimal thickening induced by balloon catheterization, and that this might be due to the inactivation of aberrant smooth muscle cells by this agent.
Assuntos
Anticoagulantes/farmacologia , Artérias Carótidas/efeitos dos fármacos , Glicosaminoglicanos/farmacologia , Túnica Íntima/efeitos dos fármacos , Angioplastia Coronária com Balão/efeitos adversos , Animais , Anticoagulantes/administração & dosagem , Peso Corporal , Artérias Carótidas/patologia , Lesões das Artérias Carótidas , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Glicosaminoglicanos/administração & dosagem , Imuno-Histoquímica , Injeções Subcutâneas , Lipídeos/sangue , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Ratos , Ratos Sprague-Dawley , Trombose/sangue , Trombose/patologia , Trombose/prevenção & controle , Túnica Íntima/lesões , Túnica Íntima/patologiaRESUMO
To determine the in vivo activity of BAYw6228 (BAYw), a newly developed 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, we examined its effect on balloon catheterization-induced carotid arterial intimal thickening in Japanese white rabbits. In all rabbits weighing approximately 3.5 kg, a balloon catheter was inserted from a peripheral branch of the left external carotid artery to the aorta in order to denude the endothelium of the left common carotid artery. At day 12, they were divided into control and BAYw groups. The latter were subcutaneously injected with BAYw, 1 mg/kg/day, for the following 17 days. At day 15, the second balloon catheterization was performed in the same left common carotid artery in both groups. After another two weeks, the left common carotid artery was removed and stained with Elastica-Masson (EM) and anti-rabbit macrophage antibody (RAM 11). With RAM 11 staining, the number of positive cells in the intimal thickening was markedly decreased in the BAYw group compared with the control group (P < 0.01). Compared with the area ratio of the thickened intima/media layer of the control group, that of the BAYw group was significantly decreased to 45% (P < 0.05). These results indicate that BAYw prevents accumulation of macrophages and consequently contributes to the inhibition of intimal thickening induced by balloon catheterization.
Assuntos
Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/patologia , Cateterismo , Inibidores Enzimáticos/farmacologia , Macrófagos/efeitos dos fármacos , Piridinas/farmacologia , Animais , Movimento Celular/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases , Imuno-Histoquímica , Macrófagos/fisiologia , Masculino , Neovascularização Fisiológica , Coelhos , Túnica Íntima/crescimento & desenvolvimento , Túnica Íntima/patologiaRESUMO
The effect of picrotoxinin on glycine-induced chloride currents was studied in dissociated rat hippocampal neuron culture in whole-cell and excised outside-out patches. Picrotoxinin blocked the glycine induced chloride currents. The picrotoxinin effect at 20 microM on glycine dose response relationship suggested a competitive mechanism. However, at 1 mM, the picrotoxinin effect was largely noncompetitive. In excised patches, glycine activated two types of channels distinguished by a difference in conductances. The first group had single channel conductances of around 47 pS and another around 100 pS. Occasionally, both types of channels were found in the same excised patch. Low concentration of picrotoxinin selectively blocked large conductance channels. At higher concentrations of 0.5 to 1 mM, picrotoxinin blocked the small conductance channels by a flickering block. These findings indicate that the whole-cell glycine current in rat hippocampal neurons is mediated by at least two types of channels. The two types of channels have distinct conductance, picrotoxinin sensitivity and different mechanism of picrotoxinin block.
Assuntos
Canais de Cloreto/antagonistas & inibidores , Cloretos/metabolismo , Antagonistas GABAérgicos/farmacologia , Hipocampo/citologia , Proteínas do Tecido Nervoso/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Picrotoxina/análogos & derivados , Receptores de Glicina/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Canais de Cloreto/química , Hipocampo/efeitos dos fármacos , Transporte de Íons/efeitos dos fármacos , Ionóforos/farmacologia , Proteínas do Tecido Nervoso/metabolismo , Técnicas de Patch-Clamp , Picrotoxina/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Glicina/metabolismo , SesterterpenosRESUMO
1. The aim of this study was to determine whether BAYw6228 (BAYw), a newly developed 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, could suppress an atherogenic process such as intimal thickening by a mechanism other than lowering the level of serum cholesterol. 2. First, we evaluated the in vitro effect of BAYw on the proliferation of vascular smooth muscle cells (SMC) from various species: Sprague-Dawley (SD) rats. New Zealand (NZ) white rabbits, intimal cells from Watanabe hereditary hyperlipidemic (WHHL) rabbit and SMC from the new-born human aorta. The increasing rate of total protein content of these cells was inhibited by the addition of BAYw in a dose-dependent fashion. In the presence of 2% foetal calf serum (FCS), the value of IC50 was 1.0 microM in SD rats, 2.1 microM in NZ white rabbits, and 0.3 microM in WHHL rabbits. With human SMC, the value was 0.02 microM in the presence of 10% FCS and 0.2 microM with a mixture of growth factors. 3. Based on these above in vitro findings, we next examined the in vivo effect of the agent to determine whether it could suppress rabbit intimal thickening induced by balloon catheterization. A balloon catheter was inserted from a peripheral branch of the left external carotid artery to the aorta to denude the endothelium of the left common carotid artery in Japanese white rabbits. After 12 days they were divided into control and BAYw groups. The former were subcutaneously injected with saline and the latter with BAYw 1 mg kg-1 day-1. Two days after the beginning of treatment, a second balloon injury was performed to the previously injured left common carotid artery in both groups. After another two weeks, the left common carotid artery was removed and variously stained. Although the total serum cholesterol in the BAYw group was significantly lower than in the control (P < 0.05), the difference was not enough to affect intimal thickening. In addition, the BAYw group had a smaller intima/media ratio than the control group, decreasing to 45% of control (P < 0.05). By anti-alpha smooth muscle actin antibody staining, these intimal thickening areas were entirely occupied by SMCs, and their amount was attenuated by BAYw. By anti-rabbit macrophage antibody (RAM 11) staining, the number of positive cells in the intimal thickening was markedly decreased in the BAYw group compared to control (P < 0.01). 4. These results indicate that BAYw has an inhibitory effect on intimal thickening by attenuating intimal SMC proliferation and infiltration of macrophages, suggesting that BAYw could be effective in the prevention of the progression of atherosclerotic plaque-like restenosis after angioplasty.
Assuntos
Arteriosclerose/tratamento farmacológico , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases , Músculo Liso Vascular/efeitos dos fármacos , Piridinas/farmacologia , Animais , Arteriosclerose/metabolismo , Arteriosclerose/patologia , Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/metabolismo , Artérias Carótidas/patologia , Cateterismo , Divisão Celular/efeitos dos fármacos , Células Cultivadas , DNA/metabolismo , Humanos , Hiperlipidemias/tratamento farmacológico , Piridinas/administração & dosagem , Coelhos , Ratos , Ratos Sprague-Dawley , EstereoisomerismoRESUMO
Indirect glutamate toxicity can be demonstrated by exposing dissociated rat hippocampal cultures to the media of the same culture transiently exposed (1 min) to glutamate (0.5 mM). The toxicity was maximum when the media was collected 5 min after the glutamate exposure. While the primary glutamate toxicity was attenuated by ionotropic glutamate receptor antagonists, the transferred, indirect toxicity was unaffected by the same antagonists. The changes in nuclear morphology indicated chromatin condensation and nuclear fragmentation in both primary and transferred toxicity. The stain for DNA damage by TUNEL method also revealed cells staining positive in both primary and transferred glutamate toxicity. These observations demonstrate that glutamate-induced neurotoxicity can be propagated to the uninjured cells by an unknown toxin released into the extracellular space. This neurotoxin induced both apoptosis and necrosis in cultured rat hippocampal cells.
Assuntos
Ácido Glutâmico/intoxicação , Hipocampo/efeitos dos fármacos , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Animais , Apoptose/efeitos dos fármacos , Morte Celular/fisiologia , Técnicas de Cultura , Fragmentação do DNA , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipocampo/patologia , Hipocampo/fisiopatologia , Necrose , Neuroglia/efeitos dos fármacos , Neuroglia/patologia , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
RATIONALE: While several environmental situations may produce cocaine craving, there is little research on whether patterns of drug cue reactivity are similar across different environmental situations. OBJECTIVE: This study examined whether two different environmental situations, psychological stress and drug cues, produce similar or varying patterns of cue reactivity in 20 cocaine dependent individuals. METHODS: All subjects participated in a single laboratory session and were exposed to stress, drug cues and neutral-relaxing imagery conditions. Cocaine and alcohol craving, emotion state ratings, subjective anxiety, heart rate and salivary cortisol measures were assessed. RESULTS: Significant increases in cocaine and alcohol craving were observed with stress and drug cues imagery but not with neutral-relaxing imagery. In addition, stress and drug cues situations produced similar increases in subjective anxiety, heart rate and salivary cortisol levels. Significant increases in negative emotion ratings and decreases in positive emotion ratings were found for stress and drug cues conditions as compared to the neutral condition. CONCLUSIONS: The findings indicate that a similar and comparable pattern of cue reactivity is induced by stress and drug cue manipulations. Furthermore, the comparable increases in subjective anxiety and negative affect observed with stress-induced and drug cue-induced craving provides support for the negative reinforcement model of drug craving and relapse. The negative affectivity co-occurring with the craving state appears to be an important target in the development of new treatments for cocaine dependence.
Assuntos
Transtornos Relacionados ao Uso de Cocaína/etiologia , Sinais (Psicologia) , Estresse Psicológico/complicações , Adulto , Alcoolismo/etiologia , Alcoolismo/psicologia , Ansiedade/complicações , Transtornos Relacionados ao Uso de Cocaína/psicologia , Emoções , Feminino , Frequência Cardíaca , Humanos , Hidrocortisona/análise , Masculino , Pessoa de Meia-Idade , Saliva/químicaRESUMO
Experiments have been performed to measure the response of a spherical tissue-equivalent proportional counter (TEPC) and a silicon-based LET spectrometer (RRMD-III) to protons with energies ranging from 50-200 MeV. This represents a large portion of the energy distribution for trapped protons encountered by astronauts in low-Earth orbit. The beam energies were obtained using plastic polycarbonate degraders with a monoenergetic beam that was extracted from a proton synchrotron. The LET spectrometer provided excellent agreement with the expected LET distribution emerging from the energy degraders. The TEPC cannot measure the LET distribution directly. However, the frequency mean value of lineal energy, y(-)(f), provided a good approximation to LET. This is in contrast to previous results for high-energy heavy ions where y(-)(f) underestimated LET, whereas the dose-averaged lineal energy, y(-)(D), provided a good approximation to LET.
Assuntos
Transferência Linear de Energia , Prótons , Radiometria , SilícioRESUMO
We studied the capacity for sound localization in the horizontal plane with measurement of the ocular position of the listener. The eye position responses elicited by tonal sound were asymmetrical in all six subjects and there was individual variation of frequency dependence. The sound pressure level and the angle of the loudspeaker also affected the accuracy of localization. Sound localization was more accurate, and individual variation lower, when the sound pressure level and the angle of the sound source were in the range 50 dBSL and 30 degrees, respectively. In the monoaural condition, the ear on the occluded side consistently showed displacement of responses toward the side of the non-occluded ear. Sound localization on the non-occluded side, however, showed various patterns of change in the monaural condition relative to the binaural condition. Cues as to the sound localization thus seem to differ with the side of the sound source.
Assuntos
Orelha/fisiologia , Localização de Som/fisiologia , Estimulação Acústica , Adulto , Sinais (Psicologia) , Feminino , Lateralidade Funcional/fisiologia , Humanos , MasculinoRESUMO
The expression of the cyclin-dependent kinase inhibitor p21(WAF1/CIP1) mRNA after traumatic brain injury in rats was investigated using an in situ hybridization technique, along with regulating gene p53 and stress response gene hsp70 mRNA levels. At 3 h postinjury, p21(WAF1/CIP1) mRNA was markedly increased in the cortex, white matter, thalamus, CA2, a part of CA1,3 and dentate gyrus of the injured side. Hybridization signals remained elevated at 6 h in injured cortex and hippocampus and returned to the baseline by 24 h post-insult. On the other hand, p53 mRNA induction was not observed in any brain sections throughout the post-injury time course. Slight expression of hsp70 mRNA was detected in the injured cortex 3-6 h following injury and this was similar to the temporary pattern of p21(WAF1/CIP1) mRNA expression. This study showed p21(WAF1/CIP1) mRNA to be transiently induced after traumatic brain injury, independent of p53, this possibly being an early stress response to protect cells by arresting them in the cycle and allow DNA repair.
Assuntos
Lesões Encefálicas/metabolismo , Encéfalo/metabolismo , Ciclinas/genética , Regulação da Expressão Gênica , Transcrição Gênica , Animais , Encéfalo/patologia , Lesões Encefálicas/genética , Lesões Encefálicas/patologia , Inibidor de Quinase Dependente de Ciclina p21 , Quinases Ciclina-Dependentes/antagonistas & inibidores , Inibidores Enzimáticos/metabolismo , Lateralidade Funcional , Proteínas de Choque Térmico HSP70/genética , Masculino , Especificidade de Órgãos , RNA Mensageiro/genética , Ratos , Ratos Wistar , Fatores de Tempo , Proteína Supressora de Tumor p53/metabolismoRESUMO
A new nonsteroidal anti-inflammatory agent, fentiazac, was used for analgesia after tooth extractions and minor oral surgery in two Japanese dental hospitals. The drug was administered as a single oral dose of either 50 mg or 100 mg. The 50-mg dose provided rapid analgesic effect, but its effect lasted only two to three hours in a number of patients. At a dose of 100 mg, fentiazac proved effective for 85% of 53 patients, usually providing marked reduction of disappearance of pain within one hour or less. Among patients in whom pain reappeared, the mean time for recurrence was four hours, indicating a satisfactory duration of analgesic effect. One side effect--loss of appetite--was reported by one patient in the entire series of 71 subjects. It is concluded that fentiazac is a highly effective analgesic agent with a wide margin of safety for use after dental procedures that produce pain.
Assuntos
Acetatos/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Dor Pós-Operatória/prevenção & controle , Cirurgia Bucal , Tiazóis/uso terapêutico , Extração Dentária , HumanosRESUMO
OBJECTIVE: Hyperthermia has been clinically applied to some types of brain tumors. However, the detailed mechanisms of this growth inhibition are not clear. The effect of mild hyperthermia on cultured human glioblastoma cell line, A172, was studied. METHODS: A172 cells were heat treated (43-44.5 degrees C) for 1 hour in the growing phase. Cell viability was assessed by trypan blue dye exclusion assay. The presence of apoptosis was determined by the morphological changes observed using phase contrast microscopy and nuclear changes observed using HOECHST 33342 stain. For the evaluation of cellular deoxyribonucleic acid fragmentation, the TUNEL method was used. The expression of p53 and bax proteins was evaluated by Western blot, and the bax messenger ribonucleic acid was detected by Northern blot. RESULTS: Heat treatment induced cell death in time- and temperature-dependent manners. The nuclear staining with HOECHST 33342 demonstrated morphological changes consistent with apoptosis. The TUNEL stain also demonstrated damages in the deoxyribonucleic acid. These morphological changes were accompanied by the accumulation of p53 protein, bax protein, and messenger ribonucleic acid. CONCLUSION: These results indicate that mild hyperthermia induces apoptosis in A172 glioblastoma cells.
Assuntos
Apoptose/fisiologia , Glioblastoma/fisiopatologia , Temperatura Alta , Proteínas Proto-Oncogênicas c-bcl-2 , Benzimidazóis , Sobrevivência Celular/fisiologia , Fragmentação do DNA , Corantes Fluorescentes , Glioblastoma/patologia , Proteínas de Choque Térmico HSP72 , Proteínas de Choque Térmico/metabolismo , Humanos , Microscopia de Contraste de Fase , Inibidores da Síntese de Proteínas/farmacologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , RNA/biossíntese , RNA Mensageiro/metabolismo , Células Tumorais Cultivadas/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2RESUMO
In young children, there appears to be no advantage to recording steady-state response (SSR) at a stimulus rate of 40 Hz. To determine the optimal modulation frequency in auditory SSR evoked by sinusoidally amplitude-modulated (SAM) tones (amplitude-modulation following response: AMFR) in children during sleep and compare response patterns of AMFR at different modulation frequencies while awake with those during sleep, AMFR was examined in 10 adults with normal hearing while awake and during sleep and in 10 young children with normal hearing during sleep. The stimulus was a 1000 Hz, 50 dBnHL SAM tone with a modulation depth of 95%. Modulation frequency was varied from 20 to 200 Hz in 20 Hz steps. Response was determined by phase spectral analysis and the S/N ratio calculated by spectral amplitude at the modulation frequency and noise level around the modulation frequency using fast Fourier transform. Although AMFR was clearly evoked only by a modulation frequency of 40 Hz in adults while awake, AMFRs at modulation frequencies of 80 and 100 Hz were detected during sleep, in addition to 40 Hz AMFR. In children, 40 Hz AMFR was difficult to detect, but response could be clearly detected at higher modulation rates, especially at modulation frequencies of 80 and 100 Hz, compared with response in adults during sleep. Modulation frequencies from 80 to 100 Hz would thus appear optimal for detecting AMFR during sleep in children.
Assuntos
Limiar Auditivo/fisiologia , Potenciais Evocados Auditivos/fisiologia , Sono/fisiologia , Adulto , Envelhecimento/fisiologia , Pré-Escolar , Interpretação Estatística de Dados , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The computed tomographic (CT) and other roentgenological characteristics of a skull diploic epidermoid cyst in a 14-year-old boy with Ito syndrome, a neurocutaneous syndrome, are presented. When this boy was 3 years 10 months of age, a plain roentgenogram of the skull showed an area of decreased density in the left parietal bone. The area has grown for the subsequent 10 years plus and a characteristic sclerotic margin has become evident. CT examination showed a cystic lesion in the diploe, the outer third of high density and the inner third low density. CT allowed prediction of the operative and histological findings. It was useful not only for the diagnosis but also in the pathogenesis.
Assuntos
Cisto Epidérmico/patologia , Osso Parietal , Adolescente , Doenças Ósseas/complicações , Doenças Ósseas/diagnóstico por imagem , Doenças Ósseas/patologia , Cisto Epidérmico/complicações , Cisto Epidérmico/diagnóstico por imagem , Humanos , Masculino , Doenças do Sistema Nervoso/complicações , Dermatopatias/complicações , Síndrome , Tomografia Computadorizada por Raios XRESUMO
Novel branched cyclomaltooligosaccharide carboxylic acid (cyclodextrin carboxylic acid) derivatives were synthesized by microbial oxidation using Pseudogluconobacter saccharoketogenes to oxidize five types of branched cyclodextrins, including maltosyl beta-cyclodextrin (maltosyl-beta-CyD). For each novel cyclodextrin carboxylic acid derivative synthesized, the hydroxymethyl group of the terminal glucose residue in the branched part of the molecule was regiospecifically oxidized to a carboxyl group to give the corresponding uronic acid. In addition, the physicochemical properties of cyclomaltoheptaosyl-(6-->1)-alpha-D-glucopyranosyl-(4-->1)-alpha-D-glucopyranosiduronic acid (GUG-beta-CyD) (1) and its sodium salt were studied more extensively, as these compounds are most likely to have a practical application.
Assuntos
Ciclodextrinas/biossíntese , beta-Ciclodextrinas , Álcool Desidrogenase/metabolismo , Bactérias/enzimologia , Configuração de Carboidratos , Ciclodextrinas/química , Ciclodextrinas/metabolismo , Oligossacarídeos/química , Oxirredução , Especificidade por SubstratoRESUMO
A new method using a flow injection system with electrochemical detection was developed to determine acid values of fats and oils. VK3 (2-methyl-1,4-naphthoquinone) solution, i.e., ethanol containing 3 mM VK3 and 38 mM LiClO4, was used as the carrier solution. Flow signals were monitored at -0.33 V vs. Ag/AgCl. For preparation of a sample solution, an oil sample was completely dissolved in VK3 solution, or fatty acids were extracted from the sample into this solution. Aliquots (5 microliters) of the sample solution were injected into the flow injection system. Acid values were determined based on flow signals for 14 samples and the results were found to be consistent with those by potentiometric titration. Relative standard deviation was less than 2%. Samples were processed at the rate of 60 h-1. The stability of fish and cod liver oils was followed by measuring acid values for 8 weeks. This method proved to be a simple and rapid means for acid value determination.
Assuntos
Ácidos/análise , Eletroquímica/métodos , Gorduras/análise , Análise de Injeção de Fluxo , Óleos/análise , Estabilidade de Medicamentos , Reprodutibilidade dos TestesRESUMO
Hemangioblastomas of the medulla oblongata were successfully excised in two separate cases. The uncertainties of this procedure involve the value of preoperative radiation therapy, the relationship between the tumor and the medulla oblongata, and the surgical techniques themselves. Cardiovascular and respiratory disorders often complicate this type of surgery, and postoperative dysphagia is a frequent sequela.