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Transition-metal-catalyzed enantioselective transformations of aryl/aryl carbene are inherently challenging due to the difficulty in distinguishing between two arene rings in the reaction process thus remain largely less explored. The few successful examples reported so far, without exception, have all been catalyzed by Rh(II)-complexes. Herein, we describe our successful development of a novel cationic Rh(I)/chiral diene catalytic system capable of efficient enantioselective B-H and O-H insertions with diaryl diazomethanes, allowing the access to a broad range of gem-diarylmethine boranes and gem-diarylmethine ethers in good yields with high enantioselectivities. Notably, previously unattainable asymmetric diarylcarbene insertion into the O-H bond was achieved for the first time. A remarkable feature of this newly designed Rh(I)/diene catalyst bearing two ortho-amidophenyl substitutents is that it can distinguish between two arene rings of the diaryl carbene through a stereochemically selective control of π-π stacking interactions. DFT calculations indicate that the rotation-restricted conformation of Rh(I)/diene complex played an important role in the highly enantioselective carbene transformations. This work provides an interesting and unprecedented stereocontrol mode in diaryl metal carbene transformations.
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BACKGROUND: The real-world safety and efficacy of uninterrupted anticoagulation treatment with edoxaban (EDX) or warfarin (WFR) during the peri-procedural period of catheter ablation (CA) for atrial fibrillation (AF) are yet to be investigated. METHODS: We conducted a two-center experience, observational study to retrospectively investigate consecutive patients who underwent CA for AF and received EDX or WFR. We examined the incidence of thromboembolic and bleeding complications during the peri-procedural period. RESULTS: The EDX and WFR groups included 153 and 103 patients, respectively (total: 256 patients). Demise or thromboembolic events did not occur in either of the groups. The incidence of major bleeding in the EDX and WFR groups was 0.7% and 2.9%, respectively. The total incidence of major/minor bleeding in the EDX and WFR groups was 7.8% and 8.7%, respectively. Of note, the incidence of bleeding complications in the uninterrupted WFR strategy group was markedly high in patients with an estimated glomerular filtration rate (eGFR) <30 (75%) or a HAS-BLED score ≥3 (60%). Patients with eGFR ≥30 and a HAS-BLED score ≤2 had a lower incidence of bleeding (<10%), regardless of the administered anticoagulation drug (EDX or WFR). CONCLUSIONS: This study confirmed the safety and efficacy of uninterrupted anticoagulation therapy using EDX or WFR in real-world patients undergoing CA for AF. Patients with severely impaired renal function and/or a higher bleeding risk during uninterrupted therapy with WFR were at a prominent risk of bleeding. Therefore, particular attention should be paid in the treatment of these patients.
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BACKGROUND: Current expert consensus recommends remote monitoring for cardiac implantable electronic devices, with at least annual in-office follow-up. We studied safety and resource consumption of exclusive remote follow-up (RFU) in pacemaker patients for 2 years. METHODS: In Japan, consecutive pacemaker patients committed to remote monitoring were randomized to either RFU or conventional in-office follow-up (conventional follow-up) at twice yearly intervals. RFU patients were only seen if indicated by remote monitoring. All returned to hospital after 2 years. The primary end point was a composite of death, stroke, or cardiovascular events requiring surgery, and the primary hypothesis was noninferiority with 5% margin. RESULTS: Of 1274 randomized patients (50.4% female, age 77±10 years), 558 (RFU) and 550 (Conventional follow-up) patients reached either the primary end point or 24 months follow-up. The primary end point occurred in 10.9% and 11.8%, respectively (P=0.0012 for noninferiority). The median (interquartile range) number of in-office follow-ups was 0.50 (0.50-0.63) in RFU and 2.01 (1.93-2.05) in conventional follow-up per patient-year (P<0.001). Insurance claims for follow-ups and directly related diagnostic procedures were 18 800 Yen (16 500-20 700 Yen) in RFU and 21 400 Yen (16 700-25 900 Yen) in conventional follow-up (P<0.001). Only 1.4% of remote follow-ups triggered an unscheduled in-office follow-up, and only 1.5% of scheduled in-office follow-ups were considered actionable. CONCLUSIONS: Replacing periodic in-office follow-ups with remote follow-ups for 2 years in pacemaker patients committed to remote monitoring does not increase the occurrence of major cardiovascular events and reduces resource consumption. Registration: URL: https://clinicaltrials.gov; Unique identifier: NCT01523704.
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Arritmias Cardíacas/terapia , Estimulação Cardíaca Artificial , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Visita a Consultório Médico , Marca-Passo Artificial , Tecnologia de Sensoriamento Remoto/instrumentação , Telemedicina/instrumentação , Potenciais de Ação , Idoso , Idoso de 80 Anos ou mais , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/mortalidade , Arritmias Cardíacas/fisiopatologia , Estimulação Cardíaca Artificial/efeitos adversos , Estimulação Cardíaca Artificial/mortalidade , Desenho de Equipamento , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do TratamentoRESUMO
High-speed isolation of microparticles (e.g., microplastics, heavy metal particles, microbes, cells) from heterogeneous populations is the key element of high-throughput sorting instruments for chemical, biological, industrial and medical applications. Unfortunately, the performance of continuous microparticle isolation or so-called sorting is fundamentally limited by the trade-off between throughput, purity, and yield. For example, at a given throughput, high-purity sorting needs to sacrifice yield, or vice versa. This is due to Poisson statistics of events (i.e., microparticles, microparticle clusters, microparticle debris) in which the interval between successive events is stochastic and can be very short. Here we demonstrate an on-chip microparticle sorter with an ultrashort switching window in both time (10 µs) and space (10 µm) at a high flow speed of 1 m s-1, thereby overcoming the Poisson trade-off. This is made possible by using femtosecond laser pulses that can produce highly localized transient cavitation bubbles in a microchannel to kick target microparticles from an acoustically focused, densely aligned, bumper-to-bumper stream of microparticles. Our method is important for rare-microparticle sorting applications where both high purity and high yield are required to avoid missing rare microparticles.
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OBJECTIVE: The purpose of this study is to propose a palm-sized cryoprobe system with a built-in thermocouple (TC) for highly accurate and sensitive temperature measurements, and to verify the effectiveness of the system. METHODS: Conventional cryoprobe systems based on the boiling effect of a refrigerant have triple coaxial tubes. In the proposed system, the outer and middle coaxial tubes are made of two different metals that are welded only at the probe tip, thereby forming a TC. The thermoelectric properties of the built-in TC and measurement accuracy were investigated in agar in a constant-temperature chamber. The system was also applied in a penicillin G-induced rat brain epilepsy model. RESULTS: We verified that the built-in TC has appropriate thermoelectric properties and that the system more accurately and sensitively measured transient temperature changes at the probe tip wall compared to conventional systems, showing the cooling performance of the system. In the rat model, epileptiform activities disappeared on freezing, and reliable cell necrosis was achieved at an end temperature of -45.2 ± 1.6 °C. CONCLUSIONS: The proposed system is suitable for reliable cryosurgery. SIGNIFICANCE: The system is probably to be valuable for clarifying the relationship between freezing temperature and cell necrosis in vivo.
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Criocirurgia/instrumentação , Epilepsia/cirurgia , Microcirurgia/instrumentação , Animais , Encéfalo/cirurgia , Modelos Animais de Doenças , Eletrocorticografia , Desenho de Equipamento , Modelos Biológicos , Ratos , TemperaturaRESUMO
OBJECTIVES: Cryosurgery is an alternative technique for minimally invasive treatment of lesions. We have recently examined cryosurgery for epilepsy in animal models, and found that penicillin G (PG)-induced epileptiform discharges (EDs) mostly vanished after freezing. However, EDs were provoked again after insufficient freezing. Inadequate freezing is not visually detectable during and just after freezing and is not predictable beforehand. To manage this problem, we examined whether intraoperative monitoring of electrocorticograms (ECoGs) can predict recurrence of EDs after cryosurgery. METHODS: A palm-sized cryoprobe system was applied to focal seizures in a Wistar rat model in which EDs were induced in advance by intracerebral injection of PG. During stable induction of EDs, the cryoprobe was carefully inserted into the epileptic region and this region was immediately frozen. After the series of prefreezing, freezing, and postfreezing, rats in which PG-induced EDs relapsed within 3â¯h were defined as the ED-relapsed (EDR) group, and other rats were defined as the ED-vanished (EDV) group. Time-frequency analysis was conducted on the ECoGs in each group through each freezing series. RESULTS: Relapse of PG-induced EDs on ECoG after the freezing series was associated with the remaining power of the delta band in the freezing period more strongly in the EDR group than in the EDV group. CONCLUSIONS: Success or failure of the freezing procedure can be predicted by the specificity of the delta band of the ECoG obtained intraoperatively.
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Encéfalo/fisiopatologia , Encéfalo/cirurgia , Criocirurgia , Eletrocorticografia , Convulsões/fisiopatologia , Convulsões/cirurgia , Animais , Ritmo Delta , Modelos Animais de Doenças , Penicilinas , Ratos Wistar , Análise Espaço-TemporalRESUMO
Focal brain cooling (FBC) is under investigation in preclinical trials of intractable epilepsy (IE), including status epilepticus (SE). This method has been studied in rodents as a possible treatment for epileptic disorders, but more evidence from large animal studies is required. To provide evidence that FBC is a safe and effective therapy for IE, we investigated if FBC using a titanium cooling plate can reduce or terminate focal neocortical seizures without having a significant impact on brain tissue. Two cats and two macaque monkeys were chronically implanted with an epidural FBC device over the somatosensory and motor cortex. Penicillin G was delivered via the intracranial cannula for induction of local seizures. Repetitive FBC was performed using a cooling device implanted for a medium-term period (FBC for 30min at least twice every week; 3 months total) in three of the four animals. The animals exhibited seizures with repetitive epileptiform discharges (EDs) after administration of penicillin G, and these discharges decreased at less than 20°C cooling with no adverse histological effects. The results of this study suggest that epidural FBC is a safe and effective potential treatment for IE and SE.
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Epilepsia/terapia , Hipotermia Induzida , Córtex Motor/fisiopatologia , Animais , Gatos , Modelos Animais de Doenças , Eletrocorticografia , Epilepsia/induzido quimicamente , Epilepsia/fisiopatologia , Feminino , Hipotermia Induzida/efeitos adversos , Hipotermia Induzida/instrumentação , Hipotermia Induzida/métodos , Macaca , MasculinoRESUMO
GOAL: The purpose of this study is to propose the palm-sized cryoprobe system based on a new concept and to suggest that the freezing technique could be used for treatment of epilepsy. METHODS: We propose herein a cryoprobe system based on the boiling effect that uses a specific refrigerants with a boiling point higher than that of liquid nitrogen yet low enough to result in cell necrosis. To evaluate and verify the effectiveness of the proposed system, cooling characteristics are investigated in agar. In addition, the system is applied to a Wistar rat brain-model, in which the epileptic activities are induced in advance by a potent epileptogenic substance. RESULTS: The design concept yielded the following benefits: 1) the selected refrigerant promotes sealing in the tank; 2) the tank can be made as compact as possible, limited only by the volume required for the refrigerant; 3) because the tank and probe units can be separated by a nonconducting, flexible, and high-pressure tube, the tank unit can be manipulated without disturbing the probe tip with mechanical vibrations and electrical noise. Although the agar experiments, we verified that the proposed system can uniquely and reproducibly create an ice ball. Moreover, in the rat experiments in vivo, it was confirmed that penicillin G-induced epileptic activities disappeared on freezing with the proposed system. CONCLUSIONS: The palm-sized system has desired characteristics and can apply for an animal model of epilepsy. SIGNIFICANCE: Results of in vivo experiments suggest that cryosurgery may be an effective treatment for epilepsy.
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Crioterapia/instrumentação , Crioterapia/métodos , Epilepsia/terapia , Animais , Encéfalo/fisiologia , Encéfalo/cirurgia , Modelos Animais de Doenças , Epilepsia/induzido quimicamente , Desenho de Equipamento , Necrose , Penicilina G/efeitos adversos , Imagens de Fantasmas , Ratos , Ratos WistarRESUMO
An iron-N-heterocyclic carbene catalyst generated from an iron(III) salt, an imidazolinium salt, and a Grignard reagent promotes alkylation and alkenylation reactions at the indole C2-position with vinylarenes and internal alkynes, respectively, via imine-directed C-H activation. The former reaction affords 1,1-diarylalkane derivatives with exclusive regioselectivity. Deuterium-labeling experiments suggest that these reactions involve oxidative addition of the C-H bond to the iron center, insertion of the unsaturated bond into the Fe-H bond, and C-C reductive elimination.
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OBJECTIVE: Recently, focal brain cooling (FBC) was proposed as a method for treating refractory epilepsy. However, the precise influence of cooling on the molecular basis of epilepsy has not been elucidated. Thus the aim of this study was to assess the effect of FBC on glutamate (Glu) concentration, cerebral blood flow (CBF), and glucose metabolism in patients with intractable epilepsy. METHODS: Nine patients underwent FBC at 15°C for 30 min prior to cortical resection (n = 6) or hippocampectomy (n = 3). Measurement of metabolites and CBF, as well as electrocorticography (ECoG), was performed. RESULTS: Epileptic discharge (ED), as observed by ECoG, disappeared in the cooling period and reappeared in the rewarming period. Glu concentrations were high during the precooling period and were reduced to 51.2% during the cooling period (p = 0.025). Glycerol levels showed a similar decrease (p = 0.028). Lactate concentration was high during the precooling period and was reduced during the cooling period (21.3% decrease; p = 0.005). Glucose and pyruvate levels were maintained throughout the procedure. Changes in CBF were parallel to those observed by ECoG. SIGNIFICANCE: FBC reduced EDs and concentrations of Glu and glycerol. This demonstrates the neuroprotective effect of FBC. Our findings confirm that FBC is a reasonable and optimal treatment option for patients with intractable epilepsy.
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Glicemia/metabolismo , Encéfalo/irrigação sanguínea , Córtex Cerebral/cirurgia , Epilepsias Parciais/cirurgia , Epilepsia do Lobo Temporal/cirurgia , Ácido Glutâmico/metabolismo , Hipocampo/cirurgia , Hipotermia Induzida/métodos , Cuidados Pré-Operatórios/métodos , Adolescente , Adulto , Córtex Cerebral/fisiopatologia , Eletroencefalografia , Epilepsias Parciais/fisiopatologia , Epilepsia do Lobo Temporal/fisiopatologia , Feminino , Glicerol/metabolismo , Hipocampo/fisiopatologia , Humanos , Ácido Láctico/metabolismo , Masculino , Pessoa de Meia-Idade , Ácido Pirúvico/metabolismo , Fluxo Sanguíneo Regional/fisiologia , Reaquecimento , Processamento de Sinais Assistido por Computador , Adulto JovemRESUMO
A cobalt-N-heterocyclic carbene catalyst generated from CoBr2 , imidazolium salt, and cyclohexylmagnesium bromide was found to promote the imine-directed C2-alkylation of indoles with nonconjugated arylalkenes through a tandem alkene isomerization-hydroarylation process, affording 1,1-diarylalkanes with exclusive regioselectivity. The feasibility of the tandem catalysis was demonstrated for allyl-, homoallyl-, and bishomoallylbenzene derivatives. The catalytic system is also applicable to a variety of ß-substituted styrene derivatives. Mechanistic experiments using deuterium-labeled indole substrate and Grignard reagent provided insight into the cobalt-mediated C-H activation step, which likely involves exchange of the C2-hydrogen atom of the former and the ß-hydrogen atoms of the latter.
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To elucidate a relationship between changes in focal brain temperature and severity of abnormal brain activity, epileptiform discharges and behavioral seizures were induced by Penicillin G in anesthetized rats, and focal brain-temperature was measured. Penicillin G was injected into the right primary sensorimotor cortex (400IU/µl). After the injection, epileptiform discharges induced a temperature increase gradually by 0.65±0.24°C. Moreover, when behavioral seizures were induced by reducing the anesthesia level, the temperature was raised by 0.26±0.22°C. These results suggest that elevation of the focal brain temperature is associated with the severity of epileptic activity.
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Encéfalo/fisiopatologia , Córtex Cerebral/fisiopatologia , Epilepsia/fisiopatologia , Penicilinas/toxicidade , Animais , Modelos Animais de Doenças , Eletroencefalografia/métodos , Epilepsia/induzido quimicamente , Masculino , Ratos , Ratos Wistar , TemperaturaRESUMO
Although systemic hypothermia provides favorable outcomes in stroke patients, it has only been adopted in a limited number of patients because of fatal complications. To resolve these issues, focal brain cooling (FBC) has recently drawn attention as a less-invasive treatment for brain injuries. Therefore, we investigated whether FBC has a favorable effect on focal cerebral ischemia (FCI). Male-adult-Wistar rats were used. Under general anesthesia, a small burr hole was made and FCI was induced in the primary sensorimotor area (SI-MI) using photothrombosis. An additional craniotomy was made over the SI-MI and FBC was performed at a temperature of 15°C for 5h. Electrocorticograms (ECoG) were recorded on the border cortex of the ischemic focus. Thereafter, rats were sacrificed and the infarct area was measured. In another experiment, rats were allowed to recover for 5 days after cooling and neurobehavioral function was evaluated. FBC suppressed all ECoG frequency bands during and after cooling (p<0.05), except for the delta frequency band in the precooling versus rewarming periods. The injured areas in the cooling and non-cooling groups were 0.99±0.30 and 1.71±0.54 mm(2), respectively (p<0.03). The grip strength at 2 days after surgery was preserved in the cooling group (p<0.05). We report the novel finding that epileptiform discharges were suppressed in the ischemic border, the infarct area was reduced and neurobehaviour was preserved by FBC. These results indicate that FBC is neuroprotective in the ischemic brain and has demonstrated therapeutic potential for cerebral infarction.
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Isquemia Encefálica/terapia , Ondas Encefálicas/fisiologia , Infarto Cerebral/prevenção & controle , Hipotermia Induzida/métodos , Análise de Variância , Animais , Isquemia Encefálica/complicações , Infarto Cerebral/etiologia , Modelos Animais de Doenças , Eletroencefalografia , Força da Mão/fisiologia , Masculino , Processos Fotoquímicos , Fotoquímica/métodos , Ratos , Ratos Wistar , Estatísticas não Paramétricas , Fatores de TempoRESUMO
A cobalt-triarylphosphine catalyst promotes an annulation reaction of an α,ß-unsaturated imine and an internal alkyne to afford a polysubstituted dihydropyridine derivative in good yield under mild conditions. The reaction likely involves alkenylation of the olefinic C-H bond via cobalt-mediated nitrogen-assisted C-H activation followed by facile 6π electrocyclization of the resulting azatriene intermediate.
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OBJECTIVE: The goal of the study was to investigate the effects of focal brain cooling on epileptic discharges (EDs) and background rhythms in the sensorimotor cortex of anesthetized rats using spectral analysis of electroencephalography (EEG). METHODS: Penicillin G was administered intracortically into superficial layers of the left sensorimotor cortex and EDs were induced. Focal brain cooling was achieved using a cooling device attached to the cortical surface. The cortical surface was cooled to 25°C, 20°C and 15°C, and EEG was continuously recorded just beneath the cooling device. EEG spectral powers were determined using fast Fourier transform before and during cooling. RESULTS: Penicillin G induced EDs and increased the Alpha and Beta power spectra. Cooling suppressed EDs with an effect that depended on the brain temperature. Cooling to 25°C attenuated Beta powers, cooling to 20°C attenuated Alpha and Beta powers, and cooling to 15°C suppressed spectral powers ranging from Delta to Beta bands. CONCLUSIONS: These results suggest that focal brain cooling can terminate EDs in the cortex and suppress spectral powers with a temperature-dependent effect. SIGNIFICANCE: These findings may contribute to development of a new clinical treatment for patients with epilepsy.
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Antibacterianos/efeitos adversos , Encéfalo/fisiologia , Epilepsia/induzido quimicamente , Epilepsia/terapia , Hipotermia Induzida/métodos , Penicilina G/efeitos adversos , Anestésicos/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Ondas Encefálicas/efeitos dos fármacos , Ondas Encefálicas/fisiologia , Modelos Animais de Doenças , Eletroencefalografia , Análise de Fourier , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de TempoRESUMO
PURPOSE: Focal brain cooling is effective for suppression of epileptic seizures, but it is unclear if seizures can be suppressed without a substantial influence on normal neurologic function. To address the issue, a thermoelectrically driven cooling system was developed and applied in free-moving rat models of focal seizure and epilepsy. METHODS: Focal seizures limited to the unilateral forelimb were induced by local application of a penicillin G solution or cobalt powder to the unilateral sensorimotor cortex. A proportional integration and differentiation (PID)-controlled, thermoelectrically driven cooling device (weight of 11 g) and bipolar electrodes were chronically implanted on the eloquent area (on the epileptic focus) and the effects of cooling (20, 15, and 10°C) on electrocorticography, seizure frequency, and neurologic changes were investigated. KEY FINDINGS: Cooling was associated with a distinct reduction of the epileptic discharges. In both models, cooling of epileptic foci significantly improved both seizure frequency and neurologic functions from 20°C down to 15°C. Cooling to 10°C also suppressed seizures, but with no further improvement in neurologic function. Subsequent investigation of sensorimotor function revealed significant deterioration in foot-fault tests and the receptive field size at 15°C. SIGNIFICANCE: Despite the beneficial effects in ictal rats, sensorimotor functions deteriorated at 15°C, thereby suggesting a lower limit for the therapeutic temperature. These results provide important evidence of a therapeutic effect of temperatures from 20 to 15°C using an implantable, hypothermal device for focal epilepsy.
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Epilepsias Parciais/fisiopatologia , Epilepsias Parciais/terapia , Epilepsia/fisiopatologia , Epilepsia/terapia , Hipotermia Induzida/métodos , Córtex Motor/fisiopatologia , Animais , Temperatura Corporal/fisiologia , Ondas Encefálicas/efeitos dos fármacos , Ondas Encefálicas/fisiologia , Cobalto/toxicidade , Convulsivantes/toxicidade , Modelos Animais de Doenças , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Hipotermia Induzida/efeitos adversos , Hipotermia Induzida/instrumentação , Masculino , Penicilina G/toxicidade , Ratos , Ratos WistarRESUMO
AIM: To investigate the prevalence and severity of oral health-related quality of life in patients treated with removable partial dentures at a publicly-funded dental hospital. The association between patients' demographic profiles, denture-related, variables and oral health-related quality of life was also investigated. METHODS: A questionnaire was designed to investigate the use and satisfaction of removable partial dentures, and oral health-related quality of life of removable partial denture wearers using the Oral Health Impact Profile-14. The questionnaire was administered to 740 randomly-selected patients who received removable partial dentures during 2005-2008. The response rate was 31.35%. Non-parametric tests and a logistic regression model were used to analyze the association between denture-related variables and oral health-related quality of life. A question on symptoms unrelated to dentures was also analyzed. RESULTS: The Oral Health Impact Profile-14 prevalence calculated was 43.1%. The removable partial denture experience and frequency of use was inversely associated with Oral Health Impact Profile-14 scores. Metal-based removable partial dentures were associated with lower Oral Health Impact Profile prevalence and severity scores. No significant association was found between demographic profile, circumstance for provision of removable partial dentures and Oral Health Impact Profile-14 score. CONCLUSION: The participants of this study indicated that perceived denture performance, removable partial dentures material, experience, and frequency of use are associated with oral health-related quality of life.
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Prótese Parcial Removível/efeitos adversos , Saúde Bucal/estatística & dados numéricos , Satisfação do Paciente/estatística & dados numéricos , Qualidade de Vida , Perfil de Impacto da Doença , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas , Inquéritos e QuestionáriosRESUMO
Direct arylation of the ortho-C-H bond of an aryl pyridine or an aryl imine with an aryl Grignard reagent has been achieved by using an iron-diamine catalyst and a dichloroalkane as an oxidant in a short reaction time (e.g., 5 min) under mild conditions (0 °C). The use of an aromatic co-solvent, such as chlorobenzene and benzene, and slow addition of the Grignard reagent are essential for the high efficiency of the reaction. The present arylation reaction has distinct merits over the previously developed reaction that used an arylzinc reagent, such as its reaction rate and atom economy. Selective C-H bond activation occurs in the presence of a leaving group, such as a tosyloxy, chloro, and bromo group. Studies on a stoichiometric reaction and kinetic isotope effects shed light on the reaction intermediate and the C-H bond-activation step.
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Both severe calcified lesions and hemodialysis (HD) are predictors for high rates of restenosis, even in the drug-eluting stent era. We sought to investigate the angiographic and clinical outcome in a population of HD versus non-hemodialysis (non-HD) patients with severe calcified lesions requiring rotational atherectomy. One hundred consecutive lesions (28 lesions in the HD group, 72 in the non-HD group) from 82 patients (19 patients in the HD group, 63 in the non-HD group) requiring rotational atherectomy prior to sirolimus-eluting stent (SES) implantation were analyzed post-procedure and at 8 months. Clinical outcomes were assessed at 12 months. Inclusion criteria were calcified lesions with >270° of superficial calcification on the intravascular ultrasound (IVUS), lesions that the IVUS could not cross, or undilatable lesions. There were no differences in patient characteristics except for age. Although both baseline and post-procedure angiographic findings were similar between the two groups, late loss in stented segment was significantly greater in the HD group than in the non-HD group (HD vs. non-HD: 0.69 ± 0.74 mm vs. 0.34 ± 0.50; P = 0.030). Also, the HD group revealed significantly worse clinical outcomes. In conclusion, mid-term results of highly complex, severely calcified lesions requiring rotational atherectomy in non-HD patients were permissible as compared to on-label lesions. However, in HD patients, both angiographic and clinical outcomes were still suboptimal in this lesion subset, even using SES.