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1.
Sci Rep ; 14(1): 5835, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38461347

RESUMO

This study introduces a novel method for enhancing Boiling Water Reactor (BWR) operation simulations by integrating machine learning (ML) models with conventional simulation techniques. The ML model is trained to identify and correct errors in low-fidelity simulation outputs, traditionally derived from core physics computations. These corrections aim to align the low-fidelity results closely with high-fidelity data. Precise predictions of nuclear reactor parameters like core eigenvalue and power distribution are crucial for efficient fuel management and adherence to technical specifications. Current high-fidelity transport calculations, while accurate, are impractical for real-time predictions due to extensive computational demands. Our approach, therefore, utilizes the standard two-step simulation process-assembly-level lattice physics calculations followed by whole-core nodal diffusion computations-to generate initial results, which are then refined using the ML-based error correction model. The methodology focuses on improving simulation accuracy in regular BWR operations rather than developing a universal ML predictor for reactor physics. By training an advanced neural network model on the difference in high-fidelity and low-fidelity simulations, the model can reduce the nodal power error from low-fidelity simulations to around 1% on average and the core eigenvalue down to under 100 pcm. This result is under the condition of the normal variations of control rod pattern and core flow rate changes in standard BWR operations used in the training and evaluation of the machine learning model. This work suggests a promising approach for achieving more accurate, computationally feasible simulation solutions in nuclear reactor operation and management.

2.
Appl Radiat Isot ; 149: 182-199, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31075563

RESUMO

We report the results of an experiment conducted near the High Flux Isotope Reactor of Oak Ridge National Laboratory, designed to address the question of whether a flux of reactor-generated electron antineutrinos (ν¯e) can alter the rates of weak nuclear interaction induced decays of 54Mn, 22Na, and 60Co. This experiment has small statistical errors but, when systematic uncertainties are included, has null results. Perturbations greater than one part in 104 are excluded at 95% confidence level in ß± decay and electron capture processes, in the presence of an antineutrino flux of 3 × 1012 cm-2s-1. The present experimental methods are applicable to a wide range of radionuclides. Improved sensitivity in future experiments can be anticipated as we continue to better understand and reduce the dominant systematic uncertainties.

3.
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2017: 4163-4166, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29060814

RESUMO

Electrical cortical stimulation (ECS) is often used in presurgical evaluation procedures for patients suffering from pharmacoresistant epilepsy. Real-time functional mapping (RTFM) is an alternative brain mapping methodology that can accompany traditional functional mapping approaches like ECS. In this paper, we present a combined RTFM/ECS system that aims to exploit the common ground and the advantages of the two procedures for improved time/effort effectiveness, patients' experience and safety. Using the RTFM and ECS data from four patients who suffer epilepsy, we demonstrate that the RTFM-guided ECS procedure hypothetically reduces the number of electrical stimulations necessary for eloquent cortex detection by 40%.


Assuntos
Epilepsia , Mapeamento Encefálico , Córtex Cerebral , Sistemas Computacionais , Estimulação Elétrica , Eletroencefalografia , Humanos , Imageamento por Ressonância Magnética
6.
Rev Sci Instrum ; 88(8): 087101, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28863687

RESUMO

The article of Chauhan et al. ["Plasma fireball: A unique tool to fabricate patterned nanodots," Rev. Sci. Instrum. 88(6), 063507 (2017)] describes the very interesting idea of utilising the plasma phenomenon of fireballs for the creation of patterned nanodots on a GaSb substrate. For this purpose, the authors obtained a large plasma fireball in a magnetised background plasma and used it to accelerate ions in the sheath, which surrounds such a fireball. Chauhan et al. were able to demonstrate the production of large ion fluxes that can be extracted from the fireball and that the properties of these fluxes define the geometric structure of the nanodots on the substrate surface. Hence, the nanodot pattern can be easily controlled by the discharge parameters of the plasma fireball. This is clearly a novel method of fireball-induced surface modification. However, plasma fireballs themselves have been known for about hundred years, although as a very particular plasma phenomenon. Therefore, this letter aims at providing some additional background information and references on this topic for the interested reader.

7.
Curr Med Res Opin ; 29(3): 251-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23339578

RESUMO

OBJECTIVE: Larch arabinogalactan (ResistAid * ) may prevent cold infections due to its immune-stimulatory properties. In a placebo-controlled, double-blind, randomized clinical trial, the effect of a proprietary larch arabinogalactan preparation on the incidences of common colds and its effect on cold symptoms, as a well established model for immune function, was compared to placebo. RESEARCH DESIGN AND METHODS: A total of 199 healthy participants who had a self reported cold infection rate of three in 6 months were randomly assigned to receive a total of either 4.5 g of an arabinogalactan preparation (n = 101) or placebo (n = 98) over a period of 12 weeks. MAIN OUTCOME MEASURES: The participants documented each common cold episode in a diary, and rated 10 predefined infection symptoms on a 4 point rating scale during an infection period, resulting in an infection score. The common cold episodes were confirmed by medical doctors. CLINICAL TRIAL REGISTRATION: ISRCTN41183655. RESULTS: In the full analysis set (FAS), arabinogalactan tended to decrease the incidence of common cold (p = 0.055). The number of participants affected by a cold was significantly reduced by arabinogalactan supplementation (p = 0.038). Concerning the per protocol (PP) collective, the incidences of common cold (p = 0.040) and the number of participants affected by the infection (p = 0.033) were significantly fewer after arabinogalactan compared to placebo consumption. The severity of symptoms at episode start as experienced by the participants was significantly higher after arabinogalactan supplementation (p = 0.028). The treatment was well tolerated with no significant differences between the study groups. CONCLUSION: The present study demonstrated that larch arabinogalactan increased the body's potential to defend against common cold infection. While the immunomodulatory effect of arabinogalactan can be assumed, its mechanism of action remains to be elucidated.


Assuntos
Resfriado Comum/tratamento farmacológico , Resfriado Comum/prevenção & controle , Galactanos/efeitos adversos , Galactanos/uso terapêutico , Imunomodulação/efeitos dos fármacos , Adulto , Idoso , Resfriado Comum/epidemiologia , Método Duplo-Cego , Feminino , Humanos , Incidência , Larix/química , Masculino , Pessoa de Meia-Idade , Placebos , Extratos Vegetais/efeitos adversos , Extratos Vegetais/uso terapêutico , Resultado do Tratamento , Adulto Jovem
8.
PLoS One ; 7(7): e41863, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22860021

RESUMO

Diagnosing bone infection in its acute early stage is of utmost clinical importance as the failure to do so results in a therapeutically recalcitrant chronic infection that can only be resolved with extensive surgical intervention, the end result often being a structurally unstable defect requiring reconstructive procedures. [(18)F]-FDG-PET has been extensively investigated for this purpose, but the results have been mixed in that, while highly sensitive, its specificity with respect to distinguishing between acute infection and sterile inflammatory processes, including normal recuperative post-surgical healing, is limited. This study investigated the possibility that alternative means of acquiring and analyzing FDG-PET data could be used to overcome this lack of specificity without an unacceptable loss of sensitivity. This was done in the context of an experimental rabbit model of post-surgical osteomyelitis with the objective of distinguishing between acute infection and sterile post-surgical inflammation. Imaging was done 7 and 14 days after surgery with continuous data acquisition for a 90-minute period after administration of tracer. Results were evaluated based on both single and dual time point data analysis. The results suggest that the diagnostic utility of FDG-PET is likely limited to well-defined clinical circumstances. We conclude that, in the complicated clinical context of acute post-surgical or post-traumatic infection, the diagnostic utility accuracy of FDG-PET is severely limited based on its focus on the increased glucose utilization that is generally characteristic of inflammatory processes.


Assuntos
Fluordesoxiglucose F18 , Osteomielite/diagnóstico por imagem , Compostos Radiofarmacêuticos , Rádio (Anatomia)/diagnóstico por imagem , Infecções Estafilocócicas/diagnóstico por imagem , Infecção da Ferida Cirúrgica/diagnóstico por imagem , Animais , Fluordesoxiglucose F18/farmacocinética , Masculino , Osteomielite/microbiologia , Tomografia por Emissão de Pósitrons , Coelhos , Compostos Radiofarmacêuticos/farmacocinética , Rádio (Anatomia)/microbiologia , Rádio (Anatomia)/cirurgia , Infecções Estafilocócicas/microbiologia , Infecção da Ferida Cirúrgica/microbiologia
9.
Haematologica ; 96(2): 333-6, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20952514

RESUMO

We prospectively evaluated the bone changes associated with proteasome inhibition using single agent bortezomib in relapsed or refractory myeloma patients. Ten patients received bortezomib 1.3 mg/m(2) per days 1, 4, 8 and 11 for three 21-day cycles, and 6 patients received 1 mg/m(2) per day with the same schedule. Bone architecture and metabolism changes were assessed by bone markers, micro-CT, bone histomorphometry, tetracycline labeling and serum parathormone levels. Bone parameter variations were compared by response to treatment. Microarchitectural changes were observed in all evaluable responsive patients. Bone alkaline phosphatase changes were associated with disease response (≥PR vs. others P=0.03 cycle 1, day 11) serum parathormone levels were also significantly increased (P=0.04 on days 11, 21, 33) in responding individuals. This study demonstrates that the myeloma control produced by proteasome inhibition is associated with bone changes and to a discrete pattern of hormonal variation.


Assuntos
Biomarcadores/metabolismo , Remodelação Óssea/efeitos dos fármacos , Ácidos Borônicos/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/metabolismo , Inibidores de Proteases/uso terapêutico , Pirazinas/uso terapêutico , Fosfatase Alcalina/metabolismo , Bortezomib , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Hormônio Paratireóideo/metabolismo , Prognóstico , Estudos Prospectivos
11.
Adv Ther ; 24(2): 439-47, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17565935

RESUMO

This study was undertaken to compare the effects on plasma cholesterol concentration of a new isolated soy protein in which the protein structure is kept in its native, nondenaturated form (verum 1) versus a conventional isolated soy protein (verum 2) and milk protein (placebo). This prospective, randomized, double-blind, placebo-controlled study was conducted in an outpatient clinical study center in Berlin, Germany. Over 8 wk, 120 patients (total cholesterol, 5.2-7.8 mmol/L) were given verum 1, verum 2, or placebo at a dosage of 25 g protein daily. At the end of the treatment period, total cholesterol levels were significantly reduced by 10.7% in the verum 1 group compared with placebo (P<.001), and levels were reduced by 5.8% in the verum 2 group (P=.008). The difference between the 2 verum groups was statistically significant (P=.008). Low-density lipoprotein cholesterol levels were significantly reduced with nondenaturated isolated soy protein only: levels were reduced by 9.4% in the verum 1 group (P=.002) and by 4.9% in the verum 2 group (P=.107). Again, the difference between the verum groups was significant (P=.05). The results of this study confirm that supplementation with isolated soy protein can lead to significant reductions in plasma concentrations of total and low-density lipoprotein cholesterol. These reductions are significantly more pronounced with an isolated soy protein that maintains the native protein structure than with a commercially available reference isolated soy protein.


Assuntos
Anticolesterolemiantes/uso terapêutico , Colesterol/sangue , Hipercolesterolemia/tratamento farmacológico , Proteínas de Soja/uso terapêutico , Adulto , Idoso , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas do Leite/farmacologia , Estudos Prospectivos
13.
Adv Ther ; 18(4): 174-80, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11697020

RESUMO

This 4-week double-blind, placebo-controlled study assessed the efficacy of impulse magnetic-field therapy for insomnia. One hundred one patients were randomly assigned to either active treatment (n = 50) or placebo (n = 51) and allocated to one of three diagnostic groups: (1) sleep latency; (2) interrupted sleep; or (3) nightmares. Efficacy endpoints were intensity of sleep latency, frequency of interruptions, sleepiness after rising, daytime sleepiness, difficulty with concentration, and daytime headaches. In the active-treatment group, the values of all criteria were significantly lower at study end (P < .00001). The placebo group also showed significant symptomatic improvement (P < .05), but the differences between groups were highly significant (P < .00001). Seventy percent (n = 34) of the patients given active treatment experienced substantial or even complete relief of their complaints; 24% (n = 12) reported clear improvement; 6% (n = 3) noted a slight improvement. Only one placebo patient (2%) had very clear relief; 49% (n = 23) reported slight or clear improvement; and 49% (n = 23) saw no change in their symptoms. No adverse effects of treatment were reported.


Assuntos
Magnetismo/uso terapêutico , Distúrbios do Início e da Manutenção do Sono/terapia , Adolescente , Adulto , Idoso , Terapias Complementares , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Probabilidade , Valores de Referência , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Estatísticas não Paramétricas , Resultado do Tratamento
14.
Adv Ther ; 18(3): 101-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11571822

RESUMO

This double-blind, placebo-controlled study assessed the efficacy of 4 weeks of impulse magnetic-field therapy (16 Hz, 5 microTs), delivered through a small device, for different types of headache and migraine. Eighty-two patients were randomly assigned to receive either active treatment or placebo (n = 41 each) and were characterized according to one of seven diagnoses (migraine, migraine combined with tension, tension, cluster, weather-related, posttraumatic, or other). Efficacy was assessed in terms of duration, severity, and frequency of migraine and headache attacks, as well as ability to concentrate. Data for 77 patients were analyzed. In the active-treatment group, all assessed criteria were significantly improved at the end of the study (P < .0001 vs baseline and placebo). Seventy-six percent of active-treatment patients experienced clear or very clear relief of their complaints. Only 1 placebo-patient (2.5%) felt some relief; 8% noted slight and 2% reported significant worsening of symptoms. No side effects were noted.


Assuntos
Cefaleia/terapia , Magnetismo/uso terapêutico , Adolescente , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/terapia
15.
Adv Ther ; 18(5): 230-6, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11783460

RESUMO

The lipid-lowering effect of a carob pulp preparation rich in insoluble dietary fiber and polyphenols was investigated in a noncomparative, open-label pilot study. Over 8 weeks, 47 volunteers with moderate hypercholesterolemia (total cholesterol 232-302 mg/dL) consumed 15 g of carob per day in three products (breakfast cereal, fruit muesli bar, powdered drink) as a supplement to their regular diet. After 4 weeks, reductions of 7.1% in mean total cholesterol and 10.6% in LDL cholesterol were noted; respective decreases after 6 weeks were 7.8% and 12.2% (all P<.001). HDL cholesterol and triglyceride levels remained unchanged. Overall compliance was good. Only 3 volunteers (6%) reported a sensation of fullness, which led to 2 of the 3 dropouts. The carob preparation may have value in the dietary treatment of hypercholesterolemia.


Assuntos
Anticolesterolemiantes/uso terapêutico , Hipercolesterolemia/tratamento farmacológico , Lipídeos/sangue , Extratos Vegetais/uso terapêutico , Polissacarídeos/uso terapêutico , Adulto , Idoso , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Galactanos , Humanos , Hipercolesterolemia/sangue , Masculino , Mananas , Pessoa de Meia-Idade , Projetos Piloto , Gomas Vegetais , Fatores de Tempo , Resultado do Tratamento , Triglicerídeos/sangue
16.
Adv Ther ; 15(1): 25-44, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-10178636

RESUMO

Ginger is well known in the form of ginger sticks or ginger ale. If these are consumed during travel, the traveler imbibes, albeit subconsciously, a healing plant for motion sickness. The efficacy of ginger rhizome for the prevention of nausea, dizziness, and vomiting as symptoms of motion sickness (kinetosis), as well as for postoperative vomiting and vomiting of pregnancy, has been well documented and proved beyond doubt in numerous high-quality clinical studies. The use of this ancient medicine for gastrointestinal problems (stimulation of digestion) has been given scientific approval. Today, medicinal ginger is used mainly for prevention of the symptoms of travel sickness.


Assuntos
Fitoterapia , Plantas Medicinais/uso terapêutico , Zingiberales/uso terapêutico , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Enjoo devido ao Movimento/terapia , Náusea/terapia , Plantas Medicinais/química , Plantas Medicinais/fisiologia , Gravidez , Complicações na Gravidez/terapia , Doenças Reumáticas/terapia , Zingiberales/química , Zingiberales/fisiologia
17.
J Arthroplasty ; 12(7): 736-40, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9355002

RESUMO

Fourteen patients (21 hips) with osteonecrosis of the femoral head with collapse had the femoral head resurfaced with a cemented titanium shell. All of the femoral heads were Ficat stage III or IV. Of the 21 surgeries, 7 were failures. Treatment for all 4 patients with sickle cell disease or trait failed (100%). When the cases of 17 patients who did not have sickle cell disease or trait were reviewed separately, the success rate was 14 of 17 (82%). The follow-up periods (all > 5 years) of the 14 successful patients in this group averaged 6.2 years, and their average Harris hip score was 87 (10 excellent, 4 good). Of the 14 successes, 10 patients had a follow-up period longer than 5 years (average, 7.7 years) and an average Harris hip score of 94 (7 excellent, and 3 good). There was no evidence of loosening and there was no osteolysis. It is concluded that this operation provides an alternative to hemiarthroplasty, total joint arthroplasty surgery, or bipolar arthroplasty. This is a time-buying first-stage operation and, for younger patients, will not last a lifetime. The concept appears prudent because the surgical procedure is directed at the site of primary disease, the femoral head.


Assuntos
Necrose da Cabeça do Fêmur/cirurgia , Cabeça do Fêmur/cirurgia , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , Reoperação , Resultado do Tratamento
18.
J Trauma ; 35(1): 23-7, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8331708

RESUMO

The strength and stability of an intramedullary device when used to fix intertrochanteric fractures were determined and compared with the dynamic hip screw (DHS). A standard four-part osteotomy was created in eight paired fresh frozen human cadaver femurs. The intramedullary fixation device and a DHS were implanted in each pair member, and mechanical testing was performed. Micromotion was measured during cyclic loading to determine implant stability, and then the specimens were loaded to failure. The intramedullary fixation device had significantly greater stability in cyclic loading than the DHS and required more than twice the force for failure. For patients with osteoporosis, this device may be a useful alternative to standard sliding nail systems.


Assuntos
Fixação Intramedular de Fraturas/instrumentação , Fraturas do Quadril/cirurgia , Fenômenos Biomecânicos , Fêmur/fisiopatologia , Fêmur/cirurgia , Fraturas do Quadril/fisiopatologia , Humanos , Próteses e Implantes
20.
J Cardiovasc Pharmacol ; 10 Suppl 6: S91-6, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-2485035

RESUMO

The role of intracellular free Ca2+ in arterial smooth muscle was investigated in aortic smooth muscle cells from spontaneously hypertensive and normotensive rats, as well as in porcine aortic smooth muscle. Intracellular free Ca2+ in aortic smooth muscle from spontaneously hypertensive rats was elevated. Incubation of porcine aortic smooth muscle with plasma from essential hypertensive and normotensive subjects revealed a humoral factor in subjects with essential hypertension, which increased intracellular free Ca2+. Cross-circulation experiments between spontaneously hypertensive and normotensive rats demonstrated a transmission of hypertension to the normotensive animals as a result of a circulating hypertensive factor possibly produced in the kidneys and adrenals. The experiments suggest that vasoconstriction in primary hypertension may be caused by a humoral factor that increases intracellular free Ca2+ in arterial smooth muscle.


Assuntos
Cálcio/metabolismo , Hipertensão/metabolismo , Músculo Liso Vascular/metabolismo , Animais , Artérias/metabolismo , Ratos , Ratos Endogâmicos , Resistência Vascular/fisiologia
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